src/android_webview/browser/browser_view_renderer.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/browser_view_renderer.h"
   6
   7 #include "android_webview/browser/browser_view_renderer_client.h"
   8 #include "android_webview/browser/shared_renderer_state.h"
   9 #include "android_webview/common/aw_switches.h"
  10 #include "android_webview/public/browser/draw_gl.h"
  11 #include "base/android/jni_android.h"
  12 #include "base/auto_reset.h"
  13 #include "base/command_line.h"
  14 #include "base/debug/trace_event.h"
  15 #include "base/json/json_writer.h"
  16 #include "base/logging.h"
  17 #include "base/strings/string_number_conversions.h"
  18 #include "base/strings/stringprintf.h"
  19 #include "cc/output/compositor_frame.h"
  20 #include "content/public/browser/browser_thread.h"
  21 #include "content/public/browser/web_contents.h"
  22 #include "content/public/common/content_switches.h"
  23 #include "third_party/skia/include/core/SkBitmap.h"
  24 #include "third_party/skia/include/core/SkCanvas.h"
  25 #include "third_party/skia/include/core/SkPicture.h"
  26 #include "third_party/skia/include/core/SkPictureRecorder.h"
  27 #include "ui/gfx/vector2d_conversions.h"
  28
  29 using base::android::AttachCurrentThread;
  30 using base::android::JavaRef;
  31 using base::android::ScopedJavaLocalRef;
  32 using content::BrowserThread;
  33 using content::SynchronousCompositorMemoryPolicy;
  34
  35 namespace android_webview {
  36
  37 namespace {
  38
  39 const int64 kFallbackTickTimeoutInMilliseconds = 100;
  40
  41 // Used to calculate memory allocation. Determined experimentally.
  42 const size_t kMemoryMultiplier = 20;
  43 const size_t kBytesPerPixel = 4;
  44 const size_t kMemoryAllocationStep = 5 * 1024 * 1024;
  45
  46 // Used to calculate tile allocation. Determined experimentally.
  47 const size_t kTileMultiplier = 12;
  48 const size_t kTileAllocationStep = 20;
  49 // This will be set by static function CalculateTileMemoryPolicy() during init.
  50 // See AwMainDelegate::BasicStartupComplete.
  51 size_t g_tile_area;
  52
  53 class TracedValue : public base::debug::ConvertableToTraceFormat {
  54  public:
  55   explicit TracedValue(base::Value* value) : value_(value) {}
  56   static scoped_refptr<base::debug::ConvertableToTraceFormat> FromValue(
  57       base::Value* value) {
  58     return scoped_refptr<base::debug::ConvertableToTraceFormat>(
  59         new TracedValue(value));
  60   }
  61   virtual void AppendAsTraceFormat(std::string* out) const OVERRIDE {
  62     std::string tmp;
  63     base::JSONWriter::Write(value_.get(), &tmp);
  64     *out += tmp;
  65   }
  66
  67  private:
  68   virtual ~TracedValue() {}
  69   scoped_ptr<base::Value> value_;
  70
  71   DISALLOW_COPY_AND_ASSIGN(TracedValue);
  72 };
  73
  74 }  // namespace
  75
  76 // static
  77 void BrowserViewRenderer::CalculateTileMemoryPolicy(bool use_zero_copy) {
  78   if (!use_zero_copy) {
  79     // Use chrome's default tile size, which varies from 256 to 512.
  80     // Be conservative here and use the smallest tile size possible.
  81     g_tile_area = 256 * 256;
  82
  83     // Also use a high tile limit since there are no file descriptor issues.
  84     GlobalTileManager::GetInstance()->SetTileLimit(1000);
  85     return;
  86   }
  87
  88   CommandLine* cl = CommandLine::ForCurrentProcess();
  89   const char kDefaultTileSize[] = "384";
  90
  91   if (!cl->HasSwitch(switches::kDefaultTileWidth))
  92     cl->AppendSwitchASCII(switches::kDefaultTileWidth, kDefaultTileSize);
  93
  94   if (!cl->HasSwitch(switches::kDefaultTileHeight))
  95     cl->AppendSwitchASCII(switches::kDefaultTileHeight, kDefaultTileSize);
  96
  97   size_t tile_size;
  98   base::StringToSizeT(kDefaultTileSize, &tile_size);
  99   g_tile_area = tile_size * tile_size;
 100 }
 101
 102 BrowserViewRenderer::BrowserViewRenderer(
 103     BrowserViewRendererClient* client,
 104     SharedRendererState* shared_renderer_state,
 105     content::WebContents* web_contents,
 106     const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner)
 107     : client_(client),
 108       shared_renderer_state_(shared_renderer_state),
 109       web_contents_(web_contents),
 110       ui_task_runner_(ui_task_runner),
 111       compositor_(NULL),
 112       is_paused_(false),
 113       view_visible_(false),
 114       window_visible_(false),
 115       attached_to_window_(false),
 116       hardware_enabled_(false),
 117       dip_scale_(0.0),
 118       page_scale_factor_(1.0),
 119       on_new_picture_enable_(false),
 120       clear_view_(false),
 121       compositor_needs_continuous_invalidate_(false),
 122       block_invalidates_(false),
 123       width_(0),
 124       height_(0),
 125       num_tiles_(0u),
 126       num_bytes_(0u) {
 127   CHECK(web_contents_);
 128   content::SynchronousCompositor::SetClientForWebContents(web_contents_, this);
 129
 130   // Currently the logic in this class relies on |compositor_| remaining
 131   // NULL until the DidInitializeCompositor() call, hence it is not set here.
