src/cc/layers/layer_position_constraint_unittest.cc

   1 // Copyright 2013 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/layers/layer_position_constraint.h"
   6
   7 #include <vector>
   8
   9 #include "cc/layers/layer_impl.h"
  10 #include "cc/test/fake_impl_proxy.h"
  11 #include "cc/test/fake_layer_tree_host_impl.h"
  12 #include "cc/test/geometry_test_utils.h"
  13 #include "cc/test/test_shared_bitmap_manager.h"
  14 #include "cc/trees/layer_tree_host_common.h"
  15 #include "testing/gtest/include/gtest/gtest.h"
  16
  17 namespace cc {
  18 namespace {
  19
  20 void SetLayerPropertiesForTesting(LayerImpl* layer,
  21                                   const gfx::Transform& transform,
  22                                   const gfx::Point3F& transform_origin,
  23                                   const gfx::PointF& position,
  24                                   const gfx::Size& bounds,
  25                                   bool flatten_transform) {
  26   layer->SetTransform(transform);
  27   layer->SetTransformOrigin(transform_origin);
  28   layer->SetPosition(position);
  29   layer->SetBounds(bounds);
  30   layer->SetShouldFlattenTransform(flatten_transform);
  31   layer->SetContentBounds(bounds);
  32 }
  33
  34 void ExecuteCalculateDrawProperties(LayerImpl* root_layer,
  35                                     float device_scale_factor,
  36                                     float page_scale_factor,
  37                                     LayerImpl* page_scale_application_layer,
  38                                     bool can_use_lcd_text) {
  39   gfx::Transform identity_matrix;
  40   std::vector<LayerImpl*> dummy_render_surface_layer_list;
  41   LayerImpl* scroll_layer = root_layer->children()[0];
  42   gfx::Size device_viewport_size =
  43       gfx::Size(root_layer->bounds().width() * device_scale_factor,
  44                 root_layer->bounds().height() * device_scale_factor);
  45
  46   // We are probably not testing what is intended if the scroll_layer bounds are
  47   // empty.
  48   DCHECK(!scroll_layer->bounds().IsEmpty());
  49   LayerTreeHostCommon::CalcDrawPropsImplInputsForTesting inputs(
  50       root_layer, device_viewport_size, &dummy_render_surface_layer_list);
  51   inputs.device_scale_factor = device_scale_factor;
  52   inputs.page_scale_factor = page_scale_factor;
  53   inputs.page_scale_application_layer = page_scale_application_layer;
  54   inputs.can_use_lcd_text = can_use_lcd_text;
  55   LayerTreeHostCommon::CalculateDrawProperties(&inputs);
  56 }
  57
  58 void ExecuteCalculateDrawProperties(LayerImpl* root_layer) {
  59   LayerImpl* page_scale_application_layer = NULL;
  60   ExecuteCalculateDrawProperties(
  61       root_layer, 1.f, 1.f, page_scale_application_layer, false);
  62 }
  63
  64 class LayerPositionConstraintTest : public testing::Test {
  65  public:
  66   LayerPositionConstraintTest() : host_impl_(&proxy_, &shared_bitmap_manager_) {
  67     root_ = CreateTreeForTest();
  68     scroll_ = root_->children()[0];
  69     fixed_to_top_left_.set_is_fixed_position(true);
  70     fixed_to_bottom_right_.set_is_fixed_position(true);
  71     fixed_to_bottom_right_.set_is_fixed_to_right_edge(true);
  72     fixed_to_bottom_right_.set_is_fixed_to_bottom_edge(true);
  73   }
  74
  75   scoped_ptr<LayerImpl> CreateTreeForTest() {
  76     scoped_ptr<LayerImpl> root =
  77         LayerImpl::Create(host_impl_.active_tree(), 42);
  78     scoped_ptr<LayerImpl> scroll_layer =
  79         LayerImpl::Create(host_impl_.active_tree(), 1);
  80     scoped_ptr<LayerImpl> child =
  81         LayerImpl::Create(host_impl_.active_tree(), 2);
  82     scoped_ptr<LayerImpl> grand_child =
  83         LayerImpl::Create(host_impl_.active_tree(), 3);
  84     scoped_ptr<LayerImpl> great_grand_child =
  85         LayerImpl::Create(host_impl_.active_tree(), 4);
  86
  87     gfx::Transform IdentityMatrix;
  88     gfx::Point3F transform_origin;
  89     gfx::PointF position;
  90     gfx::Size bounds(200, 200);
  91     gfx::Size clip_bounds(100, 100);
  92     SetLayerPropertiesForTesting(scroll_layer.get(),
  93                                  IdentityMatrix,
  94                                  transform_origin,
  95                                  position,
  96                                  bounds,
  97                                  true);
  98     SetLayerPropertiesForTesting(
  99         child.get(), IdentityMatrix, transform_origin, position, bounds, true);
 100     SetLayerPropertiesForTesting(grand_child.get(),
 101                                  IdentityMatrix,
 102                                  transform_origin,
 103                                  position,
 104                                  bounds,
 105                                  true);
 106     SetLayerPropertiesForTesting(great_grand_child.get(),
 107                                  IdentityMatrix,
 108                                  transform_origin,
 109                                  position,
 110                                  bounds,
 111                                  true);
 112
 113     root->SetBounds(clip_bounds);
 114     scroll_layer->SetScrollClipLayer(root->id());
 115     child->SetScrollClipLayer(root->id());
 116     grand_child->SetScrollClipLayer(root->id());
 117
 118     grand_child->AddChild(great_grand_child.Pass());
 119     child->AddChild(grand_child.Pass());
 120     scroll_layer->AddChild(child.Pass());
 121     root->AddChild(scroll_layer.Pass());
 122
 123     return root.Pass();
 124   }
 125
 126  protected:
 127   FakeImplProxy proxy_;
 128   TestSharedBitmapManager shared_bitmap_manager_;
 129   FakeLayerTreeHostImpl host_impl_;
 130   scoped_ptr<LayerImpl> root_;
 131   LayerImpl* scroll_;
 132
 133   LayerPositionConstraint fixed_to_top_left_;
 134   LayerPositionConstraint fixed_to_bottom_right_;
 135 };
 136
 137 namespace {
 138
 139 void SetFixedContainerSizeDelta(LayerImpl* scroll_layer,
 140                                 const gfx::Vector2d& delta) {
 141   DCHECK(scroll_layer);
 142   DCHECK(scroll_layer->scrollable());
 143
 144   LayerImpl* container_layer = scroll_layer->scroll_clip_layer();
 145   container_layer->SetBoundsDelta(delta);
 146 }
 147 }  // namespace
 148
 149 TEST_F(LayerPositionConstraintTest,
 150      ScrollCompensationForFixedPositionLayerWithDirectContainer) {
 151   // This test checks for correct scroll compensation when the fixed-position
 152   // container is the direct parent of the fixed-position layer.
