Absolute positioned items should apear inside padding but outside border

Summary:
Absolute positioned elements were not correctly respecting border / padding.

https://github.com/facebook/css-layout/issues/245
fixes #245

Reviewed By: gkassabli

Differential Revision: D4153332

fbshipit-source-id: 251e29e02018a433f60349b78c03feb121512797

CSSLayout/CSSLayout.c

@@ -1115,12 +1115,14 @@ static void absoluteLayoutChild(const CSSNodeRef node,
   if (isTrailingPosDefined(child, mainAxis) && !isLeadingPosDefined(child, mainAxis)) {
     child->layout.position[leading[mainAxis]] = node->layout.measuredDimensions[dim[mainAxis]] -
                                                 child->layout.measuredDimensions[dim[mainAxis]] -
+                                                getTrailingBorder(node, mainAxis) -
                                                 getTrailingPosition(child, mainAxis);
   }
 
   if (isTrailingPosDefined(child, crossAxis) && !isLeadingPosDefined(child, crossAxis)) {
     child->layout.position[leading[crossAxis]] = node->layout.measuredDimensions[dim[crossAxis]] -
                                                  child->layout.measuredDimensions[dim[crossAxis]] -
+                                                 getTrailingBorder(node, crossAxis) - 
                                                  getTrailingPosition(child, crossAxis);
   }
 }
@@ -1830,16 +1832,14 @@ static void layoutNodeImpl(const CSSNodeRef node,
                                                   getLeadingMargin(child, mainAxis);
         }
       } else {
-        if (performLayout) {
-          // If the child is position absolute (without top/left) or relative,
-          // we put it at the current accumulated offset.
-          child->layout.position[pos[mainAxis]] += mainDim;
-        }
-
         // Now that we placed the element, we need to update the variables.
         // We need to do that only for relative elements. Absolute elements
         // do not take part in that phase.
         if (child->style.positionType == CSSPositionTypeRelative) {
+          if (performLayout) {
+            child->layout.position[pos[mainAxis]] += mainDim;
+          }
+
           if (canSkipFlex) {
             // If we skipped the flex step, then we can't rely on the
             // measuredDims because
@@ -1857,6 +1857,8 @@ static void layoutNodeImpl(const CSSNodeRef node,
             // can only be one element in that cross dimension.
             crossDim = fmaxf(crossDim, getDimWithMargin(child, crossAxis));
           }
+        } else if (performLayout) {
+          child->layout.position[pos[mainAxis]] += getLeadingBorder(node, mainAxis) + leadingMainDim;
         }
       }
     }
@@ -1901,7 +1903,7 @@ static void layoutNodeImpl(const CSSNodeRef node,
                                                      getLeadingMargin(child, crossAxis);
           } else {
             child->layout.position[pos[crossAxis]] =
-                leadingPaddingAndBorderCross + getLeadingMargin(child, crossAxis);
+                getLeadingBorder(node, crossAxis) + getLeadingMargin(child, crossAxis);
           }
         } else {
           float leadingCrossDim = leadingPaddingAndBorderCross;

csharp/tests/Facebook.CSSLayout/CSSLayoutAbsolutePositionTest.cs

@@ -31,6 +31,11 @@
     <div style="width: 100px; height: 100px;"></div>
   </div>
 </div>
+
+<div id="absolute_layout_within_border" style="height:100px; width:100px; border-width: 10px; margin: 10px; padding: 10px;">
+  <div style="position: absolute; width: 50px; height: 50px; left: 0px; top: 0px;"></div>
+  <div style="position: absolute; width: 50px; height: 50px; right: 0px; bottom: 0px;"></div>
+</div>
  *
  */
 
@@ -264,5 +269,76 @@ namespace Facebook.CSSLayout
             Assert.AreEqual(100, root_child0_child0.LayoutHeight);
         }
 
