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(类似于你在网页上看到的文本字段)。我见过一些人问同样的问题，但没有找到一个完整的例子。

我有一些代码就在那里，但是在调整大小的时候它会闪烁，所以我猜我缺少一些关于调整策略或布局的东西。

这是我的“工作”例子。理论非常简单，您只需测量小部件的mousePressEvent中鼠标移动的距离，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

好吧，原来我离得很近。我在这里为任何想解决类似问题的人发了一个答案！

我真正需要从我的原始代码中更改的是引用globalPos()而不是本地pos()。感谢你的帮助，特别是尼克发现移动事件导致了问题。

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)

Answer 2

试一试：

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 3

或者，对于其他解决方案，您可以使用QSizeGrip，就像它从盒子里出来一样：

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_())