将 ScrollHandDrag 表单左键单击更改为中键单击 PYQT5
Change ScrollHandDrag form left click to middle click PYQT5
我很好奇是否有一种方法可以将 QGraphicsView.ScrollHandDrag 更改为在用户放大点时使用中心按钮而不是鼠标左键进行平移。还有没有办法对用户也可以平移的位置没有任何限制？谢谢你的帮助。我在下面附上了一些代码。
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from math import sqrt
class Point(QGraphicsItem):
def __init__(self, x, y):
super(Point, self).__init__()
self.setFlag(QGraphicsItem.ItemIsSelectable, True)
self.rectF = QRectF(0, 0, 30, 30)
self.x=x
self.y=y
self._brush = QBrush(Qt.black)
def setBrush(self, brush):
self._brush = brush
self.update()
def boundingRect(self):
return self.rectF
def paint(self, painter=None, style=None, widget=None):
painter.fillRect(self.rectF, self._brush)
def hoverMoveEvent(self, event):
point = event.pos().toPoint()
print(point)
QGraphicsItem.hoverMoveEvent(self, event)
class PhotoViewer(QGraphicsView):
photoClicked = pyqtSignal(QPoint)
def __init__(self, parent):
super(PhotoViewer, self).__init__(parent)
self._zoom = 0
self._empty = True
self._scene = QGraphicsScene(self)
self.setTransformationAnchor(QGraphicsView.AnchorUnderMouse)
self.setResizeAnchor(QGraphicsView.AnchorUnderMouse)
self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.setFrameShape(QFrame.NoFrame)
self.area = float()
self.setPoints()
def setItems(self):
self.data = {'x': [-2414943.8686, -2417160.6592, -2417160.6592, -2417856.1783, -2417054.7618, -2416009.9966, -2416012.5232, -2418160.8952, -2418160.8952, -2416012.5232, -2417094.7694, -2417094.7694], 'y': [10454269.7008,
10454147.2672, 10454147.2672, 10453285.2456, 10452556.8132, 10453240.2808, 10455255.8752, 10455183.1912, 10455183.1912, 10455255.8752, 10456212.5959, 10456212.5959]}
maxX = max(self.data['x'])
minX = min(self.data['x'])
maxY = max(self.data['y'])
minY = min(self.data['y'])
distance = sqrt((maxX-minX)**2+(maxY-minY)**2)
self.area = QRectF(minX, minY, distance, distance)
for i,x in enumerate(self.data['x']):
x = self.data['x'][i]
y = self.data['y'][i]
p = Point(x,y)
p.setPos(x,y)
self._scene.addItem(p)
self.setScene(self._scene)
def fitInView(self, scale=True):
rect = QRectF(self.area)
if not rect.isNull():
self.setSceneRect(rect)
unity = self.transform().mapRect(QRectF(0, 0, 1, 1))
self.scale(1 / unity.width(), 1 / unity.height())
viewrect = self.viewport().rect()
scenerect = self.transform().mapRect(rect)
factor = min(viewrect.width() / scenerect.width(),
viewrect.height() / scenerect.height())
self.scale(factor, factor)
self._zoom = 0
def setPoints(self):
self._zoom = 0
self.setItems()
self.setDragMode(QGraphicsView.ScrollHandDrag)
self.fitInView()
def wheelEvent(self, event):
if event.angleDelta().y() > 0:
factor = 1.25
self._zoom += 1
else:
factor = 0.8
self._zoom -= 1
if self._zoom > 0:
self.scale(factor, factor)
elif self._zoom == 0:
self.fitInView()
else:
self._zoom = 0
def mousePressEvent(self, event):
if event.button() == Qt.MidButton:
#Im Sure I have to do something here.
pass
super(PhotoViewer, self).mousePressEvent(event)
class Window(QWidget):
def __init__(self):
super(Window, self).__init__()
self.viewer = PhotoViewer(self)
# 'Load image' button
self.btnLoad = QToolButton(self)
self.btnLoad.setText('Load Points')
self.btnLoad.clicked.connect(self.loadPoints)
VBlayout = QVBoxLayout(self)
VBlayout.addWidget(self.viewer)
HBlayout = QHBoxLayout()
HBlayout.setAlignment(Qt.AlignLeft)
HBlayout.addWidget(self.btnLoad)
VBlayout.addLayout(HBlayout)
def loadPoints(self):
self.viewer.setPoints()
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
window = Window()
window.setGeometry(500, 300, 800, 600)
window.show()
sys.exit(app.exec_())
是的，您可以更改平移光标。
请将您的代码部分更改为这些。
def mousePressEvent(self, event):
if event.button() == Qt.MidButton:
self.viewport().setCursor(Qt.ClosedHandCursor)
self.original_event = event
handmade_event = QMouseEvent(QEvent.MouseButtonPress,QPointF(event.pos()),Qt.LeftButton,event.buttons(),Qt.KeyboardModifiers())
self.mousePressEvent(handmade_event)
#Im Sure I have to do something here.
