Add 03-7-03

Image Viewer Example 图像查看器案例

Author: muziing

03-QtWidgets-常用控件/07-QScrollArea-滚动区域/03-ImageViewerExample-图像查看器案例.py

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+import sys
+from typing import List
+
+from PySide6.QtCore import QDir, QMimeData, QStandardPaths
+from PySide6.QtGui import *
+from PySide6.QtWidgets import *
+
+"""
+Image Viewer Example 图像查看器案例
+本案例为Qt官方同名案例的PySide6移植版，结合QLabel与QScrollArea实现图像显示功能
+https://doc.qt.io/qt-6/qtwidgets-widgets-imageviewer-example.html
+
+注意本脚本仍有部分函数未能完全完成改写
+
+"""
+
+
+def clipboard_image() -> QImage:
+    mime_data: QMimeData = QMimeData()
+    if mime_data == QGuiApplication.clipboard().mimeData():
+        if mime_data.hasImage():
+            pass
+        # TODO 写完此函数
+
+
+class ImageViewer(QMainWindow):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self.image: QImage = QImage()
+        self.scale_factor: float = 1.0
+        self.setWindowTitle("Image Viewer")
+        self.resize(QGuiApplication.primaryScreen().availableSize() * 3 / 5)
+
+        self.image_label = QLabel(self)
+        self.image_label.setSizePolicy(QSizePolicy.Ignored, QSizePolicy.Ignored)
+        self.image_label.setScaledContents(True)
+
+        self.scroll_area = QScrollArea(self)
+        self.scroll_area.setBackgroundRole(QPalette.Dark)
+        self.scroll_area.setWidget(self.image_label)
+        self.scroll_area.setVisible(False)
+
+        self.setCentralWidget(self.scroll_area)
+
+        self.save_as_act = QAction()
+        self.print_act = QAction()
+        self.copy_act = QAction()
+        self.zoom_in_act = QAction()
+        self.zoom_out_act = QAction()
+        self.normal_size_act = QAction()
+        self.fit_to_window_act = QAction()
+        self.create_actions()
+
+    def load_file(self, file_name: str) -> bool:
+        """
+        打开文件，加载图片 \n
+        :param file_name: 文件名
+        :return: 是否成功加载文件
+        """
+
+        reader = QImageReader(file_name)
+        reader.setAutoTransform(True)
+        new_image = reader.read()
+        if new_image.isNull():
+            QMessageBox.information(
+                self,
+                QGuiApplication.applicationDisplayName(),
+                f"Cannot load {QDir.toNativeSeparators(file_name)}: {reader.errorString()}",
+            )
+            return False
+
+        self.set_image(new_image)
+
+        self.setWindowFilePath(file_name)
+
+        message = (
+            f"Opened '{QDir.toNativeSeparators(file_name)}', "
+            f"{self.image.width()}x{self.image.height()}, Depth: {self.image.depth()}"
+        )
+        self.statusBar().showMessage(message)
+        return True
+
+    def set_image(self, new_image: QImage) -> None:
+        """
+        将图像设置到滚动区域中，并展示 \n
+        :param new_image: QImage图像
+        :return: None
+        """
+
+        self.image = new_image
+        if self.image.colorSpace().isValid():
+            self.image.convertToColorSpace(QColorSpace.SRgb)
+        self.image_label.setPixmap(QPixmap.fromImage(self.image))
+
+        self.scale_factor = 1.0
+
+        self.scroll_area.setVisible(True)
+        self.print_act.setEnabled(True)
+        self.fit_to_window_act.setEnabled(True)
+        self.update_actions()
+
+        if not self.fit_to_window_act.isChecked():
+            self.image_label.adjustSize()
+
+    def save_file(self, file_name: str) -> bool:
+        writer = QImageWriter(file_name)
+
+        if not writer.write(self.image):
+            QMessageBox.information(
+                self,
+                QGuiApplication.applicationDisplayName(),
+                f"Cannot write {QDir.toNativeSeparators(file_name)}: {writer.errorString()}",
+            )
+            return False