 153   LayerImpl* child = scroll_->children()[0];
 154   LayerImpl* grand_child = child->children()[0];
 155
 156   child->SetIsContainerForFixedPositionLayers(true);
 157   grand_child->SetPositionConstraint(fixed_to_top_left_);
 158
 159   // Case 1: scroll delta of 0, 0
 160   child->SetScrollDelta(gfx::Vector2d(0, 0));
 161   ExecuteCalculateDrawProperties(root_.get());
 162
 163   gfx::Transform expected_child_transform;
 164   gfx::Transform expected_grand_child_transform = expected_child_transform;
 165
 166   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 167                                   child->draw_transform());
 168   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 169                                   grand_child->draw_transform());
 170
 171   // Case 2: scroll delta of 10, 10
 172   child->SetScrollDelta(gfx::Vector2d(10, 10));
 173   ExecuteCalculateDrawProperties(root_.get());
 174
 175   // Here the child is affected by scroll delta, but the fixed position
 176   // grand_child should not be affected.
 177   expected_child_transform.MakeIdentity();
 178   expected_child_transform.Translate(-10.0, -10.0);
 179
 180   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 181                                   child->draw_transform());
 182   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 183                                   grand_child->draw_transform());
 184
 185   // Case 3: fixed-container size delta of 20, 20
 186   SetFixedContainerSizeDelta(child, gfx::Vector2d(20, 20));
 187   ExecuteCalculateDrawProperties(root_.get());
 188
 189   // Top-left fixed-position layer should not be affected by container size.
 190   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 191                                   child->draw_transform());
 192   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 193                                   grand_child->draw_transform());
 194
 195   // Case 4: Bottom-right fixed-position layer.
 196   grand_child->SetPositionConstraint(fixed_to_bottom_right_);
 197   ExecuteCalculateDrawProperties(root_.get());
 198
 199   // Bottom-right fixed-position layer moves as container resizes.
 200   expected_grand_child_transform.MakeIdentity();
 201   // Apply size delta from the child(container) layer.
 202   expected_grand_child_transform.Translate(20.0, 20.0);
 203
 204   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 205                                   child->draw_transform());
 206   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 207                                   grand_child->draw_transform());
 208 }
 209
 210 TEST_F(LayerPositionConstraintTest,
 211      ScrollCompensationForFixedPositionLayerWithTransformedDirectContainer) {
 212   // This test checks for correct scroll compensation when the fixed-position
 213   // container is the direct parent of the fixed-position layer, but that
 214   // container is transformed.  In this case, the fixed position element
 215   // inherits the container's transform, but the scroll delta that has to be
 216   // undone should not be affected by that transform.
 217   //
 218   // Transforms are in general non-commutative; using something like a
 219   // non-uniform scale helps to verify that translations and non-uniform scales
 220   // are applied in the correct order.
 221   LayerImpl* child = scroll_->children()[0];
 222   LayerImpl* grand_child = child->children()[0];
 223
 224   // This scale will cause child and grand_child to be effectively 200 x 800
 225   // with respect to the render target.
 226   gfx::Transform non_uniform_scale;
 227   non_uniform_scale.Scale(2.0, 8.0);
 228   child->SetTransform(non_uniform_scale);
 229
 230   child->SetIsContainerForFixedPositionLayers(true);
 231   grand_child->SetPositionConstraint(fixed_to_top_left_);
 232
 233   // Case 1: scroll delta of 0, 0
 234   child->SetScrollDelta(gfx::Vector2d(0, 0));
 235   ExecuteCalculateDrawProperties(root_.get());
 236
 237   gfx::Transform expected_child_transform;
 238   expected_child_transform.PreconcatTransform(non_uniform_scale);
 239
 240   gfx::Transform expected_grand_child_transform = expected_child_transform;
 241
 242   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 243                                   child->draw_transform());
 244   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 245                                   grand_child->draw_transform());
 246
 247   // Case 2: scroll delta of 10, 20
 248   child->SetScrollDelta(gfx::Vector2d(10, 20));
 249   ExecuteCalculateDrawProperties(root_.get());
 250
 251   // The child should be affected by scroll delta, but the fixed position
 252   // grand_child should not be affected.
 253   expected_child_transform.MakeIdentity();
 254   expected_child_transform.Translate(-10.0, -20.0);  // scroll delta
 255   expected_child_transform.PreconcatTransform(non_uniform_scale);
 256
 257   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 258                                   child->draw_transform());
 259   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 260                                   grand_child->draw_transform());
 261
 262   // Case 3: fixed-container size delta of 20, 20
 263   SetFixedContainerSizeDelta(child, gfx::Vector2d(20, 20));
 264   ExecuteCalculateDrawProperties(root_.get());
 265
 266   // Top-left fixed-position layer should not be affected by container size.
 267   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 268                                   child->draw_transform());
 269   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 270                                   grand_child->draw_transform());
 271
 272   // Case 4: Bottom-right fixed-position layer.
 273   grand_child->SetPositionConstraint(fixed_to_bottom_right_);
 274   ExecuteCalculateDrawProperties(root_.get());
 275
 276   // Bottom-right fixed-position layer moves as container resizes.
 277   expected_grand_child_transform.MakeIdentity();
 278   // Apply child layer transform.
 279   expected_grand_child_transform.PreconcatTransform(non_uniform_scale);
 280   // Apply size delta from the child(container) layer.
 281   expected_grand_child_transform.Translate(20.0, 20.0);
 282
 283   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 284                                   child->draw_transform());
 285   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 286                                   grand_child->draw_transform());
 287 }
 288
 289 TEST_F(LayerPositionConstraintTest,
 290      ScrollCompensationForFixedPositionLayerWithDistantContainer) {
 291   // This test checks for correct scroll compensation when the fixed-position
 292   // container is NOT the direct parent of the fixed-position layer.
