1 files changed, 159 insertions, 0 deletions
diff --git a/WebCore/platform/graphics/qt/ContextShadowQt.cpp b/WebCore/platform/graphics/qt/ContextShadowQt.cpp
new file mode 100644
index 0000000..342e027
--- /dev/null
+++ b/WebCore/platform/graphics/qt/ContextShadowQt.cpp
@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2010 Sencha, Inc.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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.
+ */
+
+#include "config.h"
+#include "ContextShadow.h"
+
+#include <QPainter>
+#include <QTimerEvent>
+
+namespace WebCore {
+
+// ContextShadow needs a scratch image as the buffer for the blur filter.
+// Instead of creating and destroying the buffer for every operation,
+// we create a buffer which will be automatically purged via a timer.
+
+class ShadowBuffer: public QObject {
+public:
+    ShadowBuffer(QObject* parent = 0);
+
+    QImage* scratchImage(const QSize& size);
+
+    void schedulePurge();
+
+protected:
+    void timerEvent(QTimerEvent* event);
+
+private:
+    QImage image;
+    int timerId;
+};
+
+ShadowBuffer::ShadowBuffer(QObject* parent)
+    : QObject(parent)
+    , timerId(0)
+{
+}
+
+QImage* ShadowBuffer::scratchImage(const QSize& size)
+{
+    int width = size.width();
+    int height = size.height();
+
+    // We do not need to recreate the buffer if the buffer is reasonably
+    // larger than the requested size. However, if the requested size is
+    // much smaller than our buffer, reduce our buffer so that we will not
+    // keep too many allocated pixels for too long.
+    if (!image.isNull() && (image.width() > width) && (image.height() > height))
+        if (((2 * width) > image.width()) && ((2 * height) > image.height())) {
+            image.fill(Qt::transparent);
+            return &image;
+        }
+
+    // Round to the nearest 32 pixels so we do not grow the buffer everytime
+    // there is larger request by 1 pixel.
+    width = (1 + (width >> 5)) << 5;
+    height = (1 + (height >> 5)) << 5;
+
+    image = QImage(width, height, QImage::Format_ARGB32_Premultiplied);
+    image.fill(Qt::transparent);
+    return &image;
+}
+
+void ShadowBuffer::schedulePurge()
+{
+    static const double BufferPurgeDelay = 2; // seconds
+    killTimer(timerId);
+    timerId = startTimer(BufferPurgeDelay * 1000);
+}
+
+void ShadowBuffer::timerEvent(QTimerEvent* event)
+{
+    if (event->timerId() == timerId) {
+        killTimer(timerId);
+        image = QImage();
+    }
+    QObject::timerEvent(event);
+}
+
+Q_GLOBAL_STATIC(ShadowBuffer, scratchShadowBuffer)
+
+PlatformContext ContextShadow::beginShadowLayer(PlatformContext p, const FloatRect& layerArea)
+{
+    QRect clipRect;
+    if (p->hasClipping())
+#if QT_VERSION >= QT_VERSION_CHECK(4, 8, 0)
+        clipRect = p->clipBoundingRect().toAlignedRect();
+#else
+        clipRect = p->clipRegion().boundingRect();
+#endif
+    else
+        clipRect = p->transform().inverted().mapRect(p->window());
+
+    calculateLayerBoundingRect(layerArea, IntRect(clipRect.x(), clipRect.y(), clipRect.width(), clipRect.height()));
+
+    // Don't paint if we are totally outside the clip region.
+    if (m_layerRect.isEmpty())
+        return 0;
+
+    ShadowBuffer* shadowBuffer = scratchShadowBuffer();
+    QImage* shadowImage = shadowBuffer->scratchImage(m_layerRect.size());
+    m_layerImage = QImage(*shadowImage);
+
+    m_layerContext = new QPainter;
+    m_layerContext->begin(&m_layerImage);
+    m_layerContext->setFont(p->font());
+    m_layerContext->translate(m_offset.width(), m_offset.height());
+
+    // The origin is now the top left corner of the scratch image.
+    m_layerContext->translate(-m_layerRect.x(), -m_layerRect.y());
+
+    return m_layerContext;
+}
+
+void ContextShadow::endShadowLayer(PlatformContext p)
+{
+    m_layerContext->end();
+    delete m_layerContext;
+    m_layerContext = 0;
+
+    if (m_type == BlurShadow) {
+        blurLayerImage(m_layerImage.bits(), IntSize(m_layerImage.width(), m_layerImage.height()),
+                       m_layerImage.bytesPerLine());
+
+        // "Colorize" with the right shadow color.
+        QPainter p(&m_layerImage);
+        p.setCompositionMode(QPainter::CompositionMode_SourceIn);
+        p.fillRect(m_layerImage.rect(), m_color.rgb());
+        p.end();
+    }
+
+    p->drawImage(m_layerRect.topLeft(), m_layerImage);
+    scratchShadowBuffer()->schedulePurge();
+}
+
+}