super(PhotoViewer, self).mousePressEvent(event)
def mouseReleaseEvent(self, event):
if event.button() == Qt.MidButton:
#for changing back to Qt.OpenHandCursor
self.viewport().setCursor(Qt.OpenHandCursor)
handmade_event = QMouseEvent(QEvent.MouseButtonRelease,QPointF(event.pos()),Qt.LeftButton,event.buttons(),Qt.KeyboardModifiers())
self.mouseReleaseEvent(handmade_event)
super(PhotoViewer, self).mouseReleaseEvent(event)
说明
用于更改 QGraphicsView 上的鼠标光标图片，基本上，
QGraphicsView.vieport().setCursor()
为什么Qt.LeftButton可以默认改变光标？
我认为是默认的setting.Probably，Qt的开发者预测当光标形状为OpenHandCursor时，用户希望通过按左键来平移屏幕。
因此，您可能无法在 LeftButton 的情况下保持光标 "open"，反之亦然。
它嵌入在 super(PhotoViewer, self).mousePressEvent(event)
我们将无法连接内容。
所以你不想用 LeftMouse 改变，你写 return 然后你在这里写其他命令。
手工活动对象
如果你按下MidButton，你自己制作LeftButton MouseEvent，
然后将它传递给 mousePressEvent。
mousePressEvent 接受它，并将其处理为 leftButton 事件。
如果只把手工码放在mousePressEvent，你就无法逃脱trap.So你也把手工码放在mouseReleaseEvent.
Perfect.It 取决于您在事件处理程序中编写的命令。
如果你不想让 leftButton 平移，你可以在其中做同样的事情。
也就是说，你可以在LeftButton和MidButton之间切换事件！
我很好奇是否有一种方法可以将 QGraphicsView.ScrollHandDrag 更改为在用户放大点时使用中心按钮而不是鼠标左键进行平移。还有没有办法对用户也可以平移的位置没有任何限制？谢谢你的帮助。我在下面附上了一些代码。
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from math import sqrt
class Point(QGraphicsItem):
def __init__(self, x, y):
super(Point, self).__init__()
self.setFlag(QGraphicsItem.ItemIsSelectable, True)
self.rectF = QRectF(0, 0, 30, 30)
self.x=x
self.y=y
self._brush = QBrush(Qt.black)
def setBrush(self, brush):
self._brush = brush
self.update()
def boundingRect(self):
return self.rectF
def paint(self, painter=None, style=None, widget=None):
painter.fillRect(self.rectF, self._brush)
def hoverMoveEvent(self, event):
point = event.pos().toPoint()
print(point)
QGraphicsItem.hoverMoveEvent(self, event)
class PhotoViewer(QGraphicsView):
photoClicked = pyqtSignal(QPoint)
def __init__(self, parent):
super(PhotoViewer, self).__init__(parent)
self._zoom = 0
self._empty = True
self._scene = QGraphicsScene(self)
self.setTransformationAnchor(QGraphicsView.AnchorUnderMouse)
self.setResizeAnchor(QGraphicsView.AnchorUnderMouse)
self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.setFrameShape(QFrame.NoFrame)
self.area = float()
self.setPoints()
def setItems(self):
self.data = {'x': [-2414943.8686, -2417160.6592, -2417160.6592, -2417856.1783, -2417054.7618, -2416009.9966, -2416012.5232, -2418160.8952, -2418160.8952, -2416012.5232, -2417094.7694, -2417094.7694], 'y': [10454269.7008,
10454147.2672, 10454147.2672, 10453285.2456, 10452556.8132, 10453240.2808, 10455255.8752, 10455183.1912, 10455183.1912, 10455255.8752, 10456212.5959, 10456212.5959]}
maxX = max(self.data['x'])
minX = min(self.data['x'])
maxY = max(self.data['y'])
minY = min(self.data['y'])
distance = sqrt((maxX-minX)**2+(maxY-minY)**2)
self.area = QRectF(minX, minY, distance, distance)
for i,x in enumerate(self.data['x']):
x = self.data['x'][i]
y = self.data['y'][i]
p = Point(x,y)
p.setPos(x,y)
self._scene.addItem(p)
