Implement basic parts of hit regions on canvas2d.

Source/core/html/canvas/CanvasRenderingContext2D.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012, 2013 Intel Corporation. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
@@ skipping 19 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/html/canvas/CanvasRenderingContext2D.h"
 
 #include "CSSPropertyNames.h"
 #include "bindings/v8/ExceptionMessages.h"
 #include "bindings/v8/ExceptionState.h"
 #include "bindings/v8/ExceptionStatePlaceholder.h"
-#include "core/accessibility/AXObjectCache.h"
 #include "core/css/CSSFontSelector.h"
 #include "core/css/parser/BisonCSSParser.h"
 #include "core/css/StylePropertySet.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/fetch/ImageResource.h"
 #include "core/frame/ImageBitmap.h"
 #include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLImageElement.h"
 #include "core/html/HTMLMediaElement.h"
@@ skipping 28 matching lines @@
 static const double TryRestoreContextInterval = 0.5;
 static const unsigned MaxTryRestoreContextAttempts = 4;
 
 static bool contextLostRestoredEventsEnabled()
 {
     return RuntimeEnabledFeatures::experimentalCanvasFeaturesEnabled();
 }
 
 CanvasRenderingContext2D::CanvasRenderingContext2D(HTMLCanvasElement* canvas, const Canvas2DContextAttributes* attrs, bool usesCSSCompatibilityParseMode)
     : CanvasRenderingContext(canvas)
+    , m_hitRegionManager(HitRegionManager::create())
     , m_usesCSSCompatibilityParseMode(usesCSSCompatibilityParseMode)
     , m_hasAlpha(!attrs || attrs->alpha())
     , m_isContextLost(false)
     , m_contextRestorable(true)
     , m_storageMode(!attrs ? PersistentStorage : attrs->parsedStorage())
     , m_tryRestoreContextAttemptCount(0)
     , m_dispatchContextLostEventTimer(this, &CanvasRenderingContext2D::dispatchContextLostEvent)
     , m_dispatchContextRestoredEventTimer(this, &CanvasRenderingContext2D::dispatchContextRestoredEvent)
     , m_tryRestoreContextEventTimer(this, &CanvasRenderingContext2D::tryRestoreContextEvent)
 {
@@ skipping 62 matching lines @@
             m_isContextLost = false;
         }
     }
 }
 
 void CanvasRenderingContext2D::trace(Visitor* visitor)
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_stateStack);
     visitor->trace(m_fetchedFonts);
+    visitor->trace(m_hitRegionManager);
 #endif
     CanvasRenderingContext::trace(visitor);
 }
 
 void CanvasRenderingContext2D::dispatchContextLostEvent(Timer<CanvasRenderingContext2D>*)
 {
     if (contextLostRestoredEventsEnabled()) {
         RefPtrWillBeRawPtr<Event> event = Event::createCancelable(EventTypeNames::contextlost);
         canvas()->dispatchEvent(event);
         if (event->defaultPrevented()) {
@@ skipping 1056 matching lines @@
         context->setAlphaAsFloat(1);
     }
     if (state().m_globalComposite != CompositeSourceOver) {
         if (!saved) {
             context->save();
             saved = true;
         }
         context->setCompositeOperation(CompositeSourceOver);
     }
     context->clearRect(rect);
+    m_hitRegionManager->removeHitRegionsInRect(rect, state().m_transform);
     if (saved)
         context->restore();
 
     validateStateStack();
     didDraw(dirtyRect);
 }
 
 void CanvasRenderingContext2D::fillRect(float x, float y, float width, float height)
 {
     if (!validateRectForCanvas(x, y, width, height))
@@ skipping 1092 matching lines @@
     c->save();
     c->setAlphaAsFloat(1.0);
     c->clearShadow();
     c->setCompositeOperation(CompositeSourceOver, blink::WebBlendModeNormal);
     c->drawFocusRing(path, focusRingWidth, focusRingOutline, focusRingColor);
     c->restore();
     validateStateStack();
     didDraw(dirtyRect);
 }
 
+void CanvasRenderingContext2D::addHitRegion(ExceptionState& exceptionState)
+{
+    addHitRegion(Dictionary(), exceptionState);
+}
+
+void CanvasRenderingContext2D::addHitRegion(const Dictionary& options, ExceptionState& exceptionState)
+{
+    HitRegionOptions passOptions;
+
+    bool hasId = options.getWithUndefinedOrNullCheck("id", passOptions.id) && !passOptions.id.isEmpty();
+    bool hasControl = options.getWithUndefinedOrNullCheck("control", passOptions.control) && passOptions.control;
+
+    if (!(hasId || hasControl)) {
+        exceptionState.throwDOMException(NotSupportedError, "Both id and control are null.");
+        return;
+    }
+
+    FloatRect clipBounds;
+    GraphicsContext* context = drawingContext();
+
+    if (m_path.isEmpty() || !context || !state().m_invertibleCTM
+        || !context->getTransformedClipBounds(&clipBounds)) {
+        exceptionState.throwDOMException(NotSupportedError, "The specified path has no pixels.");
+        return;
+    }
+
+    // This clipPath isn't always empty.
+    Path clipPath;
+    clipPath.addRect(clipBounds);

[fs, 2014/06/04 08:13:40]

clipBounds vs. CRC2D.clip()

(i.e. what if it is a circle - or any other non-rectangular geometry really -
add test?)

[zino, 2014/06/06 06:35:17]

Done.
But I didn't add some tests yet.
I'll upload them soon.

+
+    Path specifiedPath = m_path;
+    specifiedPath.transform(state().m_transform);
+    specifiedPath.intersectPath(clipPath);
+
+    passOptions.path = specifiedPath;
+
+    addHitRegionInternal(passOptions, exceptionState);
+}
+
+void CanvasRenderingContext2D::addHitRegionInternal(const HitRegionOptions& options, ExceptionState& exceptionState)
+{
+    // Remove previous region (with id or control)
+    m_hitRegionManager->removeHitRegionById(options.id);
+    m_hitRegionManager->removeHitRegionByControl(options.control.get());
+
+    RefPtrWillBeRawPtr<HitRegion> hitRegion = HitRegion::create(options);
+    hitRegion->updateAccessibility(canvas());
+    m_hitRegionManager->addHitRegion(hitRegion.release());
+}
+
+void CanvasRenderingContext2D::removeHitRegion(const String& id)
+{
+    m_hitRegionManager->removeHitRegionById(id);
+}
+
+void CanvasRenderingContext2D::clearHitRegions()
+{
+    m_hitRegionManager->removeAllHitRegions();
+}
+
+HitRegion* CanvasRenderingContext2D::hitRegionAtPoint(const LayoutPoint& point)
+{
+    return m_hitRegionManager->getHitRegionAtPoint(point);
+}
+
 } // namespace WebCore