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      1 /*
      2  * Copyright (C) 2012 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.ide.eclipse.gltrace.state.transforms;
     18 
     19 import com.android.ide.eclipse.gltrace.state.GLSparseArrayProperty;
     20 import com.android.ide.eclipse.gltrace.state.IGLProperty;
     21 
     22 /**
     23  * A {@link SparseArrayElementAddTransform} changes given state by adding an
     24  * element to a sparse array, if there is no item with the same key already.
     25  */
     26 public class SparseArrayElementAddTransform implements IStateTransform {
     27     private IGLPropertyAccessor mAccessor;
     28     private int mKey;
     29     private IGLProperty mOldValue;
     30 
     31     public SparseArrayElementAddTransform(IGLPropertyAccessor accessor, int key) {
     32         mAccessor = accessor;
     33         mKey = key;
     34     }
     35 
     36     @Override
     37     public void apply(IGLProperty currentState) {
     38         GLSparseArrayProperty propertyArray = getArray(currentState);
     39         if (propertyArray != null) {
     40             mOldValue = propertyArray.getProperty(mKey);
     41             if (mOldValue == null) {
     42                 // add only if there is no item with this key already present
     43                 propertyArray.add(mKey);
     44             }
     45         }
     46     }
     47 
     48     @Override
     49     public void revert(IGLProperty currentState) {
     50         GLSparseArrayProperty propertyArray = getArray(currentState);
     51         if (propertyArray != null) {
     52             if (mOldValue == null) {
     53                 // delete only if we actually added this key
     54                 propertyArray.delete(mKey);
     55             }
     56         }
     57     }
     58 
     59     @Override
     60     public IGLProperty getChangedProperty(IGLProperty currentState) {
     61         return getArray(currentState);
     62     }
     63 
     64     private GLSparseArrayProperty getArray(IGLProperty state) {
     65         IGLProperty p = state;
     66 
     67         if (mAccessor != null) {
     68             p = mAccessor.getProperty(p);
     69         }
     70 
     71         if (p instanceof GLSparseArrayProperty) {
     72             return (GLSparseArrayProperty) p;
     73         } else {
     74             return null;
     75         }
     76     }
     77 }
     78