如何防止在特定区域夹住 QRubberband？
How to prevent clip a QRubberband in a certain region?
我打算制作一个小型照片裁剪软件，我遇到了这个问题，当我移动我制作的 QRubberband 时，它有点移动到 QLabel 的边界。
示例代码如下：（左键单击并拖动以创建 QRubberband 并右键单击以移动 QRubberband）
import sys
from PyQt5.QtGui import *
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
class ResizableRubberBand(QWidget):
def __init__(self, parent=None):
super(ResizableRubberBand, self).__init__(parent)
self.draggable = True
self.dragging_threshold = 5
self.mousePressPos = None
self.mouseMovePos = None
self.borderRadius = 5
self.setWindowFlags(Qt.SubWindow)
layout = QHBoxLayout(self)
layout.setContentsMargins(0, 0, 0, 0)
layout.addWidget(
QSizeGrip(self), 0,
Qt.AlignLeft | Qt.AlignTop)
layout.addWidget(
QSizeGrip(self), 0,
Qt.AlignRight | Qt.AlignBottom)
self._band = QRubberBand(
QRubberBand.Rectangle, self)
self._band.show()
self.show()
def resizeEvent(self, event):
self._band.resize(self.size())
def paintEvent(self, event):
# Get current window size
window_size = self.size()
qp = QPainter()
qp.begin(self)
qp.setRenderHint(QPainter.Antialiasing, True)
qp.drawRoundedRect(0, 0, window_size.width(), window_size.height(),
self.borderRadius, self.borderRadius)
qp.end()
def mousePressEvent(self, event):
if self.draggable and event.button() == Qt.RightButton:
self.mousePressPos = event.globalPos() # global
self.mouseMovePos = event.globalPos() - self.pos() # local
super(ResizableRubberBand, self).mousePressEvent(event)
def mouseMoveEvent(self, event):
if self.draggable and event.buttons() & Qt.RightButton:
globalPos = event.globalPos()
moved = globalPos - self.mousePressPos
if moved.manhattanLength() > self.dragging_threshold:
# Move when user drag window more than dragging_threshold
diff = globalPos - self.mouseMovePos
self.move(diff)
self.mouseMovePos = globalPos - self.pos()
super(ResizableRubberBand, self).mouseMoveEvent(event)
def mouseReleaseEvent(self, event):
if self.mousePressPos is not None:
if event.button() == Qt.RightButton:
moved = event.globalPos() - self.mousePressPos
if moved.manhattanLength() > self.dragging_threshold:
# Do not call click event or so on
event.ignore()
self.mousePressPos = None
super(ResizableRubberBand, self).mouseReleaseEvent(event)
class mQLabel(QLabel):
def __init__(self, parent=None):
QLabel.__init__(self, parent)
self.setContentsMargins(0,0,0,0)
self.setAlignment(Qt.AlignTop | Qt.AlignLeft)
self.setSizePolicy(QSizePolicy.MinimumExpanding, QSizePolicy.MinimumExpanding)
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton: #and (hasattr(self, 'bla')):
self.first_mouse_location = (event.x(), event.y())
self.band = ResizableRubberBand(self)
self.band.setGeometry(event.x(), event.y(), 0, 0)
def mouseMoveEvent(self, event):
if event.buttons() & Qt.LeftButton:
first_mouse_location_x = self.first_mouse_location[0]
first_mouse_location_y = self.first_mouse_location[1]
new_x, new_y = event.x(), event.y()
difference_x = new_x - first_mouse_location_x
difference_y = new_y - first_mouse_location_y
self.band.resize(difference_x, difference_y)
class App(QWidget):
def __init__(self):
super().__init__()
## Set main window attributes
self.setFixedSize(1000,600)
# Add Label
self.label = mQLabel()
self.label.setStyleSheet("border: 1px solid black;")
self.label_layout = QHBoxLayout(self)
self.label_layout.addWidget(self.label)
self.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = App()
sys.exit(app.exec_())
我真的想不出一个可以做到的简单解决方案。我的第一直觉是获取父级的大小，但我不知道下一步该怎么做。
您需要根据父 rectangle.geometry 比较 widget geometry。
请注意，您不应使用全局位置，因为跟踪应始终发生在局部坐标（相对于父坐标）中。此外，一旦开始拖动，您就不需要再次检查 manhattanLength()，并且 self.mousePressPos 在任何情况下都应该在发布时被清除。
class ResizableRubberBand(QRubberBand):
is_dragging = False
def mousePressEvent(self, event):
if self.draggable and event.button() == Qt.RightButton:
self.mousePressPos = event.pos()
super(ResizableRubberBand, self).mousePressEvent(event)
def mouseMoveEvent(self, event):
if self.draggable and event.buttons() & Qt.RightButton:
diff = event.pos() - self.mousePressPos
if not self.is_dragging:
if diff.manhattanLength() > self.dragging_threshold:
self.is_dragging = True
