Fix calculation of scrollbar widths for laying out fixed-position frames. Also make sure that the fixed frames are reflowed if scrollbar widths change. Fix for bug 5195. r=evaughan,sr=attinasi

layout/generic/nsGfxScrollFrame.cpp

@@ -1134,7 +1134,8 @@ nsGfxScrollFrameInner::Layout(nsBoxLayoutState& aState)
   if (mHasVerticalScrollbar)
      AddVerticalScrollbar(aState, scrollAreaRect, scrollBarRight);
      
-
+  nsRect oldScrollAreaBounds;
+  mScrollAreaBox->GetClientRect(oldScrollAreaBounds);
 
   // layout our the scroll area
   LayoutBox(aState, mScrollAreaBox, scrollAreaRect);
@@ -1347,7 +1348,34 @@ nsGfxScrollFrameInner::Layout(nsBoxLayoutState& aState)
      needsLayout = PR_FALSE;
   }
 
+  // may need to update fixed position children of the viewport,
+  // if the client area changed size because of some dirty reflow
+  // (if the reflow is initial or resize, the fixed children will
+  // be re-laid out anyway)
+  if ((oldScrollAreaBounds.width != scrollAreaRect.width
+      || oldScrollAreaBounds.height != scrollAreaRect.height)
+      && nsBoxLayoutState::Dirty == aState.GetLayoutReason()) {
+    nsIFrame* parentFrame;
+    mOuter->GetParent(&parentFrame);
+    if (parentFrame) {
+      nsCOMPtr<nsIAtom> parentFrameType;
+      parentFrame->GetFrameType(getter_AddRefs(parentFrameType));
+      if (parentFrameType.get() == nsLayoutAtoms::viewportFrame) {
+        // Usually there are no fixed children, so don't do anything unless there's
+        // at least one fixed child
+        nsIFrame* child;
+        if (NS_SUCCEEDED(parentFrame->FirstChild(mOuter->mPresContext,
+          nsLayoutAtoms::fixedList, &child)) && child) {
+          nsCOMPtr<nsIPresShell> presShell;
+          mOuter->mPresContext->GetShell(getter_AddRefs(presShell));
 
+          // force a reflow of the fixed children
+          nsFrame::CreateAndPostReflowCommand(presShell, parentFrame,
+            nsIReflowCommand::UserDefined, nsnull, nsnull, nsLayoutAtoms::fixedList);
+        }
+      }
+    }
+  }
   
   return NS_OK;
 }

layout/generic/nsViewportFrame.cpp

@@ -25,7 +25,7 @@
 #include "nsHTMLIIDs.h"
 #include "nsLayoutAtoms.h"
 #include "nsIViewManager.h"
-#include "nsIScrollableView.h"
+#include "nsIScrollableFrame.h"
 #include "nsIDeviceContext.h"
 #include "nsIPresContext.h"
 #include "nsIReflowCommand.h"
@@ -310,30 +310,18 @@ ViewportFrame::CalculateFixedContainingBlockSize(nsIPresContext*          aPresC
 
   // Get our prinicpal child frame and see if we're scrollable
   nsIFrame* kidFrame = mFrames.FirstChild();
-  nsIView*  kidView;
+  nsCOMPtr<nsIScrollableFrame> scrollingFrame(do_QueryInterface(kidFrame));
 
-  kidFrame->GetView(aPresContext, &kidView);
-  if (nsnull != kidView) {
-    nsIScrollableView* scrollingView;
-    
-    if (NS_SUCCEEDED(kidView->QueryInterface(NS_GET_IID(nsIScrollableView), (void**)&scrollingView))) {
-      // Get the scrollbar dimensions
-      float             sbWidth, sbHeight;
-      nsCOMPtr<nsIDeviceContext> dc;
-      aPresContext->GetDeviceContext(getter_AddRefs(dc));
-
-      dc->GetScrollBarDimensions(sbWidth, sbHeight);
-      
-      // See if the scrollbars are visible
-      PRBool  vertSBVisible, horzSBVisible;
-      
-      scrollingView->GetScrollbarVisibility(&vertSBVisible, &horzSBVisible);
-      if (vertSBVisible) {
-        aWidth -= NSToCoordRound(sbWidth);
-      }
-      if (horzSBVisible) {
-        aHeight -= NSToCoordRound(sbHeight);
+  if (scrollingFrame) {
+    nscoord sbWidth = 0, sbHeight = 0;
+    PRBool sbHVisible = PR_FALSE, sbVVisible = PR_FALSE;
+    scrollingFrame->GetScrollbarSizes(aPresContext, &sbWidth, &sbHeight);
+    scrollingFrame->GetScrollbarVisibility(aPresContext, &sbVVisible, &sbHVisible);
+    if (sbVVisible) {
+      aWidth -= sbWidth;
     }
+    if (sbHVisible) {
+      aHeight -= sbHeight;
     }
   }
 }
@@ -402,9 +390,6 @@ void
 ViewportFrame::ReflowFixedFrames(nsIPresContext*          aPresContext,
                                  const nsHTMLReflowState& aReflowState) const
 {
-  NS_PRECONDITION(eReflowReason_Incremental != aReflowState.reason,
-                  "unexpected reflow reason");
-
   // Calculate how much room is available for the fixed items. That means
   // determining if the viewport is scrollable and whether the vertical and/or
   // horizontal scrollbars are visible
@@ -490,8 +475,17 @@ ViewportFrame::Reflow(nsIPresContext*          aPresContext,
   nsIFrame* nextFrame = nsnull;
   PRBool    isHandled = PR_FALSE;
   
