history.h Example File

  /****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the demonstration applications 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."
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/

  #ifndef HISTORY_H
  #define HISTORY_H

  #include "modelmenu.h"

  #include <QtCore/QDateTime>
  #include <QtCore/QHash>
  #include <QtCore/QObject>
  #include <QtCore/QTimer>
  #include <QtCore/QUrl>

  #include <QtCore/QSortFilterProxyModel>

  class HistoryItem
  {
  public:
      HistoryItem() {}
      HistoryItem(const QString &u,
                  const QDateTime &d = QDateTime(), const QString &t = QString())
          : title(t), url(u), dateTime(d) {}

      inline bool operator==(const HistoryItem &other) const
          { return other.title == title
            && other.url == url && other.dateTime == dateTime; }

      // history is sorted in reverse
      inline bool operator <(const HistoryItem &other) const
          { return dateTime > other.dateTime; }

      QString title;
      QString url;
      QDateTime dateTime;
  };

  class AutoSaver;
  class HistoryModel;
  class HistoryFilterModel;
  class HistoryTreeModel;

  class HistoryManager : public QObject
  {
      Q_OBJECT
      Q_PROPERTY(int historyLimit READ historyLimit WRITE setHistoryLimit)

  signals:
      void historyReset();
      void entryAdded(const HistoryItem &item);
      void entryRemoved(const HistoryItem &item);
      void entryUpdated(int offset);

  public:
      HistoryManager(QObject *parent = 0);
      ~HistoryManager();

      bool historyContains(const QString &url) const;

      void addHistoryEntry(const QString &url);
      void removeHistoryEntry(const QString &url);

      void updateHistoryItem(const QUrl &url, const QString &title);

      int historyLimit() const;
      void setHistoryLimit(int limit);

      QList<HistoryItem>& history();
      void setHistory(const QList<HistoryItem> &history, bool loadedAndSorted = false);

      // History manager keeps around these models for use by the completer and other classes
      HistoryModel *historyModel() const;
      HistoryFilterModel *historyFilterModel() const;
      HistoryTreeModel *historyTreeModel() const;

  public slots:
      void clear();
      void loadSettings();

  private slots:
      void save();
      void checkForExpired(bool removeExpiredEntriesDirectly = false);

  protected:
      void addHistoryItem(const HistoryItem &item);
      void removeHistoryItem(const HistoryItem &item);

  private:
      void load();

      AutoSaver *m_saveTimer;
      int m_historyLimit;
      QTimer m_expiredTimer;
      QList<HistoryItem> m_history;
      QString m_lastSavedUrl;

      HistoryModel *m_historyModel;
      HistoryFilterModel *m_historyFilterModel;
      HistoryTreeModel *m_historyTreeModel;
  };

  class HistoryModel : public QAbstractTableModel
  {
      Q_OBJECT

  public slots:
      void historyReset();
      void entryAdded(const HistoryItem &item);
      void entryRemoved(const HistoryItem &item);
      void entryUpdated(int offset);

  public:
      enum Roles {
          DateRole = Qt::UserRole + 1,
          DateTimeRole = Qt::UserRole + 2,
          UrlRole = Qt::UserRole + 3,
          UrlStringRole = Qt::UserRole + 4
      };

      HistoryModel(HistoryManager *history, QObject *parent = 0);
      QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const;
      QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;
      int columnCount(const QModelIndex &parent = QModelIndex()) const;
      int rowCount(const QModelIndex &parent = QModelIndex()) const;
      bool removeRows(int row, int count, const QModelIndex &parent = QModelIndex());

  private:
      HistoryManager *m_history;
  };

  /*!
      Proxy model that will remove any duplicate entries.
      Both m_sourceRow and m_historyHash store their offsets not from
      the front of the list, but as offsets from the back.
    */
  class HistoryFilterModel : public QAbstractProxyModel
  {
      Q_OBJECT

  public:
      HistoryFilterModel(QAbstractItemModel *sourceModel, QObject *parent = 0);

      inline bool historyContains(const QString &url) const
          { load(); return m_historyHash.contains(url); }

      QModelIndex mapFromSource(const QModelIndex &sourceIndex) const;
      QModelIndex mapToSource(const QModelIndex &proxyIndex) const;
      void setSourceModel(QAbstractItemModel *sourceModel);
      QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const;
      int rowCount(const QModelIndex &parent = QModelIndex()) const;
      int columnCount(const QModelIndex &parent = QModelIndex()) const;
      QModelIndex index(int, int, const QModelIndex& = QModelIndex()) const;
      QModelIndex parent(const QModelIndex& index= QModelIndex()) const;
      bool removeRows(int row, int count, const QModelIndex &parent = QModelIndex());

  private slots:
      void sourceReset();
      void sourceDataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight);
      void sourceRowsInserted(const QModelIndex &parent, int start, int end);
      void sourceRowsRemoved(const QModelIndex &, int, int);

  private:
      void load() const;

      mutable QList<int> m_sourceRow;
      mutable QHash<QString, int> m_historyHash;
      mutable bool m_loaded;
  };

  /*
      The history menu
      - Removes the first twenty entries and puts them as children of the top level.
      - If there are less then twenty entries then the first folder is also removed.

