Home | History | Annotate | Download | only in qt 
      1 /*
      2  * Copyright (C) 2006 Dirk Mueller <mueller (at) kde.org>
      3  * Copyright (C) 2006 Zack Rusin <zack (at) kde.org>
      4  * Copyright (C) 2006 George Staikos <staikos (at) kde.org>
      5  * Copyright (C) 2006 Simon Hausmann <hausmann (at) kde.org>
      6  * Copyright (C) 2006 Allan Sandfeld Jensen <sandfeld (at) kde.org>
      7  * Copyright (C) 2006 Nikolas Zimmermann <zimmermann (at) kde.org>
      8  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
      9  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies).
     10  * Copyright (C) 2008 Dirk Schulze <vbs85 (at) gmx.de>
     11  *
     12  * All rights reserved.
     13  *
     14  * Redistribution and use in source and binary forms, with or without
     15  * modification, are permitted provided that the following conditions
     16  * are met:
     17  * 1. Redistributions of source code must retain the above copyright
     18  *    notice, this list of conditions and the following disclaimer.
     19  * 2. Redistributions in binary form must reproduce the above copyright
     20  *    notice, this list of conditions and the following disclaimer in the
     21  *    documentation and/or other materials provided with the distribution.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     24  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     26  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     27  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     28  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     29  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     31  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     33  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     34  */
     35 
     36 #ifndef TransparencyLayer_h
     37 #define TransparencyLayer_h
     38 
     39 #include <QPaintEngine>
     40 #include <QPainter>
     41 #include <QPixmap>
     42 
     43 namespace WebCore {
     44 
     45 struct TransparencyLayer {
     46     WTF_MAKE_FAST_ALLOCATED;
     47 public:
     48     TransparencyLayer(const QPainter* p, const QRect &rect, qreal opacity, QPixmap& alphaMask)
     49         : pixmap(rect.width(), rect.height())
     50         , opacity(opacity)
     51         , alphaMask(alphaMask)
     52         , saveCounter(1) // see the comment for saveCounter
     53     {
     54         offset = rect.topLeft();
     55         pixmap.fill(Qt::transparent);
     56         painter.begin(&pixmap);
     57         painter.setRenderHints(p->renderHints());
     58         painter.translate(-offset);
     59         painter.setPen(p->pen());
     60         painter.setBrush(p->brush());
     61         painter.setTransform(p->transform(), true);
     62         painter.setFont(p->font());
     63         painter.setOpacity(1);
     64     }
     65 
     66     TransparencyLayer()
     67     {
     68     }
     69 
     70     QPixmap pixmap;
     71     QPoint offset;
     72     QPainter painter;
     73     qreal opacity;
     74     // for clipToImageBuffer
     75     QPixmap alphaMask;
     76     // saveCounter is only used in combination with alphaMask
     77     // otherwise, its value is unspecified
     78     int saveCounter;
     79 private:
     80     TransparencyLayer(const TransparencyLayer &) {}
     81     TransparencyLayer & operator=(const TransparencyLayer &) { return *this; }
     82 };
     83 
     84 } // namespace WebCore
     85 
     86 #endif // TransparencyLayer_h
     87