butterfly_viewer.butterfly_viewer

   1#!/usr/bin/env python3
   2
   3"""Multi-image viewer for comparing images with synchronized zooming, panning, and sliding overlays.
   4
   5Intended to be run as a script:
   6    $ python butterfly_viewer.py
   7
   8Features:
   9    Image windows have synchronized zoom and pan by default, but can be optionally unsynced.
  10    Image windows will auto-arrange and can be set as a grid, column, or row. 
  11    Users can create sliding overlays up to 2x2 and adjust their transparencies.
  12
  13Credits:
  14    PyQt MDI Image Viewer by tpgit (http://tpgit.github.io/MDIImageViewer/) for sync pan and zoom.
  15"""
  16# SPDX-License-Identifier: GPL-3.0-or-later
  17
  18
  19
  20import sip
  21import time
  22import os
  23from datetime import datetime
  24
  25from PyQt5 import QtCore, QtGui, QtWidgets
  26
  27from aux_splitview import SplitView
  28from aux_functions import strippedName, toBool, determineSyncSenderDimension, determineSyncAdjustmentFactor
  29from aux_trackers import EventTrackerSplitBypassInterface
  30from aux_interfaces import SplitViewCreator, SlidersOpacitySplitViews, SplitViewManager
  31from aux_mdi import QMdiAreaWithCustomSignals
  32from aux_layouts import GridLayoutFloatingShadow
  33from aux_exif import get_exif_rotation_angle
  34from aux_buttons import ViewerButton
  35import icons_rc
  36
  37
  38
  39os.environ["QT_ENABLE_HIGHDPI_SCALING"]   = "1"
  40os.environ["QT_AUTO_SCREEN_SCALE_FACTOR"] = "1"
  41os.environ["QT_SCALE_FACTOR"]             = "1"
  42
  43sip.setapi('QDate', 2)
  44sip.setapi('QTime', 2)
  45sip.setapi('QDateTime', 2)
  46sip.setapi('QUrl', 2)
  47sip.setapi('QTextStream', 2)
  48sip.setapi('QVariant', 2)
  49sip.setapi('QString', 2)
  50
  51COMPANY = "Butterfly Apps"
  52DOMAIN = "https://github.com/olive-groves/butterfly_viewer/"
  53APPNAME = "Butterfly Viewer"
  54VERSION = "1.1"
  55
  56SETTING_RECENTFILELIST = "recentfilelist"
  57SETTING_FILEOPEN = "fileOpenDialog"
  58SETTING_SCROLLBARS = "scrollbars"
  59SETTING_STATUSBAR = "statusbar"
  60SETTING_SYNCHZOOM = "synchzoom"
  61SETTING_SYNCHPAN = "synchpan"
  62
  63
  64
  65class SplitViewMdiChild(SplitView):
  66    """Extends SplitView for use in Butterfly Viewer.
  67
  68    Extends SplitView with keyboard shortcut to lock the position of the split 
  69    in the Butterfly Viewer.
  70
  71    Overrides SplitView by checking split lock status before updating split.
  72    
  73    Args:
  74        See parent method for full documentation.
  75    """
  76
  77    shortcut_shift_x_was_activated = QtCore.pyqtSignal()
  78
  79    def __init__(self, pixmap, filename_main_topleft, name, pixmap_topright, pixmap_bottomleft, pixmap_bottomright, transform_mode_smooth):
  80        super().__init__(pixmap, filename_main_topleft, name, pixmap_topright, pixmap_bottomleft, pixmap_bottomright, transform_mode_smooth)
  81
  82        self.setAttribute(QtCore.Qt.WA_DeleteOnClose)
  83        self._isUntitled = True
  84
  85        self.toggle_lock_split_shortcut = QtWidgets.QShortcut(QtGui.QKeySequence("Shift+X"), self)
  86        self.toggle_lock_split_shortcut.activated.connect(self.toggle_lock_split)
  87
  88        self._sync_this_zoom = True
  89        self._sync_this_pan = True
  90    
  91    @property
  92    def sync_this_zoom(self):
  93        """bool: Setting of whether to sync this by zoom (or not)."""
  94        return self._sync_this_zoom
  95    
  96    @sync_this_zoom.setter
  97    def sync_this_zoom(self, bool: bool):
  98        """bool: Set whether to sync this by zoom (or not)."""
  99        self._sync_this_zoom = bool
 100
 101    @property
 102    def sync_this_pan(self):
 103        """bool: Setting of whether to sync this by pan (or not)."""
 104        return self._sync_this_pan
 105    
 106    @sync_this_pan.setter
 107    def sync_this_pan(self, bool: bool):
 108        """bool: Set whether to sync this by pan (or not)."""
 109        self._sync_this_pan = bool
 110
 111    # Control the split of the sliding overlay
 112
 113    def toggle_lock_split(self):
 114        """Toggle the split lock.
 115        
 116        Toggles the status of the split lock (e.g., if locked, it will become unlocked; vice versa).
 117        """
 118        self.split_locked = not self.split_locked
 119        self.shortcut_shift_x_was_activated.emit()
 120    
 121    def update_split(self, pos = None, pos_is_global=False, ignore_lock=False):
 122        """Update the position of the split while considering the status of the split lock.
 123        
 124        See parent method for full documentation.
 125        """
 126        if not self.split_locked or ignore_lock:
 127            super().update_split(pos,pos_is_global,ignore_lock=ignore_lock)
 128
 129    
 130    # Events
 131
 132    def enterEvent(self, event):
 133        """Pass along enter event to parent method."""
 134        super().enterEvent(event)
 135
 136
 137
 138class MultiViewMainWindow(QtWidgets.QMainWindow):
 139    """View multiple images with split-effect and synchronized panning and zooming.
 140
 141    Extends QMainWindow as main window of Butterfly Viewer with user interface:
 142
 143    - Create sliding overlays.
 144    - Adjust sliding overlay transparencies.
 145    - Change viewer settings.
 146    """
 147    
 148    MaxRecentFiles = 10
 149
 150    def __init__(self):
 151        super(MultiViewMainWindow, self).__init__()
 152
 153        self._recentFileActions = []
 154        self._handlingScrollChangedSignal = False
 155        self._last_accessed_fullpath = None
 156
 157        self._mdiArea = QMdiAreaWithCustomSignals()
 158        self._mdiArea.file_path_dragged.connect(self.display_dragged_grayout)
 159        self._mdiArea.file_path_dragged_and_dropped.connect(self.load_from_dragged_and_dropped_file)
 160        self._mdiArea.shortcut_escape_was_activated.connect(self.set_fullscreen_off)
 161        self._mdiArea.shortcut_f_was_activated.connect(self.toggle_fullscreen)
 162        self._mdiArea.shortcut_h_was_activated.connect(self.toggle_interface)
 163        self._mdiArea.shortcut_ctrl_c_was_activated.connect(self.copy_view)
 164        self._mdiArea.first_subwindow_was_opened.connect(self.on_first_subwindow_was_opened)
 165        self._mdiArea.last_remaining_subwindow_was_closed.connect(self.on_last_remaining_subwindow_was_closed)
 166
 167        self._mdiArea.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAsNeeded)
 168        self._mdiArea.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAsNeeded)
 169        self._mdiArea.subWindowActivated.connect(self.subWindowActivated)
 170
 171        self._mdiArea.setBackground(QtGui.QColor(32,32,32))
 172
 173        self._label_mouse = QtWidgets.QLabel() # Pixel coordinates of mouse in a view
 174        self._label_mouse.setText("")
 175        self._label_mouse.adjustSize()
 176        self._label_mouse.setVisible(False)
 177        self._label_mouse.setAlignment(QtCore.Qt.AlignLeft | QtCore.Qt.AlignBottom)
 178        self._label_mouse.setStyleSheet("QLabel {color: white; background-color: rgba(0, 0, 0, 191); border: 0px solid black; margin-left: 0.09em; margin-top: 0.09em; margin-right: 0.09em; margin-bottom: 0.09em; font-size: 7.5pt; border-radius: 0.09em; }")
 179
 180        self._splitview_creator = SplitViewCreator()
 181        self._splitview_creator.clicked_create_splitview_pushbutton.connect(self.on_create_splitview)
 182        tracker_creator = EventTrackerSplitBypassInterface(self._splitview_creator)
 183        tracker_creator.mouse_position_changed.connect(self.update_split)
 184        layout_mdiarea_topleft = GridLayoutFloatingShadow()
 185        layout_mdiarea_topleft.addWidget(self._label_mouse, 1, 0, alignment=QtCore.Qt.AlignLeft|QtCore.Qt.AlignBottom)
 186        layout_mdiarea_topleft.addWidget(self._splitview_creator, 0, 0, alignment=QtCore.Qt.AlignLeft)
 187        self.interface_mdiarea_topleft = QtWidgets.QWidget()
 188        self.interface_mdiarea_topleft.setLayout(layout_mdiarea_topleft)
 189
 190        self._mdiArea.subWindowActivated.connect(self.update_sliders)
 191        self._mdiArea.subWindowActivated.connect(self.update_window_highlight)
 192        self._mdiArea.subWindowActivated.connect(self.update_window_labels)
 193        self._mdiArea.subWindowActivated.connect(self.updateMenus)
 194        self._mdiArea.subWindowActivated.connect(self.auto_tile_subwindows_on_close)
 195        self._mdiArea.subWindowActivated.connect(self.update_mdi_buttons)
 196
 197        self._sliders_opacity_splitviews = SlidersOpacitySplitViews()
 198        self._sliders_opacity_splitviews.was_changed_slider_base_value.connect(self.on_slider_opacity_base_changed)
 199        self._sliders_opacity_splitviews.was_changed_slider_topright_value.connect(self.on_slider_opacity_topright_changed)
 200        self._sliders_opacity_splitviews.was_changed_slider_bottomright_value.connect(self.on_slider_opacity_bottomright_changed)
 201        self._sliders_opacity_splitviews.was_changed_slider_bottomleft_value.connect(self.on_slider_opacity_bottomleft_changed)
 202        tracker_sliders = EventTrackerSplitBypassInterface(self._sliders_opacity_splitviews)
 203        tracker_sliders.mouse_position_changed.connect(self.update_split)
 204
 205        self._splitview_manager = SplitViewManager()
 206        self._splitview_manager.hovered_xy.connect(self.set_split_from_manager)
 207        self._splitview_manager.clicked_xy.connect(self.set_and_lock_split_from_manager)
 208        self._splitview_manager.lock_split_locked.connect(self.lock_split)
 209        self._splitview_manager.lock_split_unlocked.connect(self.unlock_split)
 210
 211        layout_mdiarea_bottomleft = GridLayoutFloatingShadow()
 212        layout_mdiarea_bottomleft.addWidget(self._sliders_opacity_splitviews, 0, 0, alignment=QtCore.Qt.AlignBottom)
 213        layout_mdiarea_bottomleft.addWidget(self._splitview_manager, 0, 1, alignment=QtCore.Qt.AlignLeft|QtCore.Qt.AlignTop)
 214        self.interface_mdiarea_bottomleft = QtWidgets.QWidget()
 215        self.interface_mdiarea_bottomleft.setLayout(layout_mdiarea_bottomleft)
 216        
 217        
 218        self.centralwidget_during_fullscreen_pushbutton = QtWidgets.QToolButton() # Needed for users to return the image viewer to the main window if the window of the viewer is lost during fullscreen
 219        self.centralwidget_during_fullscreen_pushbutton.setText("Close Fullscreen") # Needed for users to return the image viewer to the main window if the window of the viewer is lost during fullscreen
 220        self.centralwidget_during_fullscreen_pushbutton.clicked.connect(self.set_fullscreen_off)
 221        self.centralwidget_during_fullscreen_pushbutton.setStyleSheet("font-size: 11pt")
 222        self.centralwidget_during_fullscreen_layout = QtWidgets.QVBoxLayout()
 223        self.centralwidget_during_fullscreen_layout.setAlignment(QtCore.Qt.AlignCenter)
 224        self.centralwidget_during_fullscreen_layout.addWidget(self.centralwidget_during_fullscreen_pushbutton, alignment=QtCore.Qt.AlignCenter)
 225        self.centralwidget_during_fullscreen = QtWidgets.QWidget()
 226        self.centralwidget_during_fullscreen.setLayout(self.centralwidget_during_fullscreen_layout)
 227
 228        self.fullscreen_pushbutton = ViewerButton()
 229        self.fullscreen_pushbutton.setIcon(":/icons/full-screen.svg")
 230        self.fullscreen_pushbutton.setCheckedIcon(":/icons/full-screen-exit.svg")
 231        self.fullscreen_pushbutton.setToolTip("Fullscreen on/off (F)")
 232        self.fullscreen_pushbutton.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 233        self.fullscreen_pushbutton.setMouseTracking(True)
 234        self.fullscreen_pushbutton.setCheckable(True)
 235        self.fullscreen_pushbutton.toggled.connect(self.set_fullscreen)
 236        self.is_fullscreen = False
 237
 238        self.interface_toggle_pushbutton = ViewerButton()
 239        self.interface_toggle_pushbutton.setCheckedIcon(":/icons/eye.svg")
 240        self.interface_toggle_pushbutton.setIcon(":/icons/eye-cancelled.svg")
 241        self.interface_toggle_pushbutton.setToolTip("Hide interface (H)")
 242        self.interface_toggle_pushbutton.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 243        self.interface_toggle_pushbutton.setMouseTracking(True)
 244        self.interface_toggle_pushbutton.setCheckable(True)
