应用程序选择器示例¶

# Copyright (C) 2010 Riverbank Computing Limited.
# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
from __future__ import annotations

import sys

from PySide6.QtCore import (QPointF, QPropertyAnimation, QRect, QRectF, Qt,
                            Signal)
from PySide6.QtGui import QPixmap
from PySide6.QtWidgets import (QApplication, QGraphicsScene, QGraphicsView,
                               QGraphicsWidget)
from PySide6.QtStateMachine import QState, QStateMachine

import appchooser_rc  # noqa: F401


class Pixmap(QGraphicsWidget):
    clicked = Signal()

    def __init__(self, pix, parent=None):
        super().__init__(parent)

        self.orig = QPixmap(pix)
        self.p = QPixmap(pix)

    def paint(self, painter, option, widget):
        painter.drawPixmap(QPointF(), self.p)

    def mousePressEvent(self, ev):
        self.clicked.emit()

    def setGeometry(self, rect):
        super(Pixmap, self).setGeometry(rect)

        if rect.size().width() > self.orig.size().width():
            self.p = self.orig.scaled(rect.size().toSize())
        else:
            self.p = QPixmap(self.orig)


def create_states(objects, selectedRect, parent):
    for obj in objects:
        state = QState(parent)
        state.assignProperty(obj, 'geometry', selectedRect)
        parent.addTransition(obj.clicked, state)


def create_animations(objects, machine):
    for obj in objects:
        animation = QPropertyAnimation(obj, b'geometry', obj)
        machine.addDefaultAnimation(animation)


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

    p1 = Pixmap(QPixmap(':/digikam.png'))
    p2 = Pixmap(QPixmap(':/akregator.png'))
    p3 = Pixmap(QPixmap(':/accessories-dictionary.png'))
    p4 = Pixmap(QPixmap(':/k3b.png'))

    p1.setGeometry(QRectF(0.0, 0.0, 64.0, 64.0))
    p2.setGeometry(QRectF(236.0, 0.0, 64.0, 64.0))
    p3.setGeometry(QRectF(236.0, 236.0, 64.0, 64.0))
    p4.setGeometry(QRectF(0.0, 236.0, 64.0, 64.0))

    scene = QGraphicsScene(0, 0, 300, 300)
    scene.setBackgroundBrush(Qt.white)
    scene.addItem(p1)
    scene.addItem(p2)
    scene.addItem(p3)
    scene.addItem(p4)

    window = QGraphicsView(scene)
    window.setFrameStyle(0)
    window.setAlignment(Qt.AlignLeft | Qt.AlignTop)
    window.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
    window.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)

    machine = QStateMachine()
    machine.setGlobalRestorePolicy(QStateMachine.RestoreProperties)

    group = QState(machine)
    selected_rect = QRect(86, 86, 128, 128)

    idle_state = QState(group)
    group.setInitialState(idle_state)

    objects = [p1, p2, p3, p4]
    create_states(objects, selected_rect, group)
    create_animations(objects, machine)

    machine.setInitialState(group)
    machine.start()

    window.resize(300, 300)
    window.show()

    sys.exit(app.exec())