 293   LayerImpl* child = scroll_->children()[0];
 294   LayerImpl* grand_child = child->children()[0];
 295   LayerImpl* great_grand_child = grand_child->children()[0];
 296
 297   child->SetIsContainerForFixedPositionLayers(true);
 298   grand_child->SetPosition(gfx::PointF(8.f, 6.f));
 299   great_grand_child->SetPositionConstraint(fixed_to_top_left_);
 300
 301   // Case 1: scroll delta of 0, 0
 302   child->SetScrollDelta(gfx::Vector2d(0, 0));
 303   ExecuteCalculateDrawProperties(root_.get());
 304
 305   gfx::Transform expected_child_transform;
 306   gfx::Transform expected_grand_child_transform;
 307   expected_grand_child_transform.Translate(8.0, 6.0);
 308
 309   gfx::Transform expected_great_grand_child_transform =
 310       expected_grand_child_transform;
 311
 312   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 313                                   child->draw_transform());
 314   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 315                                   grand_child->draw_transform());
 316   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 317                                   great_grand_child->draw_transform());
 318
 319   // Case 2: scroll delta of 10, 10
 320   child->SetScrollDelta(gfx::Vector2d(10, 10));
 321   ExecuteCalculateDrawProperties(root_.get());
 322
 323   // Here the child and grand_child are affected by scroll delta, but the fixed
 324   // position great_grand_child should not be affected.
 325   expected_child_transform.MakeIdentity();
 326   expected_child_transform.Translate(-10.0, -10.0);
 327   expected_grand_child_transform.MakeIdentity();
 328   expected_grand_child_transform.Translate(-2.0, -4.0);
 329   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 330                                   child->draw_transform());
 331   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 332                                   grand_child->draw_transform());
 333   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 334                                   great_grand_child->draw_transform());
 335
 336   // Case 3: fixed-container size delta of 20, 20
 337   SetFixedContainerSizeDelta(child, gfx::Vector2d(20, 20));
 338   ExecuteCalculateDrawProperties(root_.get());
 339
 340   // Top-left fixed-position layer should not be affected by container size.
 341   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 342                                   child->draw_transform());
 343   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 344                                   grand_child->draw_transform());
 345   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 346                                   great_grand_child->draw_transform());
 347
 348   // Case 4: Bottom-right fixed-position layer.
 349   great_grand_child->SetPositionConstraint(fixed_to_bottom_right_);
 350   ExecuteCalculateDrawProperties(root_.get());
 351
 352   // Bottom-right fixed-position layer moves as container resizes.
 353   expected_great_grand_child_transform.MakeIdentity();
 354   // Apply size delta from the child(container) layer.
 355   expected_great_grand_child_transform.Translate(20.0, 20.0);
 356   // Apply layer position from the grand child layer.
 357   expected_great_grand_child_transform.Translate(8.0, 6.0);
 358
 359   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 360                                   child->draw_transform());
 361   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 362                                   grand_child->draw_transform());
 363   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 364                                   great_grand_child->draw_transform());
 365 }
 366
 367 TEST_F(LayerPositionConstraintTest,
 368      ScrollCompensationForFixedPositionLayerWithDistantContainerAndTransforms) {
 369   // This test checks for correct scroll compensation when the fixed-position
 370   // container is NOT the direct parent of the fixed-position layer, and the
 371   // hierarchy has various transforms that have to be processed in the correct
 372   // order.
 373   LayerImpl* child = scroll_->children()[0];
 374   LayerImpl* grand_child = child->children()[0];
 375   LayerImpl* great_grand_child = grand_child->children()[0];
 376
 377   gfx::Transform rotation_about_z;
 378   rotation_about_z.RotateAboutZAxis(90.0);
 379
 380   child->SetIsContainerForFixedPositionLayers(true);
 381   child->SetTransform(rotation_about_z);
 382   grand_child->SetPosition(gfx::PointF(8.f, 6.f));
 383   grand_child->SetTransform(rotation_about_z);
 384   // great_grand_child is positioned upside-down with respect to the render
 385   // target.
 386   great_grand_child->SetPositionConstraint(fixed_to_top_left_);
 387
 388   // Case 1: scroll delta of 0, 0
 389   child->SetScrollDelta(gfx::Vector2d(0, 0));
 390   ExecuteCalculateDrawProperties(root_.get());
 391
 392   gfx::Transform expected_child_transform;
 393   expected_child_transform.PreconcatTransform(rotation_about_z);
 394
 395   gfx::Transform expected_grand_child_transform;
 396   expected_grand_child_transform.PreconcatTransform(
 397       rotation_about_z);  // child's local transform is inherited
 398   // translation because of position occurs before layer's local transform.
 399   expected_grand_child_transform.Translate(8.0, 6.0);
 400   expected_grand_child_transform.PreconcatTransform(
 401       rotation_about_z);  // grand_child's local transform
 402
 403   gfx::Transform expected_great_grand_child_transform =
 404       expected_grand_child_transform;
 405
 406   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 407                                   child->draw_transform());
 408   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 409                                   grand_child->draw_transform());
 410   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 411                                   great_grand_child->draw_transform());
 412
 413   // Case 2: scroll delta of 10, 20
 414   child->SetScrollDelta(gfx::Vector2d(10, 20));
 415   ExecuteCalculateDrawProperties(root_.get());
 416
 417   // Here the child and grand_child are affected by scroll delta, but the fixed
 418   // position great_grand_child should not be affected.
 419   expected_child_transform.MakeIdentity();
 420   expected_child_transform.Translate(-10.0, -20.0);  // scroll delta
 421   expected_child_transform.PreconcatTransform(rotation_about_z);
 422
 423   expected_grand_child_transform.MakeIdentity();
 424   expected_grand_child_transform.Translate(
 425       -10.0, -20.0);      // child's scroll delta is inherited
 426   expected_grand_child_transform.PreconcatTransform(
 427       rotation_about_z);  // child's local transform is inherited
 428   // translation because of position occurs before layer's local transform.
 429   expected_grand_child_transform.Translate(8.0, 6.0);
 430   expected_grand_child_transform.PreconcatTransform(
 431       rotation_about_z);  // grand_child's local transform
 432
 433   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 434                                   child->draw_transform());
 435   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 436                                   grand_child->draw_transform());
 437   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 438                                   great_grand_child->draw_transform());
 439
 440   // Case 3: fixed-container size delta of 20, 20
 441   SetFixedContainerSizeDelta(child, gfx::Vector2d(20, 20));
 442   ExecuteCalculateDrawProperties(root_.get());
 443
 444   // Top-left fixed-position layer should not be affected by container size.
 445   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 446                                   child->draw_transform());
 447   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 448                                   grand_child->draw_transform());
 449   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 450                                   great_grand_child->draw_transform());
 451
 452   // Case 4: Bottom-right fixed-position layer.
