Add support for disabling CSS Properties at runtime

Source/core/page/RuntimeCSSEnabled.cpp

Index: Source/core/page/RuntimeCSSEnabled.cpp
diff --git a/Source/core/page/RuntimeCSSEnabled.cpp b/Source/core/page/RuntimeCSSEnabled.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..aba8ad753e15ce62e428ebab71e2101b4e698b54
--- /dev/null
+++ b/Source/core/page/RuntimeCSSEnabled.cpp
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.

[abarth-chromium, 2013/04/24 20:47:34]

Adobe?

+ *
+ * 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;

[Use mkwst_at_chromium.org plz., 2013/04/24 20:51:43]

As a drive-by,
https://src.chromium.org/viewvc/blink/trunk/Source/wtf/BitVector.h is probably
what you're looking for. It was not purged. :)

[abarth-chromium, 2013/04/24 21:02:13]

If you don't use WTF::BitVector, you should use a different name so folks aren't
confused.

[ojan, 2013/04/25 02:25:21]

+1 to just using BitVector.

+
+static void setFromFeatureValue(bool featureFlag, CSSPropertyID* properties, size_t length)

[ojan, 2013/04/25 02:25:21]

Nit: this doesn't need to take a length. It can just call WTF_ARRAY_LENGTH
directly.

Also, this name is weird. Maybe setMultipleProperties? And, it's customary for a
set function to take the value it's setting as the second argument (e.g. as
setCSSPropertyEnabled does).

+{
+    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)

[abarth-chromium, 2013/04/24 21:02:13]

static

+{
+    // 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)

[abarth-chromium, 2013/04/24 21:02:13]

static

+{
+    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)

[ojan, 2013/04/25 02:25:21]

I don't think it makes sense to put these stubs in until we're actually going to
use them. I'm not sure we'll ever use this. We can already runtime disable CSS
values. Also, it's not really correct to call a given value enabled/disabled.
It's enabled/disabled as a value for a given property, which is why the current
way of disabling it in CSSParser.cpp seems better to me.

+{
+    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