+        [Test]
+        public void Test_absolute_layout_within_border()
+        {
+            CSSNode root = new CSSNode();
+            root.SetMargin(CSSEdge.Left, 10);
+            root.SetMargin(CSSEdge.Top, 10);
+            root.SetMargin(CSSEdge.Right, 10);
+            root.SetMargin(CSSEdge.Bottom, 10);
+            root.SetPadding(CSSEdge.Left, 10);
+            root.SetPadding(CSSEdge.Top, 10);
+            root.SetPadding(CSSEdge.Right, 10);
+            root.SetPadding(CSSEdge.Bottom, 10);
+            root.SetBorder(CSSEdge.Left, 10);
+            root.SetBorder(CSSEdge.Top, 10);
+            root.SetBorder(CSSEdge.Right, 10);
+            root.SetBorder(CSSEdge.Bottom, 10);
+            root.StyleWidth = 100;
+            root.StyleHeight = 100;
+
+            CSSNode root_child0 = new CSSNode();
+            root_child0.PositionType = CSSPositionType.Absolute;
+            root_child0.SetPosition(CSSEdge.Left, 0);
+            root_child0.SetPosition(CSSEdge.Top, 0);
+            root_child0.StyleWidth = 50;
+            root_child0.StyleHeight = 50;
+            root.Insert(0, root_child0);
+
+            CSSNode root_child1 = new CSSNode();
+            root_child1.PositionType = CSSPositionType.Absolute;
+            root_child1.SetPosition(CSSEdge.Right, 0);
+            root_child1.SetPosition(CSSEdge.Bottom, 0);
+            root_child1.StyleWidth = 50;
+            root_child1.StyleHeight = 50;
+            root.Insert(1, root_child1);
+            root.StyleDirection = CSSDirection.LeftToRight;
+            root.CalculateLayout();
+
+            Assert.AreEqual(10, root.LayoutX);
+            Assert.AreEqual(10, root.LayoutY);
+            Assert.AreEqual(100, root.LayoutWidth);
+            Assert.AreEqual(100, root.LayoutHeight);
+
+            Assert.AreEqual(10, root_child0.LayoutX);
+            Assert.AreEqual(10, root_child0.LayoutY);
+            Assert.AreEqual(50, root_child0.LayoutWidth);
+            Assert.AreEqual(50, root_child0.LayoutHeight);
+
+            Assert.AreEqual(40, root_child1.LayoutX);
+            Assert.AreEqual(40, root_child1.LayoutY);
+            Assert.AreEqual(50, root_child1.LayoutWidth);
+            Assert.AreEqual(50, root_child1.LayoutHeight);
+
+            root.StyleDirection = CSSDirection.RightToLeft;
+            root.CalculateLayout();
+
+            Assert.AreEqual(10, root.LayoutX);
+            Assert.AreEqual(10, root.LayoutY);
+            Assert.AreEqual(100, root.LayoutWidth);
+            Assert.AreEqual(100, root.LayoutHeight);
+
+            Assert.AreEqual(10, root_child0.LayoutX);
+            Assert.AreEqual(10, root_child0.LayoutY);
+            Assert.AreEqual(50, root_child0.LayoutWidth);
+            Assert.AreEqual(50, root_child0.LayoutHeight);
+
+            Assert.AreEqual(40, root_child1.LayoutX);
+            Assert.AreEqual(40, root_child1.LayoutY);
+            Assert.AreEqual(50, root_child1.LayoutWidth);
+            Assert.AreEqual(50, root_child1.LayoutHeight);
+        }
+
     }
 }

gentest/fixtures/CSSLayoutAbsolutePositionTest.html

@@ -19,3 +19,8 @@
     <div style="width: 100px; height: 100px;"></div>
   </div>
 </div>
+
+<div id="absolute_layout_within_border" style="height:100px; width:100px; border-width: 10px; margin: 10px; padding: 10px;">
+  <div style="position: absolute; width: 50px; height: 50px; left: 0px; top: 0px;"></div>
+  <div style="position: absolute; width: 50px; height: 50px; right: 0px; bottom: 0px;"></div>
+</div>

java/tests/com/facebook/csslayout/CSSLayoutAbsolutePositionTest.java

@@ -31,6 +31,11 @@
     <div style="width: 100px; height: 100px;"></div>
   </div>
 </div>
+
+<div id="absolute_layout_within_border" style="height:100px; width:100px; border-width: 10px; margin: 10px; padding: 10px;">
+  <div style="position: absolute; width: 50px; height: 50px; left: 0px; top: 0px;"></div>
+  <div style="position: absolute; width: 50px; height: 50px; right: 0px; bottom: 0px;"></div>
+</div>
  *
  */
 
@@ -258,4 +263,74 @@ public class CSSLayoutAbsolutePositionTest {
     assertEquals(100, root_child0_child0.getLayoutHeight(), 0.0f);
   }
 