+        message = f"Wrote '{QDir.toNativeSeparators(file_name)}'"
+        self.statusBar().showMessage(message)
+        return True
+
+    def initialize_image_file_dialog(
+        self, dialog: QFileDialog, accept_mode: QFileDialog.AcceptMode
+    ) -> None:
+        """
+        配置文件对话框为只接受图像模式 \n
+        :param dialog: 待配置的对话框
+        :param accept_mode: 接受模式
+        :return: None
+        """
+
+        first_dialog = True
+
+        if first_dialog:
+            first_dialog = False
+            pictures_locations = QStandardPaths.standardLocations(QStandardPaths.PicturesLocation)
+            if not pictures_locations:
+                dialog_dir = QDir.currentPath()
+            else:
+                dialog_dir = pictures_locations[-1]
+            dialog.setDirectory(dialog_dir)
+
+        mime_type_filters: List[str] = []
+        if accept_mode == QFileDialog.AcceptOpen:
+            supported_mime_types = QImageReader.supportedMimeTypes()
+        else:
+            supported_mime_types = QImageWriter.supportedMimeTypes()
+
+        for mime_type_name in supported_mime_types:
+            mime_type_filters.append(str(mime_type_name))
+        mime_type_filters.sort()
+
+        dialog.setMimeTypeFilters(mime_type_filters)
+        dialog.selectMimeTypeFilter("image/jpeg")
+        dialog.setAcceptMode(accept_mode)
+        if accept_mode == QFileDialog.AcceptSave:
+            dialog.setDefaultSuffix("jpg")
+
+    def open(self) -> None:
+        dialog = QFileDialog(self, "Open File")
+        self.initialize_image_file_dialog(dialog, QFileDialog.AcceptOpen)
+        while dialog.exec() == QDialog.Accepted and not self.load_file(dialog.selectedFiles()[0]):
+            ...
+
+    def save_as(self) -> None:
+        dialog = QFileDialog(self, "Save File As")
+        self.initialize_image_file_dialog(dialog, QFileDialog.AcceptSave)
+
+        while dialog.exec() == QDialog.Accepted and not self.save_file(dialog.selectedFiles()[0]):
+            ...
+
+    def print(self) -> None:
+        pass
+
+    def copy(self) -> None:
+        QGuiApplication.clipboard().setImage(self.image)
+
+    def paste(self) -> None:
+        new_image = clipboard_image()
+
+    def zoom_in(self) -> None:
+        self.scale_image(1.25)
+
+    def zoom_out(self) -> None:
+        self.scale_image(0.8)
+
+    def normal_size(self) -> None:
+        self.image_label.adjustSize()
+        self.scale_factor = 1.0
+
+    def fit_to_window(self) -> None:
+        fit_to_window_: bool = self.fit_to_window_act.isChecked()
+        self.scroll_area.setWidgetResizable(fit_to_window_)
+        if not fit_to_window_:
+            self.normal_size()
+        self.update_actions()
+
+    def about(self) -> None:
+        """
+        展示本应用程序的关于信息 \n
+        :return: None
+        """
+
+        QMessageBox.about(
+            self,
+            "About Image Viewer",
+            "<p>The <b>Image Viewer</b> example shows how to combine QLabel "
+            "and QScrollArea to display an image. QLabel is typically used "
+            "for displaying a text, but it can also display an image. "
+            "QScrollArea provides a scrolling view around another widget. "
+            "If the child widget exceeds the size of the frame, QScrollArea "
+            "automatically provides scroll bars. </p><p>The example "
+            "demonstrates how QLabel's ability to scale its contents "
+            "(QLabel::scaledContents), and QScrollArea's ability to "
+            "automatically resize its contents "
+            "(QScrollArea::widgetResizable), can be used to implement "
+            "zooming and scaling features. </p><p>In addition the example "
