Source/core/svg/properties/NewSVGListPropertyTearOffHelper.h

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#ifndef NewSVGListPropertyTearOffHelper_h
#define NewSVGListPropertyTearOffHelper_h

#include "bindings/v8/ExceptionState.h"
#include "core/svg/properties/NewSVGPropertyTearOff.h"
#include "wtf/HashMap.h"

namespace WebCore {

template<typename Derived, typename ListProperty>
class NewSVGListPropertyTearOffHelper : public NewSVGPropertyTearOff<ListProperty> {
public:
    typedef ListProperty ListPropertyType;
    typedef typename ListPropertyType::ItemPropertyType ItemPropertyType;
    typedef typename ItemPropertyType::TearOffType ItemTearOffType;

    // SVG*List DOM interface:

    // WebIDL requires "unsigned long" type instead of size_t.
    unsigned long numberOfItems()
    {
        return toDerived()->target()->numberOfItems();
    }

    void clear(ExceptionState& exceptionState)
    {
        if (toDerived()->isImmutable()) {
            exceptionState.throwDOMException(NoModificationAllowedError, "The object is read-only.");
            return;
        }

        toDerived()->target()->clear();
    }

    PassRefPtr<ItemTearOffType> initialize(PassRefPtr<ItemTearOffType> passItem, ExceptionState& exceptionState)
    {
        RefPtr<ItemTearOffType> item = passItem;

        if (toDerived()->isImmutable()) {
            exceptionState.throwDOMException(NoModificationAllowedError, "The object is read-only.");
            return 0;
        }

        if (!item) {
            exceptionState.throwTypeError("Lists must be initialized with a valid item.");
            return 0;
        }

        RefPtr<ItemPropertyType> value = toDerived()->target()->initialize(cloneTargetIfNeeded(item));
        toDerived()->commitChange();

        return createItemTearOff(value.release());
    }

    PassRefPtr<ItemTearOffType> getItem(unsigned long index, ExceptionState& exceptionState)
    {
        RefPtr<ItemPropertyType> value = toDerived()->target()->getItem(index, exceptionState);
        return createItemTearOff(value.release());
    }

    PassRefPtr<ItemTearOffType> insertItemBefore(PassRefPtr<ItemTearOffType> passItem, unsigned long index, ExceptionState& exceptionState)
    {
        RefPtr<ItemTearOffType> item = passItem;

        if (toDerived()->isImmutable()) {
            exceptionState.throwDOMException(NoModificationAllowedError, "The object is read-only.");
            return 0;
        }

        if (!item) {
            exceptionState.throwTypeError("An invalid item cannot be inserted to a list.");
            return 0;
        }

        RefPtr<ItemPropertyType> value = toDerived()->target()->insertItemBefore(cloneTargetIfNeeded(item), index);
        toDerived()->commitChange();

        return createItemTearOff(value.release());
    }

    PassRefPtr<ItemTearOffType> replaceItem(PassRefPtr<ItemTearOffType> passItem, unsigned long index, ExceptionState& exceptionState)
    {
        RefPtr<ItemTearOffType> item = passItem;

        if (toDerived()->isImmutable()) {
            exceptionState.throwDOMException(NoModificationAllowedError, "The object is read-only.");
            return 0;
        }

        if (!item) {
            exceptionState.throwTypeError("An invalid item cannot be replaced with an existing list item.");
            return 0;
        }

        RefPtr<ItemPropertyType> value = toDerived()->target()->replaceItem(cloneTargetIfNeeded(item), index, exceptionState);
        toDerived()->commitChange();

        return createItemTearOff(value.release());
    }

    PassRefPtr<ItemTearOffType> removeItem(unsigned long index, ExceptionState& exceptionState)
    {
        RefPtr<ItemPropertyType> value = toDerived()->target()->removeItem(index, exceptionState);
        toDerived()->commitChange();

        return createItemTearOff(value.release());
    }

    PassRefPtr<ItemTearOffType> appendItem(PassRefPtr<ItemTearOffType> passItem, ExceptionState& exceptionState)
    {
        RefPtr<ItemTearOffType> item = passItem;

        if (toDerived()->isImmutable()) {
            exceptionState.throwDOMException(NoModificationAllowedError, "The object is read-only.");
            return 0;
        }

        if (!item) {
            exceptionState.throwTypeError("An invalid item cannot be appended to a list.");
            return 0;
        }

        RefPtr<ItemPropertyType> value = toDerived()->target()->appendItem(cloneTargetIfNeeded(item));
        toDerived()->commitChange();

        return createItemTearOff(value.release());
    }

protected:
    NewSVGListPropertyTearOffHelper(PassRefPtr<ListPropertyType> target, SVGElement* contextElement, PropertyIsAnimValType propertyIsAnimVal, const QualifiedName& attributeName = nullQName())
        : NewSVGPropertyTearOff<ListPropertyType>(target, contextElement, propertyIsAnimVal, attributeName)
    {
    }

    PassRefPtr<ItemPropertyType> cloneTargetIfNeeded(PassRefPtr<ItemTearOffType> passNewItem)
    {
        RefPtr<ItemTearOffType> newItem = passNewItem;

        // |newItem| is immutable, OR
        // |newItem| belongs to a SVGElement, but it does not belong to an animated list
        // (for example: "textElement.x.baseVal.appendItem(rectElement.width.baseVal)")
        if (newItem->isImmutable()
            || (newItem->contextElement() && !newItem->target()->ownerList())) {
            // We have to copy the incoming |newItem|, as we're not allowed to insert this tear off as is into our wrapper cache.
            // Otherwise we'll end up having two tearoffs that operate on the same SVGProperty. Consider the example above:
            // SVGRectElements SVGAnimatedLength 'width' property baseVal points to the same tear off object
            // that's inserted into SVGTextElements SVGAnimatedLengthList 'x'. textElement.x.baseVal.getItem(0).value += 150 would
            // mutate the rectElement width _and_ the textElement x list. That's obviously wrong, take care of that.
            return newItem->target()->clone();
        }

        return newItem->target();
    }

    PassRefPtr<ItemTearOffType> createItemTearOff(PassRefPtr<ItemPropertyType> value)
    {
        if (!value)
            return 0;

        return ItemTearOffType::create(value, toDerived()->contextElement(), toDerived()->propertyIsAnimVal(), toDerived()->attributeName());
    }

private:
    Derived* toDerived() { return static_cast<Derived*>(this); }
};

}

#endif // NewSVGListPropertyTearOffHelper_h