class RectangleSelectionAction(UserInteraction):
"""
Select items in the scene using a Rectangle selection
"""
def __init__(self, document, *args, **kwargs):
UserInteraction.__init__(self, document, *args, **kwargs)
# The initial selection at drag start
self.initial_selection = None
# Selection when last updated in a mouseMoveEvent
self.last_selection = None
# A selection rect (`QRectF`)
self.selection_rect = None
# Keyboard modifiers
self.modifiers = 0
def mousePressEvent(self, event):
pos = event.scenePos()
any_item = self.scene.item_at(pos)
if not any_item and event.button() & Qt.LeftButton:
self.modifiers = event.modifiers()
self.selection_rect = QRectF(pos, QSizeF(0, 0))
self.rect_item = QGraphicsRectItem(
self.selection_rect.normalized()
)
self.rect_item.setPen(
QPen(QBrush(QColor(51, 153, 255, 192)),
0.4, Qt.SolidLine, Qt.RoundCap)
)
self.rect_item.setBrush(
QBrush(QColor(168, 202, 236, 192))
)
self.rect_item.setZValue(-100)
# Clear the focus if necessary.
if not self.scene.stickyFocus():
self.scene.clearFocus()
if not self.modifiers & Qt.ControlModifier:
self.scene.clearSelection()
event.accept()
return True
else:
self.cancel(self.ErrorReason)
return False
def mouseMoveEvent(self, event):
if not self.rect_item.scene():
# Add the rect item to the scene when the mouse moves.
self.scene.addItem(self.rect_item)
self.update_selection(event)
return True
def mouseReleaseEvent(self, event):
if event.button() == Qt.LeftButton:
if self.initial_selection is None:
# A single click.
self.scene.clearSelection()
else:
self.update_selection(event)
self.end()
return True
def update_selection(self, event):
"""
Update the selection rectangle from a QGraphicsSceneMouseEvent
`event` instance.
"""
if self.initial_selection is None:
self.initial_selection = set(self.scene.selectedItems())
self.last_selection = self.initial_selection
pos = event.scenePos()
self.selection_rect = QRectF(self.selection_rect.topLeft(), pos)
# Make sure the rect_item does not cause the scene rect to grow.
rect = self._bound_selection_rect(self.selection_rect.normalized())
# Need that 0.5 constant otherwise the sceneRect will still
# grow (anti-aliasing correction by QGraphicsScene?)
pw = self.rect_item.pen().width() + 0.5
self.rect_item.setRect(rect.adjusted(pw, pw, -pw, -pw))
selected = self.scene.items(self.selection_rect.normalized(),
Qt.IntersectsItemShape,
Qt.AscendingOrder)
selected = set([item for item in selected if \
item.flags() & Qt.ItemIsSelectable])
if self.modifiers & Qt.ControlModifier:
for item in selected | self.last_selection | \
self.initial_selection:
item.setSelected(
(item in selected) ^ (item in self.initial_selection)
)
else:
for item in selected.union(self.last_selection):
item.setSelected(item in selected)
self.last_selection = set(self.scene.selectedItems())
def end(self):
self.initial_selection = None
self.last_selection = None
self.modifiers = 0
self.rect_item.hide()
if self.rect_item.scene() is not None:
self.scene.removeItem(self.rect_item)
UserInteraction.end(self)
def viewport_rect(self):
"""
Return the bounding rect of the document's viewport on the scene.
"""
view = self.document.view()
vsize = view.viewport().size()
viewportrect = QRect(0, 0, vsize.width(), vsize.height())
return view.mapToScene(viewportrect).boundingRect()
def _bound_selection_rect(self, rect):
"""
Bound the selection `rect` to a sensible size.
"""
srect = self.scene.sceneRect()
vrect = self.viewport_rect()
maxrect = srect.united(vrect)
return rect.intersected(maxrect)
class RectangleSelectionAction(UserInteraction):
"""
Select items in the scene using a Rectangle selection
"""
def __init__(self, document, *args, **kwargs):
UserInteraction.__init__(self, document, *args, **kwargs)
# The initial selection at drag start
self.initial_selection = None
# Selection when last updated in a mouseMoveEvent
self.last_selection = None
# A selection rect (`QRectF`)
self.selection_rect = None
# Keyboard modifiers
self.modifiers = 0
def mousePressEvent(self, event):
pos = event.scenePos()
any_item = self.scene.item_at(pos)
if not any_item and event.button() & Qt.LeftButton:
self.modifiers = event.modifiers()
self.selection_rect = QRectF(pos, QSizeF(0, 0))
self.rect_item = QGraphicsRectItem(
self.selection_rect.normalized())
self.rect_item.setPen(
QPen(QBrush(QColor(51, 153, 255, 192)), 0.4, Qt.SolidLine,
Qt.RoundCap))
self.rect_item.setBrush(QBrush(QColor(168, 202, 236, 192)))
self.rect_item.setZValue(-100)
# Clear the focus if necessary.
if not self.scene.stickyFocus():
self.scene.clearFocus()
if not self.modifiers & Qt.ControlModifier:
self.scene.clearSelection()
event.accept()
return True
else:
self.cancel(self.ErrorReason)
return False
def mouseMoveEvent(self, event):
if not self.rect_item.scene():
# Add the rect item to the scene when the mouse moves.
self.scene.addItem(self.rect_item)
self.update_selection(event)
return True
def mouseReleaseEvent(self, event):
if event.button() == Qt.LeftButton:
if self.initial_selection is None:
# A single click.
self.scene.clearSelection()
else:
self.update_selection(event)
self.end()
return True
def update_selection(self, event):
"""
Update the selection rectangle from a QGraphicsSceneMouseEvent
`event` instance.
"""
if self.initial_selection is None:
self.initial_selection = set(self.scene.selectedItems())
self.last_selection = self.initial_selection
pos = event.scenePos()
self.selection_rect = QRectF(self.selection_rect.topLeft(), pos)
# Make sure the rect_item does not cause the scene rect to grow.
rect = self._bound_selection_rect(self.selection_rect.normalized())
# Need that 0.5 constant otherwise the sceneRect will still
# grow (anti-aliasing correction by QGraphicsScene?)
pw = self.rect_item.pen().width() + 0.5
self.rect_item.setRect(rect.adjusted(pw, pw, -pw, -pw))
selected = self.scene.items(self.selection_rect.normalized(),
Qt.IntersectsItemShape, Qt.AscendingOrder)
selected = set([item for item in selected if \
item.flags() & Qt.ItemIsSelectable])
if self.modifiers & Qt.ControlModifier:
for item in selected | self.last_selection | \
self.initial_selection:
item.setSelected((item in selected)
^ (item in self.initial_selection))
else:
for item in selected.union(self.last_selection):
item.setSelected(item in selected)
self.last_selection = set(self.scene.selectedItems())
def end(self):
self.initial_selection = None
self.last_selection = None
self.modifiers = 0
self.rect_item.hide()
if self.rect_item.scene() is not None:
self.scene.removeItem(self.rect_item)
UserInteraction.end(self)
def viewport_rect(self):
"""
Return the bounding rect of the document's viewport on the scene.
"""
view = self.document.view()
vsize = view.viewport().size()
viewportrect = QRect(0, 0, vsize.width(), vsize.height())
return view.mapToScene(viewportrect).boundingRect()
def _bound_selection_rect(self, rect):
"""
Bound the selection `rect` to a sensible size.
"""
srect = self.scene.sceneRect()
vrect = self.viewport_rect()
maxrect = srect.united(vrect)
return rect.intersected(maxrect)
