Home | History | Annotate | Download | only in view 
      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<>(MAX_POOL_SIZE);
     32 
     33     /** The magnification scaling factor. */
     34     public float scale = 1.0f;
     35 
     36     /**
     37      * The X coordinate, in unscaled screen-relative pixels, around which
     38      * magnification is focused.
     39      */
     40     public float offsetX;
     41 
     42     /**
     43      * The Y coordinate, in unscaled screen-relative pixels, around which
     44      * magnification is focused.
     45      */
     46     public float offsetY;
     47 
     48     private MagnificationSpec() {
     49         /* do nothing - reducing visibility */
     50     }
     51 
     52     public void initialize(float scale, float offsetX, float offsetY) {
     53         if (scale < 1) {
     54             throw new IllegalArgumentException("Scale must be greater than or equal to one!");
     55         }
     56         this.scale = scale;
     57         this.offsetX = offsetX;
     58         this.offsetY = offsetY;
     59     }
     60 
     61     public boolean isNop() {
     62         return scale == 1.0f && offsetX == 0 && offsetY == 0;
     63     }
     64 
     65     public static MagnificationSpec obtain(MagnificationSpec other) {
     66         MagnificationSpec info = obtain();
     67         info.scale = other.scale;
     68         info.offsetX = other.offsetX;
     69         info.offsetY = other.offsetY;
     70         return info;
     71     }
     72 
     73     public static MagnificationSpec obtain() {
     74         MagnificationSpec spec = sPool.acquire();
     75         return (spec != null) ? spec : new MagnificationSpec();
     76     }
     77 
     78     public void recycle() {
     79         clear();
     80         sPool.release(this);
     81     }
     82 
     83     public void clear() {
     84        scale = 1.0f;
     85        offsetX = 0.0f;
     86        offsetY = 0.0f;
     87     }
     88 
     89     public void setTo(MagnificationSpec other) {
     90         scale = other.scale;
     91         offsetX = other.offsetX;
     92         offsetY = other.offsetY;
     93     }
     94 
     95     @Override
     96     public int describeContents() {
     97         return 0;
     98     }
     99 
    100     @Override
    101     public void writeToParcel(Parcel parcel, int flags) {
    102         parcel.writeFloat(scale);
    103         parcel.writeFloat(offsetX);
    104         parcel.writeFloat(offsetY);
    105         recycle();
    106     }
    107 
    108     @Override
    109     public boolean equals(Object other) {
    110         if (this == other) {
    111             return true;
    112         }
    113 
    114         if (other == null || getClass() != other.getClass()) {
    115             return false;
    116         }
    117 
    118         final MagnificationSpec s = (MagnificationSpec) other;
    119         return scale == s.scale && offsetX == s.offsetX && offsetY == s.offsetY;
    120     }
    121 
    122     @Override
    123     public int hashCode() {
    124         int result = (scale != +0.0f ? Float.floatToIntBits(scale) : 0);
    125         result = 31 * result + (offsetX != +0.0f ? Float.floatToIntBits(offsetX) : 0);
    126         result = 31 * result + (offsetY != +0.0f ? Float.floatToIntBits(offsetY) : 0);
    127         return result;
    128     }
    129 
    130     @Override
    131     public String toString() {
    132         StringBuilder builder = new StringBuilder();
    133         builder.append("<scale:");
    134         builder.append(Float.toString(scale));
    135         builder.append(",offsetX:");
    136         builder.append(Float.toString(offsetX));
    137         builder.append(",offsetY:");
    138         builder.append(Float.toString(offsetY));
    139         builder.append(">");
    140         return builder.toString();
    141     }
    142 
    143     private void initFromParcel(Parcel parcel) {
    144         scale = parcel.readFloat();
    145         offsetX = parcel.readFloat();
    146         offsetY = parcel.readFloat();
    147     }
    148 
    149     public static final Creator<MagnificationSpec> CREATOR = new Creator<MagnificationSpec>() {
    150         @Override
    151         public MagnificationSpec[] newArray(int size) {
    152             return new MagnificationSpec[size];
    153         }
    154 
    155         @Override
    156         public MagnificationSpec createFromParcel(Parcel parcel) {
    157             MagnificationSpec spec = MagnificationSpec.obtain();
    158             spec.initFromParcel(parcel);
    159             return spec;
    160         }
    161     };
    162 }
    163