1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
5  * use this file except in compliance with the License. You may obtain a copy of
6  * 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, WITHOUT
12  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13  * License for the specific language governing permissions and limitations under
14  * the License.
15  */
16 
17 package android.view.inputmethod;
18 
19 import android.graphics.RectF;
20 import android.os.Parcel;
21 import android.os.Parcelable;
22 
23 import java.util.Arrays;
24 
25 /**
26  * An implementation of SparseArray specialized for {@link android.graphics.RectF}.
27  * <p>
28  * As this is a sparse array, it represents an array of {@link RectF} most of which are null. This
29  * class could be in some other packages like android.graphics or android.util but currently
30  * belong to android.view.inputmethod because this class is hidden and used only in input method
31  * framework.
32  * </p>
33  * @hide
34  */
35 public final class SparseRectFArray implements Parcelable {
36     /**
37      * The keys, in ascending order, of those {@link RectF} that are not null. For example,
38      * {@code [null, null, null, Rect1, null, Rect2]} would be represented by {@code [3,5]}.
39      * @see #mCoordinates
40      */
41     private final int[] mKeys;
42 
43     /**
44      * Stores coordinates of the rectangles, in the order of
45      * {@code rects[mKeys[0]].left}, {@code rects[mKeys[0]].top},
46      * {@code rects[mKeys[0]].right}, {@code rects[mKeys[0]].bottom},
47      * {@code rects[mKeys[1]].left}, {@code rects[mKeys[1]].top},
48      * {@code rects[mKeys[1]].right}, {@code rects[mKeys[1]].bottom},
49      * {@code rects[mKeys[2]].left}, {@code rects[mKeys[2]].top}, ....
50      */
51     private final float[] mCoordinates;
52 
53     /**
54      * Stores visibility information.
55      */
56     private final int[] mFlagsArray;
57 
SparseRectFArray(final Parcel source)58     public SparseRectFArray(final Parcel source) {
59         mKeys = source.createIntArray();
60         mCoordinates = source.createFloatArray();
61         mFlagsArray = source.createIntArray();
62     }
63 
64     /**
65      * Used to package this object into a {@link Parcel}.
66      *
67      * @param dest The {@link Parcel} to be written.
68      * @param flags The flags used for parceling.
69      */
70     @Override
writeToParcel(Parcel dest, int flags)71     public void writeToParcel(Parcel dest, int flags) {
72         dest.writeIntArray(mKeys);
73         dest.writeFloatArray(mCoordinates);
74         dest.writeIntArray(mFlagsArray);
75     }
76 
77     @Override
hashCode()78     public int hashCode() {
79         // TODO: Improve the hash function.
80         if (mKeys == null || mKeys.length == 0) {
81             return 0;
82         }
83         int hash = mKeys.length;
84         // For performance reasons, only the first rectangle is used for the hash code now.
85         for (int i = 0; i < 4; i++) {
86             hash *= 31;
87             hash += mCoordinates[i];
88         }
89         hash *= 31;
90         hash += mFlagsArray[0];
91         return hash;
92     }
93 
94     @Override
equals(Object obj)95     public boolean equals(Object obj){
96         if (obj == null) {
97             return false;
98         }
99         if (this == obj) {
100             return true;
101         }
102         if (!(obj instanceof SparseRectFArray)) {
103             return false;
104         }
105         final SparseRectFArray that = (SparseRectFArray) obj;
106 
107         return Arrays.equals(mKeys, that.mKeys) && Arrays.equals(mCoordinates, that.mCoordinates)
108                 && Arrays.equals(mFlagsArray, that.mFlagsArray);
109     }
110 
111     @Override
toString()112     public String toString() {
113         if (mKeys == null || mCoordinates == null || mFlagsArray == null) {
114             return "SparseRectFArray{}";
115         }
116         final StringBuilder sb = new StringBuilder();
117         sb.append("SparseRectFArray{");
118         for (int i = 0; i < mKeys.length; i++) {
119             if (i != 0) {
120                 sb.append(", ");
121             }
122             final int baseIndex = i * 4;
123             sb.append(mKeys[i]);
124             sb.append(":[");
125             sb.append(mCoordinates[baseIndex + 0]);
126             sb.append(",");
127             sb.append(mCoordinates[baseIndex + 1]);
128             sb.append("],[");
129             sb.append(mCoordinates[baseIndex + 2]);
130             sb.append(",");
131             sb.append(mCoordinates[baseIndex + 3]);
132             sb.append("]:flagsArray=");
133             sb.append(mFlagsArray[i]);
134         }
135         sb.append("}");
136         return sb.toString();
137     }
138 
139     /**
140      * Builder for {@link SparseRectFArray}. This class is not designed to be thread-safe.
141      * @hide
142      */
143     public static final class SparseRectFArrayBuilder {
144         /**
145          * Throws {@link IllegalArgumentException} to make sure that this class is correctly used.
146          * @param key key to be checked.
147          */
checkIndex(final int key)148         private void checkIndex(final int key) {
149             if (mCount == 0) {
150                 return;
151             }
152             if (mKeys[mCount - 1] >= key) {
153                 throw new IllegalArgumentException("key must be greater than all existing keys.");
154             }
155         }
156 
157         /**
158          * Extends the internal array if necessary.