 245        self.interface_toggle_pushbutton.setChecked(True)
 246        self.interface_toggle_pushbutton.clicked.connect(self.show_interface)
 247
 248        self.is_interface_showing = True
 249        self.is_quiet_mode = False
 250        self.is_global_transform_mode_smooth = False
 251        self.scene_background_color = None
 252        self.sync_zoom_by = "box"
 253
 254        self.close_all_pushbutton = ViewerButton(style="trigger-severe")
 255        self.close_all_pushbutton.setIcon(":/icons/clear.svg")
 256        self.close_all_pushbutton.setToolTip("Close all image windows")
 257        self.close_all_pushbutton.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 258        self.close_all_pushbutton.setMouseTracking(True)
 259        self.close_all_pushbutton.clicked.connect(self._mdiArea.closeAllSubWindows)
 260
 261        self.tile_default_pushbutton = ViewerButton(style="trigger")
 262        self.tile_default_pushbutton.setIcon(":/icons/capacity.svg")
 263        self.tile_default_pushbutton.setToolTip("Grid arrange windows")
 264        self.tile_default_pushbutton.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 265        self.tile_default_pushbutton.setMouseTracking(True)
 266        self.tile_default_pushbutton.clicked.connect(self._mdiArea.tileSubWindows)
 267        self.tile_default_pushbutton.clicked.connect(self.fit_to_window)
 268        self.tile_default_pushbutton.clicked.connect(self.refreshPan)
 269
 270        self.tile_horizontally_pushbutton = ViewerButton(style="trigger")
 271        self.tile_horizontally_pushbutton.setIcon(":/icons/split-vertically.svg")
 272        self.tile_horizontally_pushbutton.setToolTip("Horizontally arrange windows in a single row")
 273        self.tile_horizontally_pushbutton.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 274        self.tile_horizontally_pushbutton.setMouseTracking(True)
 275        self.tile_horizontally_pushbutton.clicked.connect(self._mdiArea.tile_subwindows_horizontally)
 276        self.tile_horizontally_pushbutton.clicked.connect(self.fit_to_window)
 277        self.tile_horizontally_pushbutton.clicked.connect(self.refreshPan)
 278
 279        self.tile_vertically_pushbutton = ViewerButton(style="trigger")
 280        self.tile_vertically_pushbutton.setIcon(":/icons/split-horizontally.svg")
 281        self.tile_vertically_pushbutton.setToolTip("Vertically arrange windows in a single column")
 282        self.tile_vertically_pushbutton.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 283        self.tile_vertically_pushbutton.setMouseTracking(True)
 284        self.tile_vertically_pushbutton.clicked.connect(self._mdiArea.tile_subwindows_vertically)
 285        self.tile_vertically_pushbutton.clicked.connect(self.fit_to_window)
 286        self.tile_vertically_pushbutton.clicked.connect(self.refreshPan)
 287
 288        self.fit_to_window_pushbutton = ViewerButton(style="trigger")
 289        self.fit_to_window_pushbutton.setIcon(":/icons/pan.svg")
 290        self.fit_to_window_pushbutton.setToolTip("Fit and center image in active window (affects all if synced)")
 291        self.fit_to_window_pushbutton.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 292        self.fit_to_window_pushbutton.setMouseTracking(True)
 293        self.fit_to_window_pushbutton.clicked.connect(self.fit_to_window)
 294
 295        self.info_pushbutton = ViewerButton(style="trigger-transparent")
 296        self.info_pushbutton.setIcon(":/icons/about.svg")
 297        self.info_pushbutton.setToolTip("About...")
 298        self.info_pushbutton.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 299        self.info_pushbutton.setMouseTracking(True)
 300        self.info_pushbutton.clicked.connect(self.info_button_clicked)
 301
 302        self.stopsync_toggle_pushbutton = ViewerButton(style="green-yellow")
 303        self.stopsync_toggle_pushbutton.setIcon(":/icons/refresh.svg")
 304        self.stopsync_toggle_pushbutton.setCheckedIcon(":/icons/refresh-cancelled.svg")
 305        self.stopsync_toggle_pushbutton.setToolTip("Unsynchronize zoom and pan (currently synced)")
 306        self.stopsync_toggle_pushbutton.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 307        self.stopsync_toggle_pushbutton.setMouseTracking(True)
 308        self.stopsync_toggle_pushbutton.setCheckable(True)
 309        self.stopsync_toggle_pushbutton.toggled.connect(self.set_stopsync_pushbutton)
 310
 311        self.save_view_pushbutton = ViewerButton()
 312        self.save_view_pushbutton.setIcon(":/icons/download.svg")
 313        self.save_view_pushbutton.setToolTip("Save a screenshot of the viewer... | Copy screenshot to clipboard (Ctrl·C)")
 314        self.save_view_pushbutton.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 315        self.save_view_pushbutton.setMouseTracking(True)
 316        self.save_view_pushbutton.clicked.connect(self.save_view)
 317
 318        self.open_new_pushbutton = ViewerButton()
 319        self.open_new_pushbutton.setIcon(":/icons/open-file.svg")
 320        self.open_new_pushbutton.setToolTip("Open image(s) as single windows...")
 321        self.open_new_pushbutton.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 322        self.open_new_pushbutton.setMouseTracking(True)
 323        self.open_new_pushbutton.clicked.connect(self.open_multiple)
 324
 325        self.buffer_label = ViewerButton(style="invisible")
 326        self.buffer_label.setAttribute(QtCore.Qt.WA_TransparentForMouseEvents)
 327        self.buffer_label.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
 328        self.buffer_label.setMouseTracking(True)
 329
 330        self.label_mdiarea = QtWidgets.QLabel()
 331        self.label_mdiarea.setText("Drag images directly to create individual image windows\n\n—\n\nCreate sliding overlays to compare images directly over each other\n\n—\n\nRight-click image windows to change settings and add tools")
 332        self.label_mdiarea.setStyleSheet("""
 333            QLabel { 
 334                color: white;
 335                border: 0.13em dashed gray;
 336                border-radius: 0.25em;
 337                background-color: transparent;
 338                padding: 1em;
 339                font-size: 10pt;
 340                } 
 341            """)
 342        self.label_mdiarea.setAttribute(QtCore.Qt.WA_TransparentForMouseEvents)
 343        self.label_mdiarea.setAlignment(QtCore.Qt.AlignCenter)
 344
 345        layout_mdiarea_bottomright_vertical = GridLayoutFloatingShadow()
 346        layout_mdiarea_bottomright_vertical.addWidget(self.fullscreen_pushbutton, 5, 0)
 347        layout_mdiarea_bottomright_vertical.addWidget(self.tile_default_pushbutton, 4, 0)
 348        layout_mdiarea_bottomright_vertical.addWidget(self.tile_horizontally_pushbutton, 3, 0)
 349        layout_mdiarea_bottomright_vertical.addWidget(self.tile_vertically_pushbutton, 2, 0)
 350        layout_mdiarea_bottomright_vertical.addWidget(self.fit_to_window_pushbutton, 1, 0)
 351        layout_mdiarea_bottomright_vertical.addWidget(self.info_pushbutton, 0, 0)
 352        layout_mdiarea_bottomright_vertical.setContentsMargins(0,0,0,16)
 353        self.interface_mdiarea_bottomright_vertical = QtWidgets.QWidget()
 354        self.interface_mdiarea_bottomright_vertical.setLayout(layout_mdiarea_bottomright_vertical)
 355        tracker_interface_mdiarea_bottomright_vertical = EventTrackerSplitBypassInterface(self.interface_mdiarea_bottomright_vertical)
 356        tracker_interface_mdiarea_bottomright_vertical.mouse_position_changed.connect(self.update_split)
 357
 358        layout_mdiarea_bottomright_horizontal = GridLayoutFloatingShadow()
 359        layout_mdiarea_bottomright_horizontal.addWidget(self.buffer_label, 0, 6)
 360        layout_mdiarea_bottomright_horizontal.addWidget(self.interface_toggle_pushbutton, 0, 5)
 361        layout_mdiarea_bottomright_horizontal.addWidget(self.close_all_pushbutton, 0, 4)
 362        layout_mdiarea_bottomright_horizontal.addWidget(self.stopsync_toggle_pushbutton, 0, 3)
 363        layout_mdiarea_bottomright_horizontal.addWidget(self.save_view_pushbutton, 0, 2)
 364        layout_mdiarea_bottomright_horizontal.addWidget(self.open_new_pushbutton, 0, 1)
 365        layout_mdiarea_bottomright_horizontal.setContentsMargins(0,0,0,16)
 366        self.interface_mdiarea_bottomright_horizontal = QtWidgets.QWidget()
 367        self.interface_mdiarea_bottomright_horizontal.setLayout(layout_mdiarea_bottomright_horizontal)
 368        tracker_interface_mdiarea_bottomright_horizontal = EventTrackerSplitBypassInterface(self.interface_mdiarea_bottomright_horizontal)
 369        tracker_interface_mdiarea_bottomright_horizontal.mouse_position_changed.connect(self.update_split)
 370
 371
 372        self.loading_grayout_label = QtWidgets.QLabel("Loading...") # Needed to give users feedback when loading views
 373        self.loading_grayout_label.setWordWrap(True)
 374        self.loading_grayout_label.setAlignment(QtCore.Qt.AlignCenter | QtCore.Qt.AlignVCenter)
 375        self.loading_grayout_label.setVisible(False)
 376        self.loading_grayout_label.setStyleSheet("""
 377            QLabel { 
 378                color: white;
 379                background-color: rgba(0,0,0,223);
 380                font-size: 10pt;
 381                } 
 382            """)
 383
 384        self.dragged_grayout_label = QtWidgets.QLabel("Drop to create single view(s)...") # Needed to give users feedback when dragging in images
 385        self.dragged_grayout_label.setAttribute(QtCore.Qt.WA_TransparentForMouseEvents)
 386        self.dragged_grayout_label.setWordWrap(True)
 387        self.dragged_grayout_label.setAlignment(QtCore.Qt.AlignCenter | QtCore.Qt.AlignVCenter)
 388        self.dragged_grayout_label.setVisible(False)
 389        self.dragged_grayout_label.setStyleSheet("""
 390            QLabel { 
 391                color: white;
 392                background-color: rgba(63,63,63,223);
 393                border: 0.13em dashed gray;
 394                border-radius: 0.25em;
 395                margin-left: 0.25em;
 396                margin-top: 0.25em;
 397                margin-right: 0.25em;
 398                margin-bottom: 0.25em;
 399                font-size: 10pt;
 400                } 
 401            """)    
 402
 403
 404        layout_mdiarea = QtWidgets.QGridLayout()
 405        layout_mdiarea.setContentsMargins(0, 0, 0, 0)
 406        layout_mdiarea.setSpacing(0)
 407        layout_mdiarea.addWidget(self._mdiArea, 0, 0)
 408        layout_mdiarea.addWidget(self.label_mdiarea, 0, 0, QtCore.Qt.AlignCenter)
 409        layout_mdiarea.addWidget(self.dragged_grayout_label, 0, 0)
 410        layout_mdiarea.addWidget(self.loading_grayout_label, 0, 0)
 411        layout_mdiarea.addWidget(self.interface_mdiarea_topleft, 0, 0, QtCore.Qt.AlignTop | QtCore.Qt.AlignLeft)
 412        layout_mdiarea.addWidget(self.interface_mdiarea_bottomleft, 0, 0, QtCore.Qt.AlignBottom | QtCore.Qt.AlignLeft)
 413        layout_mdiarea.addWidget(self.interface_mdiarea_bottomright_horizontal, 0, 0, QtCore.Qt.AlignBottom | QtCore.Qt.AlignRight)
 414        layout_mdiarea.addWidget(self.interface_mdiarea_bottomright_vertical, 0, 0, QtCore.Qt.AlignBottom | QtCore.Qt.AlignRight)
 415
 416        self.mdiarea_plus_buttons = QtWidgets.QWidget()
 417        self.mdiarea_plus_buttons.setLayout(layout_mdiarea)
 418
 419        self.setCentralWidget(self.mdiarea_plus_buttons)
 420
 421        self.subwindow_was_just_closed = False
 422
 423        self._windowMapper = QtCore.QSignalMapper(self)
 424
 425        self._actionMapper = QtCore.QSignalMapper(self)
 426        self._actionMapper.mapped[str].connect(self.mappedImageViewerAction)
 427        self._recentFileMapper = QtCore.QSignalMapper(self)
 428        self._recentFileMapper.mapped[str].connect(self.openRecentFile)
 429
 430        self.createActions()
 431        self.addAction(self._activateSubWindowSystemMenuAct)
 432
 433        self.createMenus()
 434        self.updateMenus()
 435        self.createStatusBar()
 436
 437        self.readSettings()
 438        self.updateStatusBar()
 439
 440        self.setUnifiedTitleAndToolBarOnMac(True)
 441        
 442        self.showNormal()
 443        self.menuBar().hide()
 444
 445        self.setStyleSheet("QWidget{font-size: 9pt}")
 446
 447
 448    # Screenshot window
 449
 450    def copy_view(self):
 451        """Screenshot MultiViewMainWindow and copy to clipboard as image."""
