mainwindow.cpp Example File

  /****************************************************************************
  **
  ** Copyright (C) 2017 The Qt Company Ltd.
  ** Contact: http://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, 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(this))
      , m_detailsText(new QTextEdit(this))
      , 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(this);
      setCentralWidget(centralSplitter);
      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());
  }