def zoom_to_items(self, items):
"""Centres view on the centre of the items and, if view is set to
'fit to view', sets the zoom level to encompass items.
Emits viewport_changed.
"""
united = unite_rects(i.sceneBoundingRect() for i in items)
if 'whole_scene' == self.zoom_mode:
debug_print('Ensuring [{0}] items visible'.format(len(items)))
self.ensureVisible(united)
self.viewport_changed.emit(self.normalised_scene_rect())
else:
debug_print('Showing [{0}] items'.format(len(items)))
# Add some padding around the selection
padding = 20
if 'follow_selection' == self.zoom_mode:
# Update zoom
united.adjust(-padding, -padding, 2 * padding, 2 * padding)
self.fitInView(united, Qt.KeepAspectRatio)
if self.absolute_zoom > self.MAXIMUM_ZOOM:
# new_absolute_zoom() emits viewport_changed
self.new_absolute_zoom(self.MAXIMUM_ZOOM)
else:
self.viewport_changed.emit(self.normalised_scene_rect())
else:
# zoom_mode == fixed
self.ensureVisible(united, xMargin=padding, yMargin=padding)
def zoom_to_items(self, items):
"""Centres view on the centre of the items and, if view is set to
'fit to view', sets the zoom level to encompass items.
Emits viewport_changed.
"""
united = unite_rects(i.sceneBoundingRect() for i in items)
if 'whole_scene' == self.zoom_mode:
debug_print('Ensuring [{0}] items visible'.format(len(items)))
self.ensureVisible(united)
self.viewport_changed.emit(self.normalised_scene_rect())
else:
debug_print('Showing [{0}] items'.format(len(items)))
# Add some padding around the selection
padding = 20
if 'follow_selection' == self.zoom_mode:
# Update zoom
united.adjust(-padding, -padding, 2 * padding, 2 * padding)
self.fitInView(united, Qt.KeepAspectRatio)
if self.absolute_zoom > self.MAXIMUM_ZOOM:
# new_absolute_zoom() emits viewport_changed
self.new_absolute_zoom(self.MAXIMUM_ZOOM)
else:
self.viewport_changed.emit(self.normalised_scene_rect())
else:
# zoom_mode == fixed
self.ensureVisible(united, xMargin=padding, yMargin=padding)
def new_absolute_zoom(self, factor):
"""Sets a new absolute zoom
"""
f = factor
scene_rect = self.scene().sceneRect() # Scene
view_rect = self.viewport().rect() # Available space
# The size of the scene if the new transform is applied
t_scene_rect = QtGui.QTransform.fromScale(f, f).mapRect(scene_rect)
if (t_scene_rect.width() < view_rect.width()
and t_scene_rect.height() < view_rect.height()):
# The user wants to zoom out so that the image is smaller than the
# view
self.zoom_home()
else:
f = min(self.MAXIMUM_ZOOM, f)
msg = 'Change absolute zoom from [{0}] to [{1}]'
debug_print(msg.format(self.absolute_zoom, f))
self.setTransform(QtGui.QTransform.fromScale(f, f))
self.fit_to_view = False
selected = self.scene().selectedItems()
if selected:
# Centre on selected items
#self.ensureVisible(unite_rects([i.rect() for i in selected]))
self.centerOn(
unite_rects([i.rect() for i in selected]).center())
def selectionChanged(self, selected, deselected):
"""QAbstractItemView virtual
"""
# Tell the scene about the new selection
# TODO LH Use a timer to implement a delayed refresh
if not self.handling_selection_update:
# TODO Context for this
debug_print('GraphicsItemView.selectionChanged')
self.handling_selection_update = True
try:
current = set(self.scene.selectedItems())
new = set(self._rows[i.row()]
for i in self.selectionModel().selectedIndexes())
for item in new.difference(current):
item.setSelected(True)
item.update()
for item in current.difference(new):
item.setSelected(False)
item.update()
if 1 == len(new):
rect = new.pop().rect()
for view in self.scene.views():
view.centerOn(rect.center())
elif 1 < len(new):
# Ensure that the selected items are visible
rect = unite_rects([i.rect() for i in new])
debug_print('GraphicsItemView will make visible', rect)
new.pop().ensureVisible(rect)
finally:
self.handling_selection_update = False
def new_absolute_zoom(self, factor):
"""Sets a new absolute zoom and emits viewport_changed.
