Bug 737786 - 1/5 - Show/hide placeholder based on display lists instead of CSS class. r=bz

content/html/content/public/nsITextControlElement.h

@@ -18,8 +18,8 @@ class nsTextControlFrame;
 
 // IID for the nsITextControl interface
 #define NS_ITEXTCONTROLELEMENT_IID    \
-{ 0xe0a05008, 0xef02, 0x4fa2,    \
-  { 0x93, 0xf2, 0x78, 0xe1, 0xec, 0xf7, 0x5b, 0x79 } }
+{ 0x669bd7ca, 0x42af, 0x4f1e, \
+  { 0xa6, 0xe2, 0x86, 0xc4, 0x0a, 0x14, 0x73, 0x4e } }
 
 /**
  * This interface is used for the text control frame to get the editor and
@@ -153,7 +153,12 @@ public:
   /**
    * Show/hide the placeholder for the control.
    */
-  NS_IMETHOD_(void) SetPlaceholderClass(bool aVisible, bool aNotify) = 0;
+  NS_IMETHOD_(void) SetPlaceholderVisibility(bool aVisible, bool aNotify) = 0;
+
+  /**
+   * Returns the current expected placeholder visibility state.
+   */
+  NS_IMETHOD_(bool) GetPlaceholderVisibility() = 0;
 
   /**
    * Callback called whenever the value is changed.

content/html/content/src/nsHTMLInputElement.cpp

@@ -1474,14 +1474,25 @@ nsHTMLInputElement::GetPlaceholderNode()
 }
 
 NS_IMETHODIMP_(void)
-nsHTMLInputElement::SetPlaceholderClass(bool aVisible, bool aNotify)
+nsHTMLInputElement::SetPlaceholderVisibility(bool aVisible, bool aNotify)
 {
   nsTextEditorState *state = GetEditorState();
   if (state) {
-    state->SetPlaceholderClass(aVisible, aNotify);
+    state->SetPlaceholderVisibility(aVisible, aNotify);
   }
 }
 
+NS_IMETHODIMP_(bool)
+nsHTMLInputElement::GetPlaceholderVisibility()
+{
+  nsTextEditorState* state = GetEditorState();
+  if (!state) {
+    return false;
+  }
+
+  return state->GetPlaceholderVisibility();
+}
+
 void
 nsHTMLInputElement::GetDisplayFileName(nsAString& aValue) const
 {

content/html/content/src/nsHTMLInputElement.h

@@ -150,7 +150,8 @@ public:
   NS_IMETHOD_(nsIContent*) GetRootEditorNode();
   NS_IMETHOD_(nsIContent*) CreatePlaceholderNode();
   NS_IMETHOD_(nsIContent*) GetPlaceholderNode();
-  NS_IMETHOD_(void) SetPlaceholderClass(bool aVisible, bool aNotify);
+  NS_IMETHOD_(void) SetPlaceholderVisibility(bool aVisible, bool aNotify);
+  NS_IMETHOD_(bool) GetPlaceholderVisibility();
   NS_IMETHOD_(void) InitializeKeyboardEventListeners();
   NS_IMETHOD_(void) OnValueChanged(bool aNotify);
   NS_IMETHOD_(bool) HasCachedSelection();

content/html/content/src/nsHTMLTextAreaElement.cpp

@@ -122,7 +122,8 @@ public:
   NS_IMETHOD_(nsIContent*) GetRootEditorNode();
   NS_IMETHOD_(nsIContent*) CreatePlaceholderNode();
   NS_IMETHOD_(nsIContent*) GetPlaceholderNode();
-  NS_IMETHOD_(void) SetPlaceholderClass(bool aVisible, bool aNotify);
+  NS_IMETHOD_(void) SetPlaceholderVisibility(bool aVisible, bool aNotify);
+  NS_IMETHOD_(bool) GetPlaceholderVisibility();
   NS_IMETHOD_(void) InitializeKeyboardEventListeners();
   NS_IMETHOD_(void) OnValueChanged(bool aNotify);
   NS_IMETHOD_(bool) HasCachedSelection();
@@ -513,9 +514,15 @@ nsHTMLTextAreaElement::GetPlaceholderNode()
 }
 