159          */
ensureBufferSize()160         private void ensureBufferSize() {
161             if (mKeys == null) {
162                 mKeys = new int[INITIAL_SIZE];
163             }
164             if (mCoordinates == null) {
165                 mCoordinates = new float[INITIAL_SIZE * 4];
166             }
167             if (mFlagsArray == null) {
168                 mFlagsArray = new int[INITIAL_SIZE];
169             }
170             final int requiredIndexArraySize = mCount + 1;
171             if (mKeys.length <= requiredIndexArraySize) {
172                 final int[] newArray = new int[requiredIndexArraySize * 2];
173                 System.arraycopy(mKeys, 0, newArray, 0, mCount);
174                 mKeys = newArray;
175             }
176             final int requiredCoordinatesArraySize = (mCount + 1) * 4;
177             if (mCoordinates.length <= requiredCoordinatesArraySize) {
178                 final float[] newArray = new float[requiredCoordinatesArraySize * 2];
179                 System.arraycopy(mCoordinates, 0, newArray, 0, mCount * 4);
180                 mCoordinates = newArray;
181             }
182             final int requiredFlagsArraySize = requiredIndexArraySize;
183             if (mFlagsArray.length <= requiredFlagsArraySize) {
184                 final int[] newArray = new int[requiredFlagsArraySize * 2];
185                 System.arraycopy(mFlagsArray, 0, newArray, 0, mCount);
186                 mFlagsArray = newArray;
187             }
188         }
189 
190         /**
191          * Puts the rectangle with an integer key.
192          * @param key the key to be associated with the rectangle. It must be greater than all
193          * existing keys that have been previously specified.
194          * @param left left of the rectangle.
195          * @param top top of the rectangle.
196          * @param right right of the rectangle.
197          * @param bottom bottom of the rectangle.
198          * @param flags an arbitrary integer value to be associated with this rectangle.
199          * @return the receiver object itself for chaining method calls.
200          * @throws IllegalArgumentException If the index is not greater than all of existing keys.
201          */
append(final int key, final float left, final float top, final float right, final float bottom, final int flags)202         public SparseRectFArrayBuilder append(final int key,
203                 final float left, final float top, final float right, final float bottom,
204                 final int flags) {
205             checkIndex(key);
206             ensureBufferSize();
207             final int baseCoordinatesIndex = mCount * 4;
208             mCoordinates[baseCoordinatesIndex + 0] = left;
209             mCoordinates[baseCoordinatesIndex + 1] = top;
210             mCoordinates[baseCoordinatesIndex + 2] = right;
211             mCoordinates[baseCoordinatesIndex + 3] = bottom;
212             final int flagsIndex = mCount;
213             mFlagsArray[flagsIndex] = flags;
214             mKeys[mCount] = key;
215             ++mCount;
216             return this;
217         }
218         private int mCount = 0;
219         private int[] mKeys = null;
220         private float[] mCoordinates = null;
221         private int[] mFlagsArray = null;
222         private static int INITIAL_SIZE = 16;
223 
isEmpty()224         public boolean isEmpty() {
225             return mCount <= 0;
226         }
227 
228         /**
229          * @return {@link SparseRectFArray} using parameters in this {@link SparseRectFArray}.
230          */
build()231         public SparseRectFArray build() {
232             return new SparseRectFArray(this);
233         }
234 
reset()235         public void reset() {
236             if (mCount == 0) {
237                 mKeys = null;
238                 mCoordinates = null;
239                 mFlagsArray = null;
240             }
241             mCount = 0;
242         }
243     }
244 
SparseRectFArray(final SparseRectFArrayBuilder builder)245     private SparseRectFArray(final SparseRectFArrayBuilder builder) {
246         if (builder.mCount == 0) {
247             mKeys = null;
248             mCoordinates = null;
249             mFlagsArray = null;
250         } else {
251             mKeys = new int[builder.mCount];
252             mCoordinates = new float[builder.mCount * 4];
253             mFlagsArray = new int[builder.mCount];
254             System.arraycopy(builder.mKeys, 0, mKeys, 0, builder.mCount);
255             System.arraycopy(builder.mCoordinates, 0, mCoordinates, 0, builder.mCount * 4);
256             System.arraycopy(builder.mFlagsArray, 0, mFlagsArray, 0, builder.mCount);
257         }
258     }
259 
get(final int index)260     public RectF get(final int index) {
261         if (mKeys == null) {
262             return null;
263         }
264         if (index < 0) {
265             return null;
266         }
267         final int arrayIndex = Arrays.binarySearch(mKeys, index);
268         if (arrayIndex < 0) {
269             return null;
270         }
271         final int baseCoordIndex = arrayIndex * 4;
272         return new RectF(mCoordinates[baseCoordIndex],
273                 mCoordinates[baseCoordIndex + 1],
274                 mCoordinates[baseCoordIndex + 2],
275                 mCoordinates[baseCoordIndex + 3]);
276     }
277 
getFlags(final int index, final int valueIfKeyNotFound)278     public int getFlags(final int index, final int valueIfKeyNotFound) {
279         if (mKeys == null) {
280             return valueIfKeyNotFound;
281         }
282         if (index < 0) {
283             return valueIfKeyNotFound;
284         }
285         final int arrayIndex = Arrays.binarySearch(mKeys, index);
286         if (arrayIndex < 0) {
287             return valueIfKeyNotFound;
288         }
289         return mFlagsArray[arrayIndex];
290     }
291 
292     /**
293      * Used to make this class parcelable.
294      */
295     public static final @android.annotation.NonNull Parcelable.Creator<SparseRectFArray> CREATOR =
296             new Parcelable.Creator<SparseRectFArray>() {
297                 @Override
298                 public SparseRectFArray createFromParcel(Parcel source) {
299                     return new SparseRectFArray(source);
300                 }
301                 @Override
302                 public SparseRectFArray[] newArray(int size) {
303                     return new SparseRectFArray[size];
304                 }
305             };
306 
307     @Override
describeContents()308     public int describeContents() {
309         return 0;
310     }
311 }
312 
313