"""
f = factor
scene_rect = self.scene().sceneRect() # Scene
view_rect = self.viewport().rect() # Available space
# The size of the scene if the new transform is applied
t_scene_rect = QTransform.fromScale(f, f).mapRect(scene_rect)
if (t_scene_rect.width() < view_rect.width() and
t_scene_rect.height() < view_rect.height()):
# The user wants to zoom out so that the image is smaller than the
# view
self.zoom_home()
else:
f = min(self.MAXIMUM_ZOOM, f)
msg = 'Change absolute zoom from [{0}] to [{1}]'
debug_print(msg.format(self.absolute_zoom, f))
selected = self.scene().selectedItems()
if not selected:
# No selection so we want to centre on the mouse cursor, if it
# is within the view. We need to get the mouse position in
# scene coords before applying the zoom.
mouse_pos = self.mapFromGlobal(QCursor.pos())
if self.rect().contains(mouse_pos, proper=True):
mouse_pos = self.mapToScene(mouse_pos)
else:
mouse_pos = None
self.setTransform(QTransform.fromScale(f, f))
if selected:
# Centre on selected items
self.centerOn(
unite_rects(i.sceneBoundingRect() for i in selected).center()
)
elif mouse_pos:
# Centre on mouse position
self.centerOn(mouse_pos)
else:
# Default behaviour is fine
pass
self.viewport_changed.emit(self.normalised_scene_rect())
def new_absolute_zoom(self, factor):
"""Sets a new absolute zoom and emits viewport_changed.
"""
f = factor
scene_rect = self.scene().sceneRect() # Scene
view_rect = self.viewport().rect() # Available space
# The size of the scene if the new transform is applied
t_scene_rect = QTransform.fromScale(f, f).mapRect(scene_rect)
if (t_scene_rect.width() < view_rect.width()
and t_scene_rect.height() < view_rect.height()):
# The user wants to zoom out so that the image is smaller than the
# view
self.zoom_home()
else:
f = min(self.MAXIMUM_ZOOM, f)
msg = 'Change absolute zoom from [{0}] to [{1}]'
debug_print(msg.format(self.absolute_zoom, f))
selected = self.scene().selectedItems()
if not selected:
# No selection so we want to centre on the mouse cursor, if it
# is within the view. We need to get the mouse position in
# scene coords before applying the zoom.
mouse_pos = self.mapFromGlobal(QCursor.pos())
if self.rect().contains(mouse_pos, proper=True):
mouse_pos = self.mapToScene(mouse_pos)
else:
mouse_pos = None
self.setTransform(QTransform.fromScale(f, f))
if selected:
# Centre on selected items
self.centerOn(
unite_rects(i.sceneBoundingRect()
for i in selected).center())
elif mouse_pos:
# Centre on mouse position
self.centerOn(mouse_pos)
else:
# Default behaviour is fine
pass
self.viewport_changed.emit(self.normalised_scene_rect())
def zoom_to_items(self, items):
"""Centres view on the centre of the items and, if view is set to
'fit to view', sets the zoom level to encompass items.
"""
united = unite_rects(i.sceneBoundingRect() for i in items)
if self.fit_to_view:
debug_print('Ensuring [{0}] items visible'.format(len(items)))
self.ensureVisible(united)
else:
# Some space
# TODO LH Space should be in visible units
debug_print('Zooming on [{0}] items'.format(len(items)))
united.adjust(-20, -20, 40, 40)
self.fitInView(united, Qt.KeepAspectRatio)
# TODO LH Need a better solution
if self.absolute_zoom > self.MAXIMUM_ZOOM:
self.new_absolute_zoom(self.MAXIMUM_ZOOM)
def toggle_zoom(self):
"""Toggles between 'fit to screen' and a mild zoom / zoom to selected
"""
if self.fit_to_view:
selected = self.scene().selectedItems()
if selected:
r = unite_rects([i.rect() for i in selected])
# Some space
r.adjust(-20, -20, 40, 40)
self.fitInView(r, Qt.KeepAspectRatio)
self.fit_to_view = False
# TODO LH Need a better solution
if self.absolute_zoom > self.MAXIMUM_ZOOM:
self.new_absolute_zoom(self.MAXIMUM_ZOOM)
else:
self.new_relative_zoom(4.0)
else:
self.zoom_home()
