content/browser/compositor/browser_compositor_view_mac.mm

   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 "content/browser/compositor/browser_compositor_view_mac.h"
   6
   7 #include "base/debug/trace_event.h"
   8 #include "base/lazy_instance.h"
   9 #include "content/browser/gpu/gpu_process_host_ui_shim.h"
  10 #include "content/browser/compositor/browser_compositor_ca_layer_tree_mac.h"
  11 #include "content/common/gpu/gpu_messages.h"
  12
  13 ////////////////////////////////////////////////////////////////////////////////
  14 // BrowserCompositorViewMac
  15
  16 namespace content {
  17 namespace {
  18
  19 // The number of placeholder objects allocated. If this reaches zero, then
  20 // the BrowserCompositorCALayerTreeMac being held on to for recycling,
  21 // |g_recyclable_ca_layer_tree|, will be freed.
  22 uint32 g_placeholder_count = 0;
  23
  24 // A spare BrowserCompositorCALayerTreeMac kept around for recycling.
  25 base::LazyInstance<scoped_ptr<BrowserCompositorCALayerTreeMac>>
  26   g_recyclable_ca_layer_tree;
  27
  28 }  // namespace
  29
  30 BrowserCompositorViewMac::BrowserCompositorViewMac(
  31     BrowserCompositorViewMacClient* client,
  32     NSView* native_view,
  33     ui::Layer* ui_root_layer)
  34       : client_(client),
  35         native_view_(native_view),
  36         ui_root_layer_(ui_root_layer) {
  37   // Try to use the recyclable BrowserCompositorCALayerTreeMac if there is one,
  38   // otherwise allocate a new one.
  39   // TODO(ccameron): If there exists a frame in flight (swap has been called
  40   // by the compositor, but the frame has not arrived from the GPU process
  41   // yet), then that frame may inappropriately flash in the new view.
  42   ca_layer_tree_ = g_recyclable_ca_layer_tree.Get().Pass();
  43   if (!ca_layer_tree_)
  44     ca_layer_tree_.reset(new BrowserCompositorCALayerTreeMac);
  45   ca_layer_tree_->SetView(this);
  46 }
  47
  48 BrowserCompositorViewMac::~BrowserCompositorViewMac() {
  49   // Make this BrowserCompositorCALayerTreeMac recyclable for future instances.
  50   ca_layer_tree_->ResetView();
  51   g_recyclable_ca_layer_tree.Get() = ca_layer_tree_.Pass();
  52
  53   // If there are no placeholders allocated, destroy the recyclable
  54   // BrowserCompositorCALayerTreeMac that we just populated.
  55   if (!g_placeholder_count)
  56     g_recyclable_ca_layer_tree.Get().reset();
  57 }
  58
  59 ui::Compositor* BrowserCompositorViewMac::GetCompositor() const {
  60   DCHECK(ca_layer_tree_);
  61   return ca_layer_tree_->compositor();
  62 }
  63
  64 bool BrowserCompositorViewMac::HasFrameOfSize(
  65     const gfx::Size& dip_size) const {
  66   if (ca_layer_tree_)
  67     return ca_layer_tree_->HasFrameOfSize(dip_size);
  68   return false;
  69 }
  70
  71 void BrowserCompositorViewMac::BeginPumpingFrames() {
  72   if (ca_layer_tree_)
  73     ca_layer_tree_->BeginPumpingFrames();
  74 }
  75
  76 void BrowserCompositorViewMac::EndPumpingFrames() {
  77   if (ca_layer_tree_)
  78     ca_layer_tree_->EndPumpingFrames();
  79 }
  80
  81 ////////////////////////////////////////////////////////////////////////////////
  82 // BrowserCompositorViewPlaceholderMac
  83
  84 BrowserCompositorViewPlaceholderMac::BrowserCompositorViewPlaceholderMac() {
  85   g_placeholder_count += 1;
  86 }
  87
  88 BrowserCompositorViewPlaceholderMac::~BrowserCompositorViewPlaceholderMac() {
  89   DCHECK_GT(g_placeholder_count, 0u);
  90   g_placeholder_count -= 1;
  91
  92   // If there are no placeholders allocated, destroy the recyclable
  93   // BrowserCompositorCALayerTreeMac.
  94   if (!g_placeholder_count)
  95     g_recyclable_ca_layer_tree.Get().reset();
  96 }
  97
  98 }  // namespace content