 132 }
 133
 134 BrowserViewRenderer::~BrowserViewRenderer() {
 135   content::SynchronousCompositor::SetClientForWebContents(web_contents_, NULL);
 136   // OnDetachedFromWindow should be called before the destructor, so the memory
 137   // policy should have already been updated.
 138 }
 139
 140 // This function updates the cached memory policy in shared renderer state, as
 141 // well as the tile resource allocation in GlobalTileManager.
 142 void BrowserViewRenderer::TrimMemory(const int level, const bool visible) {
 143   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 144   // Constants from Android ComponentCallbacks2.
 145   enum {
 146     TRIM_MEMORY_RUNNING_LOW = 10,
 147     TRIM_MEMORY_UI_HIDDEN = 20,
 148     TRIM_MEMORY_BACKGROUND = 40,
 149   };
 150
 151   // Not urgent enough. TRIM_MEMORY_UI_HIDDEN is treated specially because
 152   // it does not indicate memory pressure, but merely that the app is
 153   // backgrounded.
 154   if (level < TRIM_MEMORY_RUNNING_LOW || level == TRIM_MEMORY_UI_HIDDEN)
 155     return;
 156
 157   // Do not release resources on view we expect to get DrawGL soon.
 158   if (level < TRIM_MEMORY_BACKGROUND && visible)
 159     return;
 160
 161   // Just set the memory limit to 0 and drop all tiles. This will be reset to
 162   // normal levels in the next DrawGL call.
 163   SynchronousCompositorMemoryPolicy zero_policy;
 164   if (memory_policy_ == zero_policy)
 165     return;
 166
 167   TRACE_EVENT0("android_webview", "BrowserViewRenderer::TrimMemory");
 168
 169   RequestMemoryPolicy(zero_policy);
 170   EnforceMemoryPolicyImmediately(zero_policy);
 171 }
 172
 173 SynchronousCompositorMemoryPolicy
 174 BrowserViewRenderer::CalculateDesiredMemoryPolicy() {
 175   SynchronousCompositorMemoryPolicy policy;
 176   size_t width = last_on_draw_global_visible_rect_.width();
 177   size_t height = last_on_draw_global_visible_rect_.height();
 178   policy.bytes_limit = kMemoryMultiplier * kBytesPerPixel * width * height;
 179   // Round up to a multiple of kMemoryAllocationStep.
 180   policy.bytes_limit =
 181       (policy.bytes_limit / kMemoryAllocationStep + 1) * kMemoryAllocationStep;
 182
 183   size_t tiles = width * height * kTileMultiplier / g_tile_area;
 184   // Round up to a multiple of kTileAllocationStep. The minimum number of tiles
 185   // is also kTileAllocationStep.
 186   tiles = (tiles / kTileAllocationStep + 1) * kTileAllocationStep;
 187   policy.num_resources_limit = tiles;
 188   return policy;
 189 }
 190
 191 // This function updates the cached memory policy in shared renderer state, as
 192 // well as the tile resource allocation in GlobalTileManager.
 193 void BrowserViewRenderer::RequestMemoryPolicy(
 194     SynchronousCompositorMemoryPolicy& new_policy) {
 195   // This will be used in SetNumTiles.
 196   num_bytes_ = new_policy.bytes_limit;
 197
 198   GlobalTileManager* manager = GlobalTileManager::GetInstance();
 199
 200   // The following line will call BrowserViewRenderer::SetTilesNum().
