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) {
  13 }
  14
  15 ParentCompositorDrawConstraints::ParentCompositorDrawConstraints(
  16     bool is_layer,
  17     const gfx::Transform& transform,
  18     const gfx::Rect& surface_rect)
  19     : is_layer(is_layer), transform(transform), surface_rect(surface_rect) {
  20 }
  21
  22 bool ParentCompositorDrawConstraints::NeedUpdate(
  23     const ChildFrame& frame) const {
  24   if (is_layer != frame.is_layer ||
  25       transform != frame.transform_for_tile_priority) {
  26     return true;
  27   }
  28
  29   // Viewport for tile priority does not depend on surface rect in this case.
  30   if (frame.offscreen_pre_raster)
  31     return false;
  32
  33   if (is_layer) {
  34     return surface_rect != frame.viewport_rect_for_tile_priority;
  35   } else {
  36     // Workaround for corner case. See crbug.com/417479.
  37     return frame.viewport_rect_for_tile_priority.IsEmpty() &&
  38            !surface_rect.IsEmpty();
  39   }
  40 }
  41
  42 }  // namespace webview