Clip visual rect with real overflow clip rect

third_party/WebKit/Source/core/layout/LayoutObjectTest.cpp

Index: third_party/WebKit/Source/core/layout/LayoutObjectTest.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutObjectTest.cpp b/third_party/WebKit/Source/core/layout/LayoutObjectTest.cpp
index f56793a13f7f90d59823aaf3442f7c279eaaa899..c9d180173d078970d4ed7395e24fc7e72c944a17 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObjectTest.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObjectTest.cpp
@@ -212,10 +212,16 @@ TEST_F(LayoutObjectTest, OverflowRectMappingWithSelfFlippedWritingMode)
 
     LayoutBlock* target = toLayoutBlock(getLayoutObjectByElementId("target"));
     LayoutRect overflowRect = target->localOverflowRectForPaintInvalidation();
+    // -40 = -box_shadow_offset_x(40) (with target's top-right corner as the origin)
+    // 140 = width(100) + box_shadow_offset_x(40)
+    // 70 = height(50) + box_shadow_offset_y(20)
     EXPECT_EQ(LayoutRect(-40, 0, 140, 70), overflowRect);
+
     LayoutRect rect = overflowRect;
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(target, rect));
+    // This rect is in physical coordinates of target.
     EXPECT_EQ(LayoutRect(0, 0, 140, 70), rect);
+
     rect = overflowRect;
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(&layoutView(), rect));
     EXPECT_EQ(LayoutRect(222, 111, 140, 70), rect);
@@ -231,14 +237,20 @@ TEST_F(LayoutObjectTest, OverflowRectMappingWithContainerFlippedWritingMode)
 
     LayoutBlock* target = toLayoutBlock(getLayoutObjectByElementId("target"));
     LayoutRect targetOverflowRect = target->localOverflowRectForPaintInvalidation();
+    // -40 = -box_shadow_offset_x(40) (with target's top-right corner as the origin)
+    // 140 = width(100) + box_shadow_offset_x(40)
+    // 110 = height(90) + box_shadow_offset_y(20)
     EXPECT_EQ(LayoutRect(-40, 0, 140, 110), targetOverflowRect);
+
     LayoutRect rect = targetOverflowRect;
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(target, rect));
+    // This rect is in physical coordinates of target.
     EXPECT_EQ(LayoutRect(0, 0, 140, 110), rect);
 
     LayoutBlock* container = toLayoutBlock(getLayoutObjectByElementId("container"));
     rect = targetOverflowRect;
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(container, rect));
+    // 100 is the physical x location of target in container.
     EXPECT_EQ(LayoutRect(100, 0, 140, 110), rect);
     rect = targetOverflowRect;
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(&layoutView(), rect));
@@ -247,11 +259,124 @@ TEST_F(LayoutObjectTest, OverflowRectMappingWithContainerFlippedWritingMode)
     LayoutRect containerOverflowRect = container->localOverflowRectForPaintInvalidation();
     EXPECT_EQ(LayoutRect(-40, 0, 240, 110), containerOverflowRect);
     rect = containerOverflowRect;
-    EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(container, rect));
+    EXPECT_TRUE(container->mapToVisualRectInAncestorSpace(container, rect));
     EXPECT_EQ(LayoutRect(0, 0, 240, 110), rect);
     rect = containerOverflowRect;
-    EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(&layoutView(), rect));
+    EXPECT_TRUE(container->mapToVisualRectInAncestorSpace(&layoutView(), rect));
     EXPECT_EQ(LayoutRect(222, 111, 240, 110), rect);
 }
 