 201   manager->RequestTiles(new_policy.num_resources_limit, tile_manager_key_);
 202 }
 203
 204 void BrowserViewRenderer::SetNumTiles(size_t num_tiles,
 205                                       bool effective_immediately) {
 206   if (num_tiles == num_tiles_)
 207     return;
 208   num_tiles_ = num_tiles;
 209
 210   memory_policy_.num_resources_limit = num_tiles_;
 211   memory_policy_.bytes_limit = num_bytes_;
 212
 213   if (effective_immediately)
 214     EnforceMemoryPolicyImmediately(memory_policy_);
 215 }
 216
 217 void BrowserViewRenderer::EnforceMemoryPolicyImmediately(
 218     SynchronousCompositorMemoryPolicy new_policy) {
 219   compositor_->SetMemoryPolicy(new_policy);
 220   ForceFakeCompositeSW();
 221 }
 222
 223 size_t BrowserViewRenderer::GetNumTiles() const {
 224   return memory_policy_.num_resources_limit;
 225 }
 226
 227 bool BrowserViewRenderer::OnDraw(jobject java_canvas,
 228                                  bool is_hardware_canvas,
 229                                  const gfx::Vector2d& scroll,
 230                                  const gfx::Rect& global_visible_rect) {
 231   last_on_draw_scroll_offset_ = scroll;
 232   last_on_draw_global_visible_rect_ = global_visible_rect;
 233
 234   if (clear_view_)
 235     return false;
 236
 237   if (is_hardware_canvas && attached_to_window_ &&
 238       !switches::ForceAuxiliaryBitmap()) {
 239     return OnDrawHardware(java_canvas);
 240   }
 241
 242   // Perform a software draw
 243   return OnDrawSoftware(java_canvas);
 244 }
 245
 246 bool BrowserViewRenderer::OnDrawHardware(jobject java_canvas) {
 247   if (!compositor_)
 248     return false;
 249
 250   if (!hardware_enabled_) {
 251     hardware_enabled_ = compositor_->InitializeHwDraw();
 252     if (hardware_enabled_) {
 253       tile_manager_key_ = GlobalTileManager::GetInstance()->PushBack(this);
 254       gpu::GLInProcessContext* share_context = compositor_->GetShareContext();
 255       DCHECK(share_context);
 256       shared_renderer_state_->SetSharedContext(share_context);
 257     }
 258   }
 259   if (!hardware_enabled_)
 260     return false;
 261
 262   ReturnResourceFromParent();
 263   SynchronousCompositorMemoryPolicy new_policy = CalculateDesiredMemoryPolicy();
 264   RequestMemoryPolicy(new_policy);
 265   compositor_->SetMemoryPolicy(memory_policy_);
 266
 267   scoped_ptr<DrawGLInput> draw_gl_input(new DrawGLInput);
 268   draw_gl_input->scroll_offset = last_on_draw_scroll_offset_;
 269   draw_gl_input->width = width_;
 270   draw_gl_input->height = height_;
 271
 272   parent_draw_constraints_ = shared_renderer_state_->ParentDrawConstraints();
 273   gfx::Size surface_size(width_, height_);
 274   gfx::Rect viewport(surface_size);
 275   gfx::Rect clip = viewport;
 276   gfx::Transform transform_for_tile_priority =
 277       parent_draw_constraints_.transform;
 278
 279   // If the WebView is on a layer, WebView does not know what transform is
 280   // applied onto the layer so global visible rect does not make sense here.
 281   // In this case, just use the surface rect for tiling.
 282   gfx::Rect viewport_rect_for_tile_priority;
 283   if (parent_draw_constraints_.is_layer)
 284     viewport_rect_for_tile_priority = parent_draw_constraints_.surface_rect;
 285   else
 286     viewport_rect_for_tile_priority = last_on_draw_global_visible_rect_;
 287
 288   scoped_ptr<cc::CompositorFrame> frame =
 289       compositor_->DemandDrawHw(surface_size,
 290                                 gfx::Transform(),
 291                                 viewport,
 292                                 clip,
 293                                 viewport_rect_for_tile_priority,
 294                                 transform_for_tile_priority);
 295   if (!frame.get())
 296     return false;
 297
 298   GlobalTileManager::GetInstance()->DidUse(tile_manager_key_);
 299
 300   frame->AssignTo(&draw_gl_input->frame);
 301   ReturnUnusedResource(shared_renderer_state_->PassDrawGLInput());
 302   shared_renderer_state_->SetDrawGLInput(draw_gl_input.Pass());
 303   DidComposite();
 304   return client_->RequestDrawGL(java_canvas, false);
 305 }
 306
 307 void BrowserViewRenderer::UpdateParentDrawConstraints() {
 308   // Post an invalidate if the parent draw constraints are stale and there is
 309   // no pending invalidate.