 NS_IMETHODIMP_(void)
-nsHTMLTextAreaElement::SetPlaceholderClass(bool aVisible, bool aNotify)
+nsHTMLTextAreaElement::SetPlaceholderVisibility(bool aVisible, bool aNotify)
 {
-  mState.SetPlaceholderClass(aVisible, aNotify);
+  mState.SetPlaceholderVisibility(aVisible, aNotify);
+}
+
+NS_IMETHODIMP_(bool)
+nsHTMLTextAreaElement::GetPlaceholderVisibility()
+{
+  return mState.GetPlaceholderVisibility();
 }
 
 nsresult

content/html/content/src/nsTextEditorState.cpp

@@ -933,7 +933,8 @@ nsTextEditorState::nsTextEditorState(nsITextControlElement* aOwningElement)
     mInitializing(false),
     mValueTransferInProgress(false),
     mSelectionCached(true),
-    mSelectionRestoreEagerInit(false)
+    mSelectionRestoreEagerInit(false),
+    mPlaceholderVisibility(false)
 {
   MOZ_COUNT_CTOR(nsTextEditorState);
 }
@@ -1660,6 +1661,10 @@ be called if @placeholder is the empty string when trimmed from line breaks");
   rv = mPlaceholderDiv->AppendChildTo(placeholderText, false);
   NS_ENSURE_SUCCESS(rv, rv);
 
+  mPlaceholderDiv->SetAttr(kNameSpaceID_None, nsGkAtoms::_class,
+                           NS_LITERAL_STRING("anonymous-div placeholder"),
+                           false);
+
   // initialize the text
   UpdatePlaceholderText(false);
 
@@ -1969,7 +1974,7 @@ nsTextEditorState::ValueWasChanged(bool aNotify)
 
   nsAutoString valueString;
   GetValue(valueString, true);
-  SetPlaceholderClass(valueString.IsEmpty(), aNotify);
+  SetPlaceholderVisibility(valueString.IsEmpty(), aNotify);
 }
 
 void
@@ -1993,28 +1998,17 @@ nsTextEditorState::UpdatePlaceholderText(bool aNotify)
 }
 
 void
-nsTextEditorState::SetPlaceholderClass(bool aVisible,
-                                       bool aNotify)
+nsTextEditorState::SetPlaceholderVisibility(bool aVisible,
+                                            bool aNotify)
 {
   NS_ASSERTION(mPlaceholderDiv, "This function should not be called if "
                                 "mPlaceholderDiv isn't set");
 
-  // No need to do anything if we don't have a frame yet
-  if (!mBoundFrame)
-    return;
+  mPlaceholderVisibility = aVisible;
 
-  nsAutoString classValue;
-
-  classValue.Assign(NS_LITERAL_STRING("anonymous-div placeholder"));
-
-  if (!aVisible)
-    classValue.AppendLiteral(" hidden");
-
-  nsIContent* placeholderDiv = GetPlaceholderNode();
-  NS_ENSURE_TRUE_VOID(placeholderDiv);
-
-  placeholderDiv->SetAttr(kNameSpaceID_None, nsGkAtoms::_class,
-                          classValue, aNotify);
+  if (mBoundFrame && aNotify) {
+    mBoundFrame->InvalidateFrame();
+  }
 }
 
 void

content/html/content/src/nsTextEditorState.h

@@ -174,7 +174,10 @@ public:
   }
 
   // placeholder methods
-  void SetPlaceholderClass(bool aVisible, bool aNotify);
+  void SetPlaceholderVisibility(bool aVisible, bool aNotify);
+  bool GetPlaceholderVisibility() {
+    return mPlaceholderVisibility;
+  }
   void UpdatePlaceholderText(bool aNotify); 
 
   /**
@@ -278,6 +281,7 @@ private:
   bool mSelectionCached; // Whether mSelectionProperties is valid
   mutable bool mSelectionRestoreEagerInit; // Whether we're eager initing because of selection restore
   SelectionProperties mSelectionProperties;
+  bool mPlaceholderVisibility;
 };
 
