CSS Custom Properties (Variables)

third_party/WebKit/Source/core/style/StyleVariableData.h

+#ifndef StyleVariableData_h
+#define StyleVariableData_h
+
+#include "core/css/CSSVariableData.h"
+#include "wtf/Forward.h"
+#include "wtf/HashMap.h"
+#include "wtf/RefCounted.h"
+#include "wtf/text/AtomicStringHash.h"
+
+namespace blink {
+
+class StyleVariableData : public RefCounted<StyleVariableData> {
+public:
+    static PassRefPtr<StyleVariableData> create() { return adoptRef(new StyleVariableData()); }
+    PassRefPtr<StyleVariableData> copy() const { return adoptRef(new StyleVariableData(*this)); }
+
+    bool operator==(const StyleVariableData& other) const { return other.m_data == m_data; }
+    bool operator!=(const StyleVariableData& other) const { return !(*this == other); }
+
+    void setVariable(const AtomicString& name, PassRefPtr<CSSVariableData> value) { m_data.set(name, value); }
+    CSSVariableData* getVariable(const AtomicString& name) const { return m_data.get(name); }
+    void removeVariable(const AtomicString& name) { return m_data.remove(name); }
+private:
+    explicit StyleVariableData() : RefCounted<StyleVariableData>() { }

[Timothy Loh, 2015/10/15 03:43:48]

Not sure if you need to define either of these constructors, are there default
compiler generated ones? If not, you probably don't need to explicitly call the
superclass ctor here and below, explicit doesn't do anything here, and the extra
HashMap ctor below isn't needed.

[leviw_travelin_and_unemployed, 2015/10/20 21:56:53]

It's actually necessary for the copy constructor. Attempting to leave it
undefined/use the default fails:

../../third_party/WebKit/Source/core/style/StyleVariableData.h:15:70: error:
call to implicitly-deleted copy constructor of 'blink::StyleVariableData'
    PassRefPtr<StyleVariableData> copy() const { return adoptRef(new
StyleVariableData(*this)); }
                                                                     ^          
      ~~~~~
../../third_party/WebKit/Source/core/style/StyleVariableData.h:12:27: note: copy
constructor of 'StyleVariableData' is implicitly deleted because base class
'RefCounted<blink::StyleVariableData>' has a deleted copy constructor
class StyleVariableData : public RefCounted<StyleVariableData> {
                          ^
../../third_party/WebKit/Source/wtf/RefCounted.h:165:26: note: 'RefCounted' has
been explicitly marked deleted here
    WTF_MAKE_NONCOPYABLE(RefCounted);

[Timothy Loh, 2015/10/28 05:12:41]

But we can write m_data(other.m_data), right?

+    StyleVariableData(const StyleVariableData& other) : RefCounted<StyleVariableData>(), m_data(HashMap<AtomicString, RefPtr<CSSVariableData>>(other.m_data)) { }
+
+    friend class CSSVariableResolver;
+
+    HashMap<AtomicString, RefPtr<CSSVariableData>> m_data;
+};
+
+} // namespace blink
+
+#endif // StyleVariableData_h