Add support for disabling CSS Properties at runtime

Source/core/page/RuntimeCSSEnabled.cpp

+/*
+ * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above
+ *    copyright notice, this list of conditions and the following
+ *    disclaimer.
+ * 2. Redistributions in binary form must reproduce the above
+ *    copyright notice, this list of conditions and the following
+ *    disclaimer in the documentation and/or other materials
+ *    provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "RuntimeCSSEnabled.h"
+#include "RuntimeEnabledFeatures.h"
+
+namespace WebCore {
+
+// FIXME: We should use a real BitVector class instead!
+typedef Vector<bool> BitVector;
+
+static void setFromFeatureValue(bool featureFlag, CSSPropertyID* properties, size_t length)
+{
+    for (size_t i = 0; i < length; i++)
+        RuntimeCSSEnabled::setCSSPropertyEnabled(properties[i], featureFlag);
+}
+
+static void setPropertySwitchesFromRuntimeFeatures(BitVector& properties)
+{
+#if ENABLE(CSS_REGIONS)
+    CSSPropertyID regionProperites[] = {
+        CSSPropertyWebkitFlowInto,
+        CSSPropertyWebkitFlowFrom,
+        CSSPropertyWebkitRegionOverflow,
+        CSSPropertyWebkitRegionBreakAfter,
+        CSSPropertyWebkitRegionBreakBefore,
+        CSSPropertyWebkitRegionBreakInside
+    };
+    setFromFeatureValue(RuntimeEnabledFeatures::cssRegionsEnabled(), regionProperites, WTF_ARRAY_LENGTH(regionProperites));
+#endif
+#if ENABLE(CSS_EXCLUSIONS)
+    CSSPropertyID exclusionProperties[] = {
+        CSSPropertyWebkitWrap,
+        CSSPropertyWebkitWrapFlow,
+        CSSPropertyWebkitShapeMargin,
+        CSSPropertyWebkitShapePadding,
+        CSSPropertyWebkitWrapThrough,
+        CSSPropertyWebkitShapeInside,
+        CSSPropertyWebkitShapeOutside,
+    };
+    setFromFeatureValue(RuntimeEnabledFeatures::cssExclusionsEnabled(), exclusionProperties, WTF_ARRAY_LENGTH(exclusionProperties));
+#endif
+#if ENABLE(CSS_COMPOSITING)
+    RuntimeCSSEnabled::setCSSPropertyEnabled(CSSPropertyBackgroundBlendMode, RuntimeEnabledFeatures::cssCompositingEnabled());
+    RuntimeCSSEnabled::setCSSPropertyEnabled(CSSPropertyWebkitBlendMode, RuntimeEnabledFeatures::cssCompositingEnabled());
+#endif
+}
+
+static void setValueSwitchesFromRuntimeFeatures(BitVector& values)
+{
+    // FIXME: Add various runtime-enabled values here.
+}
+
+static BitVector& propertySwitches()
+{
+    static BitVector* switches = 0;
+    if (!switches) {
+        switches = new BitVector;
+        switches->fill(true, numCSSProperties);
+        setPropertySwitchesFromRuntimeFeatures(*switches);
+    }
+    return *switches;
+}
+
+static BitVector& valueSwitches()
+{
+    static BitVector* switches = 0;
+    if (!switches) {
+        switches = new BitVector;
+        switches->fill(true, numCSSValueKeywords);
+        setValueSwitchesFromRuntimeFeatures(*switches);
+    }
+    return *switches;
+}
+
+size_t indexForValue(CSSValueID valueId)
+{
+    // Values all start at 0.  Vector RELEASE_ASSERTS will catch if we're ever wrong.
+    return static_cast<size_t>(valueId);
+}
+
+size_t indexForProperty(CSSPropertyID propertyId)
+{
+    RELEASE_ASSERT(propertyId >= firstCSSProperty && propertyId <= lastCSSProperty);
+    // Values all start at 0.  Vector RELEASE_ASSERTS will catch if we're ever wrong.
+    return static_cast<size_t>(propertyId - firstCSSProperty);
+}
+
+bool RuntimeCSSEnabled::isCSSValueEnabled(CSSValueID valueId)
+{
+    return valueSwitches()[indexForValue(valueId)];
+}
+
+void RuntimeCSSEnabled::setCSSValueEnabled(CSSValueID valueId, bool enable)
+{
+    valueSwitches()[indexForValue(valueId)] = enable;
+}
+
+bool RuntimeCSSEnabled::isCSSPropertyEnabled(CSSPropertyID propertyId)
+{
+    return propertySwitches()[indexForProperty(propertyId)];
+}
+
+void RuntimeCSSEnabled::setCSSPropertyEnabled(CSSPropertyID propertyId, bool enable)
+{
+    propertySwitches()[indexForProperty(propertyId)] = enable;
+}
+
+} // namespace WebCore