 453   great_grand_child->SetPositionConstraint(fixed_to_bottom_right_);
 454   ExecuteCalculateDrawProperties(root_.get());
 455
 456   // Bottom-right fixed-position layer moves as container resizes.
 457   expected_great_grand_child_transform.MakeIdentity();
 458   // Apply child layer transform.
 459   expected_great_grand_child_transform.PreconcatTransform(rotation_about_z);
 460   // Apply size delta from the child(container) layer.
 461   expected_great_grand_child_transform.Translate(20.0, 20.0);
 462   // Apply layer position from the grand child layer.
 463   expected_great_grand_child_transform.Translate(8.0, 6.0);
 464   // Apply grand child layer transform.
 465   expected_great_grand_child_transform.PreconcatTransform(rotation_about_z);
 466
 467   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 468                                   child->draw_transform());
 469   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 470                                   grand_child->draw_transform());
 471   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 472                                   great_grand_child->draw_transform());
 473 }
 474
 475 TEST_F(LayerPositionConstraintTest,
 476      ScrollCompensationForFixedPositionLayerWithMultipleScrollDeltas) {
 477   // This test checks for correct scroll compensation when the fixed-position
 478   // container has multiple ancestors that have nonzero scroll delta before
 479   // reaching the space where the layer is fixed.  In this test, each scroll
 480   // delta occurs in a different space because of each layer's local transform.
 481   // This test checks for correct scroll compensation when the fixed-position
 482   // container is NOT the direct parent of the fixed-position layer, and the
 483   // hierarchy has various transforms that have to be processed in the correct
 484   // order.
 485   LayerImpl* child = scroll_->children()[0];
 486   LayerImpl* grand_child = child->children()[0];
 487   LayerImpl* great_grand_child = grand_child->children()[0];
 488
 489   gfx::Transform rotation_about_z;
 490   rotation_about_z.RotateAboutZAxis(90.0);
 491
 492   child->SetIsContainerForFixedPositionLayers(true);
 493   child->SetTransform(rotation_about_z);
 494   grand_child->SetPosition(gfx::PointF(8.f, 6.f));
 495   grand_child->SetTransform(rotation_about_z);
 496   // great_grand_child is positioned upside-down with respect to the render
 497   // target.
 498   great_grand_child->SetPositionConstraint(fixed_to_top_left_);
 499
 500   // Case 1: scroll delta of 0, 0
 501   child->SetScrollDelta(gfx::Vector2d(0, 0));
 502   ExecuteCalculateDrawProperties(root_.get());
 503
 504   gfx::Transform expected_child_transform;
 505   expected_child_transform.PreconcatTransform(rotation_about_z);
 506
 507   gfx::Transform expected_grand_child_transform;
 508   expected_grand_child_transform.PreconcatTransform(
 509       rotation_about_z);  // child's local transform is inherited
 510   // translation because of position occurs before layer's local transform.
 511   expected_grand_child_transform.Translate(8.0, 6.0);
 512   expected_grand_child_transform.PreconcatTransform(
 513       rotation_about_z);  // grand_child's local transform
 514
 515   gfx::Transform expected_great_grand_child_transform =
 516       expected_grand_child_transform;
 517
 518   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 519                                   child->draw_transform());
 520   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 521                                   grand_child->draw_transform());
 522   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 523                                   great_grand_child->draw_transform());
 524
 525   // Case 2: scroll delta of 10, 20
 526   child->SetScrollDelta(gfx::Vector2d(10, 0));
 527   grand_child->SetScrollDelta(gfx::Vector2d(5, 0));
 528   ExecuteCalculateDrawProperties(root_.get());
 529
 530   // Here the child and grand_child are affected by scroll delta, but the fixed
 531   // position great_grand_child should not be affected.
 532   expected_child_transform.MakeIdentity();
 533   expected_child_transform.Translate(-10.0, 0.0);  // scroll delta
 534   expected_child_transform.PreconcatTransform(rotation_about_z);
 535
 536   expected_grand_child_transform.MakeIdentity();
 537   expected_grand_child_transform.Translate(
 538       -10.0, 0.0);        // child's scroll delta is inherited
 539   expected_grand_child_transform.PreconcatTransform(
 540       rotation_about_z);  // child's local transform is inherited
 541   expected_grand_child_transform.Translate(-5.0,
 542                                            0.0);  // grand_child's scroll delta
 543   // translation because of position occurs before layer's local transform.
 544   expected_grand_child_transform.Translate(8.0, 6.0);
 545   expected_grand_child_transform.PreconcatTransform(
 546       rotation_about_z);  // grand_child's local transform
 547
 548   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 549                                   child->draw_transform());
 550   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 551                                   grand_child->draw_transform());
 552   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 553                                   great_grand_child->draw_transform());
 554
 555   // Case 3: fixed-container size delta of 20, 20
 556   SetFixedContainerSizeDelta(child, gfx::Vector2d(20, 20));
 557   ExecuteCalculateDrawProperties(root_.get());
 558
 559   // Top-left fixed-position layer should not be affected by container size.
 560   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 561                                   child->draw_transform());
 562   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 563                                   grand_child->draw_transform());
 564   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 565                                   great_grand_child->draw_transform());
 566
 567   // Case 4: Bottom-right fixed-position layer.
 568   great_grand_child->SetPositionConstraint(fixed_to_bottom_right_);
 569   ExecuteCalculateDrawProperties(root_.get());
 570
 571   // Bottom-right fixed-position layer moves as container resizes.
 572   expected_great_grand_child_transform.MakeIdentity();
 573   // Apply child layer transform.
 574   expected_great_grand_child_transform.PreconcatTransform(rotation_about_z);
 575   // Apply size delta from the child(container) layer.
 576   expected_great_grand_child_transform.Translate(20.0, 20.0);
 577   // Apply layer position from the grand child layer.
 578   expected_great_grand_child_transform.Translate(8.0, 6.0);
 579   // Apply grand child layer transform.
 580   expected_great_grand_child_transform.PreconcatTransform(rotation_about_z);
 581
 582   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 583                                   child->draw_transform());
 584   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 585                                   grand_child->draw_transform());
 586   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 587                                   great_grand_child->draw_transform());
 588 }
 589
 590 TEST_F(LayerPositionConstraintTest,
 591      ScrollCompensationForFixedPositionWithIntermediateSurfaceAndTransforms) {
 592   // This test checks for correct scroll compensation when the fixed-position
 593   // container contributes to a different render surface than the fixed-position
 594   // layer. In this case, the surface draw transforms also have to be accounted
 595   // for when checking the scroll delta.
