在 pyqt 中的选项卡更改上淡入淡出

Question

我有一个包含两个标签的页面。我想在更改标签时添加淡入淡出效果。这可能吗？

import sys
from PyQt4.QtCore import QTimeLine
from PyQt4.QtGui import *

class FaderWidget(QWidget):

    def __init__(self, old_widget, new_widget):

        QWidget.__init__(self, new_widget)

        self.old_pixmap = QPixmap(new_widget.size())
        old_widget.render(self.old_pixmap)
        self.pixmap_opacity = 1.0

        self.timeline = QTimeLine()
        self.timeline.valueChanged.connect(self.animate)
        self.timeline.finished.connect(self.close)
        self.timeline.setDuration(333)
        self.timeline.start()

        self.resize(new_widget.size())
        self.show()

    def paintEvent(self, event):

        painter = QPainter()
        painter.begin(self)
        painter.setOpacity(self.pixmap_opacity)
        painter.drawPixmap(0, 0, self.old_pixmap)
        painter.end()

    def animate(self, value):

        self.pixmap_opacity = 1.0 - value
        self.repaint()

class StackedWidget(QStackedWidget):

    def __init__(self, parent = None):
        QStackedWidget.__init__(self, parent)

    def setCurrentIndex(self, index):
        self.fader_widget = FaderWidget(self.currentWidget(), self.widget(index))
        QStackedWidget.setCurrentIndex(self, index)

    def setPage1(self):
        self.setCurrentIndex(0)

    def setPage2(self):
        self.setCurrentIndex(1)


if __name__ == "__main__":

    app = QApplication(sys.argv)

    window = QWidget()

    stack = StackedWidget()
    stack.addWidget(QCalendarWidget())
    editor = QTextEdit()
    editor.setPlainText("Hello world! "*100)
    stack.addWidget(editor)

    page1Button = QPushButton("Page 1")
    page2Button = QPushButton("Page 2")
    page1Button.clicked.connect(stack.setPage1)
    page2Button.clicked.connect(stack.setPage2)

    layout = QGridLayout(window)
    layout.addWidget(stack, 0, 0, 1, 2)
    layout.addWidget(page1Button, 1, 0)
    layout.addWidget(page2Button, 1, 1)

    window.show()

    sys.exit(app.exec_())

这是显示一些淡入淡出效果的代码，但我没有从中得到任何东西以及它是如何工作的以及如何在选项卡上实现。如果有人可以帮助我在标签上实现它，那将是非常可观的。 提前致谢。

Answer 1

使用与您显示的代码相同的逻辑，每个小部件都将放置在 QStackedWidget 中，其中一个是要显示的小部件，另一个是 FaderWidget。

class FaderWidget(QWidget):
    def __init__(self, *args, **kwargs):
        QWidget.__init__(self, *args, **kwargs)
        self.pixmap_opacity = None
        self.timeline = QTimeLine(333, self)
        self.timeline.valueChanged.connect(self.animate)
        self.timeline.finished.connect(self.close)

    def start(self, old_widget, new_widget):
        self.pixmap_opacity = 1.0
        self.old_pixmap = QPixmap(new_widget.size())
        old_widget.render(self.old_pixmap)

        self.timeline.start()

        self.resize(new_widget.size())
        self.show()

    def paintEvent(self, event):
        if self.pixmap_opacity:
            QWidget.paintEvent(self, event)
            painter = QPainter(self)
            painter.setOpacity(self.pixmap_opacity)
            painter.drawPixmap(0, 0, self.old_pixmap)

    def animate(self, value):
        self.pixmap_opacity = 1.0 - value
        self.update()


class FaderTabWidget(QTabWidget):
    def __init__(self, parent=None):
        QTabWidget.__init__(self, parent)
        self.currentChanged.connect(self.onCurrentIndex)
        self.last = -1
        self.current = self.currentIndex()

    def onCurrentIndex(self, index):
        self.last = self.current
        self.current = self.currentIndex()
        if self.widget(self.last):
            self.widget(self.last).setCurrentIndex(1)
            old_widget = self.widget(self.last).widget(0)
            current_widget = self.widget(self.current).widget(0)
            fade = self.widget(self.current).widget(1)
            fade.start(old_widget, current_widget)

    def addTab(self, widget, text):
        stack = QStackedWidget(self)
        stack.addWidget(widget)
        fade = FaderWidget(self)
        fade.timeline.finished.connect(lambda: stack.setCurrentIndex(0))
        stack.addWidget(fade)
        stack.setCurrentIndex(0 if self.currentIndex() == -1 else 1)
        QTabWidget.addTab(self, stack, text)


if __name__ == "__main__":
    app = QApplication(sys.argv)

    window = QWidget()

    tabWidget = FaderTabWidget()
    tabWidget.addTab(QCalendarWidget(), "Tab1")
    editor = QTextEdit()
    editor.setPlainText("Hello world! " * 100)
    tabWidget.addTab(editor, "Tab2")
    layout = QVBoxLayout(window)
    layout.addWidget(tabWidget)
    window.show()
    sys.exit(app.exec_())