aura: Add touch-event support for RWHVA.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 8ff3036fdf34f65decc0884841fef8270d91ea1b..e25cc9caf87591c9e82f8dcc3aa4b6ae3165f335 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -25,6 +25,8 @@
 #include "ui/gfx/gl/gl_bindings.h"
 #endif
 
+using WebKit::WebTouchEvent;
+
 namespace {
 
 #if defined(UI_COMPOSITOR_IMAGE_TRANSPORT)
@@ -36,6 +38,38 @@ void AcknowledgeSwapBuffers(int32 route_id, int gpu_host_id) {
 }
 #endif
 
+WebKit::WebTouchPoint::State TouchPointStateFromEvent(
+    const aura::TouchEvent* event) {
+  switch (event->type()) {
+    case ui::ET_TOUCH_PRESSED:
+      return WebKit::WebTouchPoint::StatePressed;
+    case ui::ET_TOUCH_RELEASED:
+      return WebKit::WebTouchPoint::StateReleased;
+    case ui::ET_TOUCH_MOVED:
+      return WebKit::WebTouchPoint::StateMoved;
+    case ui::ET_TOUCH_CANCELLED:
+      return WebKit::WebTouchPoint::StateCancelled;
+    default:
+      return WebKit::WebTouchPoint::StateUndefined;
+  }
+}
+
+WebKit::WebInputEvent::Type TouchEventTypeFromEvent(
+    const aura::TouchEvent* event) {
+  switch (event->type()) {
+    case ui::ET_TOUCH_PRESSED:
+      return WebKit::WebInputEvent::TouchStart;
+    case ui::ET_TOUCH_RELEASED:
+      return WebKit::WebInputEvent::TouchEnd;
+    case ui::ET_TOUCH_MOVED:
+      return WebKit::WebInputEvent::TouchMove;
+    case ui::ET_TOUCH_CANCELLED:
+      return WebKit::WebInputEvent::TouchCancel;
+    default:
+      return WebKit::WebInputEvent::Undefined;
+  }
+}
+
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -359,8 +393,99 @@ bool RenderWidgetHostViewAura::OnMouseEvent(aura::MouseEvent* event) {
 
 ui::TouchStatus RenderWidgetHostViewAura::OnTouchEvent(
     aura::TouchEvent* event) {
-  NOTIMPLEMENTED();
-  return ui::TOUCH_STATUS_UNKNOWN;
+  // Update the list of touch points first.
+  WebKit::WebTouchPoint* point = NULL;

[Ben Goodger (Google), 2011/10/25 15:00:30]

Can we do this in a separate factory function a la the other events?

This function is pretty gigantic.

[sadrul, 2011/10/25 15:09:45]

I was going to do this like the other functions, but it's a bit tricky: there
are some processing after the touch event is forwarded to the renderer (line 474
onward). Should this be done in two steps like this:

  WebKit::WebTouchPoint* point = content::UpdateWebTouchEvent(event,
touch_event_);
  host_->ForwardTouchEvent(touch_event_);
  if (event->type() == ui::ET_TOUCH_RELEASED) {
    RemoveTouchPoint(&touch_event_, point);
    status = ...
  } else {
    status = ...
  }
  return status;

+  ui::TouchStatus status = ui::TOUCH_STATUS_UNKNOWN;
+
+  switch (event->type()) {
+    case ui::ET_TOUCH_PRESSED:
+      // Add a new touch point.
+      if (touch_event_.touchesLength < WebTouchEvent::touchesLengthCap) {
+        point = &touch_event_.touches[touch_event_.touchesLength++];
+        point->id = event->touch_id();
+
+        if (touch_event_.touchesLength == 1) {
+          // A new touch sequence has started.
+          status = ui::TOUCH_STATUS_START;
+        }
+      }
+      break;
+    case ui::ET_TOUCH_RELEASED:
+    case ui::ET_TOUCH_CANCELLED:
+    case ui::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 (unsigned i = 0; i < touch_event_.touchesLength; ++i) {
+        point = touch_event_.touches + i;
+        if (point->id == event->touch_id())
+          break;
+        point = NULL;
+      }
+      break;
+    }
+    default:
+      DLOG(WARNING) << "Unknown touch event " << event->type();
+      break;
+  }
+
+  if (!point)
+    return ui::TOUCH_STATUS_UNKNOWN;
+
+  if (status != ui::TOUCH_STATUS_START)
+    status = ui::TOUCH_STATUS_CONTINUE;
+
+  point->radiusX = event->radius_x();
+  point->radiusY = event->radius_y();
+  point->rotationAngle = event->rotation_angle();
+  point->force = event->force();
+
+  // Update the location and state of the point.
+  point->state = TouchPointStateFromEvent(event);
+  if (point->state == WebKit::WebTouchPoint::StateMoved) {
+    // It is possible for badly written touch drivers to emit Move events even
+    // when the touch location hasn't changed. In such cases, consume the event
+    // and pretend nothing happened.
+    if (point->position.x == event->x() && point->position.y == event->y())
+      return status;
+  }
+  point->position.x = event->x();
+  point->position.y = event->y();
+
+  // TODO(sad): Convert to screen coordinates.
+  point->screenPosition.x = point->position.x;
+  point->screenPosition.y = point->position.y;
+
+  // Mark the rest of the points as stationary.
+  for (unsigned i = 0; i < touch_event_.touchesLength; ++i) {
+    WebKit::WebTouchPoint* iter = touch_event_.touches + i;
+    if (iter != point)
+      iter->state = WebKit::WebTouchPoint::StateStationary;
+  }
+
+  // Update the type of the touch event.
+  touch_event_.type = TouchEventTypeFromEvent(event);
+  touch_event_.timeStampSeconds = event->time_stamp().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 (event->type() == ui::ET_TOUCH_RELEASED) {
+    --touch_event_.touchesLength;
+    for (unsigned i = point - touch_event_.touches;
+         i < touch_event_.touchesLength;
+         ++i) {
+      touch_event_.touches[i] = touch_event_.touches[i + 1];
+    }
+    if (touch_event_.touchesLength == 0)
+      status = ui::TOUCH_STATUS_END;
+  } else if (event->type() == ui::ET_TOUCH_CANCELLED) {
+    status = ui::TOUCH_STATUS_CANCEL;
+  }
+
+  return status;
 }
 
 bool RenderWidgetHostViewAura::ShouldActivate(aura::Event* event) {