android_webview/browser/parent_compositor_draw_constraints.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "android_webview/browser/parent_compositor_draw_constraints.h"
   6
   7 #include "android_webview/browser/child_frame.h"
   8
   9 namespace android_webview {
  10
  11 ParentCompositorDrawConstraints::ParentCompositorDrawConstraints()
  12     : is_layer(false), surface_rect_empty(false) {
  13 }
  14
  15 ParentCompositorDrawConstraints::ParentCompositorDrawConstraints(
  16     bool is_layer,
  17     const gfx::Transform& transform,
  18     bool surface_rect_empty)
  19     : is_layer(is_layer),
  20       transform(transform),
  21       surface_rect_empty(surface_rect_empty) {}
  22
  23 bool ParentCompositorDrawConstraints::NeedUpdate(
  24     const ChildFrame& frame) const {
  25   if (is_layer != frame.is_layer ||
  26       transform != frame.transform_for_tile_priority) {
  27     return true;
  28   }
  29
  30   // Viewport for tile priority does not depend on surface rect in this case.
  31   if (frame.offscreen_pre_raster || is_layer)
  32     return false;
  33
  34   // Workaround for corner case. See crbug.com/417479.
  35   return frame.viewport_rect_for_tile_priority_empty && !surface_rect_empty;
  36 }
  37
  38 }  // namespace webview