Use nine-patch resource for drawing Aura overlay scrollbar thumb.

cc/quads/nine_patch_generator.cc

Index: cc/quads/nine_patch_generator.cc
diff --git a/cc/quads/nine_patch_generator.cc b/cc/quads/nine_patch_generator.cc
new file mode 100644
index 0000000000000000000000000000000000000000..27e9f772a1390284c4dd98e9f100996eca5e0b87
--- /dev/null
+++ b/cc/quads/nine_patch_generator.cc
@@ -0,0 +1,398 @@
+// Copyright 2016 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/quads/nine_patch_generator.h"
+
+#include "cc/layers/draw_properties.h"
+#include "cc/quads/render_pass.h"
+#include "cc/quads/texture_draw_quad.h"
+#include "cc/trees/layer_tree_impl.h"
+#include "ui/gfx/geometry/rect_conversions.h"
+#include "ui/gfx/geometry/rect_f.h"
+
+namespace cc {
+
+namespace {
+
+// Maximum number of patches that can be produced for one NinePatchLayer.
+const int kMaxOcclusionPatches = 12;
+const int kMaxPatches = 9;
+
+gfx::RectF BoundsToRect(int x1, int y1, int x2, int y2) {
+  return gfx::RectF(x1, y1, x2 - x1, y2 - y1);
+}
+
+gfx::RectF NormalizedRect(const gfx::RectF& rect,
+                          float total_width,
+                          float total_height) {
+  return gfx::RectF(rect.x() / total_width, rect.y() / total_height,
+                    rect.width() / total_width, rect.height() / total_height);
+}
+
+}  // namespace
+
+NinePatchGenerator::Patch::Patch(const gfx::RectF& image_rect,
+                                 const gfx::Size& total_image_bounds,
+                                 const gfx::RectF& output_rect)
+    : image_rect(image_rect),
+      normalized_image_rect(NormalizedRect(image_rect,
+                                           total_image_bounds.width(),
+                                           total_image_bounds.height())),
+      output_rect(output_rect) {}
+
+NinePatchGenerator::NinePatchGenerator()
+    : fill_center_(false), nearest_neighbor_(false) {}
+
+bool NinePatchGenerator::SetLayout(const gfx::Size& image_bounds,
+                                   const gfx::Size& output_bounds,
+                                   const gfx::Rect& aperture,
+                                   const gfx::Rect& border,
+                                   const gfx::Rect& output_occlusion,
+                                   bool fill_center,
+                                   bool nearest_neighbor) {
+  if (image_bounds_ == image_bounds && output_bounds_ == output_bounds &&
+      image_aperture_ == aperture && border_ == border &&
+      fill_center_ == fill_center && output_occlusion_ == output_occlusion &&
+      nearest_neighbor_ == nearest_neighbor)
+    return false;
+
+  image_bounds_ = image_bounds;
+  output_bounds_ = output_bounds;
+  image_aperture_ = aperture;
+  border_ = border;
+  fill_center_ = fill_center;
+  output_occlusion_ = output_occlusion;
+  nearest_neighbor_ = nearest_neighbor;
+
+  CheckGeometryLimitations();
+
+  return true;
+}
+
+void NinePatchGenerator::CheckGeometryLimitations() {
+  // |border| is in layer space.  It cannot exceed the bounds of the layer.
+  DCHECK_GE(output_bounds_.width(), border_.width());
+  DCHECK_GE(output_bounds_.height(), border_.height());
+
+  // Sanity Check on |border|
+  DCHECK_LE(border_.x(), border_.width());
+  DCHECK_LE(border_.y(), border_.height());
+  DCHECK_GE(border_.x(), 0);
+  DCHECK_GE(border_.y(), 0);
+
+  // |aperture| is in image space.  It cannot exceed the bounds of the bitmap.
+  DCHECK(!image_aperture_.size().IsEmpty());
+  DCHECK(gfx::Rect(image_bounds_).Contains(image_aperture_))
+      << "image_bounds_ " << gfx::Rect(image_bounds_).ToString()
+      << " image_aperture_ " << image_aperture_.ToString();
+
+  // Sanity check on |output_occlusion_|. It should always be within the
+  // border.
