touch: Return an enum from OnTouchEvent.

chrome/browser/renderer_host/render_widget_host_view_views.cc

 // Copyright (c) 2010 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 "chrome/browser/renderer_host/render_widget_host_view_views.h"
 
 #include <algorithm>
 #include <string>
 
 #include "app/l10n_util.h"
@@ skipping 651 matching lines @@
 #if 0
 TODO(bryeung): key bindings
   if (!event.skip_in_browser &&
       key_bindings_handler_->Match(event, &edit_commands)) {
     host_->ForwardEditCommandsForNextKeyEvent(edit_commands);
   }
 #endif
   host_->ForwardKeyboardEvent(event);
 }
 
-bool RenderWidgetHostViewViews::OnTouchEvent(const views::TouchEvent& e) {
+views::View::TouchStatus RenderWidgetHostViewViews::OnTouchEvent(
+    const views::TouchEvent& e) {
   // Update the list of touch points first.
   WebKit::WebTouchPoint* point = NULL;
+  TouchStatus status = TOUCH_STATUS_UNKNOWN;
 
   switch (e.GetType()) {
     case views::Event::ET_TOUCH_PRESSED:
       // Add a new touch point.
       if (touch_event_.touchPointsLength <
           WebTouchEvent::touchPointsLengthCap) {
         point = &touch_event_.touchPoints[touch_event_.touchPointsLength++];
         point->id = e.identity();
+
+        if (touch_event_.touchPointsLength == 1) {
+          // A new touch sequence has started.
+          status = TOUCH_STATUS_START;
+        }
       }
       break;
     case views::Event::ET_TOUCH_RELEASED:
     case views::Event::ET_TOUCH_CANCELLED:
     case views::Event::ET_TOUCH_MOVED: {
       // The touch point should have been added to the event from an earlier
       // _PRESSED event. So find that.
       // At the moment, only a maximum of 4 touch-points are allowed. So a
       // simple loop should be sufficient.
       for (int i = 0; i < WebTouchEvent::touchPointsLengthCap; ++i) {
         point = touch_event_.touchPoints + i;
         if (point->id == e.identity()) {
           break;
         }
         point = NULL;
       }
-      DCHECK(point != NULL) << "Touchpoint not found for event " << e.GetType();
       break;
     }
     default:
       DLOG(WARNING) << "Unknown touch event " << e.GetType();
       break;
   }
 
   if (!point)
-    return false;
+    return TOUCH_STATUS_UNKNOWN;
+
+  if (status != TOUCH_STATUS_START)
+    status = TOUCH_STATUS_CONTINUE;
 
   // Update the location and state of the point.
   UpdateTouchPointPosition(&e, GetPosition(), point);
   point->state = TouchPointStateFromEvent(&e);
 
   // Mark the rest of the points as stationary.
   for (int i = 0; i < touch_event_.touchPointsLength; ++i) {
     WebKit::WebTouchPoint* iter = touch_event_.touchPoints + i;
     if (iter != point) {
       iter->state = WebKit::WebTouchPoint::StateStationary;
     }
   }
 
   // Update the type of the touch event.
   touch_event_.type = TouchEventTypeFromEvent(&e);
   touch_event_.timeStampSeconds = base::Time::Now().ToDoubleT();
 
   // The event and all the touches have been updated. Dispatch.
   host_->ForwardTouchEvent(touch_event_);
 
   // If the touch was released, then remove it from the list of touch points.
   if (e.GetType() == views::Event::ET_TOUCH_RELEASED) {
     --touch_event_.touchPointsLength;
     for (int i = point - touch_event_.touchPoints;
          i < touch_event_.touchPointsLength;
          ++i) {
       touch_event_.touchPoints[i] = touch_event_.touchPoints[i + 1];
     }
+    if (touch_event_.touchPointsLength == 0)
+      status = TOUCH_STATUS_END;
+  } else if (e.GetType() == views::Event::ET_TOUCH_CANCELLED) {
+    status = TOUCH_STATUS_CANCEL;
   }
 
-  return true;
+  return status;
 }
 
 // static
 RenderWidgetHostView*
     RenderWidgetHostView::GetRenderWidgetHostViewFromNativeView(
         gfx::NativeView widget) {
   gpointer user_data = g_object_get_data(G_OBJECT(widget),
                                          kRenderWidgetHostViewKey);
   return reinterpret_cast<RenderWidgetHostView*>(user_data);
 }