 310   if (!parent_draw_constraints_.Equals(
 311           shared_renderer_state_->ParentDrawConstraints()))
 312     EnsureContinuousInvalidation(true);
 313 }
 314
 315 void BrowserViewRenderer::ReturnUnusedResource(scoped_ptr<DrawGLInput> input) {
 316   if (!input.get())
 317     return;
 318
 319   cc::CompositorFrameAck frame_ack;
 320   cc::TransferableResource::ReturnResources(
 321       input->frame.delegated_frame_data->resource_list,
 322       &frame_ack.resources);
 323   if (!frame_ack.resources.empty())
 324     compositor_->ReturnResources(frame_ack);
 325 }
 326
 327 void BrowserViewRenderer::ReturnResourceFromParent() {
 328   cc::CompositorFrameAck frame_ack;
 329   shared_renderer_state_->SwapReturnedResources(&frame_ack.resources);
 330   if (!frame_ack.resources.empty()) {
 331     compositor_->ReturnResources(frame_ack);
 332   }
 333 }
 334
 335 bool BrowserViewRenderer::OnDrawSoftware(jobject java_canvas) {
 336   if (!compositor_) {
 337     TRACE_EVENT_INSTANT0(
 338         "android_webview", "EarlyOut_NoCompositor", TRACE_EVENT_SCOPE_THREAD);
 339     return false;
 340   }
 341
 342   // TODO(hush): right now webview size is passed in as the auxiliary bitmap
 343   // size, which might hurt performace (only for software draws with auxiliary
 344   // bitmap). For better performance, get global visible rect, transform it
 345   // from screen space to view space, then intersect with the webview in
 346   // viewspace.  Use the resulting rect as the auxiliary
 347   // bitmap.
 348   return BrowserViewRendererJavaHelper::GetInstance()
 349       ->RenderViaAuxilaryBitmapIfNeeded(
 350           java_canvas,
 351           last_on_draw_scroll_offset_,
 352           gfx::Size(width_, height_),
 353           base::Bind(&BrowserViewRenderer::CompositeSW,
 354                      base::Unretained(this)));
 355 }
 356
 357 skia::RefPtr<SkPicture> BrowserViewRenderer::CapturePicture(int width,
 358                                                             int height) {
 359   TRACE_EVENT0("android_webview", "BrowserViewRenderer::CapturePicture");
 360
 361   // Return empty Picture objects for empty SkPictures.
 362   if (width <= 0 || height <= 0) {
 363     SkPictureRecorder emptyRecorder;
 364     emptyRecorder.beginRecording(0, 0);
 365     return skia::AdoptRef(emptyRecorder.endRecording());
 366   }
 367
 368   // Reset scroll back to the origin, will go back to the old
 369   // value when scroll_reset is out of scope.
 370   base::AutoReset<gfx::Vector2dF> scroll_reset(&scroll_offset_dip_,
 371                                                gfx::Vector2dF());
 372
 373   SkPictureRecorder recorder;
 374   SkCanvas* rec_canvas = recorder.beginRecording(width, height, NULL, 0);
 375   if (compositor_)
 376     CompositeSW(rec_canvas);
 377   return skia::AdoptRef(recorder.endRecording());
 378 }
 379
 380 void BrowserViewRenderer::EnableOnNewPicture(bool enabled) {
 381   on_new_picture_enable_ = enabled;
 382 }
 383
 384 void BrowserViewRenderer::ClearView() {
 385   TRACE_EVENT_INSTANT0("android_webview",
 386                        "BrowserViewRenderer::ClearView",
 387                        TRACE_EVENT_SCOPE_THREAD);
 388   if (clear_view_)
 389     return;
 390
 391   clear_view_ = true;
 392   // Always invalidate ignoring the compositor to actually clear the webview.