      The mapping is done by knowing that HistoryTreeModel is over a table
      We store that row offset in our index's private data.
  */
  class HistoryMenuModel : public QAbstractProxyModel
  {
      Q_OBJECT

  public:
      HistoryMenuModel(HistoryTreeModel *sourceModel, QObject *parent = 0);
      int columnCount(const QModelIndex &parent) const;
      int rowCount(const QModelIndex &parent = QModelIndex()) const;
      QModelIndex mapFromSource(const QModelIndex & sourceIndex) const;
      QModelIndex mapToSource(const QModelIndex & proxyIndex) const;
      QModelIndex index(int, int, const QModelIndex &parent = QModelIndex()) const;
      QModelIndex parent(const QModelIndex &index = QModelIndex()) const;

      int bumpedRows() const;

  private:
      HistoryTreeModel *m_treeModel;
  };

  // Menu that is dynamically populated from the history
  class HistoryMenu : public ModelMenu
  {
      Q_OBJECT

  signals:
      void openUrl(const QUrl &url);

  public:
       HistoryMenu(QWidget *parent = 0);
       void setInitialActions(QList<QAction*> actions);

  protected:
      bool prePopulated();
      void postPopulated();

  private slots:
      void activated(const QModelIndex &index);
      void showHistoryDialog();

  private:
      HistoryManager *m_history;
      HistoryMenuModel *m_historyMenuModel;
      QList<QAction*> m_initialActions;
  };

  // proxy model for the history model that
  // exposes each url http://www.foo.com and it url starting at the host www.foo.com
  class HistoryCompletionModel : public QAbstractProxyModel
  {
      Q_OBJECT

  public:
      HistoryCompletionModel(QObject *parent = 0);
      QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;
      int rowCount(const QModelIndex &parent = QModelIndex()) const;
      int columnCount(const QModelIndex &parent = QModelIndex()) const;
      QModelIndex mapFromSource(const QModelIndex &sourceIndex) const;
      QModelIndex mapToSource(const QModelIndex &proxyIndex) const;
      QModelIndex index(int, int, const QModelIndex& = QModelIndex()) const;
      QModelIndex parent(const QModelIndex& index= QModelIndex()) const;
      void setSourceModel(QAbstractItemModel *sourceModel);

  private slots:
      void sourceReset();

  };

  // proxy model for the history model that converts the list
  // into a tree, one top level node per day.
  // Used in the HistoryDialog.
  class HistoryTreeModel : public QAbstractProxyModel
  {
      Q_OBJECT

  public:
      HistoryTreeModel(QAbstractItemModel *sourceModel, QObject *parent = 0);
      QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;
      int columnCount(const QModelIndex &parent) const;
      int rowCount(const QModelIndex &parent = QModelIndex()) const;
      QModelIndex mapFromSource(const QModelIndex &sourceIndex) const;
      QModelIndex mapToSource(const QModelIndex &proxyIndex) const;
      QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const;
      QModelIndex parent(const QModelIndex &index= QModelIndex()) const;
      bool hasChildren(const QModelIndex &parent = QModelIndex()) const;
      Qt::ItemFlags flags(const QModelIndex &index) const;
      bool removeRows(int row, int count, const QModelIndex &parent = QModelIndex());
      QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const;

      void setSourceModel(QAbstractItemModel *sourceModel);

  private slots:
      void sourceReset();
      void sourceRowsInserted(const QModelIndex &parent, int start, int end);
      void sourceRowsRemoved(const QModelIndex &parent, int start, int end);
      void sourceDataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight,
                             const QVector<int> roles);
  private:
      int sourceDateRow(int row) const;
      mutable QList<int> m_sourceRowCache;

  };

  // A modified QSortFilterProxyModel that always accepts the root nodes in the tree
  // so filtering is only done on the children.
  // Used in the HistoryDialog
  class TreeProxyModel : public QSortFilterProxyModel
  {
      Q_OBJECT

  public:
      TreeProxyModel(QObject *parent = 0);

  protected:
      bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const;
  };

  #include "ui_history.h"

  class HistoryDialog : public QDialog, public Ui_HistoryDialog
  {
      Q_OBJECT

  signals:
      void openUrl(const QUrl &url);

  public:
      HistoryDialog(QWidget *parent = 0, HistoryManager *history = 0);

  private slots:
      void customContextMenuRequested(const QPoint &pos);
      void open();
      void copy();

  };

  #endif // HISTORY_H