Change ScrollbarLayer to use UI resource

cc/layers/scrollbar_layer.cc

-
 // Copyright 2012 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 "cc/layers/scrollbar_layer.h"
 
 #include "base/auto_reset.h"
 #include "base/basictypes.h"
 #include "base/debug/trace_event.h"
 #include "cc/layers/scrollbar_layer_impl.h"
-#include "cc/resources/caching_bitmap_content_layer_updater.h"
-#include "cc/resources/layer_painter.h"
-#include "cc/resources/prioritized_resource.h"
-#include "cc/resources/resource_update_queue.h"
+#include "cc/resources/ui_resource_bitmap.h"
 #include "cc/trees/layer_tree_host.h"
+#include "cc/trees/layer_tree_impl.h"
+#include "skia/ext/platform_canvas.h"
+#include "skia/ext/refptr.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkSize.h"
 #include "ui/gfx/rect_conversions.h"
 
 namespace cc {
 
 scoped_ptr<LayerImpl> ScrollbarLayer::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
   return ScrollbarLayerImpl::Create(
       tree_impl, id(), scrollbar_->Orientation()).PassAs<LayerImpl>();
 }
 
 scoped_refptr<ScrollbarLayer> ScrollbarLayer::Create(
     scoped_ptr<Scrollbar> scrollbar,
     int scroll_layer_id) {
-  return make_scoped_refptr(new ScrollbarLayer(scrollbar.Pass(),
-                                               scroll_layer_id));
+  return make_scoped_refptr(
+      new ScrollbarLayer(scrollbar.Pass(), scroll_layer_id));
 }
 
 ScrollbarLayer::ScrollbarLayer(
     scoped_ptr<Scrollbar> scrollbar,
     int scroll_layer_id)
     : scrollbar_(scrollbar.Pass()),
-      scroll_layer_id_(scroll_layer_id),
-      texture_format_(GL_INVALID_ENUM) {
+      scroll_layer_id_(scroll_layer_id) {
   if (!scrollbar_->IsOverlay())
     SetShouldScrollOnMainThread(true);
 }
 
 ScrollbarLayer::~ScrollbarLayer() {}
 
 void ScrollbarLayer::SetScrollLayerId(int id) {
   if (id == scroll_layer_id_)
     return;
 
@@ skipping 71 matching lines @@
   }
   scrollbar_layer->set_thumb_length(thumb_length_);
   if (Orientation() == HORIZONTAL) {
     scrollbar_layer->set_track_start(track_rect_.x());
     scrollbar_layer->set_track_length(track_rect_.width());
   } else {
     scrollbar_layer->set_track_start(track_rect_.y());
     scrollbar_layer->set_track_length(track_rect_.height());
   }
 
-  if (track_ && track_->texture()->have_backing_texture())
-    scrollbar_layer->set_track_resource_id(track_->texture()->resource_id());
-  else
-    scrollbar_layer->set_track_resource_id(0);
-
-  if (thumb_ && thumb_->texture()->have_backing_texture())
-    scrollbar_layer->set_thumb_resource_id(thumb_->texture()->resource_id());
-  else
-    scrollbar_layer->set_thumb_resource_id(0);
+  if (track_resource_.get())
+    scrollbar_layer->set_track_ui_resource_id(track_resource_->id());
+  if (thumb_resource_.get())
+    scrollbar_layer->set_thumb_ui_resource_id(thumb_resource_->id());
 
   scrollbar_layer->set_is_overlay_scrollbar(scrollbar_->IsOverlay());
 
   // ScrollbarLayer must push properties every frame. crbug.com/259095
   needs_push_properties_ = true;
 }
 
 ScrollbarLayer* ScrollbarLayer::ToScrollbarLayer() {
   return this;
 }
 
 void ScrollbarLayer::SetLayerTreeHost(LayerTreeHost* host) {
+  // When the LTH is set to null or has changed, then this layer should remove
+  // all of its associated resources.
   if (!host || host != layer_tree_host()) {
-    track_updater_ = NULL;
-    track_.reset();
-    thumb_updater_ = NULL;
-    thumb_.reset();
+    track_resource_.reset();
+    thumb_resource_.reset();
   }
 