 452        
 453        self.display_loading_grayout(True, "Screenshot copied to clipboard.")
 454
 455        interface_was_already_set_hidden = not self.is_interface_showing # Needed to hide the interface temporarily while grabbing a screenshot (makes sure the screenshot only shows the views)
 456        if not interface_was_already_set_hidden:
 457            self.show_interface_off()
 458
 459        pixmap = self._mdiArea.grab()
 460        clipboard = QtWidgets.QApplication.clipboard()
 461        clipboard.setPixmap(pixmap)
 462
 463        if not interface_was_already_set_hidden:
 464            self.show_interface_on()
 465
 466        self.display_loading_grayout(False, pseudo_load_time=1)
 467
 468
 469    def save_view(self):
 470        """Screenshot MultiViewMainWindow and open Save dialog to save screenshot as image.""" 
 471
 472        self.display_loading_grayout(True, "Saving viewer screenshot...")
 473
 474        folderpath = None
 475
 476        if self.activeMdiChild:
 477            folderpath = self.activeMdiChild.currentFile
 478            folderpath = os.path.dirname(folderpath)
 479            folderpath = folderpath + "\\"
 480        else:
 481            self.display_loading_grayout(False, pseudo_load_time=0)
 482            return
 483
 484        interface_was_already_set_hidden = not self.is_interface_showing # Needed to hide the interface temporarily while grabbing a screenshot (makes sure the screenshot only shows the views)
 485        if not interface_was_already_set_hidden:
 486            self.show_interface_off()
 487
 488        pixmap = self._mdiArea.grab()
 489
 490        date_and_time = datetime.now().strftime('%Y-%m-%d %H%M%S') # Sets the default filename with date and time 
 491        filename = "Viewer screenshot " + date_and_time + ".png"
 492        name_filters = "PNG (*.png);; JPEG (*.jpeg);; TIFF (*.tiff);; JPG (*.jpg);; TIF (*.tif)" # Allows users to select filetype of screenshot
 493
 494        self.display_loading_grayout(True, "Selecting folder and name for the viewer screenshot...", pseudo_load_time=0)
 495        
 496        filepath, _ = QtWidgets.QFileDialog.getSaveFileName(self, "Save a screenshot of the viewer", folderpath+filename, name_filters)
 497        _, fileextension = os.path.splitext(filepath)
 498        fileextension = fileextension.replace('.','')
 499        if filepath:
 500            pixmap.save(filepath, fileextension)
 501        
 502        if not interface_was_already_set_hidden:
 503            self.show_interface_on()
 504
 505        self.display_loading_grayout(False)
 506
 507    
 508    # Interface and appearance
 509
 510    def display_loading_grayout(self, boolean, text="Loading...", pseudo_load_time=0.2):
 511        """Show/hide grayout screen for loading sequences.
 512
 513        Args:
 514            boolean (bool): True to show grayout; False to hide.
 515            text (str): The text to show on the grayout.
 516            pseudo_load_time (float): The delay (in seconds) to hide the grayout to give users a feeling of action.
 517        """ 
 518        if not boolean:
 519            text = "Loading..."
 520        self.loading_grayout_label.setText(text)
 521        self.loading_grayout_label.setVisible(boolean)
 522        if boolean:
 523            self.loading_grayout_label.repaint()
 524        if not boolean:
 525            time.sleep(pseudo_load_time)
 526
 527    def display_dragged_grayout(self, boolean):
 528        """Show/hide grayout screen for drag-and-drop sequences.
 529
 530        Args:
 531            boolean (bool): True to show grayout; False to hide.
 532        """ 
 533        self.dragged_grayout_label.setVisible(boolean)
 534        if boolean:
 535            self.dragged_grayout_label.repaint()
 536
 537    def on_last_remaining_subwindow_was_closed(self):
 538        """Show instructions label of MDIArea."""
 539        self.label_mdiarea.setVisible(True)
 540
 541    def on_first_subwindow_was_opened(self):
 542        """Hide instructions label of MDIArea."""
 543        self.label_mdiarea.setVisible(False)
 544
 545    def show_interface(self, boolean):
 546        """Show/hide interface elements for sliding overlay creator and transparencies.
 547
 548        Args:
 549            boolean (bool): True to show interface; False to hide.
 550        """ 
 551        if boolean:
 552            self.show_interface_on()
 553        elif not boolean:
 554            self.show_interface_off()
 555
 556    def show_interface_on(self):
 557        """Show interface elements for sliding overlay creator and transparencies.""" 
 558        if self.is_interface_showing:
 559            return
 560        
 561        self.is_interface_showing = True
 562        self.is_quiet_mode = False
 563
 564        self.update_window_highlight(self._mdiArea.activeSubWindow())
 565        self.update_window_labels(self._mdiArea.activeSubWindow())
 566        self.set_window_close_pushbuttons_always_visible(self._mdiArea.activeSubWindow(), True)
 567        self.set_window_mouse_rect_visible(self._mdiArea.activeSubWindow(), True)
 568        self.interface_mdiarea_topleft.setVisible(True)
 569        self.interface_mdiarea_bottomleft.setVisible(True)
 570
 571        self.interface_toggle_pushbutton.setToolTip("Hide interface (studio mode)")
 572
 573        if self.interface_toggle_pushbutton:
 574            self.interface_toggle_pushbutton.setChecked(True)
 575
 576    def show_interface_off(self):
 577        """Hide interface elements for sliding overlay creator and transparencies.""" 
 578        if not self.is_interface_showing:
 579            return
 580
 581        self.is_interface_showing = False
 582        self.is_quiet_mode = True
 583
 584        self.update_window_highlight(self._mdiArea.activeSubWindow())
 585        self.update_window_labels(self._mdiArea.activeSubWindow())
 586        self.set_window_close_pushbuttons_always_visible(self._mdiArea.activeSubWindow(), False)
 587        self.set_window_mouse_rect_visible(self._mdiArea.activeSubWindow(), False)
 588        self.interface_mdiarea_topleft.setVisible(False)
 589        self.interface_mdiarea_bottomleft.setVisible(False)
 590
 591        self.interface_toggle_pushbutton.setToolTip("Show interface (H)")
 592
 593        if self.interface_toggle_pushbutton:
 594            self.interface_toggle_pushbutton.setChecked(False)
 595            self.interface_toggle_pushbutton.setAttribute(QtCore.Qt.WA_UnderMouse, False)
 596
 597    def toggle_interface(self):
 598        """Toggle visibilty of interface elements for sliding overlay creator and transparencies.""" 
 599        if self.is_interface_showing: # If interface is showing, then toggle it off; if not, then toggle it on
 600            self.show_interface_off()
 601        else:
 602            self.show_interface_on()
 603
 604    def set_stopsync_pushbutton(self, boolean):
 605        """Set state of synchronous zoom/pan and appearance of corresponding interface button.
 606
 607        Args:
 608            boolean (bool): True to enable synchronized zoom/pan; False to disable.
 609        """ 
 610        self._synchZoomAct.setChecked(not boolean)
 611        self._synchPanAct.setChecked(not boolean)
 612        
 613        if self._synchZoomAct.isChecked():
 614            if self.activeMdiChild:
 615                self.activeMdiChild.fitToWindow()
 616
 617        if boolean:
 618            self.stopsync_toggle_pushbutton.setToolTip("Synchronize zoom and pan (currently unsynced)")
 619        else:
 620            self.stopsync_toggle_pushbutton.setToolTip("Unsynchronize zoom and pan (currently synced)")
 621
 622    def toggle_fullscreen(self):
 623        """Toggle fullscreen state of app."""
 624        if self.is_fullscreen:
 625            self.set_fullscreen_off()
 626        else:
 627            self.set_fullscreen_on()
 628    
 629    def set_fullscreen_on(self):
 630        """Enable fullscreen of MultiViewMainWindow.
