Move SVG container paint code to SVGContainerPainter

Source/core/paint/SVGContainerPainter.cpp

Index: Source/core/paint/SVGContainerPainter.cpp
diff --git a/Source/core/paint/SVGContainerPainter.cpp b/Source/core/paint/SVGContainerPainter.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..af52ebf284d206a2254a37e72a68c6fcb6b942fc
--- /dev/null
+++ b/Source/core/paint/SVGContainerPainter.cpp
@@ -0,0 +1,77 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/paint/SVGContainerPainter.h"
+
+#include "core/frame/Settings.h"
+#include "core/paint/ObjectPainter.h"
+#include "core/rendering/GraphicsContextAnnotator.h"
+#include "core/rendering/PaintInfo.h"
+#include "core/rendering/svg/RenderSVGContainer.h"
+#include "core/rendering/svg/RenderSVGViewportContainer.h"
+#include "core/rendering/svg/SVGRenderSupport.h"
+#include "core/rendering/svg/SVGRenderingContext.h"
+#include "core/svg/SVGSVGElement.h"
+#include "platform/graphics/GraphicsContextCullSaver.h"
+#include "platform/graphics/GraphicsContextStateSaver.h"
+
+namespace blink {
+
+void SVGContainerPainter::paint(PaintInfo& paintInfo)
+{
+    ANNOTATE_GRAPHICS_CONTEXT(paintInfo, &m_renderSVGContainer);
+
+    // Spec: groups w/o children still may render filter content.
+    if (!m_renderSVGContainer.firstChild() && !m_renderSVGContainer.selfWillPaint())
+        return;
+
+    FloatRect paintInvalidationRect = m_renderSVGContainer.paintInvalidationRectInLocalCoordinates();
+    if (!SVGRenderSupport::paintInfoIntersectsPaintInvalidationRect(paintInvalidationRect, m_renderSVGContainer.localToParentTransform(), paintInfo))
+        return;
+
+    // Spec: An empty viewBox on the <svg> element disables rendering.
+    ASSERT(m_renderSVGContainer.element());
+    if (isSVGSVGElement(*m_renderSVGContainer.element()) && toSVGSVGElement(*m_renderSVGContainer.element()).hasEmptyViewBox())

[chrishtr, 2014/10/08 21:56:38]

Are you sure adding this here rather than the subclass doesn't change semantics?
Is it because the parent class is never directly instantiated?

[pdr., 2014/10/08 23:12:28]

SVGSVGElement can create one of two kinds of renderers: RenderSVGRoot or
RenderSVGViewportContainer. We'll only get here in the second case so this
should be functionally equivalent.

+        return;
+
+    PaintInfo childPaintInfo(paintInfo);
+    {
+        GraphicsContextStateSaver stateSaver(*childPaintInfo.context);
+
+        if (m_renderSVGContainer.isSVGViewportContainer() && SVGRenderSupport::isOverflowHidden(&m_renderSVGContainer))

[chrishtr, 2014/10/08 21:56:38]

Same question here.

[pdr., 2014/10/08 23:12:28]

This one is a little more contentious and fmalita wasn't sure either.

What I did was to inline applyViewportClip here for RenderSVGViewportContainer,
and I inlined applyViewportClip into the callsite in
RenderSVGResourceMarker::draw. In a followup, the draw() functions will be moved
into paint and we can clean that up.

The alternatives aren't great. I'd like move applyViewportClip out of the
renderers but we lose the OO hierarchy when we do that. Creating an
applyViewportClip helper in SVGContainerPainter with a switch on the subclass
type seems even worse.

[chrishtr, 2014/10/08 23:23:16]

Ah I didn't see the isSVGViewportContainer() in the patch.

+            paintInfo.context->clip(toRenderSVGViewportContainer(m_renderSVGContainer).viewport());
+
+        childPaintInfo.applyTransform(m_renderSVGContainer.localToParentTransform());
+
+        SVGRenderingContext renderingContext;
+        GraphicsContextCullSaver cullSaver(*childPaintInfo.context);
+        bool continueRendering = true;
+        if (childPaintInfo.phase == PaintPhaseForeground) {
+            renderingContext.prepareToRenderSVGContent(&m_renderSVGContainer, childPaintInfo);
+            continueRendering = renderingContext.isRenderingPrepared();
+
+            if (continueRendering && m_renderSVGContainer.document().settings()->containerCullingEnabled())
+                cullSaver.cull(paintInvalidationRect);
+        }
+
+        if (continueRendering) {
+            childPaintInfo.updatePaintingRootForChildren(&m_renderSVGContainer);
+            for (RenderObject* child = m_renderSVGContainer.firstChild(); child; child = child->nextSibling())
+                child->paint(childPaintInfo, IntPoint());
+        }
+    }
+
+    // FIXME: This really should be drawn from local coordinates, but currently we hack it
+    // to avoid our clip killing our outline rect. Thus we translate our
+    // outline rect into parent coords before drawing.
+    // FIXME: This means our focus ring won't share our rotation like it should.
+    // We should instead disable our clip during PaintPhaseOutline
+    if (paintInfo.phase == PaintPhaseForeground && m_renderSVGContainer.style()->outlineWidth() && m_renderSVGContainer.style()->visibility() == VISIBLE) {
+        IntRect paintRectInParent = enclosingIntRect(m_renderSVGContainer.localToParentTransform().mapRect(paintInvalidationRect));
+        ObjectPainter(m_renderSVGContainer).paintOutline(paintInfo, paintRectInParent);
+    }
+}
+
+} // namespace blink