src/cc/resources/content_layer_updater.cc

   1 // Copyright 2011 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 "cc/resources/content_layer_updater.h"
   6
   7 #include "base/debug/trace_event.h"
   8 #include "base/time/time.h"
   9 #include "cc/debug/rendering_stats_instrumentation.h"
  10 #include "cc/resources/layer_painter.h"
  11 #include "third_party/skia/include/core/SkCanvas.h"
  12 #include "third_party/skia/include/core/SkPaint.h"
  13 #include "third_party/skia/include/core/SkRect.h"
  14 #include "third_party/skia/include/core/SkScalar.h"
  15 #include "ui/gfx/rect_conversions.h"
  16 #include "ui/gfx/rect_f.h"
  17
  18 namespace cc {
  19
  20 ContentLayerUpdater::ContentLayerUpdater(
  21     scoped_ptr<LayerPainter> painter,
  22     RenderingStatsInstrumentation* stats_instrumentation,
  23     int layer_id)
  24     : rendering_stats_instrumentation_(stats_instrumentation),
  25       layer_id_(layer_id),
  26       layer_is_opaque_(false),
  27       layer_fills_bounds_completely_(false),
  28       painter_(painter.Pass()) {}
  29
  30 ContentLayerUpdater::~ContentLayerUpdater() {}
  31
  32 void ContentLayerUpdater::set_rendering_stats_instrumentation(
  33     RenderingStatsInstrumentation* rsi) {
  34   rendering_stats_instrumentation_ = rsi;
  35 }
  36
  37 void ContentLayerUpdater::PaintContents(SkCanvas* canvas,
  38                                         const gfx::Rect& content_rect,
  39                                         float contents_width_scale,
  40                                         float contents_height_scale,
  41                                         gfx::Rect* resulting_opaque_rect) {
  42   TRACE_EVENT0("cc", "ContentLayerUpdater::PaintContents");
  43   if (!canvas)
  44     return;
  45   canvas->save();
  46   canvas->translate(SkFloatToScalar(-content_rect.x()),
  47                     SkFloatToScalar(-content_rect.y()));
  48
  49   // The |canvas| backing should be sized to hold the |content_rect|.
  50   DCHECK_EQ(content_rect.width(), canvas->getBaseLayerSize().width());
  51   DCHECK_EQ(content_rect.height(), canvas->getBaseLayerSize().height());
  52
  53   gfx::Rect layer_rect = content_rect;
  54   if (contents_width_scale != 1.f || contents_height_scale != 1.f) {
  55     canvas->scale(SkFloatToScalar(contents_width_scale),
  56                   SkFloatToScalar(contents_height_scale));
  57
  58     layer_rect = gfx::ScaleToEnclosingRect(
  59         content_rect, 1.f / contents_width_scale, 1.f / contents_height_scale);
  60   }
  61
  62   SkRect layer_sk_rect = SkRect::MakeXYWH(
  63       layer_rect.x(), layer_rect.y(), layer_rect.width(), layer_rect.height());
  64
  65   canvas->clipRect(layer_sk_rect);
  66
  67   // If the layer has opaque contents or will fill the bounds completely there
  68   // is no need to clear the canvas before painting.
  69   if (!layer_is_opaque_ && !layer_fills_bounds_completely_) {
  70     TRACE_EVENT0("cc", "Clear");
  71     canvas->drawColor(SK_ColorTRANSPARENT, SkXfermode::kSrc_Mode);
  72   }
  73
  74   gfx::RectF opaque_layer_rect;
  75   painter_->Paint(canvas, layer_rect, &opaque_layer_rect);
  76   canvas->restore();
  77
  78   gfx::Rect opaque_content_rect = gfx::ToEnclosedRect(gfx::ScaleRect(
  79       opaque_layer_rect, contents_width_scale, contents_height_scale));
  80   *resulting_opaque_rect = opaque_content_rect;
  81
  82   content_rect_ = content_rect;
  83 }
  84
  85 void ContentLayerUpdater::SetOpaque(bool opaque) {
  86   layer_is_opaque_ = opaque;
  87 }
  88
  89 void ContentLayerUpdater::SetFillsBoundsCompletely(bool fills_bounds) {
  90   layer_fills_bounds_completely_ = fills_bounds;
  91 }
  92
  93 }  // namespace cc