Implements core logic for Pixel Canvas

ui/views/paint_info_unittest.cc

Index: ui/views/paint_info_unittest.cc
diff --git a/ui/views/paint_info_unittest.cc b/ui/views/paint_info_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..873c4ad0668580d51932b76532914e0e1984c450
--- /dev/null
+++ b/ui/views/paint_info_unittest.cc
@@ -0,0 +1,242 @@
+// Copyright 2017 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 "ui/views/paint_info.h"
+
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "cc/base/region.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/compositor/compositor_switches.h"
+#include "ui/compositor/paint_context.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/geometry/size.h"
+
+namespace views {
+namespace {
+
+typedef testing::Test PaintInfoTest;
+
+// Device scale factors
+constexpr float DSF100 = 1.f;
+constexpr float DSF125 = 1.25f;
+constexpr float DSF150 = 1.5f;
+constexpr float DSF160 = 1.6f;
+constexpr float DSF166 = 1.66f;
+
+const std::vector<float> kDsfList = {DSF100, DSF125, DSF150, DSF160, DSF166};
+
+const gfx::Size kLayerSize(123, 456);
+
+//  ___________
+// |     1     |
+// |___________|
+// | 3 | 4 | 5 | <-- 2
+// |___|___|___|
+// |   7   | 8 | <-- 6
+// |_______|___|
+const gfx::Rect r_0(kLayerSize);

[sky, 2017/07/26 22:12:12]

constexpr on these.

[malaykeshav, 2017/07/28 01:24:38]

Done

+
+const gfx::Rect r_0_1(0, 0, 123, 152);
+
+const gfx::Rect r_0_2(0, 152, 123, 152);
+const gfx::Rect r_2_3(0, 0, 41, 152);
+const gfx::Rect r_2_4(41, 0, 41, 152);
+const gfx::Rect r_2_5(82, 0, 41, 152);
+
+const gfx::Rect r_0_6(0, 304, 123, 152);
+const gfx::Rect r_6_7(0, 0, 82, 152);
+const gfx::Rect r_6_8(82, 0, 41, 152);
+
+//  ___________
+// |     1     |
+// |___________|
+// | 3 | 4 | 5 | <-- 2

[sky, 2017/07/26 22:12:12]

The <-- 2 isn't clear at all. Maybe you mean there 2 wraps 3/4/5? Not sure.
Please make the rectangle names line up with the rectangles you have. I would
expect a rectangle named r1 to match 1 in the diagram.

[malaykeshav, 2017/07/28 01:24:38]

Done. Adding further comments

+// |___|___|___|
+// |   7   | 8 | <-- 6
+// |_______|___|
+// Returns the following arrangement of paint recording bounds for the given
+// |dsf|
+std::vector<PaintInfo*> GetPaintInfoSetup(const ui::PaintContext& context) {

[sky, 2017/07/26 22:12:12]

Passing around raw pointers like this is a recipe for leaks. Return a
std::vector<std::unique_ptr<PaintInfo>>

[malaykeshav, 2017/07/28 01:24:38]

Done

+  std::vector<PaintInfo*> info_list(9);
+
+  info_list[0] = new PaintInfo(context, kLayerSize);
+
+  info_list[1] = new PaintInfo(*info_list[0], r_0_1, r_0,
+                               PaintInfo::ScaleType::kScaleToFit);
+
+  info_list[2] = new PaintInfo(*info_list[0], r_0_2, r_0,
+                               PaintInfo::ScaleType::kScaleToFit);
+  info_list[3] = new PaintInfo(*info_list[2], r_2_3, r_0_2,
+                               PaintInfo::ScaleType::kScaleToFit);
+  info_list[4] = new PaintInfo(*info_list[2], r_2_4, r_0_2,
+                               PaintInfo::ScaleType::kScaleToFit);
+  info_list[5] = new PaintInfo(*info_list[2], r_2_5, r_0_2,
+                               PaintInfo::ScaleType::kScaleToFit);
+
+  info_list[6] = new PaintInfo(*info_list[0], r_0_6, r_0,
+                               PaintInfo::ScaleType::kScaleToFit);
+  info_list[7] = new PaintInfo(*info_list[6], r_6_7, r_0_6,
+                               PaintInfo::ScaleType::kScaleToFit);
+  info_list[8] = new PaintInfo(*info_list[6], r_6_8, r_0_6,
+                               PaintInfo::ScaleType::kScaleToFit);
+
+  return info_list;
+}
+
+// Verifies that the child recording bounds completely cover the parent
+// recording bounds.
+void VerifyChildBoundsCoversParent(PaintInfo* parent_paint_info,

[sky, 2017/07/26 22:12:12]

Can both of these parameters be const refs? That makes it clear the arguments
aren't mofieid.