 393   EnsureContinuousInvalidation(true);
 394 }
 395
 396 void BrowserViewRenderer::SetIsPaused(bool paused) {
 397   TRACE_EVENT_INSTANT1("android_webview",
 398                        "BrowserViewRenderer::SetIsPaused",
 399                        TRACE_EVENT_SCOPE_THREAD,
 400                        "paused",
 401                        paused);
 402   is_paused_ = paused;
 403   EnsureContinuousInvalidation(false);
 404 }
 405
 406 void BrowserViewRenderer::SetViewVisibility(bool view_visible) {
 407   TRACE_EVENT_INSTANT1("android_webview",
 408                        "BrowserViewRenderer::SetViewVisibility",
 409                        TRACE_EVENT_SCOPE_THREAD,
 410                        "view_visible",
 411                        view_visible);
 412   view_visible_ = view_visible;
 413 }
 414
 415 void BrowserViewRenderer::SetWindowVisibility(bool window_visible) {
 416   TRACE_EVENT_INSTANT1("android_webview",
 417                        "BrowserViewRenderer::SetWindowVisibility",
 418                        TRACE_EVENT_SCOPE_THREAD,
 419                        "window_visible",
 420                        window_visible);
 421   window_visible_ = window_visible;
 422   EnsureContinuousInvalidation(false);
 423 }
 424
 425 void BrowserViewRenderer::OnSizeChanged(int width, int height) {
 426   TRACE_EVENT_INSTANT2("android_webview",
 427                        "BrowserViewRenderer::OnSizeChanged",
 428                        TRACE_EVENT_SCOPE_THREAD,
 429                        "width",
 430                        width,
 431                        "height",
 432                        height);
 433   width_ = width;
 434   height_ = height;
 435 }
 436
 437 void BrowserViewRenderer::OnAttachedToWindow(int width, int height) {
 438   TRACE_EVENT2("android_webview",
 439                "BrowserViewRenderer::OnAttachedToWindow",
 440                "width",
 441                width,
 442                "height",
 443                height);
 444   attached_to_window_ = true;
 445   width_ = width;
 446   height_ = height;
 447 }
 448
 449 void BrowserViewRenderer::OnDetachedFromWindow() {
 450   TRACE_EVENT0("android_webview", "BrowserViewRenderer::OnDetachedFromWindow");
 451   attached_to_window_ = false;
 452   DCHECK(!hardware_enabled_);
 453 }
 454
 455 void BrowserViewRenderer::ReleaseHardware() {
 456   DCHECK(hardware_enabled_);
 457   ReturnUnusedResource(shared_renderer_state_->PassDrawGLInput());
 458   ReturnResourceFromParent();
 459   DCHECK(shared_renderer_state_->ReturnedResourcesEmpty());
 460
 461   compositor_->ReleaseHwDraw();
 462   shared_renderer_state_->SetSharedContext(NULL);
 463   hardware_enabled_ = false;
 464
 465   SynchronousCompositorMemoryPolicy zero_policy;
 466   RequestMemoryPolicy(zero_policy);
 467   GlobalTileManager::GetInstance()->Remove(tile_manager_key_);
 468 }
 469
 470 bool BrowserViewRenderer::IsVisible() const {
 471   // Ignore |window_visible_| if |attached_to_window_| is false.
 472   return view_visible_ && (!attached_to_window_ || window_visible_);
 473 }
 474
 475 gfx::Rect BrowserViewRenderer::GetScreenRect() const {
 476   return gfx::Rect(client_->GetLocationOnScreen(), gfx::Size(width_, height_));
 477 }
 478
 479 void BrowserViewRenderer::DidInitializeCompositor(
 480     content::SynchronousCompositor* compositor) {
 481   TRACE_EVENT0("android_webview",
 482                "BrowserViewRenderer::DidInitializeCompositor");
 483   DCHECK(compositor);
 484   DCHECK(!compositor_);
 485   compositor_ = compositor;
 486 }
 487
 488 void BrowserViewRenderer::DidDestroyCompositor(
 489     content::SynchronousCompositor* compositor) {
 490   TRACE_EVENT0("android_webview", "BrowserViewRenderer::DidDestroyCompositor");
 491   DCHECK(compositor_);
 492   compositor_ = NULL;
 493   SynchronousCompositorMemoryPolicy zero_policy;
 494   DCHECK(memory_policy_ == zero_policy);
 495 }
 496
 497 void BrowserViewRenderer::SetContinuousInvalidate(bool invalidate) {
 498   if (compositor_needs_continuous_invalidate_ == invalidate)
 499     return;
 500
 501   TRACE_EVENT_INSTANT1("android_webview",
 502                        "BrowserViewRenderer::SetContinuousInvalidate",
 503                        TRACE_EVENT_SCOPE_THREAD,
 504                        "invalidate",
 505                        invalidate);
 506   compositor_needs_continuous_invalidate_ = invalidate;
 507
 508   EnsureContinuousInvalidation(false);
 509 }
 510
 511 void BrowserViewRenderer::SetDipScale(float dip_scale) {
 512   dip_scale_ = dip_scale;
 513   CHECK(dip_scale_ > 0);
 514 }
 515
 516 gfx::Vector2d BrowserViewRenderer::max_scroll_offset() const {
 517   DCHECK_GT(dip_scale_, 0);
 518   return gfx::ToCeiledVector2d(gfx::ScaleVector2d(
 519       max_scroll_offset_dip_, dip_scale_ * page_scale_factor_));
 520 }
 521
 522 void BrowserViewRenderer::ScrollTo(gfx::Vector2d scroll_offset) {
 523   gfx::Vector2d max_offset = max_scroll_offset();
 524   gfx::Vector2dF scroll_offset_dip;
 525   // To preserve the invariant that scrolling to the maximum physical pixel
 526   // value also scrolls to the maximum dip pixel value we transform the physical
 527   // offset into the dip offset by using a proportion (instead of dividing by
 528   // dip_scale * page_scale_factor).