if self.is_dragging:
geo = self.geometry()
parentRect = self.parent().rect()
geo.translate(diff)
if not parentRect.contains(geo):
if geo.right() > parentRect.right():
geo.moveRight(parentRect.right())
elif geo.x() < parentRect.x():
geo.moveLeft(parentRect.x())
if geo.bottom() > parentRect.bottom():
geo.moveBottom(parentRect.bottom())
elif geo.y() < parentRect.y():
geo.moveTop(parentRect.y())
self.move(geo.topLeft())
self.clearMask()
super(ResizableRubberBand, self).mouseMoveEvent(event)
def mouseReleaseEvent(self, event):
if self.mousePressPos is not None:
if event.button() == Qt.RightButton and self.is_dragging:
event.ignore()
self.is_dragging = False
self.mousePressPos = None
super(ResizableRubberBand, self).mouseReleaseEvent(event)
另请注意，您实际上并没有以非常好的方式使用 QRubberBand，这也是因为您正在绘制其边界。无论如何，更好的实现是直接继承 QRubberBand:
class ResizableRubberBand(QRubberBand):
def __init__(self, parent=None):
super(ResizableRubberBand, self).__init__(QRubberBand.Rectangle, parent)
self.setAttribute(Qt.WA_TransparentForMouseEvents, False)
self.draggable = True
self.is_dragging = False
self.dragging_threshold = 5
self.mousePressPos = None
self.borderRadius = 5
self.setWindowFlags(Qt.SubWindow)
layout = QHBoxLayout(self)
layout.setContentsMargins(0, 0, 0, 0)
layout.addWidget(
QSizeGrip(self), 0,
Qt.AlignLeft | Qt.AlignTop)
layout.addWidget(
QSizeGrip(self), 0,
Qt.AlignRight | Qt.AlignBottom)
self.show()
def resizeEvent(self, event):
self.clearMask()
def paintEvent(self, event):
super().paintEvent(event)
qp = QPainter(self)
qp.setRenderHint(QPainter.Antialiasing)
qp.translate(.5, .5)
qp.drawRoundedRect(self.rect().adjusted(0, 0, -1, -1),
self.borderRadius, self.borderRadius)
如果你只是为了美观而使用 QRubberBand，你根本不需要它，你可以从 QWidget 继承并使用样式函数来绘制一个“假”橡皮筋：
def paintEvent(self, event):
qp = QPainter(self)
qp.setRenderHint(QPainter.Antialiasing)
qp.translate(.5, .5)
opt = QStyleOptionRubberBand()
opt.initFrom(self)
style = self.style()
style.drawControl(style.CE_RubberBand, opt, qp)
qp.drawRoundedRect(self.rect().adjusted(0, 0, -1, -1),
self.borderRadius, self.borderRadius)
我打算制作一个小型照片裁剪软件，我遇到了这个问题，当我移动我制作的 QRubberband 时，它有点移动到 QLabel 的边界。
示例代码如下：（左键单击并拖动以创建 QRubberband 并右键单击以移动 QRubberband）
import sys
from PyQt5.QtGui import *
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
class ResizableRubberBand(QWidget):
def __init__(self, parent=None):
super(ResizableRubberBand, self).__init__(parent)
self.draggable = True
self.dragging_threshold = 5
self.mousePressPos = None
self.mouseMovePos = None
self.borderRadius = 5
self.setWindowFlags(Qt.SubWindow)
layout = QHBoxLayout(self)
layout.setContentsMargins(0, 0, 0, 0)
layout.addWidget(
QSizeGrip(self), 0,
Qt.AlignLeft | Qt.AlignTop)
layout.addWidget(
QSizeGrip(self), 0,
Qt.AlignRight | Qt.AlignBottom)
self._band = QRubberBand(
QRubberBand.Rectangle, self)
self._band.show()
self.show()
def resizeEvent(self, event):
self._band.resize(self.size())
def paintEvent(self, event):
# Get current window size
window_size = self.size()
qp = QPainter()
qp.begin(self)
qp.setRenderHint(QPainter.Antialiasing, True)
qp.drawRoundedRect(0, 0, window_size.width(), window_size.height(),
self.borderRadius, self.borderRadius)
qp.end()
def mousePressEvent(self, event):
if self.draggable and event.button() == Qt.RightButton:
self.mousePressPos = event.globalPos() # global
self.mouseMovePos = event.globalPos() - self.pos() # local
super(ResizableRubberBand, self).mousePressEvent(event)
def mouseMoveEvent(self, event):
if self.draggable and event.buttons() & Qt.RightButton:
globalPos = event.globalPos()
moved = globalPos - self.mousePressPos
if moved.manhattanLength() > self.dragging_threshold:
# Move when user drag window more than dragging_threshold
diff = globalPos - self.mouseMovePos
self.move(diff)
self.mouseMovePos = globalPos - self.pos()
super(ResizableRubberBand, self).mouseMoveEvent(event)
def mouseReleaseEvent(self, event):
if self.mousePressPos is not None:
if event.button() == Qt.RightButton:
moved = event.globalPos() - self.mousePressPos
if moved.manhattanLength() > self.dragging_threshold:
# Do not call click event or so on
event.ignore()
self.mousePressPos = None
super(ResizableRubberBand, self).mouseReleaseEvent(event)
class mQLabel(QLabel):
def __init__(self, parent=None):
QLabel.__init__(self, parent)
self.setContentsMargins(0,0,0,0)
self.setAlignment(Qt.AlignTop | Qt.AlignLeft)
self.setSizePolicy(QSizePolicy.MinimumExpanding, QSizePolicy.MinimumExpanding)
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton: #and (hasattr(self, 'bla')):
self.first_mouse_location = (event.x(), event.y())
self.band = ResizableRubberBand(self)
self.band.setGeometry(event.x(), event.y(), 0, 0)
def mouseMoveEvent(self, event):
if event.buttons() & Qt.LeftButton:
first_mouse_location_x = self.first_mouse_location[0]
first_mouse_location_y = self.first_mouse_location[1]
new_x, new_y = event.x(), event.y()
difference_x = new_x - first_mouse_location_x
difference_y = new_y - first_mouse_location_y
self.band.resize(difference_x, difference_y)
class App(QWidget):
def __init__(self):
super().__init__()
## Set main window attributes
self.setFixedSize(1000,600)
# Add Label
self.label = mQLabel()
self.label.setStyleSheet("border: 1px solid black;")
self.label_layout = QHBoxLayout(self)
self.label_layout.addWidget(self.label)
self.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = App()
sys.exit(app.exec_())
我真的想不出一个可以做到的简单解决方案。我的第一直觉是获取父级的大小，但我不知道下一步该怎么做。
您需要根据父 rectangle.geometry 比较 widget geometry。
请注意，您不应使用全局位置，因为跟踪应始终发生在局部坐标（相对于父坐标）中。此外，一旦开始拖动，您就不需要再次检查 manhattanLength()，并且 self.mousePressPos 在任何情况下都应该在发布时被清除。
class ResizableRubberBand(QRubberBand):
is_dragging = False
def mousePressEvent(self, event):
if self.draggable and event.button() == Qt.RightButton:
self.mousePressPos = event.pos()
super(ResizableRubberBand, self).mousePressEvent(event)
def mouseMoveEvent(self, event):
if self.draggable and event.buttons() & Qt.RightButton:
diff = event.pos() - self.mousePressPos
if not self.is_dragging:
if diff.manhattanLength() > self.dragging_threshold:
self.is_dragging = True
if self.is_dragging:
geo = self.geometry()
parentRect = self.parent().rect()
geo.translate(diff)
if not parentRect.contains(geo):
if geo.right() > parentRect.right():
geo.moveRight(parentRect.right())
elif geo.x() < parentRect.x():
geo.moveLeft(parentRect.x())
if geo.bottom() > parentRect.bottom():
geo.moveBottom(parentRect.bottom())
elif geo.y() < parentRect.y():
geo.moveTop(parentRect.y())
self.move(geo.topLeft())
self.clearMask()
super(ResizableRubberBand, self).mouseMoveEvent(event)
def mouseReleaseEvent(self, event):
if self.mousePressPos is not None:
if event.button() == Qt.RightButton and self.is_dragging:
event.ignore()
self.is_dragging = False
self.mousePressPos = None
super(ResizableRubberBand, self).mouseReleaseEvent(event)
另请注意，您实际上并没有以非常好的方式使用 QRubberBand，这也是因为您正在绘制其边界。无论如何，更好的实现是直接继承 QRubberBand:
class ResizableRubberBand(QRubberBand):
def __init__(self, parent=None):
super(ResizableRubberBand, self).__init__(QRubberBand.Rectangle, parent)
self.setAttribute(Qt.WA_TransparentForMouseEvents, False)
self.draggable = True
self.is_dragging = False
self.dragging_threshold = 5
self.mousePressPos = None
self.borderRadius = 5
self.setWindowFlags(Qt.SubWindow)
layout = QHBoxLayout(self)
layout.setContentsMargins(0, 0, 0, 0)
layout.addWidget(
QSizeGrip(self), 0,
Qt.AlignLeft | Qt.AlignTop)
layout.addWidget(
QSizeGrip(self), 0,
Qt.AlignRight | Qt.AlignBottom)
self.show()
def resizeEvent(self, event):
self.clearMask()
def paintEvent(self, event):
super().paintEvent(event)
qp = QPainter(self)
qp.setRenderHint(QPainter.Antialiasing)
qp.translate(.5, .5)
qp.drawRoundedRect(self.rect().adjusted(0, 0, -1, -1),
self.borderRadius, self.borderRadius)
如果你只是为了美观而使用 QRubberBand，你根本不需要它，你可以从 QWidget 继承并使用样式函数来绘制一个“假”橡皮筋：
def paintEvent(self, event):
qp = QPainter(self)
qp.setRenderHint(QPainter.Antialiasing)
qp.translate(.5, .5)
opt = QStyleOptionRubberBand()
opt.initFrom(self)
style = self.style()
style.drawControl(style.CE_RubberBand, opt, qp)
qp.drawRoundedRect(self.rect().adjusted(0, 0, -1, -1),
self.borderRadius, self.borderRadius)