 #endif

layout/forms/nsTextControlFrame.cpp

@@ -1307,7 +1307,7 @@ nsTextControlFrame::SetValueChanged(bool aValueChanged)
     GetTextLength(&textLength);
 
     nsWeakFrame weakFrame(this);
-    txtCtrl->SetPlaceholderClass(!textLength, true);
+    txtCtrl->SetPlaceholderVisibility(!textLength, true);
     if (!weakFrame.IsAlive()) {
       return;
     }
@@ -1365,7 +1365,7 @@ nsTextControlFrame::UpdateValueDisplay(bool aNotify,
   if (mUsePlaceholder && !aBeforeEditorInit)
   {
     nsWeakFrame weakFrame(this);
-    txtCtrl->SetPlaceholderClass(value.IsEmpty(), aNotify);
+    txtCtrl->SetPlaceholderVisibility(value.IsEmpty(), aNotify);
     NS_ENSURE_STATE(weakFrame.IsAlive());
   }
 
@@ -1455,3 +1455,38 @@ nsTextControlFrame::PeekOffset(nsPeekOffsetStruct *aPos)
   return NS_ERROR_FAILURE;
 }
 
+NS_IMETHODIMP
+nsTextControlFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
+                                     const nsRect&           aDirtyRect,
+                                     const nsDisplayListSet& aLists)
+{
+  /*
+   * The implementation of this method is equivalent as:
+   * nsContainerFrame::BuildDisplayList()
+   * with the difference that we filter-out the placeholder frame when it
+   * should not be visible.
+   */
+  DO_GLOBAL_REFLOW_COUNT_DSP("nsTextControlFrame");
+
+  nsCOMPtr<nsITextControlElement> txtCtrl = do_QueryInterface(GetContent());
+  NS_ASSERTION(txtCtrl, "Content not a text control element!");
+
+  nsresult rv = DisplayBorderBackgroundOutline(aBuilder, aLists);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsIFrame* kid = mFrames.FirstChild();
+  nsDisplayListSet set(aLists, aLists.Content());
+
+  while (kid) {
+    // If the frame is the placeholder frame, we should only show it if the
+    // placeholder has to be visible.
+    if (kid->GetContent() != txtCtrl->GetPlaceholderNode() ||
+        txtCtrl->GetPlaceholderVisibility()) {
+      nsresult rv = BuildDisplayListForChild(aBuilder, kid, aDirtyRect, set, 0);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+    kid = kid->GetNextSibling();
+  }
+
+  return NS_OK;
+}

layout/forms/nsTextControlFrame.h

@@ -67,8 +67,6 @@ public:
   virtual nsSize GetMinSize(nsBoxLayoutState& aBoxLayoutState);
   virtual bool IsCollapsed();
 
-  DECL_DO_GLOBAL_REFLOW_COUNT_DSP(nsTextControlFrame, nsContainerFrame)
-
   virtual bool IsLeaf() const;
   
 #ifdef ACCESSIBILITY
@@ -101,6 +99,10 @@ public:
   NS_IMETHOD SetInitialChildList(ChildListID     aListID,
                                  nsFrameList&    aChildList) MOZ_OVERRIDE;
 
+  NS_IMETHOD BuildDisplayList(nsDisplayListBuilder*   aBuilder,
+                              const nsRect&           aDirtyRect,
+                              const nsDisplayListSet& aLists);
+
 //==== BEGIN NSIFORMCONTROLFRAME
   virtual void SetFocus(bool aOn , bool aRepaint); 
   virtual nsresult SetFormProperty(nsIAtom* aName, const nsAString& aValue);

layout/style/forms.css

@@ -161,11 +161,6 @@ textarea > .placeholder {
   white-space: pre-wrap;
 }
 
-input > .placeholder.hidden,
-textarea > .placeholder.hidden {
-  visibility: hidden;
-}
-
 input:-moz-read-write,
 textarea:-moz-read-write {
   -moz-user-modify: read-write !important;