[malaykeshav, 2017/07/28 01:24:38]

Done

+                                   std::vector<PaintInfo*> info_list) {
+  cc::Region remaining(gfx::Rect(parent_paint_info->paint_recording_size()));
+  int times_empty = 0;
+  for (auto* paint_info : info_list) {
+    const gfx::Rect& child_recording_bounds =
+        paint_info->paint_recording_bounds() -
+        parent_paint_info->paint_recording_bounds().OffsetFromOrigin();
+    EXPECT_TRUE(remaining.Contains(child_recording_bounds))
+        << "Remaining: " << remaining.ToString()
+        << " paint recording bounds: " << child_recording_bounds.ToString();
+    remaining.Subtract(child_recording_bounds);
+    times_empty += remaining.IsEmpty();
+  }
+  EXPECT_EQ(times_empty, 1);
+}
+
+void VerifyPixelCanvasCornerScaling(std::vector<PaintInfo*> info_list) {
+  // child 1, child 2 and child 6 should completely cover child 0.
+  std::vector<PaintInfo*> child_info_list;
+  child_info_list.push_back(info_list[1]);
+  child_info_list.push_back(info_list[2]);
+  child_info_list.push_back(info_list[6]);
+  VerifyChildBoundsCoversParent(info_list[0], child_info_list);
+  child_info_list.clear();
+
+  // Child 3,4 and 5 should completely cover child 2.
+  child_info_list.push_back(info_list[3]);
+  child_info_list.push_back(info_list[4]);
+  child_info_list.push_back(info_list[5]);
+  VerifyChildBoundsCoversParent(info_list[2], child_info_list);
+  child_info_list.clear();
+
+  // Child 7 and 8 should completely cover child 6.
+  child_info_list.push_back(info_list[7]);
+  child_info_list.push_back(info_list[8]);
+  VerifyChildBoundsCoversParent(info_list[6], child_info_list);
+  child_info_list.clear();
+}
+
+void ClearAllPaintInfo(std::vector<PaintInfo*> info_list) {
+  for (auto* paint_info : info_list)
+    delete paint_info;
+}
+
+void VerifyPixelSizesAreSameAsDIPSize(std::vector<PaintInfo*> info_list) {
+  EXPECT_EQ(info_list[0]->paint_recording_size(), r_0.size());
+
+  EXPECT_EQ(info_list[1]->paint_recording_size(), r_0_1.size());
+
+  EXPECT_EQ(info_list[2]->paint_recording_size(), r_0_2.size());
+  EXPECT_EQ(info_list[3]->paint_recording_size(), r_2_3.size());
+  EXPECT_EQ(info_list[4]->paint_recording_size(), r_2_4.size());
+  EXPECT_EQ(info_list[5]->paint_recording_size(), r_2_5.size());
+
+  EXPECT_EQ(info_list[6]->paint_recording_size(), r_0_6.size());
+  EXPECT_EQ(info_list[7]->paint_recording_size(), r_6_7.size());
+  EXPECT_EQ(info_list[8]->paint_recording_size(), r_6_8.size());
+}
+
+void VerifyInvalidationRects(float dsf, bool pixel_canvas_enabled) {
+  std::vector<gfx::Rect> invalidation_rects = {
+      gfx::Rect(0, 0, 123, 41),     // Intersects with 0 & 1.
+      gfx::Rect(0, 76, 60, 152),    // Intersects 0, 1, 2, 3 & 4.
+      gfx::Rect(41, 152, 41, 152),  // Intersects with 0, 2 & 4.
+      gfx::Rect(80, 320, 4, 4),     // Intersects with 0, 6, 7 & 8.
+      gfx::Rect(40, 151, 43, 154),  // Intersects all
+      gfx::Rect(82, 304, 1, 1),     // Intersects with 0, 6 & 8.
+      gfx::Rect(81, 303, 2, 2)      // Intersects with 0, 2, 4, 5, 6, 7, 8
