examples/widgets/scribble/mainwindow.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/widgets/scribble/mainwindow.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,251 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtGui>
+
+#include "mainwindow.h"
+#include "scribblearea.h"
+
+//! [0]
+MainWindow::MainWindow()
+{
+    scribbleArea = new ScribbleArea;
+    setCentralWidget(scribbleArea);
+
+    createActions();
+    createMenus();
+
+    setWindowTitle(tr("Scribble"));
+    resize(500, 500);
+}
+//! [0]
+
+//! [1]
+void MainWindow::closeEvent(QCloseEvent *event)
+//! [1] //! [2]
+{
+    if (maybeSave()) {
+        event->accept();
+    } else {
+        event->ignore();
+    }
+}
+//! [2]
+
+//! [3]
+void MainWindow::open()
+//! [3] //! [4]
+{
+    if (maybeSave()) {
+        QString fileName = QFileDialog::getOpenFileName(this,
+                                   tr("Open File"), QDir::currentPath());
+        if (!fileName.isEmpty())
+            scribbleArea->openImage(fileName);
+    }
+}
+//! [4]
+
+//! [5]
+void MainWindow::save()
+//! [5] //! [6]
+{
+    QAction *action = qobject_cast<QAction *>(sender());
+    QByteArray fileFormat = action->data().toByteArray();
+    saveFile(fileFormat);
+}
+//! [6]
+
+//! [7]
+void MainWindow::penColor()
+//! [7] //! [8]
+{
+    QColor newColor = QColorDialog::getColor(scribbleArea->penColor());
+    if (newColor.isValid())
+        scribbleArea->setPenColor(newColor);
+}
+//! [8]
+
+//! [9]
+void MainWindow::penWidth()
+//! [9] //! [10]
+{
+    bool ok;
+    int newWidth = QInputDialog::getInteger(this, tr("Scribble"),
+                                            tr("Select pen width:"),
+                                            scribbleArea->penWidth(),
+                                            1, 50, 1, &ok);
+    if (ok)
+        scribbleArea->setPenWidth(newWidth);
+}
+//! [10]
+
+//! [11]
+void MainWindow::about()
+//! [11] //! [12]
+{
+    QMessageBox::about(this, tr("About Scribble"),
+            tr("<p>The <b>Scribble</b> example shows how to use QMainWindow as the "
+               "base widget for an application, and how to reimplement some of "
+               "QWidget's event handlers to receive the events generated for "
+               "the application's widgets:</p><p> We reimplement the mouse event "
+               "handlers to facilitate drawing, the paint event handler to "
+               "update the application and the resize event handler to optimize "
+               "the application's appearance. In addition we reimplement the "
+               "close event handler to intercept the close events before "
+               "terminating the application.</p><p> The example also demonstrates "
+               "how to use QPainter to draw an image in real time, as well as "
+               "to repaint widgets.</p>"));
+}
+//! [12]
+
+//! [13]
+void MainWindow::createActions()
+//! [13] //! [14]
+{
+    openAct = new QAction(tr("&Open..."), this);
+    openAct->setShortcuts(QKeySequence::Open);
+    connect(openAct, SIGNAL(triggered()), this, SLOT(open()));
+
+    foreach (QByteArray format, QImageWriter::supportedImageFormats()) {
+        QString text = tr("%1...").arg(QString(format).toUpper());
+
+        QAction *action = new QAction(text, this);
+        action->setData(format);
+        connect(action, SIGNAL(triggered()), this, SLOT(save()));
+        saveAsActs.append(action);
+    }
+
+    printAct = new QAction(tr("&Print..."), this);
+    connect(printAct, SIGNAL(triggered()), scribbleArea, SLOT(print()));
+
+    exitAct = new QAction(tr("E&xit"), this);
+    exitAct->setShortcuts(QKeySequence::Quit);
+    connect(exitAct, SIGNAL(triggered()), this, SLOT(close()));
+
+    penColorAct = new QAction(tr("&Pen Color..."), this);
+    connect(penColorAct, SIGNAL(triggered()), this, SLOT(penColor()));
+
+    penWidthAct = new QAction(tr("Pen &Width..."), this);
+    connect(penWidthAct, SIGNAL(triggered()), this, SLOT(penWidth()));
+
+    clearScreenAct = new QAction(tr("&Clear Screen"), this);
+    clearScreenAct->setShortcut(tr("Ctrl+L"));
+    connect(clearScreenAct, SIGNAL(triggered()),
+            scribbleArea, SLOT(clearImage()));
+
+    aboutAct = new QAction(tr("&About"), this);
+    connect(aboutAct, SIGNAL(triggered()), this, SLOT(about()));
+
+    aboutQtAct = new QAction(tr("About &Qt"), this);
+    connect(aboutQtAct, SIGNAL(triggered()), qApp, SLOT(aboutQt()));
+}
+//! [14]
+
+//! [15]
+void MainWindow::createMenus()
+//! [15] //! [16]
+{
+    saveAsMenu = new QMenu(tr("&Save As"), this);
+    foreach (QAction *action, saveAsActs)
+        saveAsMenu->addAction(action);
+
+    fileMenu = new QMenu(tr("&File"), this);
+    fileMenu->addAction(openAct);
+    fileMenu->addMenu(saveAsMenu);
+    fileMenu->addAction(printAct);
+    fileMenu->addSeparator();
+    fileMenu->addAction(exitAct);
+
+    optionMenu = new QMenu(tr("&Options"), this);
+    optionMenu->addAction(penColorAct);
+    optionMenu->addAction(penWidthAct);
+    optionMenu->addSeparator();
+    optionMenu->addAction(clearScreenAct);
+
+    helpMenu = new QMenu(tr("&Help"), this);
+    helpMenu->addAction(aboutAct);
+    helpMenu->addAction(aboutQtAct);
+
+    menuBar()->addMenu(fileMenu);
+    menuBar()->addMenu(optionMenu);
+    menuBar()->addMenu(helpMenu);
+}
+//! [16]
+
+//! [17]
+bool MainWindow::maybeSave()
+//! [17] //! [18]
+{
+    if (scribbleArea->isModified()) {
+       QMessageBox::StandardButton ret;
+       ret = QMessageBox::warning(this, tr("Scribble"),
+                          tr("The image has been modified.\n"
+                             "Do you want to save your changes?"),
+                          QMessageBox::Save | QMessageBox::Discard
+			  | QMessageBox::Cancel);
+        if (ret == QMessageBox::Save) {
+            return saveFile("png");
+        } else if (ret == QMessageBox::Cancel) {
+            return false;
+        }
+    }
+    return true;
+}
+//! [18]
+
+//! [19]
+bool MainWindow::saveFile(const QByteArray &fileFormat)
+//! [19] //! [20]
+{
+    QString initialPath = QDir::currentPath() + "/untitled." + fileFormat;
+
+    QString fileName = QFileDialog::getSaveFileName(this, tr("Save As"),
+                               initialPath,
+                               tr("%1 Files (*.%2);;All Files (*)")
+                               .arg(QString(fileFormat.toUpper()))
+                               .arg(QString(fileFormat)));
+    if (fileName.isEmpty()) {
+        return false;
+    } else {
+        return scribbleArea->saveImage(fileName, fileFormat);
+    }
+}
+//! [20]