Add infrastructure for partial layouts

Source/core/rendering/PartialLayoutState.h

 /*
  * Copyright (C) 2013 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
@@ skipping 10 matching lines @@
  * 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 MIDIConnectionEvent_h
-#define MIDIConnectionEvent_h
+#ifndef PartialLayoutState_h
+#define PartialLayoutState_h
 
-#include "core/dom/Event.h"
-#include "modules/webmidi/MIDIPort.h"
+#include "core/rendering/RenderObject.h"
 
 namespace WebCore {
 
-struct MIDIConnectionEventInit : public EventInit {
-    MIDIConnectionEventInit()
-        : port(0)
+class PartialLayoutState {
+    friend class PartialLayoutDisabler;
+public:
+    PartialLayoutState()
+        : m_shouldStop(false)
+        , m_stopAtRenderer(0)
+        , m_disableCount(0)
     {
-    };
+    }
 
-    RefPtr<MIDIPort> port;
+    bool shouldStop() const { return m_shouldStop; }
+    bool checkPartialLayoutComplete(RenderObject*);
+    void setStopAtRenderer(RenderObject* renderer) { m_stopAtRenderer = renderer; }
+    RenderObject* stopAtRenderer() { return m_disableCount > 0 ? 0 : m_stopAtRenderer; }
+    void reset() { m_shouldStop = false; m_stopAtRenderer = 0; }
+
+private:
+    void disable() { m_disableCount++; }
+    void enable() { ASSERT(m_disableCount > 0); m_disableCount--; }
+
+    bool m_shouldStop;
+    RenderObject* m_stopAtRenderer;
+    int m_disableCount;
 };
 
-class MIDIConnectionEvent : public Event {
-public:
-    static PassRefPtr<MIDIConnectionEvent> create()
-    {
-        return adoptRef(new MIDIConnectionEvent());
+inline bool PartialLayoutState::checkPartialLayoutComplete(RenderObject* renderer)
+{
+    if (m_shouldStop)
+        return true;
+
+    if (renderer == stopAtRenderer()) {
+        m_shouldStop = true;
+        m_stopAtRenderer = 0;
+        return true;
     }
 
-    static PassRefPtr<MIDIConnectionEvent> create(const AtomicString& type, PassRefPtr<MIDIPort> port)
+    return false;
+}
+
+class PartialLayoutDisabler {
+    WTF_MAKE_NONCOPYABLE(PartialLayoutDisabler);
+public:
+    PartialLayoutDisabler(PartialLayoutState& partialLayout, bool disable)
+        : m_partialLayout(partialLayout)
+        , m_disable(disable)
     {
-        return adoptRef(new MIDIConnectionEvent(type, port));
+        if (m_disable)
+            m_partialLayout.disable();
     }
 
-    static PassRefPtr<MIDIConnectionEvent> create(const AtomicString& type, const MIDIConnectionEventInit& initializer)
+    ~PartialLayoutDisabler()
     {
-        return adoptRef(new MIDIConnectionEvent(type, initializer));
+        if (m_disable)
+            m_partialLayout.enable();
     }
-
-    RefPtr<MIDIPort> port() { return m_port; }
-
-    virtual const AtomicString& interfaceName() const OVERRIDE { return eventNames().interfaceForMIDIConnectionEvent; }
-
 private:
-    MIDIConnectionEvent()
-    {
-        ScriptWrappable::init(this);
-    }
-
-    MIDIConnectionEvent(const AtomicString& type, PassRefPtr<MIDIPort> port)
-        : Event(type, false, false)
-        , m_port(port)
-    {
-        ScriptWrappable::init(this);
-    }
-
-    MIDIConnectionEvent(const AtomicString& type, const MIDIConnectionEventInit& initializer)
-        : Event(type, initializer)
-        , m_port(initializer.port)
-    {
-        ScriptWrappable::init(this);
-    }
-
-    RefPtr<MIDIPort> m_port;
+    PartialLayoutState& m_partialLayout;
+    bool m_disable;
 };
 
 } // namespace WebCore
 
-#endif // MIDIConnectionEvent_h
+#endif // PartialLayoutState_h