+  gfx::Rect border_rect(border_.x(), border_.y(),
+                        output_bounds_.width() - border_.width(),
+                        output_bounds_.height() - border_.height());
+  DCHECK(output_occlusion_.IsEmpty() || output_occlusion_.Contains(border_rect))
+      << "border_rect " << border_rect.ToString() << " output_occlusion_ "
+      << output_occlusion_.ToString();
+}
+
+std::vector<NinePatchGenerator::Patch>
+NinePatchGenerator::ComputeQuadsWithoutOcclusion() const {
+  float image_width = image_bounds_.width();
+  float image_height = image_bounds_.height();
+  float output_width = output_bounds_.width();
+  float output_height = output_bounds_.height();
+  gfx::RectF output_aperture(border_.x(), border_.y(),
+                             output_width - border_.width(),
+                             output_height - border_.height());
+
+  std::vector<Patch> patches;
+  patches.reserve(kMaxPatches);
+
+  // Top-left.
+  patches.push_back(
+      Patch(BoundsToRect(0, 0, image_aperture_.x(), image_aperture_.y()),
+            image_bounds_,
+            BoundsToRect(0, 0, output_aperture.x(), output_aperture.y())));
+
+  // Top-right.
+  patches.push_back(Patch(BoundsToRect(image_aperture_.right(), 0, image_width,
+                                       image_aperture_.y()),
+                          image_bounds_,
+                          BoundsToRect(output_aperture.right(), 0, output_width,
+                                       output_aperture.y())));
+
+  // Bottom-left.
+  patches.push_back(Patch(BoundsToRect(0, image_aperture_.bottom(),
+                                       image_aperture_.x(), image_height),
+                          image_bounds_,
+                          BoundsToRect(0, output_aperture.bottom(),
+                                       output_aperture.x(), output_height)));
+
+  // Bottom-right.
+  patches.push_back(
+      Patch(BoundsToRect(image_aperture_.right(), image_aperture_.bottom(),
+                         image_width, image_height),
+            image_bounds_,
+            BoundsToRect(output_aperture.right(), output_aperture.bottom(),
+                         output_width, output_height)));
+
+  // Top.
+  patches.push_back(
+      Patch(BoundsToRect(image_aperture_.x(), 0, image_aperture_.right(),
+                         image_aperture_.y()),
+            image_bounds_,
+            BoundsToRect(output_aperture.x(), 0, output_aperture.right(),
+                         output_aperture.y())));
+
+  // Left.
+  patches.push_back(
+      Patch(BoundsToRect(0, image_aperture_.y(), image_aperture_.x(),
+                         image_aperture_.bottom()),
+            image_bounds_,
+            BoundsToRect(0, output_aperture.y(), output_aperture.x(),
+                         output_aperture.bottom())));
+
+  // Right.
+  patches.push_back(
+      Patch(BoundsToRect(image_aperture_.right(), image_aperture_.y(),
+                         image_width, image_aperture_.bottom()),
+            image_bounds_,
+            BoundsToRect(output_aperture.right(), output_aperture.y(),
+                         output_width, output_aperture.bottom())));
+
+  // Bottom.
+  patches.push_back(
+      Patch(BoundsToRect(image_aperture_.x(), image_aperture_.bottom(),
+                         image_aperture_.right(), image_height),
+            image_bounds_,
+            BoundsToRect(output_aperture.x(), output_aperture.bottom(),
+                         output_aperture.right(), output_height)));
+
+  // Center.
