kde-workspace/ksmserver/fadeeffect.h

97 lines
2.8 KiB
C++

/*
* Copyright © 2008 Fredrik Höglund <fredrik@kde.org>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef FADEEFFECT_H
#define FADEEFFECT_H
#include <QObject>
#include <QtCore/qdatetime.h>
#include "logouteffect.h"
#include <X11/Xlib.h>
class QWidget;
class QPixmap;
class BlendingThread;
/**
* This class implements an effect that will slowly fade the screen from color to grayscale.
*
* This class is X11 specific, and currently only works on little-endian systems where
* the root window has a 24/32 or 16 bit r5g6b5 pixel format.
*/
class FadeEffect : public LogoutEffect
{
Q_OBJECT
public:
/**
* Creates the FadeEffect.
*
* This effect will grab a screenshot and then slowly fade it to gray,
* rendering each frame on the pixmap you pass to the constructor.
* The animation will begin when you call start(), and each time the
* pixmap is updated, update() will be called in the @p parent widget,
* which must then paint the pixmap.
*
* The actual blending is done in a separate thread to keep the event
* loop alive.
*
* The FadeEffect can safely be deleted at any time, even while the
* effect is running, but it's important that the pixmap isn't deleted
* before the effect object.
*
* @param parent The parent widget, which will draw the pixmap.
* @param pixmap The pixmap the effect will be rendered to.
*/
FadeEffect(QWidget *parent, QPixmap *pixmap);
/**
* Destroys the fade effect.
*/
~FadeEffect();
/**
* Starts the animation.
*/
void start();
private slots:
/** @internal */
void grabImageSection();
/** @internal */
void nextFrame();
private:
BlendingThread *blender;
int alpha;
int currentY;
bool done;
XImage *image;
GC gc;
QTime time;
};
#endif