Add mime type browser example.

Add an example showing the types in QMimeDatabase in
a QTreeView with detailed information on click.
The example has menu options to detect a file type
and search by name.

Change-Id: If6f1a6661edd100a54460a49562a8a8667245ddb
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 185 insertions, 0 deletions

diff --git a/examples/corelib/mimetypes/mimetypebrowser/mainwindow.cpp b/examples/corelib/mimetypes/mimetypebrowser/mainwindow.cpp
new file mode 100644
index 0000000000..edd48021f3
--- /dev/null
+++ b/examples/corelib/mimetypes/mimetypebrowser/mainwindow.cpp
@@ -0,0 +1,185 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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 The Qt Company Ltd 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "mainwindow.h"
+#include "mimetypemodel.h"
+
+#include <QAction>
+#include <QApplication>
+#include <QFileDialog>
+#include <QInputDialog>
+#include <QMenu>
+#include <QMenuBar>
+#include <QMessageBox>
+#include <QPlainTextEdit>
+#include <QSplitter>
+#include <QStatusBar>
+#include <QTextEdit>
+#include <QTreeView>
+
+#include <QFileInfo>
+#include <QItemSelectionModel>
+#include <QMimeDatabase>
+#include <QMimeType>
+
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow(parent)
+    , m_model(new MimetypeModel(this))
+    , m_treeView(new QTreeView)
+    , m_detailsText(new QTextEdit)
+    , m_findIndex(0)
+{
+    setWindowTitle(tr("Qt Mime Database Browser"));
+
+    QMenu *fileMenu = menuBar()->addMenu(tr("&File"));
+    QAction *detectFileAction =
+        fileMenu->addAction(tr("&Detect File Type..."), this, &MainWindow::detectFile);
+    detectFileAction->setShortcuts(QKeySequence::Open);
+
+    QAction *exitAction = fileMenu->addAction(tr("E&xit"), qApp, &QApplication::closeAllWindows);
+    exitAction->setShortcuts(QKeySequence::Quit);
+
+    QMenu *findMenu = menuBar()->addMenu(tr("&Edit"));
+    QAction *findAction =
+        findMenu->addAction(tr("&Find..."), this, &MainWindow::find);
+    findAction->setShortcuts(QKeySequence::Find);
+    m_findNextAction = findMenu->addAction(tr("Find &Next"), this, &MainWindow::findNext);
+    m_findNextAction->setShortcuts(QKeySequence::FindNext);
+    m_findPreviousAction = findMenu->addAction(tr("Find &Previous"), this, &MainWindow::findPrevious);
+    m_findPreviousAction->setShortcuts(QKeySequence::FindPrevious);
+
+    menuBar()->addMenu(tr("&About"))->addAction(tr("&About Qt"), qApp, &QApplication::aboutQt);
+
+    QSplitter *centralSplitter = new QSplitter;
+    setCentralWidget(centralSplitter);
+    m_treeView = new QTreeView;
+    m_treeView->setUniformRowHeights(true);
+    m_treeView->setModel(m_model);
+
+    const auto items = m_model->findItems("application/octet-stream", Qt::MatchContains | Qt::MatchFixedString | Qt::MatchRecursive);
+    if (!items.isEmpty())
+        m_treeView->expand(m_model->indexFromItem(items.constFirst()));
+
+    connect(m_treeView->selectionModel(), &QItemSelectionModel::currentChanged,
+            this, &MainWindow::currentChanged);
+    centralSplitter->addWidget(m_treeView);
+    m_detailsText->setReadOnly(true);
+    centralSplitter->addWidget(m_detailsText);
+
+    updateFindActions();
+}
+
+void MainWindow::currentChanged(const QModelIndex &index)
+{
+    if (index.isValid())
+        m_detailsText->setText(MimetypeModel::formatMimeTypeInfo(m_model->mimeType(index)));
+    else
+        m_detailsText->clear();
+}
+
+void MainWindow::selectAndGoTo(const QModelIndex &index)
+{
+    m_treeView->scrollTo(index, QAbstractItemView::PositionAtCenter);
+    m_treeView->setCurrentIndex(index);
+}
+
+void MainWindow::detectFile()
+{
+    const QString fileName = QFileDialog::getOpenFileName(this, tr("Choose File"));
+    if (fileName.isEmpty())
+        return;
+    QMimeDatabase mimeDatabase;
+    const QFileInfo fi(fileName);
+    const QMimeType mimeType = mimeDatabase.mimeTypeForFile(fi);
+    const QModelIndex index = mimeType.isValid()
+        ? m_model->indexForMimeType(mimeType.name()) : QModelIndex();
+    if (index.isValid()) {
+        statusBar()->showMessage(tr("\"%1\" is of type \"%2\"").arg(fi.fileName(), mimeType.name()));
+        selectAndGoTo(index);
+    } else {
+        QMessageBox::information(this, tr("Unknown File Type"),
+                                 tr("The type of %1 could not be determined.")
+                                 .arg(QDir::toNativeSeparators(fileName)));
+    }
+}
+
+void MainWindow::updateFindActions()
+{
+    const bool findNextPreviousEnabled = m_findMatches.size() > 1;
+    m_findNextAction->setEnabled(findNextPreviousEnabled);
+    m_findPreviousAction->setEnabled(findNextPreviousEnabled);
+}
+
+void MainWindow::findPrevious()
+{
+    if (--m_findIndex < 0)
+        m_findIndex = m_findMatches.size() - 1;
+    if (m_findIndex >= 0)
+        selectAndGoTo(m_findMatches.at(m_findIndex));
+}
+
+void MainWindow::findNext()
+{
+    if (++m_findIndex >= m_findMatches.size())
+        m_findIndex = 0;
+    if (m_findIndex < m_findMatches.size())
+        selectAndGoTo(m_findMatches.at(m_findIndex));
+}
+
+void MainWindow::find()
+{
+    QInputDialog inputDialog(this);
+    inputDialog.setWindowTitle(tr("Find"));
+    inputDialog.setLabelText(tr("Text:"));
+    if (inputDialog.exec() != QDialog::Accepted)
+        return;
+    const QString value = inputDialog.textValue().trimmed();
+    if (value.isEmpty())
+        return;
+
+    m_findMatches.clear();
+    m_findIndex = 0;
+    foreach (const QStandardItem *item, m_model->findItems(value, Qt::MatchContains | Qt::MatchFixedString | Qt::MatchRecursive))
+        m_findMatches.append(m_model->indexFromItem(item));
+    statusBar()->showMessage(tr("%n mime types match \"%1\".", 0, m_findMatches.size()).arg(value));
+    updateFindActions();
+    if (!m_findMatches.isEmpty())
+        selectAndGoTo(m_findMatches.constFirst());
+}