Adds scroll position/scale emulation to DevTools.

third_party/WebKit/Source/core/frame/ScrollAndScaleEmulator.h

 /*
- * Copyright (C) 2010 Google Inc. All rights reserved.
+ * Copyright (C) 2016 Google 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:
  *
  *     * 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.
  */
 
-#ifndef ScopedEventQueue_h
-#define ScopedEventQueue_h
+#ifndef ScrollAndScaleEmulator_h
+#define ScrollAndScaleEmulator_h
 
 #include "core/CoreExport.h"
-#include "platform/heap/Handle.h"
+#include "platform/geometry/DoublePoint.h"
 #include "wtf/Noncopyable.h"
-#include "wtf/PassRefPtr.h"
-#include "wtf/RefPtr.h"
-#include "wtf/Vector.h"
+#include "wtf/RefCounted.h"
 
 namespace blink {
 
-class EventDispatchMediator;
+struct PageScaleConstraints;
 
-class CORE_EXPORT ScopedEventQueue {
-    WTF_MAKE_NONCOPYABLE(ScopedEventQueue); USING_FAST_MALLOC(ScopedEventQueue);
+// Overrides the scroll positions of frame and visual viewport and the page
+// scale with fixed values.
+//
+// TODO(eseckler): description of impl
+class CORE_EXPORT ScrollAndScaleEmulator final : public RefCounted<ScrollAndScaleEmulator> {
+    WTF_MAKE_NONCOPYABLE(ScrollAndScaleEmulator);
 public:
-    ~ScopedEventQueue();
+    static PassRefPtr<ScrollAndScaleEmulator> create();
 
-    void enqueueEventDispatchMediator(EventDispatchMediator*);
-    void dispatchAllEvents();
-    static ScopedEventQueue* instance();
+    virtual ~ScrollAndScaleEmulator() {}
 
-    void incrementScopingLevel();
-    void decrementScopingLevel();
-    bool shouldQueueEvents() const { return m_scopingLevel > 0; }
+    // Update override values. Returns |true| if values changed.
+    bool update(const IntPoint& framePosition, const DoublePoint& visualViewportPosition, float pageScale);
+
+    IntPoint applyFramePositionOverride(const IntPoint&);
+    DoublePoint applyVisualViewportPositionOverride(const DoublePoint&);
+    PageScaleConstraints pageScaleConstraints();
 
 private:
-    ScopedEventQueue();
-    static void initialize();
-    void dispatchEvent(EventDispatchMediator*) const;
+    ScrollAndScaleEmulator();
 
-    PersistentHeapVector<Member<EventDispatchMediator>> m_queuedEventDispatchMediators;
-    unsigned m_scopingLevel;
+    template <typename Point>
+    Point applyPositionOverride(const Point& position, const Point& override);
 
-    static ScopedEventQueue* s_instance;
-};
+    // Scroll position of frame. |x < 0| or |y < 0| disables the override for the respective coordinate.
+    IntPoint m_framePosition;
 
-class EventQueueScope {
-    WTF_MAKE_NONCOPYABLE(EventQueueScope);
-    STACK_ALLOCATED();
-public:
-    EventQueueScope() { ScopedEventQueue::instance()->incrementScopingLevel(); }
-    ~EventQueueScope() { ScopedEventQueue::instance()->decrementScopingLevel(); }
+    // Scroll position of visual viewport. |x < 0| or |y < 0| disables the override for the respective coordinate.
+    DoublePoint m_visualViewportPosition;
+
+    // Simulates visual viewport pinch zoom. |pageScale == 0| disables the override.
+    double m_pageScale;
 };
 
 } // namespace blink
 
-#endif // ScopedEventQueue_h
+#endif // ScrollAndScaleEmulator_h