 631        
 632        Moves MDIArea to secondary window and makes it fullscreen.
 633        Shows interim widget in main window.  
 634        """
 635        if self.is_fullscreen:
 636            return
 637
 638        position_of_window = self.pos()
 639
 640        centralwidget_to_be_made_fullscreen = self.mdiarea_plus_buttons
 641        widget_to_replace_central = self.centralwidget_during_fullscreen
 642
 643        centralwidget_to_be_made_fullscreen.setParent(None)
 644
 645        # move() is needed when using multiple monitors because when the widget loses its parent, its position moves to the primary screen origin (0,0) instead of retaining the app's screen
 646        # The solution is to move the widget to the position of the app window and then make the widget fullscreen
 647        # A timer is needed for showFullScreen() to apply on the app's screen (otherwise the command is made before the widget's move is established)
 648        centralwidget_to_be_made_fullscreen.move(position_of_window)
 649        QtCore.QTimer.singleShot(50, centralwidget_to_be_made_fullscreen.showFullScreen)
 650
 651        self.showMinimized()
 652
 653        self.setCentralWidget(widget_to_replace_central)
 654        widget_to_replace_central.show()
 655        
 656        self._mdiArea.tile_what_was_done_last_time()
 657        self._mdiArea.activateWindow()
 658
 659        self.is_fullscreen = True
 660        if self.fullscreen_pushbutton:
 661            self.fullscreen_pushbutton.setChecked(True)
 662
 663        if self.activeMdiChild:
 664            self.synchPan(self.activeMdiChild)
 665
 666    def set_fullscreen_off(self):
 667        """Disable fullscreen of MultiViewMainWindow.
 668        
 669        Removes interim widget in main window. 
 670        Returns MDIArea to normal (non-fullscreen) view on main window. 
 671        """
 672        if not self.is_fullscreen:
 673            return
 674        
 675        self.showNormal()
 676
 677        fullscreenwidget_to_be_made_central = self.mdiarea_plus_buttons
 678        centralwidget_to_be_hidden = self.centralwidget_during_fullscreen
 679
 680        centralwidget_to_be_hidden.setParent(None)
 681        centralwidget_to_be_hidden.hide()
 682
 683        self.setCentralWidget(fullscreenwidget_to_be_made_central)
 684
 685        self._mdiArea.tile_what_was_done_last_time()
 686        self._mdiArea.activateWindow()
 687
 688        self.is_fullscreen = False
 689        if self.fullscreen_pushbutton:
 690            self.fullscreen_pushbutton.setChecked(False)
 691            self.fullscreen_pushbutton.setAttribute(QtCore.Qt.WA_UnderMouse, False)
 692
 693        self.refreshPanDelayed(100)
 694
 695    def set_fullscreen(self, boolean):
 696        """Enable/disable fullscreen of MultiViewMainWindow.
 697        
 698        Args:
 699            boolean (bool): True to enable fullscreen; False to disable.
 700        """
 701        if boolean:
 702            self.set_fullscreen_on()
 703        elif not boolean:
 704            self.set_fullscreen_off()
 705    
 706    def update_window_highlight(self, window):
 707        """Update highlight of subwindows in MDIArea.
 708
 709        Input window should be the subwindow which is active.
 710        All other subwindow(s) will be shown no highlight.
 711        
 712        Args:
 713            window (QMdiSubWindow): The active subwindow to show highlight and indicate as active.
 714        """
 715        if window is None:
 716            return
 717        changed_window = window
 718        if self.is_quiet_mode:
 719            changed_window.widget().frame_hud.setStyleSheet("QFrame {border: 0px solid transparent}")
 720        elif self.activeMdiChild.split_locked:
 721            changed_window.widget().frame_hud.setStyleSheet("QFrame {border: 0.2em orange; border-left-style: outset; border-top-style: inset; border-right-style: inset; border-bottom-style: inset}")
 722        else:
 723            changed_window.widget().frame_hud.setStyleSheet("QFrame {border: 0.2em blue; border-left-style: outset; border-top-style: inset; border-right-style: inset; border-bottom-style: inset}")
 724
 725        windows = self._mdiArea.subWindowList()
 726        for window in windows:
 727            if window != changed_window:
 728                window.widget().frame_hud.setStyleSheet("QFrame {border: 0px solid transparent}")
 729
 730    def update_window_labels(self, window):
 731        """Update labels of subwindows in MDIArea.
 732
 733        Input window should be the subwindow which is active.
 734        All other subwindow(s) will be shown no labels.
 735        
 736        Args:
 737            window (QMdiSubWindow): The active subwindow to show label(s) of image(s) and indicate as active.
 738        """
 739        if window is None:
 740            return
 741        changed_window = window
 742        label_visible = True
 743        if self.is_quiet_mode:
 744            label_visible = False
 745        changed_window.widget().label_main_topleft.set_visible_based_on_text(label_visible)
 746        changed_window.widget().label_topright.set_visible_based_on_text(label_visible)
 747        changed_window.widget().label_bottomright.set_visible_based_on_text(label_visible)
 748        changed_window.widget().label_bottomleft.set_visible_based_on_text(label_visible)
 749
 750        windows = self._mdiArea.subWindowList()
 751        for window in windows:
 752            if window != changed_window:
 753                window.widget().label_main_topleft.set_visible_based_on_text(False)
 754                window.widget().label_topright.set_visible_based_on_text(False)
 755                window.widget().label_bottomright.set_visible_based_on_text(False)
 756                window.widget().label_bottomleft.set_visible_based_on_text(False)
 757
 758    def set_window_close_pushbuttons_always_visible(self, window, boolean):
 759        """Enable/disable the always-on visiblilty of the close X on each subwindow.
 760        
 761        Args:
 762            window (QMdiSubWindow): The active subwindow.
 763            boolean (bool): True to show the close X always; False to hide unless mouse hovers over.
 764        """
 765        if window is None:
 766            return
 767        changed_window = window
 768        always_visible = boolean
 769        changed_window.widget().set_close_pushbutton_always_visible(always_visible)
 770        windows = self._mdiArea.subWindowList()
 771        for window in windows:
 772            if window != changed_window:
 773                window.widget().set_close_pushbutton_always_visible(always_visible)
 774
 775    def set_window_mouse_rect_visible(self, window, boolean):
 776        """Enable/disable the visiblilty of the red 1x1 outline at the pointer
 777        
 778        Outline shows the relative size of a pixel in the active subwindow.
 779        
 780        Args:
 781            window (QMdiSubWindow): The active subwindow.
 782            boolean (bool): True to show 1x1 outline; False to hide.
 783        """
 784        if window is None:
 785            return
 786        changed_window = window
 787        visible = boolean
 788        changed_window.widget().set_mouse_rect_visible(visible)
 789        windows = self._mdiArea.subWindowList()
 790        for window in windows:
 791            if window != changed_window:
 792                window.widget().set_mouse_rect_visible(visible)
 793
 794    def auto_tile_subwindows_on_close(self):
 795        """Tile the subwindows of MDIArea using previously used tile method."""
 796        if self.subwindow_was_just_closed:
 797            self.subwindow_was_just_closed = False
 798            QtCore.QTimer.singleShot(50, self._mdiArea.tile_what_was_done_last_time)
 799            self.refreshPanDelayed(50)
 800
 801    def update_mdi_buttons(self, window):
 802        """Update the interface button 'Split Lock' based on the status of the split (locked/unlocked) in the given window.
 803        
 804        Args:
 805            window (QMdiSubWindow): The active subwindow.
 806        """
 807        if window is None:
 808            self._splitview_manager.lock_split_pushbutton.setChecked(False)
 809            return
 810        
 811        child = self.activeMdiChild
 812
 813        self._splitview_manager.lock_split_pushbutton.setChecked(child.split_locked)
 814
 815
 816    def set_single_window_transform_mode_smooth(self, window, boolean):
 817        """Set the transform mode of a given subwindow.
 818        
 819        Args:
 820            window (QMdiSubWindow): The subwindow.
 821            boolean (bool): True to smooth (interpolate); False to fast (not interpolate).
 822        """
 823        if window is None:
 824            return
 825        changed_window = window
 826        changed_window.widget().set_transform_mode_smooth(boolean)
 827        
 828
 829    def set_all_window_transform_mode_smooth(self, boolean):
 830        """Set the transform mode of all subwindows. 
 831        
 832        Args:
 833            boolean (bool): True to smooth (interpolate); False to fast (not interpolate).
 834        """
 835        if self._mdiArea.activeSubWindow() is None:
 836            return
 837        windows = self._mdiArea.subWindowList()
 838        for window in windows:
 839            window.widget().set_transform_mode_smooth(boolean)
 840
 841    def set_all_background_color(self, color):
 842        """Set the background color of all subwindows. 
 843        
 844        Args:
 845            color (list): Descriptor string and RGB int values. Example: ["White", 255, 255, 255].
 846        """
 847        if self._mdiArea.activeSubWindow() is None:
 848            return
 849        windows = self._mdiArea.subWindowList()
 850        for window in windows:
 851            window.widget().set_scene_background_color(color)
 852        self.scene_background_color = color
 853
 854    def set_all_sync_zoom_by(self, by: str):
 855        """[str] Set the method by which to sync zoom all windows."""
 856        if self._mdiArea.activeSubWindow() is None:
 857            return
 858        windows = self._mdiArea.subWindowList()
 859        for window in windows:
 860            window.widget().update_sync_zoom_by(by)
 861        self.sync_zoom_by = by
 862        self.refreshZoom()
 863
 864    def info_button_clicked(self):
 865        """Trigger when info button is clicked."""
 866        self.show_about()
 867        return
 868    
 869    def show_about(self):
 870        """Show about box."""
 871        sp = "<br>"
 872        title = "Butterfly Viewer"
 873        text = "Butterfly Viewer"
 874        text = text + sp + "Lars Maxfield"
 875        text = text + sp + "Version: " + VERSION
 876        text = text + sp + "License: <a href='https://www.gnu.org/licenses/gpl-3.0.en.html'>GNU GPL v3</a> or later"
 877        text = text + sp + "Source: <a href='https://github.com/olive-groves/butterfly_viewer'>github.com/olive-groves/butterfly_viewer</a>"
 878        text = text + sp + "Tutorial: <a href='https://olive-groves.github.io/butterfly_viewer'>olive-groves.github.io/butterfly_viewer</a>"
 879        box = QtWidgets.QMessageBox.about(self, title, text)
 880
 881    # View loading methods
 882
 883    def loadFile(self, filename_main_topleft, filename_topright=None, filename_bottomleft=None, filename_bottomright=None):
 884        """Load an individual image or sliding overlay into new subwindow.
 885
 886        Args:
 887            filename_main_topleft (str): The image filepath of the main image to be viewed; the basis of the sliding overlay (main; topleft)
 888            filename_topright (str): The image filepath for top-right of the sliding overlay (set None to exclude)
 889            filename_bottomleft (str): The image filepath for bottom-left of the sliding overlay (set None to exclude)
 890            filename_bottomright (str): The image filepath for bottom-right of the sliding overlay (set None to exclude)
 891        """
 892
 893        self.display_loading_grayout(True, "Loading viewer with main image '" + filename_main_topleft.split("/")[-1] + "'...")
 894
 895        activeMdiChild = self.activeMdiChild
 896        QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
 897
 898        transform_mode_smooth = self.is_global_transform_mode_smooth
 899        
 900        pixmap = QtGui.QPixmap(filename_main_topleft)
 901        pixmap_topright = QtGui.QPixmap(filename_topright)
 902        pixmap_bottomleft = QtGui.QPixmap(filename_bottomleft)
 903        pixmap_bottomright = QtGui.QPixmap(filename_bottomright)
 904        
 905        QtWidgets.QApplication.restoreOverrideCursor()
 906        
 907        if (not pixmap or
 908            pixmap.width()==0 or pixmap.height==0):
 909            self.display_loading_grayout(True, "Waiting on dialog box...")