+  if (fill_center_) {
+    patches.push_back(
+        Patch(BoundsToRect(image_aperture_.x(), image_aperture_.y(),
+                           image_aperture_.right(), image_aperture_.bottom()),
+              image_bounds_,
+              BoundsToRect(output_aperture.x(), output_aperture.y(),
+                           output_aperture.right(), output_aperture.bottom())));
+  }
+
+  return patches;
+}
+
+std::vector<NinePatchGenerator::Patch>
+NinePatchGenerator::ComputeQuadsWithOcclusion() const {
+  float image_width = image_bounds_.width();
+  float image_height = image_bounds_.height();
+
+  float output_width = output_bounds_.width();
+  float output_height = output_bounds_.height();
+
+  float layer_border_right = border_.width() - border_.x();
+  float layer_border_bottom = border_.height() - border_.y();
+
+  float image_aperture_right = image_width - image_aperture_.right();
+  float image_aperture_bottom = image_height - image_aperture_.bottom();
+
+  float output_occlusion_right = output_width - output_occlusion_.right();
+  float output_occlusion_bottom = output_height - output_occlusion_.bottom();
+
+  gfx::RectF image_occlusion(BoundsToRect(
+      border_.x() == 0
+          ? 0
+          : (output_occlusion_.x() * image_aperture_.x() / border_.x()),
+      border_.y() == 0
+          ? 0
+          : (output_occlusion_.y() * image_aperture_.y() / border_.y()),
+      image_width - (layer_border_right == 0
+                         ? 0
+                         : output_occlusion_right * image_aperture_right /
+                               layer_border_right),
+      image_height - (layer_border_bottom == 0
+                          ? 0
+                          : output_occlusion_bottom * image_aperture_bottom /
+                                layer_border_bottom)));
+  gfx::RectF output_aperture(border_.x(), border_.y(),
+                             output_width - border_.width(),
+                             output_height - border_.height());
+
+  std::vector<Patch> patches;
+  patches.reserve(kMaxOcclusionPatches);
+
+  // Top-left-left.
+  patches.push_back(
+      Patch(BoundsToRect(0, 0, image_occlusion.x(), image_aperture_.y()),
+            image_bounds_,
+            BoundsToRect(0, 0, output_occlusion_.x(), output_aperture.y())));
+
+  // Top-left-right.
+  patches.push_back(
+      Patch(BoundsToRect(image_occlusion.x(), 0, image_aperture_.x(),
+                         image_occlusion.y()),
+            image_bounds_,
+            BoundsToRect(output_occlusion_.x(), 0, output_aperture.x(),
+                         output_occlusion_.y())));
+
+  // Top-center.
+  patches.push_back(
+      Patch(BoundsToRect(image_aperture_.x(), 0, image_aperture_.right(),
+                         image_occlusion.y()),
+            image_bounds_,
+            BoundsToRect(output_aperture.x(), 0, output_aperture.right(),
+                         output_occlusion_.y())));
+
+  // Top-right-left.
+  patches.push_back(
+      Patch(BoundsToRect(image_aperture_.right(), 0, image_occlusion.right(),
+                         image_occlusion.y()),
+            image_bounds_,
+            BoundsToRect(output_aperture.right(), 0, output_occlusion_.right(),
+                         output_occlusion_.y())));
+
+  // Top-right-right.
+  patches.push_back(Patch(BoundsToRect(image_occlusion.right(), 0, image_width,
+                                       image_aperture_.y()),
+                          image_bounds_,
+                          BoundsToRect(output_occlusion_.right(), 0,
+                                       output_width, output_aperture.y())));
+
+  // Left-center.
+  patches.push_back(
+      Patch(BoundsToRect(0, image_aperture_.y(), image_occlusion.x(),
+                         image_aperture_.bottom()),
+            image_bounds_,
+            BoundsToRect(0, output_aperture.y(), output_occlusion_.x(),
+                         output_aperture.bottom())));
+
+  // Right-center.
+  patches.push_back(
+      Patch(BoundsToRect(image_occlusion.right(), image_aperture_.y(),
+                         image_width, image_aperture_.bottom()),
+            image_bounds_,
+            BoundsToRect(output_occlusion_.right(), output_aperture.y(),
+                         output_width, output_aperture.bottom())));
+
+  // Bottom-left-left.
+  patches.push_back(Patch(BoundsToRect(0, image_aperture_.bottom(),
+                                       image_occlusion.x(), image_height),
+                          image_bounds_,
+                          BoundsToRect(0, output_aperture.bottom(),
+                                       output_occlusion_.x(), output_height)));
+
+  // Bottom-left-right.
+  patches.push_back(
+      Patch(BoundsToRect(image_occlusion.x(), image_occlusion.bottom(),
+                         image_aperture_.x(), image_height),
+            image_bounds_,
+            BoundsToRect(output_occlusion_.x(), output_occlusion_.bottom(),
+                         output_aperture.x(), output_height)));
+
+  // Bottom-center.
+  patches.push_back(
+      Patch(BoundsToRect(image_aperture_.x(), image_occlusion.bottom(),
+                         image_aperture_.right(), image_height),
+            image_bounds_,
+            BoundsToRect(output_aperture.x(), output_occlusion_.bottom(),
+                         output_aperture.right(), output_height)));
+
+  // Bottom-right-left.
