mainwindow.cpp Example File

mimetypes/mimetypebrowser/mainwindow.cpp
/****************************************************************************
**
** 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());
}

© 2017 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.