 910            QtWidgets.QMessageBox.warning(self, APPNAME,
 911                                      "Cannot read file %s." % (filename_main_topleft,))
 912            self.updateRecentFileSettings(filename_main_topleft, delete=True)
 913            self.updateRecentFileActions()
 914            self.display_loading_grayout(False)
 915            return
 916        
 917        angle = get_exif_rotation_angle(filename_main_topleft)
 918        if angle:
 919            pixmap = pixmap.transformed(QtGui.QTransform().rotate(angle))
 920        
 921        angle = get_exif_rotation_angle(filename_topright)
 922        if angle:
 923            pixmap_topright = pixmap_topright.transformed(QtGui.QTransform().rotate(angle))
 924
 925        angle = get_exif_rotation_angle(filename_bottomright)
 926        if angle:
 927            pixmap_bottomright = pixmap_bottomright.transformed(QtGui.QTransform().rotate(angle))
 928
 929        angle = get_exif_rotation_angle(filename_bottomleft)
 930        if angle:
 931            pixmap_bottomleft = pixmap_bottomleft.transformed(QtGui.QTransform().rotate(angle))
 932
 933        child = self.createMdiChild(pixmap, filename_main_topleft, pixmap_topright, pixmap_bottomleft, pixmap_bottomright, transform_mode_smooth)
 934
 935        # Show filenames
 936        child.label_main_topleft.setText(filename_main_topleft)
 937        child.label_topright.setText(filename_topright)
 938        child.label_bottomright.setText(filename_bottomright)
 939        child.label_bottomleft.setText(filename_bottomleft)
 940        
 941        child.show()
 942
 943        if activeMdiChild:
 944            if self._synchPanAct.isChecked():
 945                self.synchPan(activeMdiChild)
 946            if self._synchZoomAct.isChecked():
 947                self.synchZoom(activeMdiChild)
 948                
 949        self._mdiArea.tile_what_was_done_last_time()
 950        
 951        child.fitToWindow()
 952        child.set_close_pushbutton_always_visible(self.is_interface_showing)
 953        if self.scene_background_color is not None:
 954            child.set_scene_background_color(self.scene_background_color)
 955
 956        self.updateRecentFileSettings(filename_main_topleft)
 957        self.updateRecentFileActions()
 958        
 959        self._last_accessed_fullpath = filename_main_topleft
 960
 961        self.display_loading_grayout(False)
 962
 963        self.statusBar().showMessage("File loaded", 2000)
 964
 965    def load_from_dragged_and_dropped_file(self, filename_main_topleft):
 966        """Load an individual image (convenience function — e.g., from a single emitted single filename)."""
 967        self.loadFile(filename_main_topleft)
 968    
 969    def createMdiChild(self, pixmap, filename_main_topleft, pixmap_topright, pixmap_bottomleft, pixmap_bottomright, transform_mode_smooth):
 970        """Create new viewing widget for an individual image or sliding overlay to be placed in a new subwindow.
 971
 972        Args:
 973            pixmap (QPixmap): The main image to be viewed; the basis of the sliding overlay (main; topleft)
 974            filename_main_topleft (str): The image filepath of the main image.
 975            pixmap_topright (QPixmap): The top-right image of the sliding overlay (set None to exclude).
 976            pixmap_bottomleft (QPixmap): The bottom-left image of the sliding overlay (set None to exclude).
 977            pixmap_bottomright (QPixmap): The bottom-right image of the sliding overlay (set None to exclude).
 978
 979        Returns:
 980            child (SplitViewMdiChild): The viewing widget instance.
 981        """
 982        
 983        child = SplitViewMdiChild(pixmap,
 984                         filename_main_topleft,
 985                         "Window %d" % (len(self._mdiArea.subWindowList())+1),
 986                         pixmap_topright, pixmap_bottomleft, pixmap_bottomright, 
 987                         transform_mode_smooth)
 988
 989        child.enableScrollBars(self._showScrollbarsAct.isChecked())
 990
 991        child.sync_this_zoom = True
 992        child.sync_this_pan = True
 993        
 994        self._mdiArea.addSubWindow(child, QtCore.Qt.FramelessWindowHint) # LVM: No frame, starts fitted
 995
 996        child.scrollChanged.connect(self.panChanged)
 997        child.transformChanged.connect(self.zoomChanged)
 998        
 999        child.positionChanged.connect(self.on_positionChanged)
1000        child.tracker.mouse_leaved.connect(self.on_mouse_leaved)
1001        
1002        child.scrollChanged.connect(self.on_scrollChanged)
1003
1004        child.became_closed.connect(self.on_subwindow_closed)
1005        child.was_clicked_close_pushbutton.connect(self._mdiArea.closeActiveSubWindow)
1006        child.shortcut_shift_x_was_activated.connect(self.shortcut_shift_x_was_activated_on_mdichild)
1007        child.signal_display_loading_grayout.connect(self.display_loading_grayout)
1008        child.was_set_global_transform_mode.connect(self.set_all_window_transform_mode_smooth)
1009        child.was_set_scene_background_color.connect(self.set_all_background_color)
1010        child.was_set_sync_zoom_by.connect(self.set_all_sync_zoom_by)
1011
1012        return child
1013
1014
1015    # View and split methods
1016
1017    @QtCore.pyqtSlot()
1018    def on_create_splitview(self):
1019        """Load a sliding overlay using the filepaths of the current images in the sliding overlay creator."""
1020        # Get filenames
1021        file_path_main_topleft = self._splitview_creator.drag_drop_area.app_main_topleft.file_path
1022        file_path_topright = self._splitview_creator.drag_drop_area.app_topright.file_path
1023        file_path_bottomleft = self._splitview_creator.drag_drop_area.app_bottomleft.file_path
1024        file_path_bottomright = self._splitview_creator.drag_drop_area.app_bottomright.file_path
1025
1026        # loadFile with those filenames
1027        self.loadFile(file_path_main_topleft, file_path_topright, file_path_bottomleft, file_path_bottomright)
1028
1029    def fit_to_window(self):
1030        """Fit the view of the active subwindow (if it exists)."""
1031        if self.activeMdiChild:
1032            self.activeMdiChild.fitToWindow()
1033
1034    def update_split(self):
1035        """Update the position of the split of the active subwindow (if it exists) relying on the global mouse coordinates."""
1036        if self.activeMdiChild:
1037            self.activeMdiChild.update_split() # No input = Rely on global mouse position calculation
1038
1039    def lock_split(self):
1040        """Lock the position of the overlay split of active subwindow and set relevant interface elements."""
1041        if self.activeMdiChild:
1042            self.activeMdiChild.split_locked = True
1043        self._splitview_manager.lock_split_pushbutton.setChecked(True)
1044        self.update_window_highlight(self._mdiArea.activeSubWindow())
1045
1046    def unlock_split(self):
1047        """Unlock the position of the overlay split of active subwindow and set relevant interface elements."""
1048        if self.activeMdiChild:
1049            self.activeMdiChild.split_locked = False
1050        self._splitview_manager.lock_split_pushbutton.setChecked(False)
1051        self.update_window_highlight(self._mdiArea.activeSubWindow())
1052
1053    def set_split(self, x_percent=0.5, y_percent=0.5, apply_to_all=True, ignore_lock=False, percent_of_visible=False):
1054        """Set the position of the split of the active subwindow as percent of base image's resolution.
1055        
1056        Args:
1057            x_percent (float): The position of the split as a proportion (0-1) of the base image's horizontal resolution.
1058            y_percent (float): The position of the split as a proportion (0-1) of the base image's vertical resolution.
1059            apply_to_all (bool): True to set all subwindow splits; False to set only the active subwindow.
1060            ignore_lock (bool): True to ignore the lock status of the split; False to adhere.
1061            percent_of_visible (bool): True to set split as proportion of visible area; False as proportion of the full image resolution.
1062        """
1063        if self.activeMdiChild:
1064            self.activeMdiChild.set_split(x_percent, y_percent, ignore_lock=ignore_lock, percent_of_visible=percent_of_visible)
1065        if apply_to_all:
1066            windows = self._mdiArea.subWindowList()
1067            for window in windows:
1068                window.widget().set_split(x_percent, y_percent, ignore_lock=ignore_lock, percent_of_visible=percent_of_visible)
1069        self.update_window_highlight(self._mdiArea.activeSubWindow())
1070
1071    def set_split_from_slider(self):
1072        """Set the position of the split of the active subwindow to the center of the visible area of the sliding overlay (convenience function)."""
1073        self.set_split(x_percent=0.5, y_percent=0.5, apply_to_all=False, ignore_lock=False, percent_of_visible=True)
1074    
1075    def set_split_from_manager(self, x_percent, y_percent):
1076        """Set the position of the split of the active subwindow as percent of base image's resolution (convenience function).
1077        
1078        Args:
1079            x_percent (float): The position of the split as a proportion of the base image's horizontal resolution (0-1).
1080            y_percent (float): The position of the split as a proportion of the base image's vertical resolution (0-1).
1081        """
1082        self.set_split(x_percent, y_percent, apply_to_all=False, ignore_lock=False)
1083
1084    def set_and_lock_split_from_manager(self, x_percent, y_percent):
1085        """Set and lock the position of the split of the active subwindow as percent of base image's resolution (convenience function).
1086        
1087        Args:
1088            x_percent (float): The position of the split as a proportion of the base image's horizontal resolution (0-1).
1089            y_percent (float): The position of the split as a proportion of the base image's vertical resolution (0-1).
1090        """
1091        self.set_split(x_percent, y_percent, apply_to_all=False, ignore_lock=True)
1092        self.lock_split()
1093
1094    def shortcut_shift_x_was_activated_on_mdichild(self):
1095        """Update interface button for split lock based on lock status of active subwindow."""
1096        self._splitview_manager.lock_split_pushbutton.setChecked(self.activeMdiChild.split_locked)
1097
1098    @QtCore.pyqtSlot()
1099    def on_scrollChanged(self):
1100        """Refresh position of split of all subwindows based on their respective last position."""
1101        windows = self._mdiArea.subWindowList()
1102        for window in windows:
1103            window.widget().refresh_split_based_on_last_updated_point_of_split_on_scene_main()
1104
1105    def on_subwindow_closed(self):
1106        """Record that a subwindow was closed upon the closing of a subwindow."""
1107        self.subwindow_was_just_closed = True
1108    
1109    @QtCore.pyqtSlot()
1110    def on_mouse_leaved(self):
1111        """Update displayed coordinates of mouse as N/A upon the mouse leaving the subwindow area."""
1112        self._label_mouse.setText("View pixel coordinates: ( N/A , N/A )")
1113        self._label_mouse.adjustSize()
1114        
1115    @QtCore.pyqtSlot(QtCore.QPoint)
1116    def on_positionChanged(self, pos):
1117        """Update displayed coordinates of mouse on the active subwindow using global coordinates."""
1118    
1119        point_of_mouse_on_viewport = QtCore.QPointF(pos.x(), pos.y())
1120        pos_qcursor_global = QtGui.QCursor.pos()
1121        
1122        if self.activeMdiChild:
1123        
1124            # Use mouse position to grab scene coordinates (activeMdiChild?)
