#!/usr/bin/env python ############################################################################# ## ## Copyright (C) 2010 Riverbank Computing Limited. ## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). ## All rights reserved. ## ## This file is part of the examples of PyQt. ## ## $QT_BEGIN_LICENSE:BSD$ ## You may use this file under the terms of the BSD license as follows: ## ## "Redistribution and use in source and binary forms, with or without ## modification, are permitted provided that the following conditions are ## met: ## * Redistributions of source code must retain the above copyright ## notice, this list of conditions and the following disclaimer. ## * Redistributions in binary form must reproduce the above copyright ## notice, this list of conditions and the following disclaimer in ## the documentation and/or other materials provided with the ## distribution. ## * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor ## the names of its contributors may be used to endorse or promote ## products derived from this software without specific prior written ## permission. ## ## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ## $QT_END_LICENSE$ ## ############################################################################# from PyQt4 import QtCore, QtGui class ImageViewer(QtGui.QMainWindow): def __init__(self): super(ImageViewer, self).__init__() self.printer = QtGui.QPrinter() self.scaleFactor = 0.0 self.imageLabel = QtGui.QLabel() self.imageLabel.setBackgroundRole(QtGui.QPalette.Base) self.imageLabel.setSizePolicy(QtGui.QSizePolicy.Ignored, QtGui.QSizePolicy.Ignored) self.imageLabel.setScaledContents(True) self.scrollArea = QtGui.QScrollArea() self.scrollArea.setBackgroundRole(QtGui.QPalette.Dark) self.scrollArea.setWidget(self.imageLabel) self.setCentralWidget(self.scrollArea) self.createActions() self.createMenus() self.setWindowTitle("Image Viewer") self.resize(500, 400) def open(self): fileName = QtGui.QFileDialog.getOpenFileName(self, "Open File", QtCore.QDir.currentPath()) if fileName: image = QtGui.QImage(fileName) if image.isNull(): QtGui.QMessageBox.information(self, "Image Viewer", "Cannot load %s." % fileName) return self.imageLabel.setPixmap(QtGui.QPixmap.fromImage(image)) self.scaleFactor = 1.0 self.printAct.setEnabled(True) self.fitToWindowAct.setEnabled(True) self.updateActions() if not self.fitToWindowAct.isChecked(): self.imageLabel.adjustSize() def print_(self): dialog = QtGui.QPrintDialog(self.printer, self) if dialog.exec_(): painter = QtGui.QPainter(self.printer) rect = painter.viewport() size = self.imageLabel.pixmap().size() size.scale(rect.size(), QtCore.Qt.KeepAspectRatio) painter.setViewport(rect.x(), rect.y(), size.width(), size.height()) painter.setWindow(self.imageLabel.pixmap().rect()) painter.drawPixmap(0, 0, self.imageLabel.pixmap()) def zoomIn(self): self.scaleImage(1.25) def zoomOut(self): self.scaleImage(0.8) def normalSize(self): self.imageLabel.adjustSize() self.scaleFactor = 1.0 def fitToWindow(self): fitToWindow = self.fitToWindowAct.isChecked() self.scrollArea.setWidgetResizable(fitToWindow) if not fitToWindow: self.normalSize() self.updateActions() def about(self): QtGui.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 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 createActions(self): self.openAct = QtGui.QAction("&Open...", self, shortcut="Ctrl+O", triggered=self.open) self.printAct = QtGui.QAction("&Print...", self, shortcut="Ctrl+P", enabled=False, triggered=self.print_) self.exitAct = QtGui.QAction("E&xit", self, shortcut="Ctrl+Q", triggered=self.close) self.zoomInAct = QtGui.QAction("Zoom &In (25%)", self, shortcut="Ctrl++", enabled=False, triggered=self.zoomIn) self.zoomOutAct = QtGui.QAction("Zoom &Out (25%)", self, shortcut="Ctrl+-", enabled=False, triggered=self.zoomOut) self.normalSizeAct = QtGui.QAction("&Normal Size", self, shortcut="Ctrl+S", enabled=False, triggered=self.normalSize) self.fitToWindowAct = QtGui.QAction("&Fit to Window", self, enabled=False, checkable=True, shortcut="Ctrl+F", triggered=self.fitToWindow) self.aboutAct = QtGui.QAction("&About", self, triggered=self.about) self.aboutQtAct = QtGui.QAction("About &Qt", self, triggered=QtGui.qApp.aboutQt) def createMenus(self): self.fileMenu = QtGui.QMenu("&File", self) self.fileMenu.addAction(self.openAct) self.fileMenu.addAction(self.printAct) self.fileMenu.addSeparator() self.fileMenu.addAction(self.exitAct) self.viewMenu = QtGui.QMenu("&View", self) self.viewMenu.addAction(self.zoomInAct) self.viewMenu.addAction(self.zoomOutAct) self.viewMenu.addAction(self.normalSizeAct) self.viewMenu.addSeparator() self.viewMenu.addAction(self.fitToWindowAct) self.helpMenu = QtGui.QMenu("&Help", self) self.helpMenu.addAction(self.aboutAct) self.helpMenu.addAction(self.aboutQtAct) self.menuBar().addMenu(self.fileMenu) self.menuBar().addMenu(self.viewMenu) self.menuBar().addMenu(self.helpMenu) def updateActions(self): self.zoomInAct.setEnabled(not self.fitToWindowAct.isChecked()) self.zoomOutAct.setEnabled(not self.fitToWindowAct.isChecked()) self.normalSizeAct.setEnabled(not self.fitToWindowAct.isChecked()) def scaleImage(self, factor): self.scaleFactor *= factor self.imageLabel.resize(self.scaleFactor * self.imageLabel.pixmap().size()) self.adjustScrollBar(self.scrollArea.horizontalScrollBar(), factor) self.adjustScrollBar(self.scrollArea.verticalScrollBar(), factor) self.zoomInAct.setEnabled(self.scaleFactor < 3.0) self.zoomOutAct.setEnabled(self.scaleFactor > 0.333) def adjustScrollBar(self, scrollBar, factor): scrollBar.setValue(int(factor * scrollBar.value() + ((factor - 1) * scrollBar.pageStep()/2))) if __name__ == '__main__': import sys app = QtGui.QApplication(sys.argv) imageViewer = ImageViewer() imageViewer.show() sys.exit(app.exec_())