 529   if (max_offset.x()) {
 530     scroll_offset_dip.set_x((scroll_offset.x() * max_scroll_offset_dip_.x()) /
 531                             max_offset.x());
 532   }
 533   if (max_offset.y()) {
 534     scroll_offset_dip.set_y((scroll_offset.y() * max_scroll_offset_dip_.y()) /
 535                             max_offset.y());
 536   }
 537
 538   DCHECK_LE(0, scroll_offset_dip.x());
 539   DCHECK_LE(0, scroll_offset_dip.y());
 540   DCHECK_LE(scroll_offset_dip.x(), max_scroll_offset_dip_.x());
 541   DCHECK_LE(scroll_offset_dip.y(), max_scroll_offset_dip_.y());
 542
 543   if (scroll_offset_dip_ == scroll_offset_dip)
 544     return;
 545
 546   scroll_offset_dip_ = scroll_offset_dip;
 547
 548   TRACE_EVENT_INSTANT2("android_webview",
 549                "BrowserViewRenderer::ScrollTo",
 550                TRACE_EVENT_SCOPE_THREAD,
 551                "x",
 552                scroll_offset_dip.x(),
 553                "y",
 554                scroll_offset_dip.y());
 555
 556   if (compositor_)
 557     compositor_->DidChangeRootLayerScrollOffset();
 558 }
 559
 560 void BrowserViewRenderer::DidUpdateContent() {
 561   TRACE_EVENT_INSTANT0("android_webview",
 562                        "BrowserViewRenderer::DidUpdateContent",
 563                        TRACE_EVENT_SCOPE_THREAD);
 564   clear_view_ = false;
 565   if (on_new_picture_enable_)
 566     client_->OnNewPicture();
 567 }
 568
 569 void BrowserViewRenderer::SetTotalRootLayerScrollOffset(
 570     gfx::Vector2dF scroll_offset_dip) {
 571   // TOOD(mkosiba): Add a DCHECK to say that this does _not_ get called during
 572   // DrawGl when http://crbug.com/249972 is fixed.
 573   if (scroll_offset_dip_ == scroll_offset_dip)
 574     return;
 575
 576   scroll_offset_dip_ = scroll_offset_dip;
 577
 578   gfx::Vector2d max_offset = max_scroll_offset();
 579   gfx::Vector2d scroll_offset;
 580   // For an explanation as to why this is done this way see the comment in
 581   // BrowserViewRenderer::ScrollTo.
 582   if (max_scroll_offset_dip_.x()) {
 583     scroll_offset.set_x((scroll_offset_dip.x() * max_offset.x()) /
 584                         max_scroll_offset_dip_.x());
 585   }
 586
 587   if (max_scroll_offset_dip_.y()) {
 588     scroll_offset.set_y((scroll_offset_dip.y() * max_offset.y()) /
 589                         max_scroll_offset_dip_.y());
 590   }
 591
 592   DCHECK(0 <= scroll_offset.x());
 593   DCHECK(0 <= scroll_offset.y());
 594   DCHECK(scroll_offset.x() <= max_offset.x());
 595   DCHECK(scroll_offset.y() <= max_offset.y());
 596
 597   client_->ScrollContainerViewTo(scroll_offset);
 598 }
 599
 600 gfx::Vector2dF BrowserViewRenderer::GetTotalRootLayerScrollOffset() {
 601   return scroll_offset_dip_;
 602 }
 603
 604 bool BrowserViewRenderer::IsExternalFlingActive() const {
 605   return client_->IsFlingActive();
 606 }
 607
 608 void BrowserViewRenderer::UpdateRootLayerState(
 609     const gfx::Vector2dF& total_scroll_offset_dip,
 610     const gfx::Vector2dF& max_scroll_offset_dip,
 611     const gfx::SizeF& scrollable_size_dip,
 612     float page_scale_factor,
 613     float min_page_scale_factor,
 614     float max_page_scale_factor) {
 615   TRACE_EVENT_INSTANT1(
 616       "android_webview",
 617       "BrowserViewRenderer::UpdateRootLayerState",
 618       TRACE_EVENT_SCOPE_THREAD,
 619       "state",
 620       TracedValue::FromValue(
 621           RootLayerStateAsValue(total_scroll_offset_dip, scrollable_size_dip)
 622               .release()));
 623
 624   DCHECK_GT(dip_scale_, 0);
 625
 626   max_scroll_offset_dip_ = max_scroll_offset_dip;
 627   DCHECK_LE(0, max_scroll_offset_dip_.x());
 628   DCHECK_LE(0, max_scroll_offset_dip_.y());
 629
 630   page_scale_factor_ = page_scale_factor;
 631   DCHECK_GT(page_scale_factor_, 0);
 632
