Add support for SVG Clip paths in HTML

Source/core/rendering/RenderLayerClipPathInfo.cpp

Index: Source/core/rendering/RenderLayerClipPathInfo.cpp
diff --git a/Source/core/rendering/RenderLayerClipPathInfo.cpp b/Source/core/rendering/RenderLayerClipPathInfo.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..dbc8bfb7bbf8d75996abfae5c9de9b7a120bc4d8
--- /dev/null
+++ b/Source/core/rendering/RenderLayerClipPathInfo.cpp
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2014, Google Inc. All rights reserved.

[pdr., 2014/07/28 16:23:52]

Please use the new copyright boilerplate for new files:
http://www.chromium.org/developers/coding-style#TOC-File-headers

[Shanmuga Pandi, 2014/08/01 05:20:39]

Done.

+ *
+ * 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 Google Inc. 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.
+ */
+
+#include "config.h"
+
+#include "core/rendering/RenderLayerClipPathInfo.h"
+
+#include "core/fetch/DocumentResourceReference.h"
+#include "core/rendering/RenderLayer.h"
+#include "core/rendering/svg/RenderSVGResourceContainer.h"
+
+namespace blink {
+
+RenderLayerClipPathInfoMap* RenderLayerClipPathInfo::s_clipPathMap = 0;

[pdr., 2014/07/28 16:23:52]

This patch looks like it's nearly the exact same as RenderLayerFilterInfo except
for clip paths. Can we share some of this logic instead of copy pasta?

[Stephen White, 2014/07/29 15:12:26]

+1 to this.

[Shanmuga Pandi, 2014/07/30 11:31:02]

Yes. I agree. 
But Can you let me know, how do we share those logic?
As RenderLayer can have both Filter and ClipPath sametime, we cannot keep only
one hashmap for both. 

Is it ok to have a single hasmap with pair of <RenderLayerFilterInfo ,
RenderLayerClipPathInfo> ?
Can you give me some hint or idea, it will be helpful.

[Shanmuga Pandi, 2014/08/01 05:20:39]

I have removed unnecessary hashmap code, and added member variable of this to
RenderLayer

+
+RenderLayerClipPathInfo* RenderLayerClipPathInfo::clipPathInfoForRenderLayer(const RenderLayer* layer)
+{
+    if (!s_clipPathMap)
+        return 0;
+    RenderLayerClipPathInfoMap::iterator iter = s_clipPathMap->find(layer);
+    return (iter != s_clipPathMap->end()) ? iter->value : 0;
+}
+
+RenderLayerClipPathInfo* RenderLayerClipPathInfo::createClipPathInfoForRenderLayerIfNeeded(RenderLayer* layer)
+{
+    if (!s_clipPathMap)
+        s_clipPathMap = new RenderLayerClipPathInfoMap();
+
+    RenderLayerClipPathInfoMap::iterator iter = s_clipPathMap->find(layer);
+    if (iter != s_clipPathMap->end()) {
+        ASSERT(layer->hasClipPathInfo());
+        return iter->value;
+    }
+
+    RenderLayerClipPathInfo* clipPath = new RenderLayerClipPathInfo(layer);
+    s_clipPathMap->set(layer, clipPath);
+    layer->setHasClipPathInfo(true);
+    return clipPath;
+}
+
+void RenderLayerClipPathInfo::removeClipPathInfoForRenderLayer(RenderLayer* layer)
+{
+    if (!s_clipPathMap)
+        return;
+    RenderLayerClipPathInfo* clipPath = s_clipPathMap->take(layer);
+    if (s_clipPathMap->isEmpty()) {
+        delete s_clipPathMap;
+        s_clipPathMap = 0;
+    }
+    if (!clipPath) {
+        ASSERT(!layer->hasClipPathInfo());
+        return;
+    }
+    layer->setHasClipPathInfo(false);
+    delete clipPath;
+}
+
+RenderLayerClipPathInfo::RenderLayerClipPathInfo(RenderLayer* layer)
+    : m_layer(layer)
+{
+}
+
+RenderLayerClipPathInfo::~RenderLayerClipPathInfo()
+{
+    removeReferenceClipPathClients();
+}
+
+void RenderLayerClipPathInfo::updateReferenceClipPathClients(ClipPathOperation* clipPathOperation)
+{
+    removeReferenceClipPathClients();
+    if (clipPathOperation->type() != ClipPathOperation::REFERENCE)

[f(malita), 2014/07/29 01:21:16]

This should be an ASSERT.

[Shanmuga Pandi, 2014/07/30 11:31:02]

Acknowledged.

+        return;
+    ReferenceClipPathOperation* referenceClipPathOperation = toReferenceClipPathOperation(clipPathOperation);
+    Element* clipPath = m_layer->renderer()->node()->document().getElementById(referenceClipPathOperation->fragment());
+    if (!isSVGClipPathElement(clipPath))
+        return;
+    if (clipPath->renderer())
+        toRenderSVGResourceContainer(clipPath->renderer())->addClientRenderLayer(m_layer);
+    else
+        toSVGClipPathElement(clipPath)->addClient(m_layer->renderer()->node());
+
+    m_clipPathElement = PassRefPtr<SVGClipPathElement>(toSVGClipPathElement(clipPath));
+}
+
+void RenderLayerClipPathInfo::removeReferenceClipPathClients()
+{
+    if (!m_clipPathElement)
+        return;
+
+    if (m_clipPathElement->renderer())
+        toRenderSVGResourceContainer(m_clipPathElement->renderer())->removeClientRenderLayer(m_layer);
+    else
+        m_clipPathElement->removeClient(m_layer->renderer()->node());
+
+    m_clipPathElement.clear();
+}
+
+} // namespace blink