+TEST_F(LayoutObjectTest, OverflowRectMappingWithContainerOverflowClip)
+{
+    setBodyInnerHTML(
+        "<div id='container' style='position: absolute; top: 111px; left: 222px;"
+        "    border: 10px solid red; overflow: hidden; width: 50px; height: 80px;'>"
+        "    <div id='target' style='box-shadow: 40px 20px black; width: 100px; height: 90px'></div>"
+        "</div>");
+
+    LayoutBlock* container = toLayoutBlock(getLayoutObjectByElementId("container"));
+    EXPECT_EQ(LayoutUnit(0), container->scrollTop());
+    EXPECT_EQ(LayoutUnit(0), container->scrollLeft());
+    container->setScrollTop(LayoutUnit(7));
+    container->setScrollLeft(LayoutUnit(8));
+
+    LayoutBlock* target = toLayoutBlock(getLayoutObjectByElementId("target"));
+    LayoutRect targetOverflowRect = target->localOverflowRectForPaintInvalidation();
+    // 140 = width(100) + box_shadow_offset_x(40)
+    // 110 = height(90) + box_shadow_offset_y(20)
+    EXPECT_EQ(LayoutRect(0, 0, 140, 110), targetOverflowRect);
+    LayoutRect rect = targetOverflowRect;
+    EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(target, rect));
+    EXPECT_EQ(LayoutRect(0, 0, 140, 110), rect);
+
+    rect = targetOverflowRect;
+    EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(container, rect));
+    // 2 = target_x(0) + container_border_left(10) - scroll_left(8)
+    // 3 = target_y(0) + container_border_top(10) - scroll_top(7)
+    // Rect is not clipped by container's overflow clip.
+    EXPECT_EQ(LayoutRect(2, 3, 140, 110), rect);
+
+    rect = targetOverflowRect;
+    EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(&layoutView(), rect));
+    // (2, 3, 140, 100) is first clipped by container's overflow clip, to (10, 10, 50, 80),
+    // then is by added container's offset in LayoutView (111, 222).
+    EXPECT_EQ(LayoutRect(232, 121, 50, 80), rect);
+
+    LayoutRect containerOverflowRect = container->localOverflowRectForPaintInvalidation();
+    // Because container has overflow clip, its visual overflow doesn't include overflow from children.
+    // 70 = width(50) + border_left_width(10) + border_right_width(10)
+    // 100 = height(80) + border_top_width(10) + border_bottom_width(10)
+    EXPECT_EQ(LayoutRect(0, 0, 70, 100), containerOverflowRect);
+    rect = containerOverflowRect;
+    EXPECT_TRUE(container->mapToVisualRectInAncestorSpace(container, rect));
+    // Container should not apply overflow clip on its own overflow rect.
+    EXPECT_EQ(LayoutRect(0, 0, 70, 100), rect);
+
+    rect = containerOverflowRect;
+    EXPECT_TRUE(container->mapToVisualRectInAncestorSpace(&layoutView(), rect));
+    EXPECT_EQ(LayoutRect(222, 111, 70, 100), rect);
+}
+
+TEST_F(LayoutObjectTest, OverflowRectMappingWithContainerFlippedWritingModeAndOverflowClip)
+{
+    setBodyInnerHTML(
+        "<div id='container' style='writing-mode: vertical-rl; position: absolute; top: 111px; left: 222px;"
+        "    border: solid red; border-width: 10px 20px 30px 40px;"
+        "    overflow: hidden; width: 50px; height: 80px'>"
+        "    <div id='target' style='box-shadow: 40px 20px black; width: 100px; height: 90px'></div>"
+        "    <div style='width: 100px; height: 100px'></div>"
+        "</div>");
+
+    LayoutBlock* container = toLayoutBlock(getLayoutObjectByElementId("container"));
+    EXPECT_EQ(LayoutUnit(0), container->scrollTop());
+    // The initial scroll offset is to the left-most because of flipped blocks writing mode.
+    // 150 = total_layout_overflow(100 + 100) - width(50)
+    EXPECT_EQ(LayoutUnit(150), container->scrollLeft());
+    container->setScrollTop(LayoutUnit(7));
+    container->setScrollLeft(LayoutUnit(142)); // Scroll to the right by 8 pixels.
+
+    LayoutBlock* target = toLayoutBlock(getLayoutObjectByElementId("target"));
+    LayoutRect targetOverflowRect = target->localOverflowRectForPaintInvalidation();
+    // -40 = -box_shadow_offset_x(40) (with target's top-right corner as the origin)
+    // 140 = width(100) + box_shadow_offset_x(40)
+    // 110 = height(90) + box_shadow_offset_y(20)
+    EXPECT_EQ(LayoutRect(-40, 0, 140, 110), targetOverflowRect);
+
+    LayoutRect rect = targetOverflowRect;
+    EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(target, rect));
+    // This rect is in physical coordinates of target.
+    EXPECT_EQ(LayoutRect(0, 0, 140, 110), rect);
+
+    rect = targetOverflowRect;
+    EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(container, rect));
+    // -2 = target_physical_x(100) + container_border_left(40) - scroll_left(142)
+    // 3 = target_y(0) + container_border_top(10) - scroll_top(7)
+    // Rect is not clipped by container's overflow clip.
+    EXPECT_EQ(LayoutRect(-2, 3, 140, 110), rect);
+
+    rect = targetOverflowRect;
+    EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(&layoutView(), rect));
+    // (-2, 3, 140, 100) is first clipped by container's overflow clip, to (40, 10, 50, 80),
+    // then is added by container's offset in LayoutView (111, 222).
+    // TODO(crbug.com/600039): rect.x() should be 262 (left + border-left), but is offset
+    // by extra horizontal border-widths because of layout error.
+    EXPECT_EQ(LayoutRect(322, 121, 50, 80), rect);
+
+    LayoutRect containerOverflowRect = container->localOverflowRectForPaintInvalidation();
+    // Because container has overflow clip, its visual overflow doesn't include overflow from children.
+    // 110 = width(50) + border_left_width(40) + border_right_width(20)
+    // 120 = height(80) + border_top_width(10) + border_bottom_width(30)
+    EXPECT_EQ(LayoutRect(0, 0, 110, 120), containerOverflowRect);
+
+    rect = containerOverflowRect;
+    EXPECT_TRUE(container->mapToVisualRectInAncestorSpace(container, rect));
+    EXPECT_EQ(LayoutRect(0, 0, 110, 120), rect);
+
+    rect = containerOverflowRect;
+    EXPECT_TRUE(container->mapToVisualRectInAncestorSpace(&layoutView(), rect));
+    // TODO(crbug.com/600039): rect.x() should be 222 (left), but is offset by extra horizontal
+    // border-widths because of layout error.
+    EXPECT_EQ(LayoutRect(282, 111, 110, 120), rect);
+}
+
 } // namespace blink