Allow interpolation of background-size values with keywords in CSS Animations

third_party/WebKit/Source/core/animation/LengthListPropertyFunctions.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/animation/LengthListPropertyFunctions.h"
 
 #include "core/style/ComputedStyle.h"
 
 namespace blink {
 
 namespace {
 
 const FillLayer* getFillLayer(CSSPropertyID property, const ComputedStyle& style)
 {
     switch (property) {
     case CSSPropertyBackgroundPositionX:
     case CSSPropertyBackgroundPositionY:
-    case CSSPropertyBackgroundSize:
         return &style.backgroundLayers();
     case CSSPropertyWebkitMaskPositionX:
     case CSSPropertyWebkitMaskPositionY:
-    case CSSPropertyWebkitMaskSize:
         return &style.maskLayers();
     default:
         NOTREACHED();
         return nullptr;
     }
 }
 
 FillLayer* accessFillLayer(CSSPropertyID property, ComputedStyle& style)
 {
     switch (property) {
     case CSSPropertyBackgroundPositionX:
     case CSSPropertyBackgroundPositionY:
-    case CSSPropertyBackgroundSize:
         return &style.accessBackgroundLayers();
     case CSSPropertyWebkitMaskPositionX:
     case CSSPropertyWebkitMaskPositionY:
-    case CSSPropertyWebkitMaskSize:
         return &style.accessMaskLayers();
     default:
         NOTREACHED();
         return nullptr;
     }
 }
 
 struct FillLayerMethods {
     FillLayerMethods(CSSPropertyID property)
     {
         isSet = nullptr;
         getLength = nullptr;
         setLength = nullptr;
-        getFillSize = nullptr;
-        setFillSize = nullptr;
         clear = nullptr;
         switch (property) {

[suzyh_UTC10 (ex-contributor), 2016/08/26 04:14:34]

After this change, the four CSSPropertyIDs that are valid arguments populate the
same four functions: isSet, getLength, setLength, clear. Is there now a clearer
way to write this struct? I think that might also lead to simplifications in the
rest of the file.

[alancutter (OOO until 2018), 2016/08/26 13:31:48]

We could inline the specific method calls (like setXPosition()) and copy paste
the iteration logic. That would kill this struct and the ugly member function
pointer dereferences.
I would recommend that for a separate change though, removing the size methods
doesn't really change whether it's a good idea or not.

         case CSSPropertyBackgroundPositionX:
         case CSSPropertyWebkitMaskPositionX:
             isSet = &FillLayer::isXPositionSet;
             getLength = &FillLayer::xPosition;
             setLength = &FillLayer::setXPosition;
             clear = &FillLayer::clearXPosition;
             break;
         case CSSPropertyBackgroundPositionY:
         case CSSPropertyWebkitMaskPositionY:
             isSet = &FillLayer::isYPositionSet;
             getLength = &FillLayer::yPosition;
             setLength = &FillLayer::setYPosition;
             clear = &FillLayer::clearYPosition;
             break;
-        case CSSPropertyBackgroundSize:
-        case CSSPropertyWebkitMaskSize:
-            isSet = &FillLayer::isSizeSet;
-            getFillSize = &FillLayer::size;
-            setFillSize = &FillLayer::setSize;
-            clear = &FillLayer::clearSize;
-            break;
         default:
             NOTREACHED();
             break;
         }
     }
 
     bool (FillLayer::*isSet)() const;
     const Length& (FillLayer::*getLength)() const;
     void (FillLayer::*setLength)(const Length&);
-    FillSize (FillLayer::*getFillSize)() const;
-    void (FillLayer::*setFillSize)(const FillSize&);
     void (FillLayer::*clear)();
 };
 
 } // namespace
 
 ValueRange LengthListPropertyFunctions::getValueRange(CSSPropertyID property)
 {
     switch (property) {
     case CSSPropertyBackgroundPositionX:
     case CSSPropertyBackgroundPositionY:
     case CSSPropertyObjectPosition:
     case CSSPropertyPerspectiveOrigin:
     case CSSPropertyTransformOrigin:
     case CSSPropertyWebkitMaskPositionX:
     case CSSPropertyWebkitMaskPositionY:
         return ValueRangeAll;
 
-    case CSSPropertyBackgroundSize:
     case CSSPropertyBorderBottomLeftRadius:
     case CSSPropertyBorderBottomRightRadius:
     case CSSPropertyBorderTopLeftRadius:
     case CSSPropertyBorderTopRightRadius:
     case CSSPropertyStrokeDasharray:
-    case CSSPropertyWebkitMaskSize:
         return ValueRangeNonNegative;
 
     default:
         NOTREACHED();
         return ValueRangeAll;
     }
 }
 
 bool LengthListPropertyFunctions::getInitialLengthList(CSSPropertyID property, Vector<Length>& result)
 {
@@ skipping 53 matching lines @@
     case CSSPropertyWebkitMaskPositionX:
     case CSSPropertyWebkitMaskPositionY: {
         const FillLayer* fillLayer = getFillLayer(property, style);
         FillLayerMethods fillLayerMethods(property);
         while (fillLayer && (fillLayer->*fillLayerMethods.isSet)()) {
             result.append((fillLayer->*fillLayerMethods.getLength)());
             fillLayer = fillLayer->next();
         }
         return true;
     }
-    case CSSPropertyBackgroundSize:
-    case CSSPropertyWebkitMaskSize: {
-        const FillLayer* fillLayer = getFillLayer(property, style);
-        FillLayerMethods fillLayerMethods(property);
-        while (fillLayer && (fillLayer->*fillLayerMethods.isSet)()) {
-            FillSize fillSize = (fillLayer->*fillLayerMethods.getFillSize)();
-            if (fillSize.type != SizeLength) {
-                result.clear();
-                return false;
-            }
-            result.append(fillSize.size.width());
-            result.append(fillSize.size.height());
-            fillLayer = fillLayer->next();
-        }
-        return true;
-    }
 
     default:
         NOTREACHED();
         return false;
     }
 }
 
 static LengthPoint pointFromVector(const Vector<Length>& list)
 {
     DCHECK_EQ(list.size(), 2U);
@@ skipping 57 matching lines @@
             prev = fillLayer;
             fillLayer = fillLayer->next();
         }
         while (fillLayer) {
             (fillLayer->*fillLayerMethods.clear)();
             fillLayer = fillLayer->next();
         }
         return;
     }
 
-    case CSSPropertyBackgroundSize:
-    case CSSPropertyWebkitMaskSize: {
-        DCHECK_EQ(lengthList.size() % 2, 0U);
-        FillLayer* fillLayer = accessFillLayer(property, style);
-        FillLayer* prev = nullptr;
-        FillLayerMethods fillLayerMethods(property);
-        for (size_t i = 0; i < lengthList.size() / 2; i++) {
-            if (!fillLayer)
-                fillLayer = prev->ensureNext();
-            FillSize fillSize(SizeLength, LengthSize(lengthList[2 * i], lengthList[2 * i + 1]));
-            (fillLayer->*fillLayerMethods.setFillSize)(fillSize);
-            prev = fillLayer;
-            fillLayer = fillLayer->next();
-        }
-        while (fillLayer) {
-            (fillLayer->*fillLayerMethods.clear)();
-            fillLayer = fillLayer->next();
-        }
-        return;
-    }
-
     default:
         NOTREACHED();
         break;
     }
 }
 
 } // namespace blink