 633   client_->UpdateScrollState(max_scroll_offset(),
 634                              scrollable_size_dip,
 635                              page_scale_factor,
 636                              min_page_scale_factor,
 637                              max_page_scale_factor);
 638   SetTotalRootLayerScrollOffset(total_scroll_offset_dip);
 639 }
 640
 641 scoped_ptr<base::Value> BrowserViewRenderer::RootLayerStateAsValue(
 642     const gfx::Vector2dF& total_scroll_offset_dip,
 643     const gfx::SizeF& scrollable_size_dip) {
 644   scoped_ptr<base::DictionaryValue> state(new base::DictionaryValue);
 645
 646   state->SetDouble("total_scroll_offset_dip.x", total_scroll_offset_dip.x());
 647   state->SetDouble("total_scroll_offset_dip.y", total_scroll_offset_dip.y());
 648
 649   state->SetDouble("max_scroll_offset_dip.x", max_scroll_offset_dip_.x());
 650   state->SetDouble("max_scroll_offset_dip.y", max_scroll_offset_dip_.y());
 651
 652   state->SetDouble("scrollable_size_dip.width", scrollable_size_dip.width());
 653   state->SetDouble("scrollable_size_dip.height", scrollable_size_dip.height());
 654
 655   state->SetDouble("page_scale_factor", page_scale_factor_);
 656   return state.PassAs<base::Value>();
 657 }
 658
 659 void BrowserViewRenderer::DidOverscroll(gfx::Vector2dF accumulated_overscroll,
 660                                         gfx::Vector2dF latest_overscroll_delta,
 661                                         gfx::Vector2dF current_fling_velocity) {
 662   const float physical_pixel_scale = dip_scale_ * page_scale_factor_;
 663   if (accumulated_overscroll == latest_overscroll_delta)
 664     overscroll_rounding_error_ = gfx::Vector2dF();
 665   gfx::Vector2dF scaled_overscroll_delta =
 666       gfx::ScaleVector2d(latest_overscroll_delta, physical_pixel_scale);
 667   gfx::Vector2d rounded_overscroll_delta = gfx::ToRoundedVector2d(
 668       scaled_overscroll_delta + overscroll_rounding_error_);
 669   overscroll_rounding_error_ =
 670       scaled_overscroll_delta - rounded_overscroll_delta;
 671   client_->DidOverscroll(rounded_overscroll_delta);
 672 }
 673
 674 void BrowserViewRenderer::EnsureContinuousInvalidation(bool force_invalidate) {
 675   // This method should be called again when any of these conditions change.
 676   bool need_invalidate =
 677       compositor_needs_continuous_invalidate_ || force_invalidate;
 678   if (!need_invalidate || block_invalidates_)
 679     return;
 680
 681   // Always call view invalidate. We rely the Android framework to ignore the
 682   // invalidate when it's not needed such as when view is not visible.
 683   client_->PostInvalidate();
 684
 685   // Stop fallback ticks when one of these is true.
 686   // 1) Webview is paused. Also need to check we are not in clear view since
 687   // paused, offscreen still expect clear view to recover.
 688   // 2) If we are attached to window and the window is not visible (eg when
 689   // app is in the background). We are sure in this case the webview is used
 690   // "on-screen" but that updates are not needed when in the background.
 691   bool throttle_fallback_tick =
 692       (is_paused_ && !clear_view_) || (attached_to_window_ && !window_visible_);
 693   if (throttle_fallback_tick)
 694     return;
 695
 696   block_invalidates_ = compositor_needs_continuous_invalidate_;
 697
 698   // Unretained here is safe because the callbacks are cancelled when
 699   // they are destroyed.
 700   post_fallback_tick_.Reset(base::Bind(&BrowserViewRenderer::PostFallbackTick,
 701                                        base::Unretained(this)));
 702   fallback_tick_fired_.Cancel();
 703
 704   // No need to reschedule fallback tick if compositor does not need to be
 705   // ticked. This can happen if this is reached because force_invalidate is
 706   // true.