   ContentsScalingLayer::SetLayerTreeHost(host);
 }
 
-class ScrollbarPartPainter : public LayerPainter {
- public:
-  ScrollbarPartPainter(Scrollbar* scrollbar, ScrollbarPart part)
-      : scrollbar_(scrollbar),
-        part_(part) {}
-  virtual ~ScrollbarPartPainter() {}
-
-  // LayerPainter implementation
-  virtual void Paint(SkCanvas* canvas,
-                     gfx::Rect content_rect,
-                     gfx::RectF* opaque) OVERRIDE {
-    scrollbar_->PaintPart(canvas, part_, content_rect);
-  }
-
- private:
-  Scrollbar* scrollbar_;
-  ScrollbarPart part_;
-};
-
-void ScrollbarLayer::CreateUpdaterIfNeeded() {
-  if (layer_tree_host()->settings().solid_color_scrollbars)
-    return;
-
-  texture_format_ =
-      layer_tree_host()->GetRendererCapabilities().best_texture_format;
-
-  if (!track_updater_.get()) {
-    track_updater_ = CachingBitmapContentLayerUpdater::Create(
-        scoped_ptr<LayerPainter>(
-            new ScrollbarPartPainter(scrollbar_.get(), TRACK))
-            .Pass(),
-        rendering_stats_instrumentation(),
-        id());
-  }
-  if (!track_) {
-    track_ = track_updater_->CreateResource(
-        layer_tree_host()->contents_texture_manager());
-  }
-
-  if (!thumb_updater_.get()) {
-    thumb_updater_ = CachingBitmapContentLayerUpdater::Create(
-        scoped_ptr<LayerPainter>(
-            new ScrollbarPartPainter(scrollbar_.get(), THUMB))
-            .Pass(),
-        rendering_stats_instrumentation(),
-        id());
-  }
-  if (!thumb_ && scrollbar_->HasThumb()) {
-    thumb_ = thumb_updater_->CreateResource(
-        layer_tree_host()->contents_texture_manager());
-  }
-}
-
-bool ScrollbarLayer::UpdatePart(CachingBitmapContentLayerUpdater* painter,
-                                LayerUpdater::Resource* resource,
-                                gfx::Rect rect,
-                                ResourceUpdateQueue* queue) {
-  if (layer_tree_host()->settings().solid_color_scrollbars)
-    return false;
-
-  // Skip painting and uploading if there are no invalidations and
-  // we already have valid texture data.
-  if (resource->texture()->have_backing_texture() &&
-      resource->texture()->size() == rect.size() &&
-      !is_dirty())
-    return false;
-
-  // We should always have enough memory for UI.
-  DCHECK(resource->texture()->can_acquire_backing_texture());
-  if (!resource->texture()->can_acquire_backing_texture())
-    return false;
-
-  // Paint and upload the entire part.
-  gfx::Rect painted_opaque_rect;
-  painter->PrepareToUpdate(rect,
-                           rect.size(),
-                           contents_scale_x(),
-                           contents_scale_y(),
-                           &painted_opaque_rect);
-  if (!painter->pixels_did_change() &&
-      resource->texture()->have_backing_texture()) {
-    TRACE_EVENT_INSTANT0("cc",
-                         "ScrollbarLayer::UpdatePart no texture upload needed",
-                         TRACE_EVENT_SCOPE_THREAD);
-    return false;
-  }
-
-  bool partial_updates_allowed =
-      layer_tree_host()->settings().max_partial_texture_updates > 0;
-  if (!partial_updates_allowed)
-    resource->texture()->ReturnBackingTexture();
-
-  gfx::Vector2d dest_offset(0, 0);
-  resource->Update(queue, rect, dest_offset, partial_updates_allowed);
-  return true;
-}
-
 gfx::Rect ScrollbarLayer::ScrollbarLayerRectToContentRect(
     gfx::Rect layer_rect) const {
   // Don't intersect with the bounds as in LayerRectToContentRect() because
   // layer_rect here might be in coordinates of the containing layer.
   gfx::Rect expanded_rect = gfx::ScaleToEnclosingRect(
       layer_rect, contents_scale_y(), contents_scale_y());
   // We should never return a rect bigger than the content_bounds().
   gfx::Size clamped_size = expanded_rect.size();
   clamped_size.SetToMin(content_bounds());
   expanded_rect.set_size(clamped_size);
   return expanded_rect;
 }
 
-void ScrollbarLayer::SetTexturePriorities(
-    const PriorityCalculator& priority_calc) {
-  if (layer_tree_host()->settings().solid_color_scrollbars)
-    return;
-
-  if (content_bounds().IsEmpty())
-    return;
-  DCHECK_LE(content_bounds().width(), MaxTextureSize());
-  DCHECK_LE(content_bounds().height(), MaxTextureSize());
-
-  CreateUpdaterIfNeeded();
-
-  bool draws_to_root = !render_target()->parent();
-  if (track_) {
-    track_->texture()->SetDimensions(content_bounds(), texture_format_);
-    track_->texture()->set_request_priority(
-        PriorityCalculator::UIPriority(draws_to_root));
+gfx::Rect ScrollbarLayer::OriginThumbRect() const {
+  gfx::Size thumb_size;
+  if (Orientation() == HORIZONTAL) {
+    thumb_size =
+        gfx::Size(scrollbar_->ThumbLength(), scrollbar_->ThumbThickness());
+  } else {
+    thumb_size =
+        gfx::Size(scrollbar_->ThumbThickness(), scrollbar_->ThumbLength());
   }
-  if (thumb_) {
-    gfx::Size thumb_size = OriginThumbRect().size();
-    thumb_->texture()->SetDimensions(thumb_size, texture_format_);
-    thumb_->texture()->set_request_priority(
-        PriorityCalculator::UIPriority(draws_to_root));
-  }
+  return ScrollbarLayerRectToContentRect(gfx::Rect(thumb_size));
 }
 
 bool ScrollbarLayer::Update(ResourceUpdateQueue* queue,
                             const OcclusionTracker* occlusion) {
   track_rect_ = scrollbar_->TrackRect();
 
   if (layer_tree_host()->settings().solid_color_scrollbars)
     return false;
 