 596   LayerImpl* child = scroll_->children()[0];
 597   LayerImpl* grand_child = child->children()[0];
 598   LayerImpl* great_grand_child = grand_child->children()[0];
 599
 600   child->SetIsContainerForFixedPositionLayers(true);
 601   grand_child->SetPosition(gfx::PointF(8.f, 6.f));
 602   grand_child->SetForceRenderSurface(true);
 603   great_grand_child->SetPositionConstraint(fixed_to_top_left_);
 604   great_grand_child->SetDrawsContent(true);
 605
 606   gfx::Transform rotation_about_z;
 607   rotation_about_z.RotateAboutZAxis(90.0);
 608   grand_child->SetTransform(rotation_about_z);
 609
 610   // Case 1: scroll delta of 0, 0
 611   child->SetScrollDelta(gfx::Vector2d(0, 0));
 612   ExecuteCalculateDrawProperties(root_.get());
 613
 614   gfx::Transform expected_child_transform;
 615   gfx::Transform expected_surface_draw_transform;
 616   expected_surface_draw_transform.Translate(8.0, 6.0);
 617   expected_surface_draw_transform.PreconcatTransform(rotation_about_z);
 618   gfx::Transform expected_grand_child_transform;
 619   gfx::Transform expected_great_grand_child_transform;
 620   ASSERT_TRUE(grand_child->render_surface());
 621   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 622                                   child->draw_transform());
 623   EXPECT_TRANSFORMATION_MATRIX_EQ(
 624       expected_surface_draw_transform,
 625       grand_child->render_surface()->draw_transform());
 626   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 627                                   grand_child->draw_transform());
 628   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 629                                   great_grand_child->draw_transform());
 630
 631   // Case 2: scroll delta of 10, 30
 632   child->SetScrollDelta(gfx::Vector2d(10, 30));
 633   ExecuteCalculateDrawProperties(root_.get());
 634
 635   // Here the grand_child remains unchanged, because it scrolls along with the
 636   // render surface, and the translation is actually in the render surface. But,
 637   // the fixed position great_grand_child is more awkward: its actually being
 638   // drawn with respect to the render surface, but it needs to remain fixed with
 639   // resepct to a container beyond that surface. So, the net result is that,
 640   // unlike previous tests where the fixed position layer's transform remains
 641   // unchanged, here the fixed position layer's transform explicitly contains
 642   // the translation that cancels out the scroll.
 643   expected_child_transform.MakeIdentity();
 644   expected_child_transform.Translate(-10.0, -30.0);  // scroll delta
 645
 646   expected_surface_draw_transform.MakeIdentity();
 647   expected_surface_draw_transform.Translate(-10.0, -30.0);  // scroll delta
 648   expected_surface_draw_transform.Translate(8.0, 6.0);
 649   expected_surface_draw_transform.PreconcatTransform(rotation_about_z);
 650
 651   // The rotation and its inverse are needed to place the scroll delta
 652   // compensation in the correct space. This test will fail if the
 653   // rotation/inverse are backwards, too, so it requires perfect order of
 654   // operations.
 655   expected_great_grand_child_transform.MakeIdentity();
 656   expected_great_grand_child_transform.PreconcatTransform(
 657       Inverse(rotation_about_z));
 658   // explicit canceling out the scroll delta that gets embedded in the fixed
 659   // position layer's surface.
 660   expected_great_grand_child_transform.Translate(10.0, 30.0);
 661   expected_great_grand_child_transform.PreconcatTransform(rotation_about_z);
 662
 663   ASSERT_TRUE(grand_child->render_surface());
 664   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 665                                   child->draw_transform());
 666   EXPECT_TRANSFORMATION_MATRIX_EQ(
 667       expected_surface_draw_transform,
 668       grand_child->render_surface()->draw_transform());
 669   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 670                                   grand_child->draw_transform());
 671   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 672                                   great_grand_child->draw_transform());
 673
 674   // Case 3: fixed-container size delta of 20, 20
 675   SetFixedContainerSizeDelta(child, gfx::Vector2d(20, 20));
 676   ExecuteCalculateDrawProperties(root_.get());
 677
 678   // Top-left fixed-position layer should not be affected by container size.
 679   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 680                                   child->draw_transform());
 681   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 682                                   grand_child->draw_transform());
 683   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 684                                   great_grand_child->draw_transform());
 685
 686   // Case 4: Bottom-right fixed-position layer.
 687   great_grand_child->SetPositionConstraint(fixed_to_bottom_right_);
 688   ExecuteCalculateDrawProperties(root_.get());
 689
 690   // Bottom-right fixed-position layer moves as container resizes.
 691   expected_great_grand_child_transform.MakeIdentity();
 692   // The rotation and its inverse are needed to place the scroll delta
 693   // compensation in the correct space. This test will fail if the
 694   // rotation/inverse are backwards, too, so it requires perfect order of
 695   // operations.
 696   expected_great_grand_child_transform.PreconcatTransform(
 697       Inverse(rotation_about_z));
 698   // explicit canceling out the scroll delta that gets embedded in the fixed
 699   // position layer's surface.
 700   expected_great_grand_child_transform.Translate(10.0, 30.0);
 701   // Also apply size delta in the child(container) layer space.
 702   expected_great_grand_child_transform.Translate(20.0, 20.0);
 703   expected_great_grand_child_transform.PreconcatTransform(rotation_about_z);
 704
 705   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 706                                   child->draw_transform());
 707   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 708                                   grand_child->draw_transform());
 709   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 710                                   great_grand_child->draw_transform());
 711 }
 712
 713 TEST_F(LayerPositionConstraintTest,
 714      ScrollCompensationForFixedPositionLayerWithMultipleIntermediateSurfaces) {
 715   // This test checks for correct scroll compensation when the fixed-position
 716   // container contributes to a different render surface than the fixed-position
 717   // layer, with additional render surfaces in-between. This checks that the
 718   // conversion to ancestor surfaces is accumulated properly in the final matrix
 719   // transform.
 720   LayerImpl* child = scroll_->children()[0];
 721   LayerImpl* grand_child = child->children()[0];
 722   LayerImpl* great_grand_child = grand_child->children()[0];
 723
 724   // Add one more layer to the test tree for this scenario.
