CSS4: Implement :placeholder-shown pseudo class

Source/core/html/HTMLTextAreaElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 256 matching lines @@
     if (LocalFrame* frame = document().frame())
         frame->spellChecker().didBeginEditing(this);
 }
 
 void HTMLTextAreaElement::subtreeHasChanged()
 {
     setChangedSinceLastFormControlChangeEvent(true);
     m_valueIsUpToDate = false;
     setNeedsValidityCheck();
     setAutofilled(false);
-    updatePlaceholderVisibility(false);
+    updatePlaceholderVisibility();
 
     if (!focused())
         return;
 
     // When typing in a textarea, childrenChanged is not called, so we need to force the directionality check.
     calculateAndAdjustDirectionality();
 
     ASSERT(document().isActive());
     document().frameHost()->chromeClient().didChangeValueInTextField(*this);
 }
@@ skipping 37 matching lines @@
 
 void HTMLTextAreaElement::updateValue() const
 {
     if (m_valueIsUpToDate)
         return;
 
     m_value = innerEditorValue();
     const_cast<HTMLTextAreaElement*>(this)->m_valueIsUpToDate = true;
     const_cast<HTMLTextAreaElement*>(this)->notifyFormStateChanged();
     m_isDirty = true;
-    const_cast<HTMLTextAreaElement*>(this)->updatePlaceholderVisibility(false);
+    const_cast<HTMLTextAreaElement*>(this)->updatePlaceholderVisibility();
 }
 
 String HTMLTextAreaElement::value() const
 {
     updateValue();
     return m_value;
 }
 
 void HTMLTextAreaElement::setValue(const String& value, TextFieldEventBehavior eventBehavior)
 {
@@ skipping 31 matching lines @@
                 setSelectionRange(endOfString, endOfString, SelectionHasNoDirection, NotDispatchSelectEvent, ChangeSelectionIfFocused);
             }
         }
         return;
     }
 
     m_value = normalizedValue;
     setInnerEditorValue(m_value);
     if (eventBehavior == DispatchNoEvent)
         setLastChangeWasNotUserEdit();
-    updatePlaceholderVisibility(false);
+    updatePlaceholderVisibility();
     setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::ControlValue));
     m_suggestedValue = String();
     setNeedsValidityCheck();
     if (isFinishedParsingChildren()) {
         // Set the caret to the end of the text value except for initialize.
         unsigned endOfString = m_value.length();
         setSelectionRange(endOfString, endOfString, SelectionHasNoDirection, NotDispatchSelectEvent, ChangeSelectionIfFocused);
     }
 
     notifyFormStateChanged();
@@ skipping 94 matching lines @@
 }
 
 void HTMLTextAreaElement::setSuggestedValue(const String& value)
 {
     m_suggestedValue = value;
 
     if (!value.isNull())
         setInnerEditorValue(m_suggestedValue);
     else
         setInnerEditorValue(m_value);
-    updatePlaceholderVisibility(false);
+    updatePlaceholderVisibility();
     setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::ControlValue));
 }
 
 String HTMLTextAreaElement::validationMessage() const
 {
     if (!willValidate())
         return String();
 
     if (customError())
         return customValidationMessage();
@@ skipping 98 matching lines @@
     if (placeholderText.isEmpty()) {
         if (placeholder)
             userAgentShadowRoot()->removeChild(placeholder);
         return;
     }
     if (!placeholder) {
         RefPtrWillBeRawPtr<HTMLDivElement> newElement = HTMLDivElement::create(document());
         placeholder = newElement.get();
         placeholder->setShadowPseudoId(AtomicString("-webkit-input-placeholder", AtomicString::ConstructFromLiteral));
         placeholder->setAttribute(idAttr, ShadowElementNames::placeholder());
+        placeholder->setInlineStyleProperty(CSSPropertyDisplay, isPlaceholderVisible() ? CSSValueBlock : CSSValueNone, true);

[esprehn, 2015/08/21 10:18:10]

Just call updatePlaceholderVisibility() here, no reason to copy this code.

[ramya.v, 2015/08/25 10:24:45]

updatePlaceholderText is called from inside updatePlaceholderVisibility() for
the first time when placeholder element is not present. If we add this, it would
become re-entrant.

         userAgentShadowRoot()->insertBefore(placeholder, innerEditorElement()->nextSibling());
     }
     placeholder->setTextContent(placeholderText);
 }
 
 bool HTMLTextAreaElement::isInteractiveContent() const
 {
     return true;
 }
 
@@ skipping 10 matching lines @@
 
 void HTMLTextAreaElement::copyNonAttributePropertiesFromElement(const Element& source)
 {
     const HTMLTextAreaElement& sourceElement = static_cast<const HTMLTextAreaElement&>(source);
     setValueCommon(sourceElement.value(), DispatchNoEvent, SetSeletion);
     m_isDirty = sourceElement.m_isDirty;
     HTMLTextFormControlElement::copyNonAttributePropertiesFromElement(source);
 }
 
 } // namespace blink