+  };
+
+  std::vector<std::vector<int>> repaint_indices = {
+      std::vector<int>{0, 1},
+      std::vector<int>{0, 1, 2, 3, 4},
+      std::vector<int>{0, 2, 4},
+      std::vector<int>{0, 6, 7, 8},
+      std::vector<int>{0, 1, 2, 3, 4, 5, 6, 7, 8},
+      std::vector<int>{0, 6, 8},
+      std::vector<int>{0, 2, 4, 5, 6, 7, 8}};
+
+  std::vector<PaintInfo*> info_list;
+
+  EXPECT_EQ(repaint_indices.size(), invalidation_rects.size());
+  for (size_t i = 0; i < invalidation_rects.size(); i++) {
+    ui::PaintContext context(nullptr, dsf, invalidation_rects[i],
+                             pixel_canvas_enabled);
+    info_list = GetPaintInfoSetup(context);
+    for (size_t j = 0; j < repaint_indices[i].size(); j++) {
+      EXPECT_TRUE(info_list[repaint_indices[i][j]]->context().IsRectInvalid(
+          gfx::Rect(info_list[repaint_indices[i][j]]->paint_recording_size())));
+    }
+    ClearAllPaintInfo(info_list);
+  }
+}
+
+}  // namespace
+
+TEST_F(PaintInfoTest, CornerScalingPixelCanvasEnabled) {
+  std::vector<PaintInfo*> info_list;
+  for (float dsf : kDsfList) {
+    ui::PaintContext context(nullptr, dsf, gfx::Rect(), true);
+    info_list = GetPaintInfoSetup(context);
+    VerifyPixelCanvasCornerScaling(info_list);
+    ClearAllPaintInfo(info_list);
+  }
+
+  // More accurate testing for 1.25 dsf
+  ui::PaintContext context(nullptr, DSF125, gfx::Rect(), true);
+  info_list = GetPaintInfoSetup(context);
+  VerifyPixelCanvasCornerScaling(info_list);
+  EXPECT_EQ(info_list[0]->paint_recording_size(), gfx::Size(154, 570));
+
+  EXPECT_EQ(info_list[1]->paint_recording_size(), gfx::Size(154, 190));
+
+  EXPECT_EQ(info_list[2]->paint_recording_bounds(),
+            gfx::Rect(0, 190, 154, 190));
+  EXPECT_EQ(info_list[3]->paint_recording_size(), gfx::Size(51, 190));
+  EXPECT_EQ(info_list[4]->paint_recording_bounds(),
+            gfx::Rect(51, 190, 52, 190));
+  EXPECT_EQ(info_list[5]->paint_recording_bounds(),
+            gfx::Rect(103, 190, 51, 190));
+
+  EXPECT_EQ(info_list[6]->paint_recording_bounds(),
+            gfx::Rect(0, 380, 154, 190));
+  EXPECT_EQ(info_list[7]->paint_recording_size(), gfx::Size(103, 190));
+  EXPECT_EQ(info_list[8]->paint_recording_bounds(),
+            gfx::Rect(103, 380, 51, 190));
+  ClearAllPaintInfo(info_list);
+}
+
+TEST_F(PaintInfoTest, ScalingWithPixelCanvasDisabled) {
+  // With dsf as 1, there should be no scaling and size should be same.
+  ui::PaintContext context_1(nullptr, DSF100, gfx::Rect(), false);
+  std::vector<PaintInfo*> info_list = GetPaintInfoSetup(context_1);
+  for (float dsf : kDsfList) {
+    ui::PaintContext context_2(nullptr, dsf, gfx::Rect(), false);
+    info_list = GetPaintInfoSetup(context_2);
+    VerifyPixelCanvasCornerScaling(info_list);
+    VerifyPixelSizesAreSameAsDIPSize(info_list);
+    ClearAllPaintInfo(info_list);
+  }
+}
+
+TEST_F(PaintInfoTest, Invalidation) {
+  for (float dsf : kDsfList) {
+    VerifyInvalidationRects(dsf, false);
+    VerifyInvalidationRects(dsf, true);
+  }
+}
+
+}  // namespace views