 725   {
 726     gfx::Transform identity;
 727     scoped_ptr<LayerImpl> fixed_position_child =
 728         LayerImpl::Create(host_impl_.active_tree(), 5);
 729     SetLayerPropertiesForTesting(fixed_position_child.get(),
 730                                  identity,
 731                                  gfx::Point3F(),
 732                                  gfx::PointF(),
 733                                  gfx::Size(100, 100),
 734                                  true);
 735     great_grand_child->AddChild(fixed_position_child.Pass());
 736   }
 737   LayerImpl* fixed_position_child = great_grand_child->children()[0];
 738
 739   // Actually set up the scenario here.
 740   child->SetIsContainerForFixedPositionLayers(true);
 741   grand_child->SetPosition(gfx::PointF(8.f, 6.f));
 742   grand_child->SetForceRenderSurface(true);
 743   great_grand_child->SetPosition(gfx::PointF(40.f, 60.f));
 744   great_grand_child->SetForceRenderSurface(true);
 745   fixed_position_child->SetPositionConstraint(fixed_to_top_left_);
 746   fixed_position_child->SetDrawsContent(true);
 747
 748   // The additional rotations, which are non-commutative with translations, help
 749   // to verify that we have correct order-of-operations in the final scroll
 750   // compensation.  Note that rotating about the center of the layer ensures we
 751   // do not accidentally clip away layers that we want to test.
 752   gfx::Transform rotation_about_z;
 753   rotation_about_z.Translate(50.0, 50.0);
 754   rotation_about_z.RotateAboutZAxis(90.0);
 755   rotation_about_z.Translate(-50.0, -50.0);
 756   grand_child->SetTransform(rotation_about_z);
 757   great_grand_child->SetTransform(rotation_about_z);
 758
 759   // Case 1: scroll delta of 0, 0
 760   child->SetScrollDelta(gfx::Vector2d(0, 0));
 761   ExecuteCalculateDrawProperties(root_.get());
 762
 763   gfx::Transform expected_child_transform;
 764
 765   gfx::Transform expected_grand_child_surface_draw_transform;
 766   expected_grand_child_surface_draw_transform.Translate(8.0, 6.0);
 767   expected_grand_child_surface_draw_transform.PreconcatTransform(
 768       rotation_about_z);
 769
 770   gfx::Transform expected_grand_child_transform;
 771
 772   gfx::Transform expected_great_grand_child_surface_draw_transform;
 773   expected_great_grand_child_surface_draw_transform.Translate(40.0, 60.0);
 774   expected_great_grand_child_surface_draw_transform.PreconcatTransform(
 775       rotation_about_z);
 776
 777   gfx::Transform expected_great_grand_child_transform;
 778
 779   gfx::Transform expected_fixed_position_child_transform;
 780
 781   ASSERT_TRUE(grand_child->render_surface());
 782   ASSERT_TRUE(great_grand_child->render_surface());
 783   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 784                                   child->draw_transform());
 785   EXPECT_TRANSFORMATION_MATRIX_EQ(
 786       expected_grand_child_surface_draw_transform,
 787       grand_child->render_surface()->draw_transform());
 788   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 789                                   grand_child->draw_transform());
 790   EXPECT_TRANSFORMATION_MATRIX_EQ(
 791       expected_great_grand_child_surface_draw_transform,
 792       great_grand_child->render_surface()->draw_transform());
 793   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 794                                   great_grand_child->draw_transform());
 795   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_fixed_position_child_transform,
 796                                   fixed_position_child->draw_transform());
 797
 798   // Case 2: scroll delta of 10, 30
 799   child->SetScrollDelta(gfx::Vector2d(10, 30));
 800   ExecuteCalculateDrawProperties(root_.get());
 801
 802   expected_child_transform.MakeIdentity();
 803   expected_child_transform.Translate(-10.0, -30.0);  // scroll delta
 804
 805   expected_grand_child_surface_draw_transform.MakeIdentity();
 806   expected_grand_child_surface_draw_transform.Translate(-10.0,
 807                                                         -30.0);  // scroll delta
 808   expected_grand_child_surface_draw_transform.Translate(8.0, 6.0);
 809   expected_grand_child_surface_draw_transform.PreconcatTransform(
 810       rotation_about_z);
 811
 812   // grand_child, great_grand_child, and great_grand_child's surface are not
 813   // expected to change, since they are all not fixed, and they are all drawn
 814   // with respect to grand_child's surface that already has the scroll delta
 815   // accounted for.
 816
 817   // But the great-great grandchild, "fixed_position_child", should have a
 818   // transform that explicitly cancels out the scroll delta.  The expected
 819   // transform is: compound_draw_transform.Inverse() * translate(positive scroll
 820   // delta) * compound_origin_transform from great_grand_childSurface's origin
 821   // to the root surface.
 822   gfx::Transform compound_draw_transform;
 823   compound_draw_transform.Translate(8.0,
 824                                     6.0);  // origin translation of grand_child
 825   compound_draw_transform.PreconcatTransform(
 826       rotation_about_z);                   // rotation of grand_child
 827   compound_draw_transform.Translate(
 828       40.0, 60.0);        // origin translation of great_grand_child
 829   compound_draw_transform.PreconcatTransform(
 830       rotation_about_z);  // rotation of great_grand_child
 831
 832   expected_fixed_position_child_transform.MakeIdentity();
 833   expected_fixed_position_child_transform.PreconcatTransform(
 834       Inverse(compound_draw_transform));
 835   // explicit canceling out the scroll delta that gets embedded in the fixed
 836   // position layer's surface.
 837   expected_fixed_position_child_transform.Translate(10.0, 30.0);
 838   expected_fixed_position_child_transform.PreconcatTransform(
 839       compound_draw_transform);
 840
 841   ASSERT_TRUE(grand_child->render_surface());
 842   ASSERT_TRUE(great_grand_child->render_surface());
 843   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 844                                   child->draw_transform());
 845   EXPECT_TRANSFORMATION_MATRIX_EQ(
 846       expected_grand_child_surface_draw_transform,
 847       grand_child->render_surface()->draw_transform());
 848   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 849                                   grand_child->draw_transform());
 850   EXPECT_TRANSFORMATION_MATRIX_EQ(
 851       expected_great_grand_child_surface_draw_transform,
 852       great_grand_child->render_surface()->draw_transform());
 853   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 854                                   great_grand_child->draw_transform());
 855   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_fixed_position_child_transform,
 856                                   fixed_position_child->draw_transform());
 857
 858
 859   // Case 3: fixed-container size delta of 20, 20
 860   SetFixedContainerSizeDelta(child, gfx::Vector2d(20, 20));
 861   ExecuteCalculateDrawProperties(root_.get());
 862
 863   // Top-left fixed-position layer should not be affected by container size.