-  // Check for an incremental reflow
-  if (eReflowReason_Incremental == aReflowState.reason) {
+  nsIReflowCommand::ReflowType reflowType = nsIReflowCommand::ContentChanged;
+  if (aReflowState.reflowCommand) {
+    aReflowState.reflowCommand->GetType(reflowType);
+  }
+  if (reflowType == nsIReflowCommand::UserDefined) {
+    // Reflow the fixed frames to account for changed scrolled area size
+    ReflowFixedFrames(aPresContext, aReflowState);
+    isHandled = PR_TRUE;
+
+    // Otherwise check for an incremental reflow
+  } else if (eReflowReason_Incremental == aReflowState.reason) {
     // See if we're the target frame
     nsIFrame* targetFrame;
     aReflowState.reflowCommand->GetTarget(targetFrame);

layout/html/base/src/nsGfxScrollFrame.cpp

@@ -1134,7 +1134,8 @@ nsGfxScrollFrameInner::Layout(nsBoxLayoutState& aState)
   if (mHasVerticalScrollbar)
      AddVerticalScrollbar(aState, scrollAreaRect, scrollBarRight);
      
-
+  nsRect oldScrollAreaBounds;
+  mScrollAreaBox->GetClientRect(oldScrollAreaBounds);
 
   // layout our the scroll area
   LayoutBox(aState, mScrollAreaBox, scrollAreaRect);
@@ -1347,7 +1348,34 @@ nsGfxScrollFrameInner::Layout(nsBoxLayoutState& aState)
      needsLayout = PR_FALSE;
   }
 
+  // may need to update fixed position children of the viewport,
+  // if the client area changed size because of some dirty reflow
+  // (if the reflow is initial or resize, the fixed children will
+  // be re-laid out anyway)
+  if ((oldScrollAreaBounds.width != scrollAreaRect.width
+      || oldScrollAreaBounds.height != scrollAreaRect.height)
+      && nsBoxLayoutState::Dirty == aState.GetLayoutReason()) {
+    nsIFrame* parentFrame;
+    mOuter->GetParent(&parentFrame);
+    if (parentFrame) {
+      nsCOMPtr<nsIAtom> parentFrameType;
+      parentFrame->GetFrameType(getter_AddRefs(parentFrameType));
+      if (parentFrameType.get() == nsLayoutAtoms::viewportFrame) {
+        // Usually there are no fixed children, so don't do anything unless there's
+        // at least one fixed child
+        nsIFrame* child;
+        if (NS_SUCCEEDED(parentFrame->FirstChild(mOuter->mPresContext,
+          nsLayoutAtoms::fixedList, &child)) && child) {
+          nsCOMPtr<nsIPresShell> presShell;
+          mOuter->mPresContext->GetShell(getter_AddRefs(presShell));
 
+          // force a reflow of the fixed children
+          nsFrame::CreateAndPostReflowCommand(presShell, parentFrame,
+            nsIReflowCommand::UserDefined, nsnull, nsnull, nsLayoutAtoms::fixedList);
+        }
+      }
+    }
+  }
   
   return NS_OK;
 }

layout/html/base/src/nsScrollFrame.cpp

@@ -646,6 +646,9 @@ nsScrollFrame::Reflow(nsIPresContext*          aPresContext,
   nsIFrame* targetFrame;
   nsIFrame* nextFrame;
 
+  nsRect oldKidBounds;
+  kidFrame->GetRect(oldKidBounds);
+
   // Special handling for incremental reflow
   if (eReflowReason_Incremental == aReflowState.reason) {
     // See whether we're the target of the reflow command
@@ -859,6 +862,36 @@ nsScrollFrame::Reflow(nsIPresContext*          aPresContext,
     }
   }
 
