plasma-framework/tooltipmanager.h

/***************************************************************************
 *   Copyright 2008 by Alexis Ménard <darktears31@gmail.com>               *
 *   Copyright 2008 by Aaron Seigo <aseigo@kde.org>                        *
 *   Copyright 2007 by Dan Meltzer <hydrogen@notyetimplemented.com>        *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA .        *
 ***************************************************************************/

#ifndef PLASMA_TOOLTIP_MANAGER_H
#define PLASMA_TOOLTIP_MANAGER_H

//plasma
#include <plasma/plasma.h>
#include <plasma/plasma_export.h>

namespace Plasma
{

class ToolTipManagerPrivate;
class Applet;

  /**
  * @short The class to manage tooltips on QGraphicsWidget in Plasma
  *
  * Manage tooltips on QGraphicsWidget. First you have to register your widget by calling
  * registerWidget on the ToolTipManager singleton. After this you have to set the content of
  * the tooltip by calling setToolTipContent using the struct ToolTipContent. Calling
  * setToolTipContent on a widget that is not registered will cause it to be registered.
  *
  * The tooltip manager unregister automatically the widget when it is destroyed but if 
  * you want to do it manually call unregisterWidget. 
  *
  * When a tooltip for a widget is about to be shown, the widget's toolTipAboutToShow slot will be
  * invoked if it exists. Similarly, when a tooltip is hidden, the widget's toolTipHidden() slow
  * will be invoked if it exists. This allows widgets to provide on-demand tooltip data.
  */

class PLASMA_EXPORT ToolTipManager  : public QObject
{
      Q_OBJECT
  public:

     /**
      * Content of a tooltip
      */
      struct PLASMA_EXPORT ToolTipContent
      {
          ToolTipContent();
          bool isEmpty() const;

          QString mainText; /**Important information, e.g. the title*/
          QString subText; /** Elaborates on the Main Text */
          QPixmap image; /** Icon to show */
          WId windowToPreview; /** Id of a window if you want to show a preview */
      };

      /**
        *
        * @return The singleton instance of the manager.
        **/
      static ToolTipManager *self();
      
      /**
        * Default constructor. Usually you want to use the singleton instead.
        */
      explicit ToolTipManager(QObject* parent = 0);

      /**
        * Default destructor.
        */
      ~ToolTipManager();

      /**
      * Function to show a tooltip of a widget registered in the tooltip manager
      * @param widget the widget on which the tooltip will be displayed
      */
      void showToolTip(QGraphicsWidget *widget);

      /**
      * Function to know if a tooltip of a widget is displayed
      * @param widget the desired widget
      * @return true if te tooltip of the widget is currently displayed, otherwhise no
      */
      bool isWidgetToolTipDisplayed(QGraphicsWidget *widget);

      /**
      * Function to launch a delayed hide of the current displayed tooltip
      * @param widget the desired widget
      */
      void delayedHideToolTip();

      /**
      * Function to hide the tooltip of the desired widget
      * @param widget the desired widget
      */
      void hideToolTip(QGraphicsWidget *widget);

      /**
      * Function to register a widget to the tooltip manager, after this a setWidgetToolTipContent
      * must be called
      * @param widget the desired widget
      */
      void registerWidget(QGraphicsWidget *widget);

      /**
      * Function to unregister a widget in the tooltip manager, i.e. means that memory will be free
      * @param widget the desired widget to delete
      */
      void unregisterWidget(QGraphicsWidget *widget);

      /**
       * Function to set the content of a tooltip on a desired widget.
       * 
       * @param widget the desired widget
       * @param data the content of the tooltip. If an empty ToolTipContent is passed in,
       *        the tooltip content will be reset.
       */
      void setToolTipContent(QGraphicsWidget *widget, const ToolTipContent &data);

      /**
      * Function to know if widget has a tooltip registered in the tooltip manager
      * @param widget the widget
      * @return true if this widget has a tooltip
      */
      bool widgetHasToolTip(QGraphicsWidget *widget) const;

  private:
      friend class ToolTipManagerSingleton;
      bool eventFilter(QObject * watched, QEvent * event);

      ToolTipManagerPrivate* const d;
      Q_PRIVATE_SLOT(d, void showToolTip())
      Q_PRIVATE_SLOT(d, void resetShownState())
      Q_PRIVATE_SLOT(d, void onWidgetDestroyed(QObject*))
      Q_PRIVATE_SLOT(d, void themeUpdated())
  };
}
#endif