Android Webview IPC-based sync compositing

content/renderer/android/synchronous_compositor_proxy.cc

Index: content/renderer/android/synchronous_compositor_proxy.cc
diff --git a/content/renderer/android/synchronous_compositor_proxy.cc b/content/renderer/android/synchronous_compositor_proxy.cc
new file mode 100644
index 0000000000000000000000000000000000000000..625a75164f4aa5d5a1504e2872a326a81849431a
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+++ b/content/renderer/android/synchronous_compositor_proxy.cc
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+// Copyright 2015 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 "content/renderer/android/synchronous_compositor_proxy.h"
+
+#include "base/auto_reset.h"
+#include "content/common/android/sync_compositor_messages.h"
+#include "content/common/cc_messages.h"
+#include "ipc/ipc_message.h"
+#include "ipc/ipc_sender.h"
+#include "ui/events/latency_info.h"
+
+namespace content {
+
+SynchronousCompositorProxy::SynchronousCompositorProxy(
+    int routing_id,
+    IPC::Sender* sender,
+    SynchronousCompositorOutputSurface* output_surface,
+    SynchronousCompositorExternalBeginFrameSource* begin_frame_source,
+    SynchronousInputHandlerProxy* input_handler_proxy,
+    InputHandlerManagerClient::Handler* handler)
+    : routing_id_(routing_id),
+      sender_(sender),
+      output_surface_(output_surface),
+      begin_frame_source_(begin_frame_source),
+      input_handler_proxy_(input_handler_proxy),
+      input_handler_(handler),
+      inside_receive_(false),
+      bytes_limit_(0u),
+      version_(0u),
+      page_scale_factor_(0.f),
+      min_page_scale_factor_(0.f),
+      max_page_scale_factor_(0.f),
+      need_animate_scroll_(false),
+      need_invalidate_(false),
+      need_begin_frame_(false),
+      did_activate_pending_tree_(false) {
+  DCHECK(output_surface_);
+  DCHECK(begin_frame_source_);
+  DCHECK(input_handler_proxy_);
+  DCHECK(input_handler_);
+  output_surface_->SetSyncClient(this);
+  output_surface_->SetTreeActivationCallback(
+      base::Bind(&SynchronousCompositorProxy::DidActivatePendingTree,
+                 base::Unretained(this)));
+  begin_frame_source_->SetClient(this);
+  input_handler_proxy_->SetOnlySynchronouslyAnimateRootFlings(this);
+}
+
+SynchronousCompositorProxy::~SynchronousCompositorProxy() {
+  output_surface_->SetSyncClient(nullptr);
+  output_surface_->SetTreeActivationCallback(base::Closure());
+  begin_frame_source_->SetClient(nullptr);
+  input_handler_proxy_->SetOnlySynchronouslyAnimateRootFlings(nullptr);
+}
+
+void SynchronousCompositorProxy::SetNeedsSynchronousAnimateInput() {
+  need_animate_scroll_ = true;
+  Invalidate();
+}
+
+void SynchronousCompositorProxy::UpdateRootLayerState(
+    const gfx::ScrollOffset& total_scroll_offset,
+    const gfx::ScrollOffset& max_scroll_offset,
+    const gfx::SizeF& scrollable_size,
+    float page_scale_factor,
+    float min_page_scale_factor,
+    float max_page_scale_factor) {
+  if (total_scroll_offset_ != total_scroll_offset ||
+      max_scroll_offset_ != max_scroll_offset ||
+      scrollable_size_ != scrollable_size ||
+      page_scale_factor_ != page_scale_factor ||
+      min_page_scale_factor_ != min_page_scale_factor ||
+      max_page_scale_factor_ != max_page_scale_factor) {
+    total_scroll_offset_ = total_scroll_offset;
+    max_scroll_offset_ = max_scroll_offset;
+    scrollable_size_ = scrollable_size;
+    page_scale_factor_ = page_scale_factor;
+    min_page_scale_factor_ = min_page_scale_factor;
+    max_page_scale_factor_ = max_page_scale_factor;
+
+    SendAsyncRendererStateIfNeeded();
+  }
+}
+
+void SynchronousCompositorProxy::OnNeedsBeginFramesChange(
+    bool needs_begin_frames) {
+  if (need_begin_frame_ == needs_begin_frames)
+    return;
+  need_begin_frame_ = needs_begin_frames;
+  SendAsyncRendererStateIfNeeded();
+}
+
+void SynchronousCompositorProxy::Invalidate() {
+  need_invalidate_ = true;
+  SendAsyncRendererStateIfNeeded();
+}
+
+void SynchronousCompositorProxy::DidActivatePendingTree() {
+  did_activate_pending_tree_ = true;
+  SendAsyncRendererStateIfNeeded();
+  DeliverMessages();
+}
+
+void SynchronousCompositorProxy::DeliverMessages() {
+  ScopedVector<IPC::Message> messages;
+  output_surface_->GetMessagesToDeliver(&messages);
+  for (auto* message : messages) {
+    Send(message);
+  }
+  messages.weak_clear();  // Don't double delete.