1125            active_view = self.activeMdiChild._view_main_topleft
1126            point_of_mouse_on_scene = active_view.mapToScene(point_of_mouse_on_viewport.x(), point_of_mouse_on_viewport.y())
1127
1128            if not self._label_mouse.isVisible():
1129                self._label_mouse.show()
1130            self._label_mouse.setText("View pixel coordinates: ( x = %d , y = %d )" % (point_of_mouse_on_scene.x(), point_of_mouse_on_scene.y()))
1131            
1132            pos_qcursor_view = active_view.mapFromGlobal(pos_qcursor_global)
1133            pos_qcursor_scene = active_view.mapToScene(pos_qcursor_view)
1134            # print("Cursor coords scene: ( %d , %d )" % (pos_qcursor_scene.x(), pos_qcursor_scene.y()))
1135            
1136        else:
1137            
1138            self._label_mouse.setText("View pixel coordinates: ( N/A , N/A )")
1139            
1140        self._label_mouse.adjustSize()
1141
1142    
1143    # Transparency methods
1144
1145
1146    @QtCore.pyqtSlot(int)
1147    def on_slider_opacity_base_changed(self, value):
1148        """Set transparency of base of sliding overlay of active subwindow.
1149        
1150        Triggered upon change in interface transparency slider.
1151        Temporarily sets position of split to the center of the visible area to give user a preview of the transparency effect.
1152
1153        Args:
1154            value (float,int): The transparency as percent opacity, where 100 is opaque (not transparent) and 0 is transparent (0-100).
1155        """
1156        if not self.activeMdiChild:
1157            return
1158        if not self.activeMdiChild.split_locked:
1159            self.set_split_from_slider()
1160        self.activeMdiChild.set_opacity_base(value)
1161
1162    @QtCore.pyqtSlot(int)
1163    def on_slider_opacity_topright_changed(self, value):
1164        """Set transparency of top-right of sliding overlay of active subwindow.
1165        
1166        Triggered upon change in interface transparency slider.
1167        Temporarily sets position of split to the center of the visible area to give user a preview of the transparency effect.
1168
1169        Args:
1170            value (float,int): The transparency as percent opacity, where 100 is opaque (not transparent) and 0 is transparent (0-100).
1171        """
1172        if not self.activeMdiChild:
1173            return
1174        if not self.activeMdiChild.split_locked:
1175            self.set_split_from_slider()
1176        self.activeMdiChild.set_opacity_topright(value)
1177
1178    @QtCore.pyqtSlot(int)
1179    def on_slider_opacity_bottomright_changed(self, value):
1180        """Set transparency of bottom-right of sliding overlay of active subwindow.
1181        
1182        Triggered upon change in interface transparency slider.
1183        Temporarily sets position of split to the center of the visible area to give user a preview of the transparency effect.
1184
1185        Args:
1186            value (float,int): The transparency as percent opacity, where 100 is opaque (not transparent) and 0 is transparent (0-100).
1187        """
1188        if not self.activeMdiChild:
1189            return
1190        if not self.activeMdiChild.split_locked:
1191            self.set_split_from_slider()    
1192        self.activeMdiChild.set_opacity_bottomright(value)
1193
1194    @QtCore.pyqtSlot(int)
1195    def on_slider_opacity_bottomleft_changed(self, value):
1196        """Set transparency of bottom-left of sliding overlay of active subwindow.
1197        
1198        Triggered upon change in interface transparency slider.
1199        Temporarily sets position of split to the center of the visible area to give user a preview of the transparency effect.
1200
1201        Args:
1202            value (float,int): The transparency as percent opacity, where 100 is opaque (not transparent) and 0 is transparent (0-100).
1203        """
1204        if not self.activeMdiChild:
1205            return
1206        if not self.activeMdiChild.split_locked:
1207            self.set_split_from_slider()
1208        self.activeMdiChild.set_opacity_bottomleft(value)
1209
1210    def update_sliders(self, window):
1211        """Update interface transparency sliders upon subwindow activating using the subwindow transparency values.
1212        
1213        Args:
1214            window (QMdiSubWindow): The active subwindow.
1215        """
1216        if window is None:
1217            self._sliders_opacity_splitviews.reset_sliders()
1218            return
1219
1220        child = self.activeMdiChild
1221        
1222        self._sliders_opacity_splitviews.set_enabled(True, child.pixmap_topright_exists, child.pixmap_bottomright_exists, child.pixmap_bottomleft_exists)
1223
1224        opacity_base_of_activeMdiChild = child._opacity_base
1225        opacity_topright_of_activeMdiChild = child._opacity_topright
1226        opacity_bottomright_of_activeMdiChild = child._opacity_bottomright
1227        opacity_bottomleft_of_activeMdiChild = child._opacity_bottomleft
1228
1229        self._sliders_opacity_splitviews.update_sliders(opacity_base_of_activeMdiChild, opacity_topright_of_activeMdiChild, opacity_bottomright_of_activeMdiChild, opacity_bottomleft_of_activeMdiChild)
1230
1231
1232    # [Legacy methods from derived MDI Image Viewer]
1233
1234    def createMappedAction(self, icon, text, parent, shortcut, methodName):
1235        """Create |QAction| that is mapped via methodName to call.
1236
1237        :param icon: icon associated with |QAction|
1238        :type icon: |QIcon| or None
1239        :param str text: the |QAction| descriptive text
1240        :param QObject parent: the parent |QObject|
1241        :param QKeySequence shortcut: the shortcut |QKeySequence|
1242        :param str methodName: name of method to call when |QAction| is
1243                               triggered
1244        :rtype: |QAction|"""
1245
1246        if icon is not None:
1247            action = QtWidgets.QAction(icon, text, parent,
1248                                   shortcut=shortcut,
1249                                   triggered=self._actionMapper.map)
1250        else:
1251            action = QtWidgets.QAction(text, parent,
1252                                   shortcut=shortcut,
1253                                   triggered=self._actionMapper.map)
1254        self._actionMapper.setMapping(action, methodName)
1255        return action
1256
1257    def createActions(self):
1258        """Create actions used in menus."""
1259        #File menu actions
1260        self._openAct = QtWidgets.QAction(
1261            "&Open...", self,
1262            shortcut=QtGui.QKeySequence.Open,
1263            statusTip="Open an existing file",
1264            triggered=self.open)
1265
1266        self._switchLayoutDirectionAct = QtWidgets.QAction(
1267            "Switch &layout direction", self,
1268            triggered=self.switchLayoutDirection)
1269
1270        #create dummy recent file actions
1271        for i in range(MultiViewMainWindow.MaxRecentFiles):
1272            self._recentFileActions.append(
1273                QtWidgets.QAction(self, visible=False,
1274                              triggered=self._recentFileMapper.map))
1275
1276        self._exitAct = QtWidgets.QAction(
1277            "E&xit", self,
1278            shortcut=QtGui.QKeySequence.Quit,
1279            statusTip="Exit the application",
1280            triggered=QtWidgets.QApplication.closeAllWindows)
1281
1282        #View menu actions
1283        self._showScrollbarsAct = QtWidgets.QAction(
1284            "&Scrollbars", self,
1285            checkable=True,
1286            statusTip="Toggle display of subwindow scrollbars",
1287            triggered=self.toggleScrollbars)
1288
1289        self._showStatusbarAct = QtWidgets.QAction(
1290            "S&tatusbar", self,
1291            checkable=True,
1292            statusTip="Toggle display of statusbar",
1293            triggered=self.toggleStatusbar)
1294
1295        self._synchZoomAct = QtWidgets.QAction(
1296            "Synch &Zoom", self,
1297            checkable=True,
1298            statusTip="Synch zooming of subwindows",
1299            triggered=self.toggleSynchZoom)
1300
1301        self._synchPanAct = QtWidgets.QAction(
1302            "Synch &Pan", self,
1303            checkable=True,
1304            statusTip="Synch panning of subwindows",
1305            triggered=self.toggleSynchPan)
1306
1307        #Scroll menu actions
1308        self._scrollActions = [
1309            self.createMappedAction(
1310                None,
1311                "&Top", self,
1312                QtGui.QKeySequence.MoveToStartOfDocument,
1313                "scrollToTop"),
1314
1315            self.createMappedAction(
1316                None,
1317                "&Bottom", self,
1318                QtGui.QKeySequence.MoveToEndOfDocument,
1319                "scrollToBottom"),
1320
1321            self.createMappedAction(
1322                None,
1323                "&Left Edge", self,
1324                QtGui.QKeySequence.MoveToStartOfLine,
1325                "scrollToBegin"),
1326
1327            self.createMappedAction(
1328                None,
1329                "&Right Edge", self,
1330                QtGui.QKeySequence.MoveToEndOfLine,
1331                "scrollToEnd"),
1332
1333            self.createMappedAction(
1334                None,
1335                "&Center", self,
1336                "5",
1337                "centerView"),
1338            ]
1339
1340        #zoom menu actions
1341        separatorAct = QtWidgets.QAction(self)
1342        separatorAct.setSeparator(True)
1343
1344        self._zoomActions = [
1345            self.createMappedAction(
1346                None,
1347                "Zoo&m In (25%)", self,
1348                QtGui.QKeySequence.ZoomIn,
1349                "zoomIn"),
1350
1351            self.createMappedAction(
1352                None,
1353                "Zoom &Out (25%)", self,
1354                QtGui.QKeySequence.ZoomOut,
1355                "zoomOut"),
1356
1357            #self.createMappedAction(
1358                #None,
1359                #"&Zoom To...", self,
1360                #"Z",
1361                #"zoomTo"),
1362
1363            separatorAct,
1364
1365            self.createMappedAction(
1366                None,
1367                "Actual &Size", self,
1368                "/",
1369                "actualSize"),
1370
1371            self.createMappedAction(
1372                None,
1373                "Fit &Image", self,
1374                "*",
1375                "fitToWindow"),
1376
1377            self.createMappedAction(
1378                None,
1379                "Fit &Width", self,
1380                "Alt+Right",
1381                "fitWidth"),
1382
1383            self.createMappedAction(
1384                None,
1385                "Fit &Height", self,
1386                "Alt+Down",
1387                "fitHeight"),
1388           ]
1389
1390        #Window menu actions
1391        self._activateSubWindowSystemMenuAct = QtWidgets.QAction(
1392            "Activate &System Menu", self,
1393            shortcut="Ctrl+ ",
1394            statusTip="Activate subwindow System Menu",
1395            triggered=self.activateSubwindowSystemMenu)
1396
1397        self._closeAct = QtWidgets.QAction(
1398            "Cl&ose", self,
1399            shortcut=QtGui.QKeySequence.Close,
1400            shortcutContext=QtCore.Qt.WidgetShortcut,
1401            #shortcut="Ctrl+Alt+F4",
1402            statusTip="Close the active window",
1403            triggered=self._mdiArea.closeActiveSubWindow)
1404
1405        self._closeAllAct = QtWidgets.QAction(
1406            "Close &All", self,
1407            statusTip="Close all the windows",
1408            triggered=self._mdiArea.closeAllSubWindows)
1409
1410        self._tileAct = QtWidgets.QAction(
1411            "&Tile", self,
1412            statusTip="Tile the windows",
1413            triggered=self._mdiArea.tileSubWindows)
1414
1415        self._tileAct.triggered.connect(self.tile_and_fit_mdiArea)
1416
1417        self._cascadeAct = QtWidgets.QAction(
1418            "&Cascade", self,
1419            statusTip="Cascade the windows",
1420            triggered=self._mdiArea.cascadeSubWindows)
1421
1422        self._nextAct = QtWidgets.QAction(
1423            "Ne&xt", self,
1424            shortcut=QtGui.QKeySequence.NextChild,
1425            statusTip="Move the focus to the next window",
1426            triggered=self._mdiArea.activateNextSubWindow)
1427
1428        self._previousAct = QtWidgets.QAction(
1429            "Pre&vious", self,
1430            shortcut=QtGui.QKeySequence.PreviousChild,
1431            statusTip="Move the focus to the previous window",
1432            triggered=self._mdiArea.activatePreviousSubWindow)
1433
1434        self._separatorAct = QtWidgets.QAction(self)
1435        self._separatorAct.setSeparator(True)
1436
1437        self._aboutAct = QtWidgets.QAction(
1438            "&About", self,
1439            statusTip="Show the application's About box",
1440            triggered=self.about)
1441
1442        self._aboutQtAct = QtWidgets.QAction(
1443            "About &Qt", self,
1444            statusTip="Show the Qt library's About box",
1445            triggered=QtWidgets.QApplication.aboutQt)
1446
1447    def createMenus(self):
1448        """Create menus."""