+  @Test
+  public void test_absolute_layout_within_border() {
+    final CSSNode root = new CSSNode();
+    root.setMargin(Spacing.LEFT, 10);
+    root.setMargin(Spacing.TOP, 10);
+    root.setMargin(Spacing.RIGHT, 10);
+    root.setMargin(Spacing.BOTTOM, 10);
+    root.setPadding(Spacing.LEFT, 10);
+    root.setPadding(Spacing.TOP, 10);
+    root.setPadding(Spacing.RIGHT, 10);
+    root.setPadding(Spacing.BOTTOM, 10);
+    root.setBorder(Spacing.LEFT, 10);
+    root.setBorder(Spacing.TOP, 10);
+    root.setBorder(Spacing.RIGHT, 10);
+    root.setBorder(Spacing.BOTTOM, 10);
+    root.setStyleWidth(100);
+    root.setStyleHeight(100);
+
+    final CSSNode root_child0 = new CSSNode();
+    root_child0.setPositionType(CSSPositionType.ABSOLUTE);
+    root_child0.setPosition(Spacing.LEFT, 0);
+    root_child0.setPosition(Spacing.TOP, 0);
+    root_child0.setStyleWidth(50);
+    root_child0.setStyleHeight(50);
+    root.addChildAt(root_child0, 0);
+
+    final CSSNode root_child1 = new CSSNode();
+    root_child1.setPositionType(CSSPositionType.ABSOLUTE);
+    root_child1.setPosition(Spacing.RIGHT, 0);
+    root_child1.setPosition(Spacing.BOTTOM, 0);
+    root_child1.setStyleWidth(50);
+    root_child1.setStyleHeight(50);
+    root.addChildAt(root_child1, 1);
+    root.setDirection(CSSDirection.LTR);
+    root.calculateLayout(null);
+
+    assertEquals(10, root.getLayoutX(), 0.0f);
+    assertEquals(10, root.getLayoutY(), 0.0f);
+    assertEquals(100, root.getLayoutWidth(), 0.0f);
+    assertEquals(100, root.getLayoutHeight(), 0.0f);
+
+    assertEquals(10, root_child0.getLayoutX(), 0.0f);
+    assertEquals(10, root_child0.getLayoutY(), 0.0f);
+    assertEquals(50, root_child0.getLayoutWidth(), 0.0f);
+    assertEquals(50, root_child0.getLayoutHeight(), 0.0f);
+
+    assertEquals(40, root_child1.getLayoutX(), 0.0f);
+    assertEquals(40, root_child1.getLayoutY(), 0.0f);
+    assertEquals(50, root_child1.getLayoutWidth(), 0.0f);
+    assertEquals(50, root_child1.getLayoutHeight(), 0.0f);
+
+    root.setDirection(CSSDirection.RTL);
+    root.calculateLayout(null);
+
+    assertEquals(10, root.getLayoutX(), 0.0f);
+    assertEquals(10, root.getLayoutY(), 0.0f);
+    assertEquals(100, root.getLayoutWidth(), 0.0f);
+    assertEquals(100, root.getLayoutHeight(), 0.0f);
+
+    assertEquals(10, root_child0.getLayoutX(), 0.0f);
+    assertEquals(10, root_child0.getLayoutY(), 0.0f);
+    assertEquals(50, root_child0.getLayoutWidth(), 0.0f);
+    assertEquals(50, root_child0.getLayoutHeight(), 0.0f);
+
+    assertEquals(40, root_child1.getLayoutX(), 0.0f);
+    assertEquals(40, root_child1.getLayoutY(), 0.0f);
+    assertEquals(50, root_child1.getLayoutWidth(), 0.0f);
+    assertEquals(50, root_child1.getLayoutHeight(), 0.0f);
+  }
+
 }

tests/CSSLayoutAbsolutePositionTest.cpp

@@ -31,6 +31,11 @@
     <div style="width: 100px; height: 100px;"></div>
   </div>
 </div>
+
+<div id="absolute_layout_within_border" style="height:100px; width:100px; border-width: 10px; margin: 10px; padding: 10px;">
+  <div style="position: absolute; width: 50px; height: 50px; left: 0px; top: 0px;"></div>
+  <div style="position: absolute; width: 50px; height: 50px; right: 0px; bottom: 0px;"></div>
+</div>
  *
  */
 
@@ -248,3 +253,72 @@ TEST(CSSLayoutTest, do_not_clamp_height_of_absolute_node_to_height_of_its_overfl
 
