我有一个使用橡皮筋选择图像上区域的小部件，可以在任何方面进行编辑。我需要添加一些功能，一旦放置橡皮筋，它就可以重新调整大小或进行编辑，因此我的想法是在鼠标释放事件后保存区域点（x，y，w，h）。
但是现在的问题是，如何在橡皮筋类之外传递鼠标释放事件中读取的数据。
这是我对橡皮筋的拖动和编辑代码。
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())
这是我有关释放事件的代码，以及需要在类外传递或读取的（x，y，w，h）数据。
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())
每次释放鼠标时我都需要数据并保存。因此，一旦用户需要重新调整大小并进行编辑，我的想法是设置橡皮筋的几何形状并重新运行该类，以便可以再次对其进行编辑。
答案 0 :(得分：0)
如果要在类之外公开数据，则应使用如下所示的信号：
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_())
另一方面，我看到您的代码非常耦合，因为如果您想在另一个小部件中使用相同的功能，则必须复制所有代码，这是不希望的，因此，我花时间创建了一个自定义QRubberband具有该功能，在下一部分中，我将显示一个示例。
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_())