// Copyright 2014 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/painted_scrollbar_layer_impl.h"

#include <stddef.h>

#include "cc/resources/ui_resource_bitmap.h"
#include "cc/test/layer_test_common.h"
#include "components/viz/common/quads/draw_quad.h"
#include "components/viz/common/quads/texture_draw_quad.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace cc {
namespace {

TEST(PaintedScrollbarLayerImplTest, Occlusion) {
  gfx::Size layer_size(10, 1000);
  float scale = 2.f;
  gfx::Size scaled_layer_size(20, 2000);
  gfx::Size viewport_size(1000, 1000);
  float thumb_opacity = 0.2f;

  LayerTestCommon::LayerImplTest impl;

  SkBitmap thumb_sk_bitmap;
  thumb_sk_bitmap.allocN32Pixels(10, 10);
  thumb_sk_bitmap.setImmutable();
  UIResourceId thumb_uid = 5;
  UIResourceBitmap thumb_bitmap(thumb_sk_bitmap);
  impl.host_impl()->CreateUIResource(thumb_uid, thumb_bitmap);

  SkBitmap track_sk_bitmap;
  track_sk_bitmap.allocN32Pixels(10, 10);
  track_sk_bitmap.setImmutable();
  UIResourceId track_uid = 6;
  UIResourceBitmap track_bitmap(track_sk_bitmap);
  impl.host_impl()->CreateUIResource(track_uid, track_bitmap);

  ScrollbarOrientation orientation = VERTICAL;

  PaintedScrollbarLayerImpl* scrollbar_layer_impl =
      impl.AddChildToRoot<PaintedScrollbarLayerImpl>(orientation, false, false);
  scrollbar_layer_impl->SetBounds(layer_size);
  scrollbar_layer_impl->SetContentsOpaque(true);
  scrollbar_layer_impl->set_internal_contents_scale_and_bounds(
      scale, scaled_layer_size);
  scrollbar_layer_impl->SetDrawsContent(true);
  scrollbar_layer_impl->SetThumbThickness(layer_size.width());
  scrollbar_layer_impl->SetThumbLength(500);
  scrollbar_layer_impl->SetTrackLength(layer_size.height());
  scrollbar_layer_impl->SetCurrentPos(100.f / 4);
  scrollbar_layer_impl->SetClipLayerLength(100.f);
  scrollbar_layer_impl->SetScrollLayerLength(200.f);
  scrollbar_layer_impl->set_track_ui_resource_id(track_uid);
  scrollbar_layer_impl->set_thumb_ui_resource_id(thumb_uid);
  scrollbar_layer_impl->set_thumb_opacity(thumb_opacity);

  impl.CalcDrawProps(viewport_size);

  gfx::Rect thumb_rect = scrollbar_layer_impl->ComputeThumbQuadRect();
  EXPECT_EQ(gfx::Rect(0, 500 / 4, 10, layer_size.height() / 2).ToString(),
            thumb_rect.ToString());

  {
    SCOPED_TRACE("No occlusion");
    gfx::Rect occluded;
    impl.AppendQuadsWithOcclusion(scrollbar_layer_impl, occluded);

    size_t partially_occluded_count = 0;
    LayerTestCommon::VerifyQuadsAreOccluded(
        impl.quad_list(), occluded, &partially_occluded_count);
    EXPECT_EQ(2u, impl.quad_list().size());
    EXPECT_EQ(0u, partially_occluded_count);

    // Note: this is also testing that the thumb and track are both
    // scaled by the internal contents scale.  It's not occlusion-related
    // but is easy to verify here.
    const viz::DrawQuad* thumb_draw_quad = impl.quad_list().ElementAt(0);
    const viz::DrawQuad* track_draw_quad = impl.quad_list().ElementAt(1);

    EXPECT_EQ(viz::DrawQuad::TEXTURE_CONTENT, thumb_draw_quad->material);
    EXPECT_EQ(viz::DrawQuad::TEXTURE_CONTENT, track_draw_quad->material);

    const viz::TextureDrawQuad* thumb_quad =
        viz::TextureDrawQuad::MaterialCast(thumb_draw_quad);
    const viz::TextureDrawQuad* track_quad =
        viz::TextureDrawQuad::MaterialCast(track_draw_quad);

    gfx::Rect scaled_thumb_rect = gfx::ScaleToEnclosingRect(thumb_rect, scale);
    EXPECT_EQ(track_quad->rect.ToString(),
              gfx::Rect(scaled_layer_size).ToString());
    EXPECT_EQ(scrollbar_layer_impl->contents_opaque(),
              track_quad->shared_quad_state->are_contents_opaque);
    EXPECT_EQ(track_quad->visible_rect.ToString(),
              gfx::Rect(scaled_layer_size).ToString());
    EXPECT_FALSE(track_quad->needs_blending);
    EXPECT_EQ(thumb_quad->rect.ToString(), scaled_thumb_rect.ToString());
    EXPECT_EQ(thumb_quad->visible_rect.ToString(),
              scaled_thumb_rect.ToString());
    EXPECT_TRUE(thumb_quad->needs_blending);
    EXPECT_EQ(scrollbar_layer_impl->contents_opaque(),
              thumb_quad->shared_quad_state->are_contents_opaque);
    for (size_t i = 0; i < 4; ++i) {
      EXPECT_EQ(thumb_opacity, thumb_quad->vertex_opacity[i]);
      EXPECT_EQ(1.f, track_quad->vertex_opacity[i]);
    }
  }

  {
    SCOPED_TRACE("Full occlusion");
    gfx::Rect occluded(scrollbar_layer_impl->visible_layer_rect());
    impl.AppendQuadsWithOcclusion(scrollbar_layer_impl, occluded);

    LayerTestCommon::VerifyQuadsExactlyCoverRect(impl.quad_list(), gfx::Rect());
    EXPECT_EQ(impl.quad_list().size(), 0u);
  }

  {
    SCOPED_TRACE("Partial occlusion");
    gfx::Rect occluded(0, 0, 5, 1000);
    impl.AppendQuadsWithOcclusion(scrollbar_layer_impl, occluded);

    size_t partially_occluded_count = 0;
    LayerTestCommon::VerifyQuadsAreOccluded(
        impl.quad_list(), occluded, &partially_occluded_count);
    // The layer outputs two quads, which is partially occluded.
    EXPECT_EQ(2u, impl.quad_list().size());
    EXPECT_EQ(2u, partially_occluded_count);
  }
}

}  // namespace
}  // namespace cc