   CSSNodeFreeRecursive(root);
 }
+
+TEST(CSSLayoutTest, absolute_layout_within_border) {
+  const CSSNodeRef root = CSSNodeNew();
+  CSSNodeStyleSetMargin(root, CSSEdgeLeft, 10);
+  CSSNodeStyleSetMargin(root, CSSEdgeTop, 10);
+  CSSNodeStyleSetMargin(root, CSSEdgeRight, 10);
+  CSSNodeStyleSetMargin(root, CSSEdgeBottom, 10);
+  CSSNodeStyleSetPadding(root, CSSEdgeLeft, 10);
+  CSSNodeStyleSetPadding(root, CSSEdgeTop, 10);
+  CSSNodeStyleSetPadding(root, CSSEdgeRight, 10);
+  CSSNodeStyleSetPadding(root, CSSEdgeBottom, 10);
+  CSSNodeStyleSetBorder(root, CSSEdgeLeft, 10);
+  CSSNodeStyleSetBorder(root, CSSEdgeTop, 10);
+  CSSNodeStyleSetBorder(root, CSSEdgeRight, 10);
+  CSSNodeStyleSetBorder(root, CSSEdgeBottom, 10);
+  CSSNodeStyleSetWidth(root, 100);
+  CSSNodeStyleSetHeight(root, 100);
+
+  const CSSNodeRef root_child0 = CSSNodeNew();
+  CSSNodeStyleSetPositionType(root_child0, CSSPositionTypeAbsolute);
+  CSSNodeStyleSetPosition(root_child0, CSSEdgeLeft, 0);
+  CSSNodeStyleSetPosition(root_child0, CSSEdgeTop, 0);
+  CSSNodeStyleSetWidth(root_child0, 50);
+  CSSNodeStyleSetHeight(root_child0, 50);
+  CSSNodeInsertChild(root, root_child0, 0);
+
+  const CSSNodeRef root_child1 = CSSNodeNew();
+  CSSNodeStyleSetPositionType(root_child1, CSSPositionTypeAbsolute);
+  CSSNodeStyleSetPosition(root_child1, CSSEdgeRight, 0);
+  CSSNodeStyleSetPosition(root_child1, CSSEdgeBottom, 0);
+  CSSNodeStyleSetWidth(root_child1, 50);
+  CSSNodeStyleSetHeight(root_child1, 50);
+  CSSNodeInsertChild(root, root_child1, 1);
+  CSSNodeCalculateLayout(root, CSSUndefined, CSSUndefined, CSSDirectionLTR);
+
+  ASSERT_EQ(10, CSSNodeLayoutGetLeft(root));
+  ASSERT_EQ(10, CSSNodeLayoutGetTop(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetWidth(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetHeight(root));
+
+  ASSERT_EQ(10, CSSNodeLayoutGetLeft(root_child0));
+  ASSERT_EQ(10, CSSNodeLayoutGetTop(root_child0));
+  ASSERT_EQ(50, CSSNodeLayoutGetWidth(root_child0));
+  ASSERT_EQ(50, CSSNodeLayoutGetHeight(root_child0));
+
+  ASSERT_EQ(40, CSSNodeLayoutGetLeft(root_child1));
+  ASSERT_EQ(40, CSSNodeLayoutGetTop(root_child1));
+  ASSERT_EQ(50, CSSNodeLayoutGetWidth(root_child1));
+  ASSERT_EQ(50, CSSNodeLayoutGetHeight(root_child1));
+
+  CSSNodeCalculateLayout(root, CSSUndefined, CSSUndefined, CSSDirectionRTL);
+
+  ASSERT_EQ(10, CSSNodeLayoutGetLeft(root));
+  ASSERT_EQ(10, CSSNodeLayoutGetTop(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetWidth(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetHeight(root));
+
+  ASSERT_EQ(10, CSSNodeLayoutGetLeft(root_child0));
+  ASSERT_EQ(10, CSSNodeLayoutGetTop(root_child0));
+  ASSERT_EQ(50, CSSNodeLayoutGetWidth(root_child0));
+  ASSERT_EQ(50, CSSNodeLayoutGetHeight(root_child0));
+
+  ASSERT_EQ(40, CSSNodeLayoutGetLeft(root_child1));
+  ASSERT_EQ(40, CSSNodeLayoutGetTop(root_child1));
+  ASSERT_EQ(50, CSSNodeLayoutGetWidth(root_child1));
+  ASSERT_EQ(50, CSSNodeLayoutGetHeight(root_child1));
+
+  CSSNodeFreeRecursive(root);
+}