I have a widget that uses rubberband to select region on an image, it can be editable on any aspect. I need to add functions that once the rubberband is placed it can be resizable or editable again so my idea is to save the region points(x,y,w,h) after the mouse release event.
But the problem now is how can I pass the data read in mouse release event outside my rubberband class.
Here is my code of drag and edit of rubberband.
class rubberBandWidget(QtGui.QWidget):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.rubberBand = QRubberBand(QRubberBand.Rectangle, self)
self.tweaking = False
self.tweakingpart = ""
def mousePressEvent(self, event):
pt = self.mapFromGlobal(event.globalPos())
rg = self.rubberBand.geometry()
if rg.isValid():
tl, tr, bl, br = rg.topLeft(), rg.topRight(), rg.bottomLeft(), rg.bottomRight()
off, offx, offy = QPoint(3, 3), QPoint(4, -3), QPoint(-3, 4)
if QRect(tl - off, tl + off).contains(pt):
self.tweakingpart = "topLeft";
self.setCursor(Qt.SizeFDiagCursor)
elif QRect(tr - off, tr + off).contains(pt):
self.tweakingpart = "topRight";
self.setCursor(Qt.SizeBDiagCursor)
elif QRect(bl - off, bl + off).contains(pt):
self.tweakingpart = "bottomLeft";
self.setCursor(Qt.SizeBDiagCursor)
elif QRect(br - off, br + off).contains(pt):
self.tweakingpart = "bottomRight";
self.setCursor(Qt.SizeFDiagCursor)
elif QRect(tl + offx, tr - offx).contains(pt):
self.tweakingpart = "top";
self.setCursor(Qt.SizeVerCursor)
elif QRect(bl + offx, br - offx).contains(pt):
self.tweakingpart = "bottom"
self.setCursor(Qt.SizeVerCursor)
elif QRect(tl + offy, bl - offy).contains(pt):
self.tweakingpart = "left";
self.setCursor(Qt.SizeHorCursor)
elif QRect(tr + offy, br - offy).contains(pt):
self.tweakingpart = "right";
self.setCursor(Qt.SizeHorCursor)
if self.tweakingpart != "":
self.tweaking = True
return
self.origin = pt
self.rubberBand.setGeometry(QRect(self.origin, QtCore.QSize()))
self.rubberBand.show()
def mouseMoveEvent(self, event):
pt = self.mapFromGlobal(event.globalPos())
if self.tweaking:
rg = self.rubberBand.geometry()
if self.tweakingpart == "topLeft":
rg.setTopLeft(pt)
elif self.tweakingpart == "topRight":
rg.setTopRight(pt)
elif self.tweakingpart == "bottomLeft":
rg.setBottomLeft(pt)
elif self.tweakingpart == "bottomRight":
rg.setBottomRight(pt)
elif self.tweakingpart == "top":
rg.setTop(pt.y())
elif self.tweakingpart == "bottom":
rg.setBottom(pt.y())
elif self.tweakingpart == "left":
rg.setLeft(pt.x())
elif self.tweakingpart == "right":
rg.setRight(pt.x())
self.rubberBand.setGeometry(rg)
else:
self.rubberBand.setGeometry(QRect(self.origin, pt).normalized())
And here is my code on release event and the data of (x, y, w, h) that need to be pass or read outside the class.
def mouseReleaseEvent(self, event):
self.tweaking = False
self.tweakingpart = ""
self.unsetCursor()
if self.rubberBand.width() != 0 and self.rubberBand.height() != 0:
print(self.rubberBand.x(), self.rubberBand.y(), self.rubberBand.width(), self.rubberBand.height())
I need the data every mouse release and save it. So once the user need to resize and edit again, my idea is to set the geometry of rubberband and re run the class so it can be editable again.
If you want to expose the data outside the class you should use signals as I show below:
import sys
from PyQt4 import QtCore, QtGui
class rubberBandWidget(QtGui.QWidget):
rectChanged = QtCore.pyqtSignal(QtCore.QRect) # create signal
...
def mouseReleaseEvent(self, event):
self.tweaking = False
self.tweakingpart = ""
self.unsetCursor()
if not self.rubberBand.geometry().isNull():
self.rectChanged.emit(self.rubberBand.geometry()) # emit signal
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
w = rubberBandWidget()
def on_rectChanged(rect):
# receiver
print(rect.x(), rect.y(), rect.width(), rect.height())
w.rectChanged.connect(on_rectChanged) # connect signal
w.show()
sys.exit(app.exec_())
On the other hand I see that your code is very coupled because if you want to use the same functionality in another widget you will have to copy all the code and that is not desirable, so I take the time to create a custom QRubberband that has that functionality, In the next part I show an example.