self.setScene(self._scene)
def fitInView(self, scale=True):
rect = QRectF(self.area)
if not rect.isNull():
self.setSceneRect(rect)
unity = self.transform().mapRect(QRectF(0, 0, 1, 1))
self.scale(1 / unity.width(), 1 / unity.height())
viewrect = self.viewport().rect()
scenerect = self.transform().mapRect(rect)
factor = min(viewrect.width() / scenerect.width(),
viewrect.height() / scenerect.height())
self.scale(factor, factor)
self._zoom = 0
def setPoints(self):
self._zoom = 0
self.setItems()
self.setDragMode(QGraphicsView.ScrollHandDrag)
self.fitInView()
def wheelEvent(self, event):
if event.angleDelta().y() > 0:
factor = 1.25
self._zoom += 1
else:
factor = 0.8
self._zoom -= 1
if self._zoom > 0:
self.scale(factor, factor)
elif self._zoom == 0:
self.fitInView()
else:
self._zoom = 0
def mousePressEvent(self, event):
if event.button() == Qt.MidButton:
#Im Sure I have to do something here.
pass
super(PhotoViewer, self).mousePressEvent(event)
class Window(QWidget):
def __init__(self):
super(Window, self).__init__()
self.viewer = PhotoViewer(self)
# 'Load image' button
self.btnLoad = QToolButton(self)
self.btnLoad.setText('Load Points')
self.btnLoad.clicked.connect(self.loadPoints)
VBlayout = QVBoxLayout(self)
VBlayout.addWidget(self.viewer)
HBlayout = QHBoxLayout()
HBlayout.setAlignment(Qt.AlignLeft)
HBlayout.addWidget(self.btnLoad)
VBlayout.addLayout(HBlayout)
def loadPoints(self):
self.viewer.setPoints()
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
window = Window()
window.setGeometry(500, 300, 800, 600)
window.show()
sys.exit(app.exec_())
是的，您可以更改平移光标。
请将您的代码部分更改为这些。
def mousePressEvent(self, event):
if event.button() == Qt.MidButton:
self.viewport().setCursor(Qt.ClosedHandCursor)
self.original_event = event
handmade_event = QMouseEvent(QEvent.MouseButtonPress,QPointF(event.pos()),Qt.LeftButton,event.buttons(),Qt.KeyboardModifiers())
self.mousePressEvent(handmade_event)
#Im Sure I have to do something here.
super(PhotoViewer, self).mousePressEvent(event)
def mouseReleaseEvent(self, event):
if event.button() == Qt.MidButton:
#for changing back to Qt.OpenHandCursor
self.viewport().setCursor(Qt.OpenHandCursor)
handmade_event = QMouseEvent(QEvent.MouseButtonRelease,QPointF(event.pos()),Qt.LeftButton,event.buttons(),Qt.KeyboardModifiers())
self.mouseReleaseEvent(handmade_event)
super(PhotoViewer, self).mouseReleaseEvent(event)
说明
用于更改 QGraphicsView 上的鼠标光标图片，基本上，
QGraphicsView.vieport().setCursor()
为什么Qt.LeftButton可以默认改变光标？
我认为是默认的setting.Probably，Qt的开发者预测当光标形状为OpenHandCursor时，用户希望通过按左键来平移屏幕。
因此，您可能无法在 LeftButton 的情况下保持光标 "open"，反之亦然。
它嵌入在 super(PhotoViewer, self).mousePressEvent(event)
我们将无法连接内容。
所以你不想用 LeftMouse 改变，你写 return 然后你在这里写其他命令。
手工活动对象
如果你按下MidButton，你自己制作LeftButton MouseEvent，
然后将它传递给 mousePressEvent。
mousePressEvent 接受它，并将其处理为 leftButton 事件。
如果只把手工码放在mousePressEvent，你就无法逃脱trap.So你也把手工码放在mouseReleaseEvent.
Perfect.It 取决于您在事件处理程序中编写的命令。
如果你不想让 leftButton 平移，你可以在其中做同样的事情。
也就是说，你可以在LeftButton和MidButton之间切换事件！