 864   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 865                                   child->draw_transform());
 866   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 867                                   grand_child->draw_transform());
 868   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 869                                   great_grand_child->draw_transform());
 870   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_fixed_position_child_transform,
 871                                   fixed_position_child->draw_transform());
 872
 873   // Case 4: Bottom-right fixed-position layer.
 874   fixed_position_child->SetPositionConstraint(fixed_to_bottom_right_);
 875   ExecuteCalculateDrawProperties(root_.get());
 876
 877   // Bottom-right fixed-position layer moves as container resizes.
 878   expected_fixed_position_child_transform.MakeIdentity();
 879   expected_fixed_position_child_transform.PreconcatTransform(
 880       Inverse(compound_draw_transform));
 881   // explicit canceling out the scroll delta that gets embedded in the fixed
 882   // position layer's surface.
 883   expected_fixed_position_child_transform.Translate(10.0, 30.0);
 884   // Also apply size delta in the child(container) layer space.
 885   expected_fixed_position_child_transform.Translate(20.0, 20.0);
 886   expected_fixed_position_child_transform.PreconcatTransform(
 887       compound_draw_transform);
 888
 889   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 890                                   child->draw_transform());
 891   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 892                                   grand_child->draw_transform());
 893   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
 894                                   great_grand_child->draw_transform());
 895   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_fixed_position_child_transform,
 896                                   fixed_position_child->draw_transform());
 897 }
 898
 899 TEST_F(LayerPositionConstraintTest,
 900      ScrollCompensationForFixedPositionLayerWithContainerLayerThatHasSurface) {
 901   // This test checks for correct scroll compensation when the fixed-position
 902   // container itself has a render surface. In this case, the container layer
 903   // should be treated like a layer that contributes to a render target, and
 904   // that render target is completely irrelevant; it should not affect the
 905   // scroll compensation.
 906   LayerImpl* child = scroll_->children()[0];
 907   LayerImpl* grand_child = child->children()[0];
 908
 909   child->SetIsContainerForFixedPositionLayers(true);
 910   child->SetForceRenderSurface(true);
 911   grand_child->SetPositionConstraint(fixed_to_top_left_);
 912   grand_child->SetDrawsContent(true);
 913
 914   // Case 1: scroll delta of 0, 0
 915   child->SetScrollDelta(gfx::Vector2d(0, 0));
 916   ExecuteCalculateDrawProperties(root_.get());
 917
 918   gfx::Transform expected_surface_draw_transform;
 919   expected_surface_draw_transform.Translate(0.0, 0.0);
 920   gfx::Transform expected_child_transform;
 921   gfx::Transform expected_grand_child_transform;
 922   ASSERT_TRUE(child->render_surface());
 923   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_surface_draw_transform,
 924                                   child->render_surface()->draw_transform());
 925   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 926                                   child->draw_transform());
 927   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 928                                   grand_child->draw_transform());
 929
 930   // Case 2: scroll delta of 10, 10
 931   child->SetScrollDelta(gfx::Vector2d(10, 10));
 932   ExecuteCalculateDrawProperties(root_.get());
 933
 934   // The surface is translated by scroll delta, the child transform doesn't
 935   // change because it scrolls along with the surface, but the fixed position
 936   // grand_child needs to compensate for the scroll translation.
 937   expected_surface_draw_transform.MakeIdentity();
 938   expected_surface_draw_transform.Translate(-10.0, -10.0);
 939   expected_grand_child_transform.MakeIdentity();
 940   expected_grand_child_transform.Translate(10.0, 10.0);
 941
 942   ASSERT_TRUE(child->render_surface());
 943   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_surface_draw_transform,
 944                                   child->render_surface()->draw_transform());
 945   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 946                                   child->draw_transform());
 947   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 948                                   grand_child->draw_transform());
 949
 950   // Case 3: fixed-container size delta of 20, 20
 951   SetFixedContainerSizeDelta(child, gfx::Vector2d(20, 20));
 952   ExecuteCalculateDrawProperties(root_.get());
 953
 954   // Top-left fixed-position layer should not be affected by container size.
 955   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 956                                   child->draw_transform());
 957   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 958                                   grand_child->draw_transform());
 959
 960   // Case 4: Bottom-right fixed-position layer.
 961   grand_child->SetPositionConstraint(fixed_to_bottom_right_);
 962   ExecuteCalculateDrawProperties(root_.get());
 963
 964   // Bottom-right fixed-position layer moves as container resizes.
 965   expected_grand_child_transform.MakeIdentity();
 966   // The surface is translated by scroll delta, the child transform doesn't
 967   // change because it scrolls along with the surface, but the fixed position
 968   // grand_child needs to compensate for the scroll translation.
 969   expected_grand_child_transform.Translate(10.0, 10.0);
 970   // Apply size delta from the child(container) layer.
 971   expected_grand_child_transform.Translate(20.0, 20.0);
 972
 973   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
 974                                   child->draw_transform());
 975   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
 976                                   grand_child->draw_transform());
 977 }
 978
 979 TEST_F(LayerPositionConstraintTest,
 980      ScrollCompensationForFixedPositionLayerThatIsAlsoFixedPositionContainer) {
 981   // This test checks the scenario where a fixed-position layer also happens to
 982   // be a container itself for a descendant fixed position layer. In particular,
 983   // the layer should not accidentally be fixed to itself.
 984   LayerImpl* child = scroll_->children()[0];
 985   LayerImpl* grand_child = child->children()[0];
 986
 987   child->SetIsContainerForFixedPositionLayers(true);
 988   grand_child->SetPositionConstraint(fixed_to_top_left_);
 989
 990   // This should not confuse the grand_child. If correct, the grand_child would
 991   // still be considered fixed to its container (i.e. "child").
 992   grand_child->SetIsContainerForFixedPositionLayers(true);
 993
 994   // Case 1: scroll delta of 0, 0
 995   child->SetScrollDelta(gfx::Vector2d(0, 0));
 996   ExecuteCalculateDrawProperties(root_.get());
 997
 998   gfx::Transform expected_child_transform;
 999   gfx::Transform expected_grand_child_transform;
1000   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
1001                                   child->draw_transform());
1002   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
1003                                   grand_child->draw_transform());
1004
1005   // Case 2: scroll delta of 10, 10
1006   child->SetScrollDelta(gfx::Vector2d(10, 10));
1007   ExecuteCalculateDrawProperties(root_.get());
1008
1009   // Here the child is affected by scroll delta, but the fixed position
1010   // grand_child should not be affected.