+            "shows how to use QPainter to print an image.</p>",
+        )
+
+    def create_actions(self) -> None:
+        """
+        创建菜单并添加actions \n
+        :return: None
+        """
+
+        file_menu: QMenu = self.menuBar().addMenu("&File")
+
+        open_act = file_menu.addAction("&Open...", self.open)
+        open_act.setShortcut(QKeySequence.Open)
+
+        # TODO 解决无法通过Mypy的问题
+        save_as_act = file_menu.addAction("&Save As...", self.save_as)
+        save_as_act.setEnabled(False)
+
+        print_act = file_menu.addAction("&Print...", self.print)
+        print_act.setShortcut(QKeySequence.Print)
+        print_act.setEnabled(False)
+
+        file_menu.addSeparator()
+
+        exit_act = file_menu.addAction("E&xit", self.close)
+        exit_act.setShortcut("Ctrl+Q")
+
+        edit_menu = self.menuBar().addMenu("&Edit")
+
+        self.copy_act = edit_menu.addAction("&Copy", self.copy)
+        self.copy_act.setShortcut(QKeySequence.Copy)
+        self.copy_act.setEnabled(False)
+
+        paste_act: QAction = edit_menu.addAction("&Paste", self.paste)
+        paste_act.setShortcut(QKeySequence.Paste)
+
+        view_menu = self.menuBar().addMenu("&View")
+
+        self.zoom_in_act = view_menu.addAction("Zoom &In (25%)", self.zoom_in)
+        self.zoom_in_act.setShortcut(QKeySequence.ZoomIn)
+        self.zoom_in_act.setEnabled(False)
+
+        self.zoom_out_act = view_menu.addAction("Zoom &Out (25%)", self.zoom_out)
+        self.zoom_out_act.setShortcut(QKeySequence.ZoomOut)
+        self.zoom_out_act.setEnabled(False)
+
+        self.normal_size_act = view_menu.addAction("&Normal Size", self.normal_size)
+        self.normal_size_act.setShortcut("Ctrl+S")
+        self.normal_size_act.setEnabled(False)
+
+        view_menu.addSeparator()
+
+        self.fit_to_window_act = view_menu.addAction("&Fit to Window", self.fit_to_window)
+        self.fit_to_window_act.setEnabled(True)
+        self.fit_to_window_act.setCheckable(True)
+        self.fit_to_window_act.setShortcut("Ctrl+F")
+
+        help_menu = self.menuBar().addMenu("&Help")
+
+        help_menu.addAction("&About", self.about)
+        help_menu.addAction("About &Qt", QApplication.aboutQt)
+
+    def update_actions(self) -> None:
+        """
+        更新actions可用状态 \n
+        :return: None
+        """
+
+        self.save_as_act.setEnabled(self.image.isNull())
+        self.copy_act.setEnabled(self.image.isNull())
+        self.zoom_in_act.setEnabled(not self.fit_to_window_act.isChecked())
+        self.zoom_out_act.setEnabled(not self.fit_to_window_act.isChecked())
+        self.normal_size_act.setEnabled(not self.fit_to_window_act.isChecked())
+
+    def scale_image(self, factor: float) -> None:
+        """
+        缩放图像并调整相关控件 \n
+        :param factor: 缩放比例系数
+        :return: None
+        """
+
+        self.scale_factor *= factor
+        self.image_label.resize(self.scale_factor * self.image_label.pixmap().size())
+        self.adjust_scroll_bar(self.scroll_area.horizontalScrollBar(), factor)
+        self.adjust_scroll_bar(self.scroll_area.verticalScrollBar(), factor)
+
+        self.zoom_in_act.setEnabled(self.scale_factor < 3.0)
+        self.zoom_out_act.setEnabled(self.scale_factor > 0.333)
+
+    def adjust_scroll_bar(self, scroll_bar: QScrollBar, factor: float):
+        """
+        调整滚动条位置 \n
+        :param scroll_bar: 滚动条实例
+        :param factor: 缩放因数
+        :return: None
+        """
+
+        scroll_bar.setValue(
+            int(factor * scroll_bar.value() + ((factor - 1) * scroll_bar.pageStep() / 2))
+        )
+
+
+if __name__ == "__main__":
+    app = QApplication(sys.argv)
+    window = ImageViewer()
+    window.show()
+    sys.exit(app.exec())