+}
+
+void SynchronousCompositorProxy::SendAsyncRendererStateIfNeeded() {
+  if (inside_receive_)
+    return;
+  SyncCompositorCommonRendererParams params;
+  PopulateCommonParams(&params);
+  Send(new SyncCompositorHostMsg_UpdateState(routing_id_, params));
+}
+
+void SynchronousCompositorProxy::PopulateCommonParams(
+    SyncCompositorCommonRendererParams* params) {
+  params->version = ++version_;
+  params->total_scroll_offset = total_scroll_offset_;
+  params->max_scroll_offset = max_scroll_offset_;
+  params->scrollable_size = scrollable_size_;
+  params->page_scale_factor = page_scale_factor_;
+  params->min_page_scale_factor = min_page_scale_factor_;
+  params->max_page_scale_factor = max_page_scale_factor_;
+  params->need_animate_scroll = need_animate_scroll_;
+  params->need_invalidate = need_invalidate_;
+  params->need_begin_frame = need_begin_frame_;
+  params->did_activate_pending_tree = did_activate_pending_tree_;
+
+  need_invalidate_ = false;
+  did_activate_pending_tree_ = false;
+}
+
+void SynchronousCompositorProxy::OnMessageReceived(
+    const IPC::Message& message) {
+  DCHECK(!inside_receive_);
+  base::AutoReset<bool> scoped_inside_receive(&inside_receive_, true);
+  IPC_BEGIN_MESSAGE_MAP(SynchronousCompositorProxy, message)
+    IPC_MESSAGE_HANDLER(SyncCompositorMsg_HandleInputEvent, HandleInputEvent)
+    IPC_MESSAGE_HANDLER(SyncCompositorMsg_BeginFrame, BeginFrame)
+    IPC_MESSAGE_HANDLER(SyncCompositorMsg_ComputeScroll, OnComputeScroll)
+    IPC_MESSAGE_HANDLER(SyncCompositorMsg_DemandDrawHw, DemandDrawHw)
+  IPC_END_MESSAGE_MAP()
+}
+
+bool SynchronousCompositorProxy::Send(IPC::Message* message) {
+  return sender_->Send(message);
+}
+
+void SynchronousCompositorProxy::HandleInputEvent(
+    const SyncCompositorCommonBrowserParams& common_params,
+    const blink::WebInputEvent* event,
+    SyncCompositorCommonRendererParams* common_renderer_params,
+    InputEventAckState* ack) {
+  ProcessCommonParams(common_params);
+  DCHECK(!input_handler_->is_null());
+  ui::LatencyInfo latency;
+  *ack = input_handler_->Run(routing_id_, event, &latency);
+  PopulateCommonParams(common_renderer_params);
+}
+
+void SynchronousCompositorProxy::BeginFrame(
+    const SyncCompositorCommonBrowserParams& common_params,
+    const cc::BeginFrameArgs& args,
+    SyncCompositorCommonRendererParams* common_renderer_params) {
+  ProcessCommonParams(common_params);
+  if (need_begin_frame_) {
+    begin_frame_source_->BeginFrame(args);
+  }
+  PopulateCommonParams(common_renderer_params);
+}
+
+void SynchronousCompositorProxy::DemandDrawHw(
+    const SyncCompositorCommonBrowserParams& common_params,
+    const SyncCompositorDemandDrawHwParams& params,
+    SyncCompositorCommonRendererParams* common_renderer_params,
+    cc::CompositorFrame* frame) {
+  DCHECK(frame);
+  ProcessCommonParams(common_params);
+  scoped_ptr<cc::CompositorFrame> frame_ptr = output_surface_->DemandDrawHw(
+      params.surface_size, params.transform, params.viewport, params.clip,
+      params.viewport_rect_for_tile_priority,
+      params.transform_for_tile_priority);
+  if (frame_ptr) {
+    frame_ptr->AssignTo(frame);
+    DeliverMessages();
+  }
+  PopulateCommonParams(common_renderer_params);
+}
+
+void SynchronousCompositorProxy::OnComputeScroll(
+    const SyncCompositorCommonBrowserParams& common_params,
+    base::TimeTicks animation_time,
+    SyncCompositorCommonRendererParams* common_renderer_params) {
+  ProcessCommonParams(common_params);
+  if (need_animate_scroll_) {
+    need_animate_scroll_ = false;
+    input_handler_proxy_->SynchronouslyAnimate(animation_time);
+  }
+  PopulateCommonParams(common_renderer_params);
+}
+
+void SynchronousCompositorProxy::ProcessCommonParams(
+    const SyncCompositorCommonBrowserParams& common_params) {
+  if (bytes_limit_ != common_params.bytes_limit) {
+    bytes_limit_ = common_params.bytes_limit;
+    output_surface_->SetMemoryPolicy(bytes_limit_);
+  }
+  if (total_scroll_offset_ != common_params.root_scroll_offset) {
+    total_scroll_offset_ = common_params.root_scroll_offset;
+    input_handler_proxy_->SynchronouslySetRootScrollOffset(
+        total_scroll_offset_);
+  }
+  if (!common_params.ack.resources.empty()) {
+    output_surface_->ReturnResources(common_params.ack);
+  }
+}
+
+}  // namespace content