 707   if (compositor_needs_continuous_invalidate_)
 708     ui_task_runner_->PostTask(FROM_HERE, post_fallback_tick_.callback());
 709 }
 710
 711 void BrowserViewRenderer::PostFallbackTick() {
 712   DCHECK(fallback_tick_fired_.IsCancelled());
 713   fallback_tick_fired_.Reset(base::Bind(&BrowserViewRenderer::FallbackTickFired,
 714                                         base::Unretained(this)));
 715   if (compositor_needs_continuous_invalidate_) {
 716     ui_task_runner_->PostDelayedTask(
 717         FROM_HERE,
 718         fallback_tick_fired_.callback(),
 719         base::TimeDelta::FromMilliseconds(kFallbackTickTimeoutInMilliseconds));
 720   }
 721 }
 722
 723 void BrowserViewRenderer::FallbackTickFired() {
 724   TRACE_EVENT1("android_webview",
 725                "BrowserViewRenderer::FallbackTickFired",
 726                "compositor_needs_continuous_invalidate_",
 727                compositor_needs_continuous_invalidate_);
 728
 729   // This should only be called if OnDraw or DrawGL did not come in time, which
 730   // means block_invalidates_ must still be true.
 731   DCHECK(block_invalidates_);
 732   if (compositor_needs_continuous_invalidate_ && compositor_)
 733     ForceFakeCompositeSW();
 734 }
 735
 736 void BrowserViewRenderer::ForceFakeCompositeSW() {
 737   DCHECK(compositor_);
 738   SkBitmap bitmap;
 739   bitmap.allocN32Pixels(1, 1);
 740   bitmap.eraseColor(0);
 741   SkCanvas canvas(bitmap);
 742   CompositeSW(&canvas);
 743 }
 744
 745 bool BrowserViewRenderer::CompositeSW(SkCanvas* canvas) {
 746   DCHECK(compositor_);
 747   ReturnResourceFromParent();
 748   bool result = compositor_->DemandDrawSw(canvas);
 749   DidComposite();
 750   return result;
 751 }
 752
 753 void BrowserViewRenderer::DidComposite() {
 754   block_invalidates_ = false;
 755   post_fallback_tick_.Cancel();
 756   fallback_tick_fired_.Cancel();
 757   EnsureContinuousInvalidation(false);
 758 }
 759
 760 std::string BrowserViewRenderer::ToString(AwDrawGLInfo* draw_info) const {
 761   std::string str;
 762   base::StringAppendF(&str, "is_paused: %d ", is_paused_);
 763   base::StringAppendF(&str, "view_visible: %d ", view_visible_);
 764   base::StringAppendF(&str, "window_visible: %d ", window_visible_);
 765   base::StringAppendF(&str, "dip_scale: %f ", dip_scale_);
 766   base::StringAppendF(&str, "page_scale_factor: %f ", page_scale_factor_);
 767   base::StringAppendF(&str,
 768                       "compositor_needs_continuous_invalidate: %d ",
 769                       compositor_needs_continuous_invalidate_);
 770   base::StringAppendF(&str, "block_invalidates: %d ", block_invalidates_);
 771   base::StringAppendF(&str, "view width height: [%d %d] ", width_, height_);
 772   base::StringAppendF(&str, "attached_to_window: %d ", attached_to_window_);
 773   base::StringAppendF(&str,
 774                       "global visible rect: %s ",
 775                       last_on_draw_global_visible_rect_.ToString().c_str());
 776   base::StringAppendF(
 777       &str, "scroll_offset_dip: %s ", scroll_offset_dip_.ToString().c_str());
 778   base::StringAppendF(&str,
 779                       "overscroll_rounding_error_: %s ",
 780                       overscroll_rounding_error_.ToString().c_str());
 781   base::StringAppendF(
 782       &str, "on_new_picture_enable: %d ", on_new_picture_enable_);
 783   base::StringAppendF(&str, "clear_view: %d ", clear_view_);
 784   if (draw_info) {
 785     base::StringAppendF(&str,
 786                         "clip left top right bottom: [%d %d %d %d] ",
 787                         draw_info->clip_left,
 788                         draw_info->clip_top,
 789                         draw_info->clip_right,
 790                         draw_info->clip_bottom);
 791     base::StringAppendF(&str,
 792                         "surface width height: [%d %d] ",
 793                         draw_info->width,
 794                         draw_info->height);
 795     base::StringAppendF(&str, "is_layer: %d ", draw_info->is_layer);
 796   }
 797   return str;
 798 }
 799
 800 }  // namespace android_webview