+  patches.push_back(
+      Patch(BoundsToRect(image_aperture_.right(), image_occlusion.bottom(),
+                         image_occlusion.right(), image_height),
+            image_bounds_,
+            BoundsToRect(output_aperture.right(), output_occlusion_.bottom(),
+                         output_occlusion_.right(), output_height)));
+
+  // Bottom-right-right.
+  patches.push_back(
+      Patch(BoundsToRect(image_occlusion.right(), image_aperture_.bottom(),
+                         image_width, image_height),
+            image_bounds_,
+            BoundsToRect(output_occlusion_.right(), output_aperture.bottom(),
+                         output_width, output_height)));
+
+  return patches;
+}
+
+std::vector<NinePatchGenerator::Patch> NinePatchGenerator::GeneratePatches()
+    const {
+  DCHECK(!output_bounds_.IsEmpty());
+
+  std::vector<Patch> patches;
+
+  if (output_occlusion_.IsEmpty() || fill_center_)
+    patches = ComputeQuadsWithoutOcclusion();
+  else
+    patches = ComputeQuadsWithOcclusion();
+
+  return patches;
+}
+
+void NinePatchGenerator::AppendQuads(LayerImpl* layer_impl,
+                                     UIResourceId ui_resource_id,
+                                     RenderPass* render_pass,
+                                     SharedQuadState* shared_quad_state,
+                                     const std::vector<Patch>& patches) {
+  if (!ui_resource_id)
+    return;
+
+  ResourceId resource =
+      layer_impl->layer_tree_impl()->ResourceIdForUIResource(ui_resource_id);
+
+  if (!resource)
+    return;
+
+  const float vertex_opacity[] = {1.0f, 1.0f, 1.0f, 1.0f};
+  const bool opaque =
+      layer_impl->layer_tree_impl()->IsUIResourceOpaque(ui_resource_id);
+  constexpr bool flipped = false;
+  constexpr bool premultiplied_alpha = true;
+
+  for (const auto& patch : patches) {
+    gfx::Rect output_rect = gfx::ToEnclosingRect(patch.output_rect);
+    gfx::Rect visible_rect =
+        layer_impl->draw_properties()
+            .occlusion_in_content_space.GetUnoccludedContentRect(output_rect);
+    gfx::Rect opaque_rect = opaque ? visible_rect : gfx::Rect();
+    if (!visible_rect.IsEmpty()) {
+      gfx::RectF image_rect = patch.normalized_image_rect;
+      TextureDrawQuad* quad =
+          render_pass->CreateAndAppendDrawQuad<TextureDrawQuad>();
+      quad->SetNew(shared_quad_state, output_rect, opaque_rect, visible_rect,
+                   resource, premultiplied_alpha, image_rect.origin(),
+                   image_rect.bottom_right(), SK_ColorTRANSPARENT,
+                   vertex_opacity, flipped, nearest_neighbor_, false);
+      layer_impl->ValidateQuadResources(quad);
+    }
+  }
+}
+
+void NinePatchGenerator::AsJson(base::DictionaryValue* dictionary) const {
+  base::ListValue* list = new base::ListValue;
+  list->AppendInteger(image_aperture_.origin().x());
+  list->AppendInteger(image_aperture_.origin().y());
+  list->AppendInteger(image_aperture_.size().width());
+  list->AppendInteger(image_aperture_.size().height());
+  dictionary->Set("ImageAperture", list);
+
+  list = new base::ListValue;
+  list->AppendInteger(image_bounds_.width());
+  list->AppendInteger(image_bounds_.height());
+  dictionary->Set("ImageBounds", list);
+
+  dictionary->Set("Border", MathUtil::AsValue(border_).release());
+
+  dictionary->SetBoolean("FillCenter", fill_center_);
+
+  list = new base::ListValue;
+  list->AppendInteger(output_occlusion_.x());
+  list->AppendInteger(output_occlusion_.y());
+  list->AppendInteger(output_occlusion_.width());
+  list->AppendInteger(output_occlusion_.height());
+  dictionary->Set("OutputOcclusion", list);
+}
+
+}  // namespace cc