   {
     base::AutoReset<bool> ignore_set_needs_commit(&ignore_set_needs_commit_,
                                                   true);
     ContentsScalingLayer::Update(queue, occlusion);
   }
 
-  dirty_rect_.Union(update_rect_);
-  if (content_bounds().IsEmpty())
-    return false;
-  if (visible_content_rect().IsEmpty())
-    return false;
 
-  CreateUpdaterIfNeeded();
-
-  gfx::Rect content_rect = ScrollbarLayerRectToContentRect(
-      gfx::Rect(scrollbar_->Location(), bounds()));
-  bool updated = UpdatePart(track_updater_.get(), track_.get(), content_rect,
-                            queue);
+  track_resource_ = ScopedUIResource::Create(
+      layer_tree_host(),
+      RasterizeScrollbarPart(ScrollbarLayerRectToContentRect(
+                                 gfx::Rect(scrollbar_->Location(), bounds())),
+                             TRACK));
 
   if (scrollbar_->HasThumb()) {
     thumb_thickness_ = scrollbar_->ThumbThickness();
     thumb_length_ = scrollbar_->ThumbLength();
-    gfx::Rect origin_thumb_rect = OriginThumbRect();
-    if (!origin_thumb_rect.IsEmpty()) {
-      updated |= UpdatePart(thumb_updater_.get(), thumb_.get(),
-                            origin_thumb_rect, queue);
-    }
+
+    thumb_resource_ = ScopedUIResource::Create(
+        layer_tree_host(), RasterizeScrollbarPart(OriginThumbRect(), THUMB));
   }
 
-  dirty_rect_ = gfx::RectF();
-  return updated;
+  return true;
 }
 
-gfx::Rect ScrollbarLayer::OriginThumbRect() const {
-  gfx::Size thumb_size;
-  if (Orientation() == HORIZONTAL) {
-    thumb_size = gfx::Size(scrollbar_->ThumbLength(),
-                           scrollbar_->ThumbThickness());
-  } else {
-    thumb_size = gfx::Size(scrollbar_->ThumbThickness(),
-                           scrollbar_->ThumbLength());
-  }
-  return ScrollbarLayerRectToContentRect(gfx::Rect(thumb_size));
+scoped_refptr<UIResourceBitmap> ScrollbarLayer::RasterizeScrollbarPart(
+    gfx::Rect rect,
+    ScrollbarPart part) {
+  DCHECK(!layer_tree_host()->settings().solid_color_scrollbars);
+
+  scoped_refptr<UIResourceBitmap> bitmap =
+      UIResourceBitmap::Create(new uint8_t[rect.width() * rect.height() * 4],
+                               UIResourceBitmap::RGBA8,
+                               rect.size());
+
+  SkBitmap skbitmap;
+  skbitmap.setConfig(SkBitmap::kARGB_8888_Config, rect.width(), rect.height());
+  skbitmap.setPixels(bitmap->GetPixels());
+
+  SkCanvas skcanvas(skbitmap);
+  skcanvas.translate(SkFloatToScalar(-rect.x()), SkFloatToScalar(-rect.y()));
+  skcanvas.scale(SkFloatToScalar(contents_scale_x()),
+                 SkFloatToScalar(contents_scale_y()));
+
+  gfx::Rect layer_rect = rect;
+  if (contents_scale_x() != 1.f || contents_scale_y() != 1.f)

[aelias_OOO_until_Jul13, 2013/08/03 01:34:23]

This if() statement doesn't change any behavior so you can get rid of it.

[powei, 2013/08/05 23:49:29]

Done.

+    layer_rect = gfx::ScaleToEnclosingRect(
+        rect, 1.f / contents_scale_x(), 1.f / contents_scale_y());
+
+  SkRect layer_skrect = SkRect::MakeXYWH(

[aelias_OOO_until_Jul13, 2013/08/03 01:34:23]

Use RectToSkRect() in ui/gfx/skia_util.h instead.

[powei, 2013/08/05 23:49:29]

Done.

+      layer_rect.x(), layer_rect.y(), layer_rect.width(), layer_rect.height());
+
+  SkPaint paint;
+  paint.setAntiAlias(false);
+  paint.setXfermodeMode(SkXfermode::kClear_Mode);
+  skcanvas.drawRect(layer_skrect, paint);
+  skcanvas.clipRect(layer_skrect);
+
+  scrollbar_->PaintPart(&skcanvas, part, layer_rect);
+
+  return bitmap;
 }
 
 }  // namespace cc