1011   expected_child_transform.MakeIdentity();
1012   expected_child_transform.Translate(-10.0, -10.0);
1013   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
1014                                   child->draw_transform());
1015   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
1016                                   grand_child->draw_transform());
1017
1018   // Case 3: fixed-container size delta of 20, 20
1019   SetFixedContainerSizeDelta(child, gfx::Vector2d(20, 20));
1020   ExecuteCalculateDrawProperties(root_.get());
1021
1022   // Top-left fixed-position layer should not be affected by container size.
1023   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
1024                                   child->draw_transform());
1025   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
1026                                   grand_child->draw_transform());
1027
1028   // Case 4: Bottom-right fixed-position layer.
1029   grand_child->SetPositionConstraint(fixed_to_bottom_right_);
1030   ExecuteCalculateDrawProperties(root_.get());
1031
1032   // Bottom-right fixed-position layer moves as container resizes.
1033   expected_grand_child_transform.MakeIdentity();
1034   // Apply size delta from the child(container) layer.
1035   expected_grand_child_transform.Translate(20.0, 20.0);
1036
1037   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
1038                                   child->draw_transform());
1039   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
1040                                   grand_child->draw_transform());
1041 }
1042
1043 TEST_F(LayerPositionConstraintTest,
1044      ScrollCompensationForFixedWithinFixedWithSameContainer) {
1045   // This test checks scroll compensation for a fixed-position layer that is
1046   // inside of another fixed-position layer and both share the same container.
1047   // In this situation, the parent fixed-position layer will receive
1048   // the scroll compensation, and the child fixed-position layer does not
1049   // need to compensate further.
1050
1051   LayerImpl* child = scroll_->children()[0];
1052   LayerImpl* grand_child = child->children()[0];
1053   LayerImpl* great_grand_child = grand_child->children()[0];
1054
1055   child->SetIsContainerForFixedPositionLayers(true);
1056   grand_child->SetPositionConstraint(fixed_to_top_left_);
1057
1058   // Note carefully - great_grand_child is fixed to bottom right, to test
1059   // sizeDelta being applied correctly; the compensation skips the grand_child
1060   // because it is fixed to top left.
1061   great_grand_child->SetPositionConstraint(fixed_to_bottom_right_);
1062
1063   // Case 1: scrollDelta
1064   child->SetScrollDelta(gfx::Vector2d(10, 10));
1065   ExecuteCalculateDrawProperties(root_.get());
1066
1067   // Here the child is affected by scroll delta, but the fixed position
1068   // grand_child should not be affected.
1069   gfx::Transform expected_child_transform;
1070   expected_child_transform.Translate(-10.0, -10.0);
1071
1072   gfx::Transform expected_grand_child_transform;
1073   gfx::Transform expected_great_grand_child_transform;
1074
1075   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
1076                                   child->draw_transform());
1077   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
1078                                   grand_child->draw_transform());
1079   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
1080                                   great_grand_child->draw_transform());
1081
1082   // Case 2: sizeDelta
1083   child->SetScrollDelta(gfx::Vector2d(0, 0));
1084   SetFixedContainerSizeDelta(child, gfx::Vector2d(20, 20));
1085   ExecuteCalculateDrawProperties(root_.get());
1086
1087   expected_child_transform.MakeIdentity();
1088
1089   expected_grand_child_transform.MakeIdentity();
1090
1091   // Fixed to bottom-right, size-delta compensation is applied.
1092   expected_great_grand_child_transform.MakeIdentity();
1093   expected_great_grand_child_transform.Translate(20.0, 20.0);
1094
1095   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_child_transform,
1096                                   child->draw_transform());
1097   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_transform,
1098                                   grand_child->draw_transform());
1099   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_transform,
1100                                   great_grand_child->draw_transform());
1101 }
1102
1103 TEST_F(LayerPositionConstraintTest,
1104      ScrollCompensationForFixedWithinFixedWithInterveningContainer) {
1105   // This test checks scroll compensation for a fixed-position layer that is
1106   // inside of another fixed-position layer, but they have different fixed
1107   // position containers. In this situation, the child fixed-position element
1108   // would still have to compensate with respect to its container.
1109
1110   LayerImpl* container1 = scroll_->children()[0];
1111   LayerImpl* fixed_to_container1 = container1->children()[0];
1112   LayerImpl* container2 = fixed_to_container1->children()[0];
1113
1114   {
1115     // Add one more layer to the hierarchy for this test.
1116     scoped_ptr<LayerImpl> fixed_to_container2_ptr =
1117         LayerImpl::Create(host_impl_.active_tree(), 5);
1118     container2->AddChild(fixed_to_container2_ptr.Pass());
1119   }
1120
1121   LayerImpl* fixed_to_container2 = container2->children()[0];
1122
1123   container1->SetIsContainerForFixedPositionLayers(true);
1124   fixed_to_container1->SetPositionConstraint(fixed_to_top_left_);
1125   container2->SetIsContainerForFixedPositionLayers(true);
1126   fixed_to_container2->SetPositionConstraint(fixed_to_top_left_);
1127
1128   container1->SetScrollDelta(gfx::Vector2d(0, 15));
1129   container2->SetScrollDelta(gfx::Vector2d(30, 0));
1130   ExecuteCalculateDrawProperties(root_.get());
1131
1132   gfx::Transform expected_container1_transform;
1133   expected_container1_transform.Translate(0.0, -15.0);
1134
1135   gfx::Transform expected_fixed_to_container1_transform;
1136
1137   // Since the container is a descendant of the fixed layer above,
1138   // the expected draw transform for container2 would not
1139   // include the scrollDelta that was applied to container1.
1140   gfx::Transform expected_container2_transform;
1141   expected_container2_transform.Translate(-30.0, 0.0);
1142
1143   gfx::Transform expected_fixed_to_container2_transform;
1144
1145   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_container1_transform,
1146                                   container1->draw_transform());
1147
1148   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_fixed_to_container1_transform,
1149                                   fixed_to_container1->draw_transform());
1150
1151   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_container2_transform,
1152                                   container2->draw_transform());
1153
1154   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_fixed_to_container2_transform,
1155                                   fixed_to_container2->draw_transform());
1156 }
1157 }  // namespace
1158 }  // namespace cc