1449        self._fileMenu = self.menuBar().addMenu("&File")
1450        self._fileMenu.addAction(self._openAct)
1451        self._fileMenu.addAction(self._switchLayoutDirectionAct)
1452
1453        self._fileSeparatorAct = self._fileMenu.addSeparator()
1454        for action in self._recentFileActions:
1455            self._fileMenu.addAction(action)
1456        self.updateRecentFileActions()
1457        self._fileMenu.addSeparator()
1458        self._fileMenu.addAction(self._exitAct)
1459
1460        self._viewMenu = self.menuBar().addMenu("&View")
1461        self._viewMenu.addAction(self._showScrollbarsAct)
1462        self._viewMenu.addAction(self._showStatusbarAct)
1463        self._viewMenu.addSeparator()
1464        self._viewMenu.addAction(self._synchZoomAct)
1465        self._viewMenu.addAction(self._synchPanAct)
1466
1467        self._scrollMenu = self.menuBar().addMenu("&Scroll")
1468        [self._scrollMenu.addAction(action) for action in self._scrollActions]
1469
1470        self._zoomMenu = self.menuBar().addMenu("&Zoom")
1471        [self._zoomMenu.addAction(action) for action in self._zoomActions]
1472
1473        self._windowMenu = self.menuBar().addMenu("&Window")
1474        self.updateWindowMenu()
1475        self._windowMenu.aboutToShow.connect(self.updateWindowMenu)
1476
1477        self.menuBar().addSeparator()
1478
1479        self._helpMenu = self.menuBar().addMenu("&Help")
1480        self._helpMenu.addAction(self._aboutAct)
1481        self._helpMenu.addAction(self._aboutQtAct)
1482
1483    def updateMenus(self):
1484        """Update menus."""
1485        hasMdiChild = (self.activeMdiChild is not None)
1486
1487        self._scrollMenu.setEnabled(hasMdiChild)
1488        self._zoomMenu.setEnabled(hasMdiChild)
1489
1490        self._closeAct.setEnabled(hasMdiChild)
1491        self._closeAllAct.setEnabled(hasMdiChild)
1492
1493        self._tileAct.setEnabled(hasMdiChild)
1494        self._cascadeAct.setEnabled(hasMdiChild)
1495        self._nextAct.setEnabled(hasMdiChild)
1496        self._previousAct.setEnabled(hasMdiChild)
1497        self._separatorAct.setVisible(hasMdiChild)
1498
1499    def updateRecentFileActions(self):
1500        """Update recent file menu items."""
1501        settings = QtCore.QSettings()
1502        files = settings.value(SETTING_RECENTFILELIST)
1503        numRecentFiles = min(len(files) if files else 0,
1504                             MultiViewMainWindow.MaxRecentFiles)
1505
1506        for i in range(numRecentFiles):
1507            text = "&%d %s" % (i + 1, strippedName(files[i]))
1508            self._recentFileActions[i].setText(text)
1509            self._recentFileActions[i].setData(files[i])
1510            self._recentFileActions[i].setVisible(True)
1511            self._recentFileMapper.setMapping(self._recentFileActions[i],
1512                                              files[i])
1513
1514        for j in range(numRecentFiles, MultiViewMainWindow.MaxRecentFiles):
1515            self._recentFileActions[j].setVisible(False)
1516
1517        self._fileSeparatorAct.setVisible((numRecentFiles > 0))
1518
1519    def updateWindowMenu(self):
1520        """Update the Window menu."""
1521        self._windowMenu.clear()
1522        self._windowMenu.addAction(self._closeAct)
1523        self._windowMenu.addAction(self._closeAllAct)
1524        self._windowMenu.addSeparator()
1525        self._windowMenu.addAction(self._tileAct)
1526        self._windowMenu.addAction(self._cascadeAct)
1527        self._windowMenu.addSeparator()
1528        self._windowMenu.addAction(self._nextAct)
1529        self._windowMenu.addAction(self._previousAct)
1530        self._windowMenu.addAction(self._separatorAct)
1531
1532        windows = self._mdiArea.subWindowList()
1533        self._separatorAct.setVisible(len(windows) != 0)
1534
1535        for i, window in enumerate(windows):
1536            child = window.widget()
1537
1538            text = "%d %s" % (i + 1, child.userFriendlyCurrentFile)
1539            if i < 9:
1540                text = '&' + text
1541
1542            action = self._windowMenu.addAction(text)
1543            action.setCheckable(True)
1544            action.setChecked(child == self.activeMdiChild)
1545            action.triggered.connect(self._windowMapper.map)
1546            self._windowMapper.setMapping(action, window)
1547
1548    def createStatusBarLabel(self, stretch=0):
1549        """Create status bar label.
1550
1551        :param int stretch: stretch factor
1552        :rtype: |QLabel|"""
1553        label = QtWidgets.QLabel()
1554        label.setFrameStyle(QtWidgets.QFrame.Panel | QtWidgets.QFrame.Sunken)
1555        label.setLineWidth(2)
1556        self.statusBar().addWidget(label, stretch)
1557        return label
1558
1559    def createStatusBar(self):
1560        """Create status bar."""
1561        statusBar = self.statusBar()
1562
1563        self._sbLabelName = self.createStatusBarLabel(1)
1564        self._sbLabelSize = self.createStatusBarLabel()
1565        self._sbLabelDimensions = self.createStatusBarLabel()
1566        self._sbLabelDate = self.createStatusBarLabel()
1567        self._sbLabelZoom = self.createStatusBarLabel()
1568
1569        statusBar.showMessage("Ready")
1570
1571
1572    @property
1573    def activeMdiChild(self):
1574        """Get active MDI child (:class:`SplitViewMdiChild` or *None*)."""
1575        activeSubWindow = self._mdiArea.activeSubWindow()
1576        if activeSubWindow:
1577            return activeSubWindow.widget()
1578        return None
1579
1580
1581    def closeEvent(self, event):
1582        """Overrides close event to save application settings.
1583
1584        :param QEvent event: instance of |QEvent|"""
1585
1586        if self.is_fullscreen: # Needed to properly close the image viewer if the main window is closed while the viewer is fullscreen
1587            self.is_fullscreen = False
1588            self.setCentralWidget(self.mdiarea_plus_buttons)
1589
1590        self._mdiArea.closeAllSubWindows()
1591        if self.activeMdiChild:
1592            event.ignore()
1593        else:
1594            self.writeSettings()
1595            event.accept()
1596            
1597    
1598    def tile_and_fit_mdiArea(self):
1599        self._mdiArea.tileSubWindows()
1600
1601    
1602    # Synchronized pan and zoom methods
1603    
1604    @QtCore.pyqtSlot(str)
1605    def mappedImageViewerAction(self, methodName):
1606        """Perform action mapped to :class:`aux_splitview.SplitView`
1607        methodName.
1608
1609        :param str methodName: method to call"""
1610        activeViewer = self.activeMdiChild
1611        if hasattr(activeViewer, str(methodName)):
1612            getattr(activeViewer, str(methodName))()
1613
1614    @QtCore.pyqtSlot()
1615    def toggleSynchPan(self):
1616        """Toggle synchronized subwindow panning."""
1617        if self._synchPanAct.isChecked():
1618            self.synchPan(self.activeMdiChild)
1619
1620    @QtCore.pyqtSlot()
1621    def panChanged(self):
1622        """Synchronize subwindow pans."""
1623        mdiChild = self.sender()
1624        while mdiChild is not None and type(mdiChild) != SplitViewMdiChild:
1625            mdiChild = mdiChild.parent()
1626        if mdiChild and self._synchPanAct.isChecked():
1627            self.synchPan(mdiChild)
1628
1629    @QtCore.pyqtSlot()
1630    def toggleSynchZoom(self):
1631        """Toggle synchronized subwindow zooming."""
1632        if self._synchZoomAct.isChecked():
1633            self.synchZoom(self.activeMdiChild)
1634
1635    @QtCore.pyqtSlot()
1636    def zoomChanged(self):
1637        """Synchronize subwindow zooms."""
1638        mdiChild = self.sender()
1639        if self._synchZoomAct.isChecked():
1640            self.synchZoom(mdiChild)
1641        self.updateStatusBar()
1642
1643    def synchPan(self, fromViewer):
1644        """Synch panning of all subwindowws to the same as *fromViewer*.
1645
1646        :param fromViewer: :class:`SplitViewMdiChild` that initiated synching"""
1647
1648        assert isinstance(fromViewer, SplitViewMdiChild)
1649        if not fromViewer:
1650            return
1651        if self._handlingScrollChangedSignal:
1652            return
1653        if fromViewer.parent() != self._mdiArea.activeSubWindow(): # Prevent circular scroll state change signals from propagating
1654            if fromViewer.parent() != self:
1655                return
1656        self._handlingScrollChangedSignal = True
1657
1658        newState = fromViewer.scrollState
1659        changedWindow = fromViewer.parent()
1660        windows = self._mdiArea.subWindowList()
1661        for window in windows:
1662            if window != changedWindow:
1663                if window.widget().sync_this_pan:
1664                    window.widget().scrollState = newState
1665                    window.widget().resize_scene()
1666
1667        self._handlingScrollChangedSignal = False
1668
1669    def synchZoom(self, fromViewer):
1670        """Synch zoom of all subwindowws to the same as *fromViewer*.
1671
1672        :param fromViewer: :class:`SplitViewMdiChild` that initiated synching"""
1673        if not fromViewer:
1674            return
1675        newZoomFactor = fromViewer.zoomFactor
1676
1677        sync_by = self.sync_zoom_by
1678
1679        sender_dimension = determineSyncSenderDimension(fromViewer.imageWidth,
1680                                                        fromViewer.imageHeight,
1681                                                        sync_by)
1682
1683        changedWindow = fromViewer.parent()
1684        windows = self._mdiArea.subWindowList()
1685        for window in windows:
1686            if window != changedWindow:
1687                receiver = window.widget()
1688                if receiver.sync_this_zoom:
1689                    adjustment_factor = determineSyncAdjustmentFactor(sync_by,
1690                                                                      sender_dimension,
1691                                                                      receiver.imageWidth,
1692                                                                      receiver.imageHeight)
1693
1694                    receiver.zoomFactor = newZoomFactor*adjustment_factor
1695                    receiver.resize_scene()
1696        self.refreshPan()
1697
1698    def refreshPan(self):
1699        if self.activeMdiChild:
1700            self.synchPan(self.activeMdiChild)
1701
1702    def refreshPanDelayed(self, ms=0):
1703        QtCore.QTimer.singleShot(ms, self.refreshPan)
1704
1705    def refreshZoom(self):
1706        if self.activeMdiChild:
1707            self.synchZoom(self.activeMdiChild)
1708
1709
1710    # Methods from PyQt MDI Image Viewer left unaltered
1711
1712    @QtCore.pyqtSlot()
1713    def activateSubwindowSystemMenu(self):
1714        """Activate current subwindow's System Menu."""
1715        activeSubWindow = self._mdiArea.activeSubWindow()
1716        if activeSubWindow:
1717            activeSubWindow.showSystemMenu()
1718
1719    @QtCore.pyqtSlot(str)
1720    def openRecentFile(self, filename_main_topleft):
1721        """Open a recent file.
