[not for review - epic CL] Adding Elastic+Momentum+Layered scrolling to views::ScrollView

ui/views/controls/scroll_view.cc

 // Copyright (c) 2012 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 "ui/views/controls/scroll_view.h"
 
 #include "base/feature_list.h"
 #include "base/logging.h"
 #include "base/macros.h"
+#include "ui/compositor/overscroll/ui_scroll_input_manager.h"
 #include "ui/events/event.h"
 #include "ui/gfx/canvas.h"
 #include "ui/native_theme/native_theme.h"
 #include "ui/views/background.h"
 #include "ui/views/border.h"
 #include "ui/views/style/platform_style.h"
 #include "ui/views/widget/widget.h"
 
 namespace views {
 
@@ skipping 434 matching lines @@
 
 void ScrollView::OnMouseExited(const ui::MouseEvent& event) {
   if (horiz_sb_)
     horiz_sb_->OnMouseExitedScrollView(event);
   if (vert_sb_)
     vert_sb_->OnMouseExitedScrollView(event);
 }
 
 void ScrollView::OnScrollEvent(ui::ScrollEvent* event) {
 #if defined(OS_MACOSX)
-  // TODO(tapted): Send |event| to a cc::InputHandler. For now, there's nothing
-  // to do because Widget::OnScrollEvent() will automatically process an
-  // unhandled ScrollEvent as a MouseWheelEvent.
+  ui::UIScrollInputManager* compositor_scroller =
+      GetWidget()->GetCompositor()->scroll_input_manager();
+  DCHECK(compositor_scroller);
+  if (compositor_scroller->OnScrollEvent(*event)) {
+    event->SetHandled();
+    event->StopPropagation();
+  }
 #endif
 }
 
 void ScrollView::OnGestureEvent(ui::GestureEvent* event) {
   // If the event happened on one of the scrollbars, then those events are
   // sent directly to the scrollbars. Otherwise, only scroll events are sent to
   // the scrollbars.
   bool scroll_event = event->type() == ui::ET_GESTURE_SCROLL_UPDATE ||
                       event->type() == ui::ET_GESTURE_SCROLL_BEGIN ||
                       event->type() == ui::ET_GESTURE_SCROLL_END ||
@@ skipping 54 matching lines @@
   }
   // No view, or the view didn't return a valid amount.
   if (is_page) {
     return is_horizontal ? contents_viewport_->width() :
                            contents_viewport_->height();
   }
   return is_horizontal ? contents_viewport_->width() / 5 :
                          contents_viewport_->height() / 5;
 }
 
+void ScrollView::OnScrollEventFromScrollBar(ui::ScrollEvent* event) {
+  // If the scroll event is passed to the cc::InputHandler as-is, then it will
+  // hit a scroll bar Layer. Layer scrolling supports that, but only if the
+  // scroll bar track and thumb Layers implement cc::ScrollbarLayerInterface.
+  // Creating one of those requires a cc::ScrollBar instance which is more than
+  // views:: really needs to care about. For now, cheat a little and pretend
+  // events are coming from the point (0, 0) on the viewport.
+  gfx::Point location;
+  ConvertPointToWidget(contents_viewport_, &location);
+  event->set_location(location);
+  OnScrollEvent(event);
+}
+
 void ScrollView::SetHeaderOrContents(View* parent,
                                      View* new_view,
                                      View** member) {
   if (*member == new_view)
     return;
 
   delete *member;
   *member = new_view;
   if (*member)
     parent->AddChildView(*member);
@@ skipping 215 matching lines @@
 
 VariableRowHeightScrollHelper::RowInfo
     FixedRowHeightScrollHelper::GetRowInfo(int y) {
   if (y < top_margin_)
     return RowInfo(0, top_margin_);
   return RowInfo((y - top_margin_) / row_height_ * row_height_ + top_margin_,
                  row_height_);
 }
 
 }  // namespace views