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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 android.view;
     18 
     19 import android.os.Parcel;
     20 import android.os.Parcelable;
     21 import android.util.Pools.SynchronizedPool;
     22 
     23 /**
     24  * This class represents spec for performing screen magnification.
     25  *
     26  * @hide
     27  */
     28 public class MagnificationSpec implements Parcelable {
     29     private static final int MAX_POOL_SIZE = 20;
     30     private static final SynchronizedPool<MagnificationSpec> sPool =
     31             new SynchronizedPool<MagnificationSpec>(MAX_POOL_SIZE);
     32 
     33     public float scale = 1.0f;
     34     public float offsetX;
     35     public float offsetY;
     36 
     37     private MagnificationSpec() {
     38         /* do nothing - reducing visibility */
     39     }
     40 
     41     public void initialize(float scale, float offsetX, float offsetY) {
     42         if (scale < 1) {
     43             throw new IllegalArgumentException("Scale must be greater than or equal to one!");
     44         }
     45         this.scale = scale;
     46         this.offsetX = offsetX;
     47         this.offsetY = offsetY;
     48     }
     49 
     50     public boolean isNop() {
     51         return scale == 1.0f && offsetX == 0 && offsetY == 0;
     52     }
     53 
     54     public static MagnificationSpec obtain(MagnificationSpec other) {
     55         MagnificationSpec info = obtain();
     56         info.scale = other.scale;
     57         info.offsetX = other.offsetX;
     58         info.offsetY = other.offsetY;
     59         return info;
     60     }
     61 
     62     public static MagnificationSpec obtain() {
     63         MagnificationSpec spec = sPool.acquire();
     64         return (spec != null) ? spec : new MagnificationSpec();
     65     }
     66 
     67     public void recycle() {
     68         clear();
     69         sPool.release(this);
     70     }
     71 
     72     public void clear() {
     73        scale = 1.0f;
     74        offsetX = 0.0f;
     75        offsetY = 0.0f;
     76     }
     77 
     78     @Override
     79     public int describeContents() {
     80         return 0;
     81     }
     82 
     83     @Override
     84     public void writeToParcel(Parcel parcel, int flags) {
     85         parcel.writeFloat(scale);
     86         parcel.writeFloat(offsetX);
     87         parcel.writeFloat(offsetY);
     88         recycle();
     89     }
     90 
     91     @Override
     92     public String toString() {
     93         StringBuilder builder = new StringBuilder();
     94         builder.append("<scale:");
     95         builder.append(scale);
     96         builder.append(",offsetX:");
     97         builder.append(offsetX);
     98         builder.append(",offsetY:");
     99         builder.append(offsetY);
    100         builder.append(">");
    101         return builder.toString();
    102     }
    103 
    104     private void initFromParcel(Parcel parcel) {
    105         scale = parcel.readFloat();
    106         offsetX = parcel.readFloat();
    107         offsetY = parcel.readFloat();
    108     }
    109 
    110     public static final Creator<MagnificationSpec> CREATOR = new Creator<MagnificationSpec>() {
    111         @Override
    112         public MagnificationSpec[] newArray(int size) {
    113             return new MagnificationSpec[size];
    114         }
    115 
    116         @Override
    117         public MagnificationSpec createFromParcel(Parcel parcel) {
    118             MagnificationSpec spec = MagnificationSpec.obtain();
    119             spec.initFromParcel(parcel);
    120             return spec;
    121         }
    122     };
    123 }
    124