自定义 QSizeGrip 以调整 QListWidget 的大小

Question

我想制作一个 QListWidget，底部有一个调整大小的句柄（类似于您在此类网页上看到的文本字段）。我看到有人问过同样的问题，但没有找到完整的例子。

我有一些代码几乎就在那里，但在调整大小时它会闪烁，所以我猜我在调整大小策略或布局或其他方面缺少一些东西......

这是我的“工作”示例。理论非常简单，您只需在小部件的 mousePressEvent 中测量鼠标移动的距离并相应地调整大小/重新定位。不幸的是，我错过了一些基本的东西，我不知道是什么：

from PyQt4 import QtGui
import sys

class Grip(QtGui.QLabel):
    def __init__(self, parent, move_widget):
        super(Grip, self).__init__(parent)
        self.move_widget = move_widget
        self.setText("+")
        self.min_height = 50

        self.mouse_start = None
        self.height_start = self.move_widget.height()
        self.resizing = False
        self.setMouseTracking(True)


    def showEvent(self, event):
        super(Grip, self).showEvent(event)
        self.reposition()

    def mousePressEvent(self, event):
        super(Grip, self).mousePressEvent(event)
        self.resizing = True
        self.height_start = self.move_widget.height()
        self.mouse_start = event.pos()

    def mouseMoveEvent(self, event):
        super(Grip, self).mouseMoveEvent(event)
        if self.resizing:
            delta = event.pos() - self.mouse_start
            height = self.height_start + delta.y()
            if height > self.min_height:
                self.move_widget.setFixedHeight(height)
            else:
                self.move_widget.setFixedHeight(self.min_height)

            self.reposition()

    def mouseReleaseEvent(self, event):
        super(Grip, self).mouseReleaseEvent(event)
        self.resizing = False

    def reposition(self):
        rect = self.move_widget.geometry()
        self.move(rect.right(), rect.bottom())


class Dialog(QtGui.QDialog):
    def __init__(self):
        super(Dialog, self).__init__()
        layout = QtGui.QVBoxLayout()
        self.setLayout(layout)
        list_widget = QtGui.QListWidget()
        layout.addWidget(list_widget)
        gripper = Grip(self, list_widget)

        layout.addWidget(QtGui.QLabel("Test"))

        self.setGeometry(200, 500, 200, 500)

Answer 1

试试看：

def mouseMoveEvent(self, event):
    super(Grip, self).mouseMoveEvent(event)
    if self.resizing:
        delta = event.pos() - self.mouse_start
        height = self.height_start + delta.y()
        if height > self.min_height:
            self.move_widget.setFixedHeight(height)
        else:
            self.move_widget.setFixedHeight(self.min_height)

        #self.reposition()                                       # <-  ---

def mouseReleaseEvent(self, event):
    super(Grip, self).mouseReleaseEvent(event)
    self.resizing = False

    self.reposition()                                             # <- +++

Answer 2

作为其他解决方案的替代方案，您可以使用 QSizeGrip 开箱即用的方式：

from PyQt4 import QtCore, QtGui
import sys

class Dialog(QtGui.QDialog):
    def __init__(self):
        super(Dialog, self).__init__()
        layoutMain = QtGui.QVBoxLayout(self)
        listWidget = QtGui.QListWidget(self)
        gripper = QtGui.QSizeGrip(listWidget)
        l = QtGui.QHBoxLayout(listWidget)

        l.setContentsMargins(0, 0, 0, 0)
        l.addWidget(gripper, 0, QtCore.Qt.AlignRight | QtCore.Qt.AlignBottom)

        layoutMain.addWidget(listWidget)
        layoutMain.addWidget(QtGui.QLabel("Test", self))

        self.setGeometry(200, 500, 200, 500)

if __name__ == '__main__':
    import sys
    app = QtGui.QApplication(sys.argv)
    w = Dialog()
    w.show()
    sys.exit(app.exec_())

Answer 3

我认为与其实现自己的QSizeGrip，不如使用QSplitter：

from PyQt4 import QtCore, QtGui
import sys


class Dialog(QtGui.QDialog):
    def __init__(self):
        super(Dialog, self).__init__()
        layout = QtGui.QVBoxLayout(self)

        splitter = QtGui.QSplitter(QtCore.Qt.Vertical)
        layout.addWidget(splitter)
        list_widget = QtGui.QListWidget()
        splitter.addWidget(list_widget)
        splitter.addWidget(QtGui.QLabel("Test"))


if __name__ == '__main__':
    import sys
    app = QtGui.QApplication(sys.argv)
    w = Dialog()
    w.show()
    sys.exit(app.exec_())

Answer 4

好吧，事实证明我真的很接近。我在这里为其他希望解决类似问题的人发布答案！

我真正需要对原始代码进行更改的只是引用globalPos() 而不是本地的pos()。感谢您的帮助，特别感谢 S. Nick 发现导致问题的移动事件。

from PyQt4 import QtGui
import sys

class Grip(QtGui.QLabel):
    def __init__(self, parent, move_widget):
        super(Grip, self).__init__(parent)
        self.move_widget = move_widget
        self.setText("+")
        self.min_height = 50

        self.mouse_start = None
        self.height_start = self.move_widget.height()
        self.resizing = False
        self.setMouseTracking(True)

        self.setCursor(QtCore.Q.SizeVerCursor)


    def showEvent(self, event):
        super(Grip, self).showEvent(event)
        self.reposition()

    def mousePressEvent(self, event):
        super(Grip, self).mousePressEvent(event)
        self.resizing = True
        self.height_start = self.move_widget.height()
        self.mouse_start = event.globalPos()

    def mouseMoveEvent(self, event):
        super(Grip, self).mouseMoveEvent(event)
        if self.resizing:
            delta = event.globalPos() - self.mouse_start
            height = self.height_start + delta.y()
            if height > self.min_height:
                self.move_widget.setFixedHeight(height)
            else:
                self.move_widget.setFixedHeight(self.min_height)

            self.reposition()

    def mouseReleaseEvent(self, event):
        super(Grip, self).mouseReleaseEvent(event)
        self.resizing = False

    def reposition(self):
        rect = self.move_widget.geometry()
        self.move(rect.right(), rect.bottom())


class Dialog(QtGui.QDialog):
    def __init__(self):
        super(Dialog, self).__init__()
        layout = QtGui.QVBoxLayout()
        self.setLayout(layout)
        list_widget = QtGui.QListWidget()
        layout.addWidget(list_widget)
        gripper = Grip(self, list_widget)

        layout.addWidget(QtGui.QLabel("Test"))

        self.setGeometry(200, 500, 200, 500)