Bug 157445. Be more aggressive about making visibility:hidden elements have visible views. r+sr=bzbarsky

layout/base/public/nsIFrame.h

@@ -1224,6 +1224,13 @@ public:
                              void*           aPropertyValue) = 0;
 #endif // IBMBIDI
 
+  /**
+   * Return PR_TRUE if and only if this frame obeys visibility:hidden.
+   * if it does not, then nsContainerFrame will hide its view even though
+   * this means children can't be made visible again.
+   */
+  virtual PRBool SupportsVisibilityHidden() { return PR_TRUE; }
+
 protected:
   // Members
   nsRect           mRect;

layout/forms/nsListControlFrame.h

@@ -223,6 +223,8 @@ public:
    */
   NS_IMETHOD GetFrameType(nsIAtom** aType) const;
 
+  virtual PRBool SupportsVisibilityHidden() { return PR_FALSE; }
+
 #ifdef DEBUG
     // nsIFrameDebug
   NS_IMETHOD GetFrameName(nsAString& aResult) const;

layout/generic/nsContainerFrame.cpp

@@ -779,25 +779,13 @@ nsContainerFrame::SyncFrameViewProperties(nsIPresContext*  aPresContext,
       viewIsVisible = PR_FALSE;
     }
     else if (NS_STYLE_VISIBILITY_HIDDEN == vis->mVisible) {
-      // If it has a widget, hide the view because the widget can't deal with it
-      nsCOMPtr<nsIWidget> widget;
-      aView->GetWidget(*getter_AddRefs(widget));
-      if (widget) {
+      // If it's a scrollable frame that can't hide its scrollbars,
+      // hide the view. This means that child elements can't override
+      // their parent's visibility, but it's not practical to leave it
+      // visible in all cases because the scrollbars will be showing
+      if (!aFrame->SupportsVisibilityHidden()) {
         viewIsVisible = PR_FALSE;
       }
-      else {
-        // If it's a scroll frame or a list control frame which is derived from the scrollframe, 
-        // then hide the view. This means that
-        // child elements can't override their parent's visibility, but
-        // it's not practical to leave it visible in all cases because
-        // the scrollbars will be showing
-        nsCOMPtr<nsIAtom> frameType;
-        aFrame->GetFrameType(getter_AddRefs(frameType));
-
-        if (frameType == nsLayoutAtoms::scrollFrame || frameType == nsLayoutAtoms::listControlFrame) {
-          viewIsVisible = PR_FALSE;
-        }
-      }
     } else {
       // if the view is for a popup, don't show the view if the popup is closed
       nsCOMPtr<nsIWidget> widget;

layout/generic/nsIFrame.h

@@ -1224,6 +1224,13 @@ public:
                              void*           aPropertyValue) = 0;
 #endif // IBMBIDI
 
+  /**
+   * Return PR_TRUE if and only if this frame obeys visibility:hidden.
+   * if it does not, then nsContainerFrame will hide its view even though
+   * this means children can't be made visible again.
+   */
+  virtual PRBool SupportsVisibilityHidden() { return PR_TRUE; }
+
 protected:
   // Members
   nsRect           mRect;

layout/html/base/src/nsContainerFrame.cpp

@@ -779,25 +779,13 @@ nsContainerFrame::SyncFrameViewProperties(nsIPresContext*  aPresContext,
       viewIsVisible = PR_FALSE;
     }
     else if (NS_STYLE_VISIBILITY_HIDDEN == vis->mVisible) {
-      // If it has a widget, hide the view because the widget can't deal with it
-      nsCOMPtr<nsIWidget> widget;
-      aView->GetWidget(*getter_AddRefs(widget));
-      if (widget) {
+      // If it's a scrollable frame that can't hide its scrollbars,
+      // hide the view. This means that child elements can't override
+      // their parent's visibility, but it's not practical to leave it
+      // visible in all cases because the scrollbars will be showing
+      if (!aFrame->SupportsVisibilityHidden()) {
         viewIsVisible = PR_FALSE;
       }
-      else {
-        // If it's a scroll frame or a list control frame which is derived from the scrollframe, 
-        // then hide the view. This means that
-        // child elements can't override their parent's visibility, but
-        // it's not practical to leave it visible in all cases because
-        // the scrollbars will be showing
-        nsCOMPtr<nsIAtom> frameType;
-        aFrame->GetFrameType(getter_AddRefs(frameType));
-
-        if (frameType == nsLayoutAtoms::scrollFrame || frameType == nsLayoutAtoms::listControlFrame) {
-          viewIsVisible = PR_FALSE;
-        }
-      }
     } else {
       // if the view is for a popup, don't show the view if the popup is closed
       nsCOMPtr<nsIWidget> widget;

layout/html/base/src/nsScrollFrame.h

@@ -123,6 +123,8 @@ public:
    */
   NS_IMETHOD GetFrameType(nsIAtom** aType) const;
 
+  virtual PRBool SupportsVisibilityHidden() { return PR_FALSE; }
+
     // nsIScrollableFrame
   NS_IMETHOD  SetScrolledFrame(nsIPresContext* aPresContext, nsIFrame *aScrolledFrame);
   NS_IMETHOD  GetScrolledFrame(nsIPresContext* aPresContext, nsIFrame *&aScrolledFrame) const;
@@ -146,7 +148,6 @@ public:
   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr); 
   NS_IMETHOD_(nsrefcnt) AddRef(void) { return NS_OK; }
   NS_IMETHOD_(nsrefcnt) Release(void) { return NS_OK; }
-
   
 #ifdef DEBUG
   NS_IMETHOD GetFrameName(nsAString& aResult) const;

layout/html/forms/src/nsListControlFrame.h

@@ -223,6 +223,8 @@ public:
    */
   NS_IMETHOD GetFrameType(nsIAtom** aType) const;
 
+  virtual PRBool SupportsVisibilityHidden() { return PR_FALSE; }
+
 #ifdef DEBUG
     // nsIFrameDebug
   NS_IMETHOD GetFrameName(nsAString& aResult) const;