+  nsRect newKidBounds;
+  kidFrame->GetRect(newKidBounds);
+
+  // may need to update fixed position children of the viewport,
+  // if the client area changed size
+  if ((oldKidBounds.width != newKidBounds.width
+      || oldKidBounds.height != newKidBounds.height)
+      && eReflowReason_Incremental == aReflowState.reason) {
+    nsIFrame* parentFrame;
+    GetParent(&parentFrame);
+    if (parentFrame) {
+      nsCOMPtr<nsIAtom> parentFrameType;
+      parentFrame->GetFrameType(getter_AddRefs(parentFrameType));
+      if (parentFrameType.get() == nsLayoutAtoms::viewportFrame) {
+        // Usually there are no fixed children, so don't do anything unless there's
+        // at least one fixed child
+        nsIFrame* child;
+        if (NS_SUCCEEDED(parentFrame->FirstChild(aPresContext,
+          nsLayoutAtoms::fixedList, &child)) && child) {
+          nsCOMPtr<nsIPresShell> presShell;
+          aPresContext->GetShell(getter_AddRefs(presShell));
+
+          // force a reflow of the fixed children
+          nsFrame::CreateAndPostReflowCommand(presShell, parentFrame,
+            nsIReflowCommand::UserDefined, nsnull, nsnull, nsLayoutAtoms::fixedList);
+        }
+      }
+    }
+  }
+  
   if (aReflowState.mStyleDisplay->mOverflow != NS_STYLE_OVERFLOW_SCROLLBARS_HORIZONTAL)
   {
 

layout/html/base/src/nsViewportFrame.cpp

@@ -25,7 +25,7 @@
 #include "nsHTMLIIDs.h"
 #include "nsLayoutAtoms.h"
 #include "nsIViewManager.h"
-#include "nsIScrollableView.h"
+#include "nsIScrollableFrame.h"
 #include "nsIDeviceContext.h"
 #include "nsIPresContext.h"
 #include "nsIReflowCommand.h"
@@ -310,30 +310,18 @@ ViewportFrame::CalculateFixedContainingBlockSize(nsIPresContext*          aPresC
 
   // Get our prinicpal child frame and see if we're scrollable
   nsIFrame* kidFrame = mFrames.FirstChild();
-  nsIView*  kidView;
+  nsCOMPtr<nsIScrollableFrame> scrollingFrame(do_QueryInterface(kidFrame));
 
-  kidFrame->GetView(aPresContext, &kidView);
-  if (nsnull != kidView) {
-    nsIScrollableView* scrollingView;
-    
-    if (NS_SUCCEEDED(kidView->QueryInterface(NS_GET_IID(nsIScrollableView), (void**)&scrollingView))) {
-      // Get the scrollbar dimensions
-      float             sbWidth, sbHeight;
-      nsCOMPtr<nsIDeviceContext> dc;
-      aPresContext->GetDeviceContext(getter_AddRefs(dc));
-
-      dc->GetScrollBarDimensions(sbWidth, sbHeight);
-      
-      // See if the scrollbars are visible
-      PRBool  vertSBVisible, horzSBVisible;
-      
-      scrollingView->GetScrollbarVisibility(&vertSBVisible, &horzSBVisible);
-      if (vertSBVisible) {
-        aWidth -= NSToCoordRound(sbWidth);
-      }
-      if (horzSBVisible) {
-        aHeight -= NSToCoordRound(sbHeight);
+  if (scrollingFrame) {
+    nscoord sbWidth = 0, sbHeight = 0;
+    PRBool sbHVisible = PR_FALSE, sbVVisible = PR_FALSE;
+    scrollingFrame->GetScrollbarSizes(aPresContext, &sbWidth, &sbHeight);
+    scrollingFrame->GetScrollbarVisibility(aPresContext, &sbVVisible, &sbHVisible);
+    if (sbVVisible) {
+      aWidth -= sbWidth;
     }
+    if (sbHVisible) {
+      aHeight -= sbHeight;
     }
   }
 }
@@ -402,9 +390,6 @@ void
 ViewportFrame::ReflowFixedFrames(nsIPresContext*          aPresContext,
                                  const nsHTMLReflowState& aReflowState) const
 {
-  NS_PRECONDITION(eReflowReason_Incremental != aReflowState.reason,
-                  "unexpected reflow reason");
-
   // Calculate how much room is available for the fixed items. That means
   // determining if the viewport is scrollable and whether the vertical and/or
   // horizontal scrollbars are visible
@@ -490,8 +475,17 @@ ViewportFrame::Reflow(nsIPresContext*          aPresContext,
   nsIFrame* nextFrame = nsnull;
   PRBool    isHandled = PR_FALSE;
   
-  // Check for an incremental reflow
-  if (eReflowReason_Incremental == aReflowState.reason) {
+  nsIReflowCommand::ReflowType reflowType = nsIReflowCommand::ContentChanged;
+  if (aReflowState.reflowCommand) {
+    aReflowState.reflowCommand->GetType(reflowType);
+  }
+  if (reflowType == nsIReflowCommand::UserDefined) {
+    // Reflow the fixed frames to account for changed scrolled area size
+    ReflowFixedFrames(aPresContext, aReflowState);
+    isHandled = PR_TRUE;
+
+    // Otherwise check for an incremental reflow
+  } else if (eReflowReason_Incremental == aReflowState.reason) {
     // See if we're the target frame
     nsIFrame* targetFrame;
     aReflowState.reflowCommand->GetTarget(targetFrame);