import sys
from PyQt4 import QtCore, QtGui
class RubberBand(QtGui.QRubberBand):
rectChanged = QtCore.pyqtSignal(QtCore.QRect)
TopLeft, TopRight, BottomLeft, BottomRight, Top, Bottom, Left, Right, NonePos = range(9)
def __init__(self, parent=None):
super(RubberBand, self).__init__(QtGui.QRubberBand.Rectangle, parent)
self._widget = None
self.setWidget(parent)
self.tweakingpart = RubberBand.NonePos
self.cursors = [QtCore.Qt.SizeFDiagCursor,
QtCore.Qt.SizeBDiagCursor,
QtCore.Qt.SizeBDiagCursor,
QtCore.Qt.SizeFDiagCursor,
QtCore.Qt.SizeVerCursor,
QtCore.Qt.SizeVerCursor,
QtCore.Qt.SizeHorCursor,
QtCore.Qt.SizeHorCursor]
def setWidget(self, widget):
if widget is None:
return
if self._widget is not None:
self._widget.removeEventFilter(self)
self._widget = widget
self._widget.installEventFilter(self)
self.setParent(widget)
def eventFilter(self, obj, event):
if self._widget is obj:
if event.type() == QtCore.QEvent.MouseButtonPress:
self.handleMousePressEvent(event.pos())
return True
elif event.type() == QtCore.QEvent.MouseMove:
self.handleMouseMoveEvent(event.pos())
return True
elif event.type() == QtCore.QEvent.MouseButtonRelease:
self.handleMouseReleaseEvent(event.pos())
return True
return super(RubberBand, self).eventFilter(obj, event)
def handleMousePressEvent(self, pt):
rg = self.geometry()
if not rg.isValid():
return
off, offx, offy = QtCore.QPoint(3, 3), QtCore.QPoint(4, -3), QtCore.QPoint(-3, 4)
rect = QtCore.QRect(-off, off)
tl, tr, bl, br = rg.topLeft(), rg.topRight(), rg.bottomLeft(), rg.bottomRight()
for i, coord in enumerate([tl, tr, bl, br]):
rect.moveCenter(coord)
if rect.contains(pt):
self.tweakingpart = i
if QtCore.QRect(tl + offx, tr - offx).contains(pt):
self.tweakingpart = RubberBand.Top
elif QtCore.QRect(bl + offx, br - offx).contains(pt):
self.tweakingpart = RubberBand.Bottom
elif QtCore.QRect(tl + offy, bl - offy).contains(pt):
self.tweakingpart = RubberBand.Left
elif QtCore.QRect(tr + offy, br - offy).contains(pt):
self.tweakingpart = RubberBand.Right
if 0 <= self.tweakingpart < RubberBand.NonePos:
self._widget.setCursor(self.cursors[self.tweakingpart])
return
self.setGeometry(QtCore.QRect(pt, QtCore.QSize()))
self.show()
def handleMouseMoveEvent(self, pt):
rg = self.geometry()
if 0 <= self.tweakingpart < RubberBand.NonePos:
if self.tweakingpart == RubberBand.TopLeft:
rg.setTopLeft(pt)
elif self.tweakingpart == RubberBand.TopRight:
rg.setTopRight(pt)
elif self.tweakingpart == RubberBand.BottomLeft:
rg.setBottomLeft(pt)
elif self.tweakingpart == RubberBand.BottomRight:
rg.setBottomRight(pt)
elif self.tweakingpart == RubberBand.Top:
rg.setTop(pt.y())
elif self.tweakingpart == RubberBand.Bottom:
rg.setBottom(pt.y())
elif self.tweakingpart == RubberBand.Left:
rg.setLeft(pt.x())
elif self.tweakingpart == RubberBand.Right:
rg.setRight(pt.x())
else:
rg = QtCore.QRect(rg.topLeft(), pt).normalized()
self.setGeometry(rg)
def handleMouseReleaseEvent(self, pt):
self.tweakingpart = RubberBand.NonePos
self._widget.unsetCursor()
if not self.geometry().isNull():
self.rectChanged.emit(self.geometry())
class TestWidget(QtGui.QWidget):
pass
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
w = TestWidget()
rubberBand = RubberBand(w)
def on_rectChanged(rect):
print(rect.x(), rect.y(), rect.width(), rect.height())
rubberBand.rectChanged.connect(on_rectChanged)
w.show()
sys.exit(app.exec_())