Bug 703241. PresShell::DoScrollContentIntoView and PresShell::ScrollFrameRectIntoView should take transforms into account. r=matspal

layout/base/nsPresShell.cpp

@@ -2964,8 +2964,8 @@ AccumulateFrameBounds(nsIFrame* aContainerFrame,
                       nsAutoLineIterator& aLines,
                       PRInt32& aCurLine)
 {
-  nsRect frameBounds = aFrame->GetRect() +
-    aFrame->GetParent()->GetOffsetTo(aContainerFrame);
+  nsIFrame* frame = aFrame;
+  nsRect frameBounds = nsRect(nsPoint(0, 0), aFrame->GetSize());
 
   // If this is an inline frame and either the bounds height is 0 (quirks
   // layout model) or aUseWholeLineHeightForInlines is set, we need to
@@ -3001,7 +3001,8 @@ AccumulateFrameBounds(nsIFrame* aContainerFrame,
 
           if (NS_SUCCEEDED(aLines->GetLine(index, &trash1, &trash2,
                                            lineBounds, &trash3))) {
-            lineBounds += f->GetOffsetTo(aContainerFrame);
+            frameBounds += frame->GetOffsetTo(f);
+            frame = f;
             if (lineBounds.y < frameBounds.y) {
               frameBounds.height = frameBounds.YMost() - lineBounds.y;
               frameBounds.y = lineBounds.y;
@@ -3012,14 +3013,17 @@ AccumulateFrameBounds(nsIFrame* aContainerFrame,
     }
   }
 
+  nsRect transformedBounds = nsLayoutUtils::TransformFrameRectToAncestor(frame,
+    frameBounds, aContainerFrame);
+
   if (aHaveRect) {
     // We can't use nsRect::UnionRect since it drops empty rects on
     // the floor, and we need to include them.  (Thus we need
     // aHaveRect to know when to drop the initial value on the floor.)
-    aRect.UnionRectEdges(aRect, frameBounds);
+    aRect.UnionRectEdges(aRect, transformedBounds);
   } else {
     aHaveRect = true;
-    aRect = frameBounds;
+    aRect = transformedBounds;
   }
 }
 
@@ -3315,8 +3319,14 @@ PresShell::ScrollFrameRectIntoView(nsIFrame*                aFrame,
         break;
       }
     }
-    rect += container->GetPosition();
-    nsIFrame* parent = container->GetParent();
+    nsIFrame* parent;
+    if (container->IsTransformed()) {
+      container->GetTransformMatrix(nsnull, &parent);
+      rect = nsLayoutUtils::TransformFrameRectToAncestor(container, rect, parent);
+    } else {
+      rect += container->GetPosition();
+      parent = container->GetParent();
+    }
     if (!parent && !(aFlags & nsIPresShell::SCROLL_NO_PARENT_FRAMES)) {
       nsPoint extraOffset(0,0);
       parent = nsLayoutUtils::GetCrossDocParentFrame(container, &extraOffset);

layout/base/tests/test_scroll_selection_into_view.html

@@ -40,6 +40,29 @@
                  <div style='height:400px;'></div>">
   </iframe>
 </div>
+<div id="c5" style="overflow-y:scroll; width:200px; height:200px; position:absolute; top:400px; left:0;">
+  <div style="-moz-transform:translateY(400px); transform:translateY(400px)">
+    <span id="target5" style="display:inline-block; vertical-align:top; height:20px;">target</span>
+  </div>
+  <div style="height:800px;"></div>
+</div>
+<div id="c6" style="overflow-y:scroll; width:200px; height:200px; position:absolute; top:400px; left:200px;">
+  <div style="height:200px"></div>
+  <div style="height:100px; -moz-transform:scale(2); transform:scale(2)">
+    <span id="target6" style="display:inline-block; vertical-align:top; height:20px;">target</span>
+  </div>
+  <div style="height:800px;"></div>
+</div>
+<div id="c7" style="overflow-y:scroll; width:200px; height:200px; position:absolute; top:400px; left:400px;">
+  <div style="overflow:auto; height:200px; -moz-transform:translateY(400px); transform:translateY(400px)">
+    <div style="height:200px;"></div>
+    <div>
+      <span id="target7" style="display:inline-block; vertical-align:top; height:20px;">target</span>
+    </div>
+    <div style="height:800px;"></div>
+  </div>
+  <div style="height:800px;"></div>
+</div>
 
 <pre id="test">
 <script class="testbody" type="text/javascript">
@@ -101,6 +124,18 @@ function doTest() {
   // visible.
   testCollapsed("4", -1, 1000, 400);
 
+  // Test that scrolling a translated element into view takes
+  // account of the transform.
+  testCollapsed("5", 0, 0, 400);
+
+  // Test that scrolling a scaled element into view takes
+  // account of the transform.
+  testCollapsed("6", 0, 0, 150);
+
+  // Test that scrolling an element with a translated, scrolling container
+  // into view takes account of the transform.
+  testCollapsed("7", 0, 0, 400);
+
   SimpleTest.finish();
 }
 

layout/generic/nsIFrame.h

@@ -1960,7 +1960,11 @@ public:
    * @param aStopAtAncestor don't look further than aStopAtAncestor. If null,
    *   all ancestors (including across documents) will be traversed.
    * @param aOutAncestor [out] The ancestor frame the frame has chosen.  If
-   *   this frame has no ancestor, *aOutAncestor will be set to null.
+   *   this frame has no ancestor, *aOutAncestor will be set to null. If
+   * this frame is not a root frame, then *aOutAncestor will be in the same
+   * document as this frame. If this frame IsTransformed(), then *aOutAncestor
+   * will be the parent frame (if not preserve-3d) or the nearest non-transformed
+   * ancestor (if preserve-3d).
    * @return A gfxMatrix that converts points in this frame's coordinate space
    *   into points in aOutAncestor's coordinate space.
    */