1722
1723        :param str filename_main_topleft: filename_main_topleft to view"""
1724        self.loadFile(filename_main_topleft, None, None, None)
1725
1726    @QtCore.pyqtSlot()
1727    def open(self):
1728        """Handle the open action."""
1729        fileDialog = QtWidgets.QFileDialog(self)
1730        settings = QtCore.QSettings()
1731        fileDialog.setNameFilters([
1732            "Common image files (*.jpeg *.jpg  *.png *.tiff *.tif *.bmp *.gif *.webp *.svg)",
1733            "JPEG image files (*.jpeg *.jpg)", 
1734            "PNG image files (*.png)", 
1735            "TIFF image files (*.tiff *.tif)",
1736            "BMP (*.bmp)",
1737            "All files (*)",])
1738        if not settings.contains(SETTING_FILEOPEN + "/state"):
1739            fileDialog.setDirectory(".")
1740        else:
1741            self.restoreDialogState(fileDialog, SETTING_FILEOPEN)
1742        fileDialog.setFileMode(QtWidgets.QFileDialog.ExistingFile)
1743        if not fileDialog.exec_():
1744            return
1745        self.saveDialogState(fileDialog, SETTING_FILEOPEN)
1746
1747        filename_main_topleft = fileDialog.selectedFiles()[0]
1748        self.loadFile(filename_main_topleft, None, None, None)
1749
1750    def open_multiple(self):
1751        """Handle the open multiple action."""
1752        last_accessed_fullpath = self._last_accessed_fullpath
1753        filters = "\
1754            Common image files (*.jpeg *.jpg  *.png *.tiff *.tif *.bmp *.gif *.webp *.svg);;\
1755            JPEG image files (*.jpeg *.jpg);;\
1756            PNG image files (*.png);;\
1757            TIFF image files (*.tiff *.tif);;\
1758            BMP (*.bmp);;\
1759            All files (*)"
1760        fullpaths, _ = QtWidgets.QFileDialog.getOpenFileNames(self, "Select image(s) to open", last_accessed_fullpath, filters)
1761
1762        for fullpath in fullpaths:
1763            self.loadFile(fullpath, None, None, None)
1764
1765
1766
1767    @QtCore.pyqtSlot()
1768    def toggleScrollbars(self):
1769        """Toggle subwindow scrollbar visibility."""
1770        checked = self._showScrollbarsAct.isChecked()
1771
1772        windows = self._mdiArea.subWindowList()
1773        for window in windows:
1774            child = window.widget()
1775            child.enableScrollBars(checked)
1776
1777    @QtCore.pyqtSlot()
1778    def toggleStatusbar(self):
1779        """Toggle status bar visibility."""
1780        self.statusBar().setVisible(self._showStatusbarAct.isChecked())
1781
1782
1783    @QtCore.pyqtSlot()
1784    def about(self):
1785        """Display About dialog box."""
1786        QtWidgets.QMessageBox.about(self, "About MDI",
1787                "<b>MDI Image Viewer</b> demonstrates how to"
1788                "synchronize the panning and zooming of multiple image"
1789                "viewer windows using Qt.")
1790    @QtCore.pyqtSlot(QtWidgets.QMdiSubWindow)
1791    def subWindowActivated(self, window):
1792        """Handle |QMdiSubWindow| activated signal.
1793
1794        :param |QMdiSubWindow| window: |QMdiSubWindow| that was just
1795                                       activated"""
1796        self.updateStatusBar()
1797
1798    @QtCore.pyqtSlot(QtWidgets.QMdiSubWindow)
1799    def setActiveSubWindow(self, window):
1800        """Set active |QMdiSubWindow|.
1801
1802        :param |QMdiSubWindow| window: |QMdiSubWindow| to activate """
1803        if window:
1804            self._mdiArea.setActiveSubWindow(window)
1805
1806
1807    def updateStatusBar(self):
1808        """Update status bar."""
1809        self.statusBar().setVisible(self._showStatusbarAct.isChecked())
1810        imageViewer = self.activeMdiChild
1811        if not imageViewer:
1812            self._sbLabelName.setText("")
1813            self._sbLabelSize.setText("")
1814            self._sbLabelDimensions.setText("")
1815            self._sbLabelDate.setText("")
1816            self._sbLabelZoom.setText("")
1817
1818            self._sbLabelSize.hide()
1819            self._sbLabelDimensions.hide()
1820            self._sbLabelDate.hide()
1821            self._sbLabelZoom.hide()
1822            return
1823
1824        filename_main_topleft = imageViewer.currentFile
1825        self._sbLabelName.setText(" %s " % filename_main_topleft)
1826
1827        fi = QtCore.QFileInfo(filename_main_topleft)
1828        size = fi.size()
1829        fmt = " %.1f %s "
1830        if size > 1024*1024*1024:
1831            unit = "MB"
1832            size /= 1024*1024*1024
1833        elif size > 1024*1024:
1834            unit = "MB"
1835            size /= 1024*1024
1836        elif size > 1024:
1837            unit = "KB"
1838            size /= 1024
1839        else:
1840            unit = "Bytes"
1841            fmt = " %d %s "
1842        self._sbLabelSize.setText(fmt % (size, unit))
1843
1844        pixmap = imageViewer.pixmap_main_topleft
1845        self._sbLabelDimensions.setText(" %dx%dx%d " %
1846                                        (pixmap.width(),
1847                                         pixmap.height(),
1848                                         pixmap.depth()))
1849
1850        self._sbLabelDate.setText(
1851            " %s " %
1852            fi.lastModified().toString(QtCore.Qt.SystemLocaleShortDate))
1853        self._sbLabelZoom.setText(" %0.f%% " % (imageViewer.zoomFactor*100,))
1854
1855        self._sbLabelSize.show()
1856        self._sbLabelDimensions.show()
1857        self._sbLabelDate.show()
1858        self._sbLabelZoom.show()
1859        
1860    def switchLayoutDirection(self):
1861        """Switch MDI subwindow layout direction."""
1862        if self.layoutDirection() == QtCore.Qt.LeftToRight:
1863            QtWidgets.QApplication.setLayoutDirection(QtCore.Qt.RightToLeft)
1864        else:
1865            QtWidgets.QApplication.setLayoutDirection(QtCore.Qt.LeftToRight)
1866
1867    def saveDialogState(self, dialog, groupName):
1868        """Save dialog state, position & size.
1869
1870        :param |QDialog| dialog: dialog to save state of
1871        :param str groupName: |QSettings| group name"""
1872        assert isinstance(dialog, QtWidgets.QDialog)
1873
1874        settings = QtCore.QSettings()
1875        settings.beginGroup(groupName)
1876
1877        settings.setValue('state', dialog.saveState())
1878        settings.setValue('geometry', dialog.saveGeometry())
1879        settings.setValue('filter', dialog.selectedNameFilter())
1880
1881        settings.endGroup()
1882
1883    def restoreDialogState(self, dialog, groupName):
1884        """Restore dialog state, position & size.
1885
1886        :param str groupName: |QSettings| group name"""
1887        assert isinstance(dialog, QtWidgets.QDialog)
1888
1889        settings = QtCore.QSettings()
1890        settings.beginGroup(groupName)
1891
1892        dialog.restoreState(settings.value('state'))
1893        dialog.restoreGeometry(settings.value('geometry'))
1894        dialog.selectNameFilter(settings.value('filter', ""))
1895
1896        settings.endGroup()
1897
1898    def writeSettings(self):
1899        """Write application settings."""
1900        settings = QtCore.QSettings()
1901        settings.setValue('pos', self.pos())
1902        settings.setValue('size', self.size())
1903        settings.setValue('windowgeometry', self.saveGeometry())
1904        settings.setValue('windowstate', self.saveState())
1905
1906        settings.setValue(SETTING_SCROLLBARS,
1907                          self._showScrollbarsAct.isChecked())
1908        settings.setValue(SETTING_STATUSBAR,
1909                          self._showStatusbarAct.isChecked())
1910        settings.setValue(SETTING_SYNCHZOOM,
1911                          self._synchZoomAct.isChecked())
1912        settings.setValue(SETTING_SYNCHPAN,
1913                          self._synchPanAct.isChecked())
1914
1915    def readSettings(self):
1916        """Read application settings."""
1917        
1918        scrollbars_always_checked_off_at_startup = True
1919        statusbar_always_checked_off_at_startup = True
1920        sync_always_checked_on_at_startup = True
1921
1922        settings = QtCore.QSettings()
1923
1924        pos = settings.value('pos', QtCore.QPoint(100, 100))
1925        size = settings.value('size', QtCore.QSize(1100, 600))
1926        self.move(pos)
1927        self.resize(size)
1928
1929        if settings.contains('windowgeometry'):
1930            self.restoreGeometry(settings.value('windowgeometry'))
1931        if settings.contains('windowstate'):
1932            self.restoreState(settings.value('windowstate'))
1933
1934        
1935        if scrollbars_always_checked_off_at_startup:
1936            self._showScrollbarsAct.setChecked(False)
1937        else:
1938            self._showScrollbarsAct.setChecked(
1939                toBool(settings.value(SETTING_SCROLLBARS, False)))
1940
1941        if statusbar_always_checked_off_at_startup:
1942            self._showStatusbarAct.setChecked(False)
1943        else:
1944            self._showStatusbarAct.setChecked(
1945                toBool(settings.value(SETTING_STATUSBAR, False)))
1946
1947        if sync_always_checked_on_at_startup:
1948            self._synchZoomAct.setChecked(True)
1949            self._synchPanAct.setChecked(True)
1950        else:
1951            self._synchZoomAct.setChecked(
1952                toBool(settings.value(SETTING_SYNCHZOOM, False)))
1953            self._synchPanAct.setChecked(
1954                toBool(settings.value(SETTING_SYNCHPAN, False)))
1955
1956    def updateRecentFileSettings(self, filename_main_topleft, delete=False):
1957        """Update recent file list setting.
1958
1959        :param str filename_main_topleft: filename_main_topleft to add or remove from recent file
1960                             list
1961        :param bool delete: if True then filename_main_topleft removed, otherwise added"""
1962        settings = QtCore.QSettings()
1963        
1964        try:
1965            files = list(settings.value(SETTING_RECENTFILELIST, []))
1966        except TypeError:
1967            files = []
1968
1969        try:
1970            files.remove(filename_main_topleft)
1971        except ValueError:
1972            pass
1973
1974        if not delete:
1975            files.insert(0, filename_main_topleft)
1976        del files[MultiViewMainWindow.MaxRecentFiles:]
1977
1978        settings.setValue(SETTING_RECENTFILELIST, files)
1979
1980
1981
1982def main():
1983    """Run MultiViewMainWindow as main app.
1984    
1985    Attributes:
1986        app (QApplication): Starts and holds the main event loop of application.
1987        mainWin (MultiViewMainWindow): The main window.
1988    """
1989    import sys
1990
1991    app = QtWidgets.QApplication(sys.argv)
1992    QtCore.QSettings.setDefaultFormat(QtCore.QSettings.IniFormat)
1993    app.setOrganizationName(COMPANY)
1994    app.setOrganizationDomain(DOMAIN)
1995    app.setApplicationName(APPNAME)
1996    app.setApplicationVersion(VERSION)
1997    app.setWindowIcon(QtGui.QIcon(":/icons/icon.png"))
1998
1999    mainWin = MultiViewMainWindow()
2000    mainWin.setWindowTitle(APPNAME)
2001
2002    mainWin.show()
2003
2004    sys.exit(app.exec_())
2005
2006if __name__ == '__main__':
2007    main()