1 /* 2 * Copyright (C) 2013 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.documentsui; 18 19 import static com.android.documentsui.DocumentsActivity.State.SORT_ORDER_DISPLAY_NAME; 20 import static com.android.documentsui.DocumentsActivity.State.SORT_ORDER_LAST_MODIFIED; 21 import static com.android.documentsui.DocumentsActivity.State.SORT_ORDER_SIZE; 22 23 import android.database.AbstractCursor; 24 import android.database.Cursor; 25 import android.os.Bundle; 26 import android.provider.DocumentsContract.Document; 27 28 /** 29 * Cursor wrapper that presents a sorted view of the underlying cursor. Handles 30 * common {@link Document} sorting modes, such as ordering directories first. 31 */ 32 public class SortingCursorWrapper extends AbstractCursor { 33 private final Cursor mCursor; 34 35 private final int[] mPosition; 36 private final String[] mValueString; 37 private final long[] mValueLong; 38 39 public SortingCursorWrapper(Cursor cursor, int sortOrder) { 40 mCursor = cursor; 41 42 final int count = cursor.getCount(); 43 mPosition = new int[count]; 44 switch (sortOrder) { 45 case SORT_ORDER_DISPLAY_NAME: 46 mValueString = new String[count]; 47 mValueLong = null; 48 break; 49 case SORT_ORDER_LAST_MODIFIED: 50 case SORT_ORDER_SIZE: 51 mValueString = null; 52 mValueLong = new long[count]; 53 break; 54 default: 55 throw new IllegalArgumentException(); 56 } 57 58 cursor.moveToPosition(-1); 59 for (int i = 0; i < count; i++) { 60 cursor.moveToNext(); 61 mPosition[i] = i; 62 63 switch (sortOrder) { 64 case SORT_ORDER_DISPLAY_NAME: 65 final String mimeType = cursor.getString( 66 cursor.getColumnIndex(Document.COLUMN_MIME_TYPE)); 67 final String displayName = cursor.getString( 68 cursor.getColumnIndex(Document.COLUMN_DISPLAY_NAME)); 69 if (Document.MIME_TYPE_DIR.equals(mimeType)) { 70 mValueString[i] = '\001' + displayName; 71 } else { 72 mValueString[i] = displayName; 73 } 74 break; 75 case SORT_ORDER_LAST_MODIFIED: 76 mValueLong[i] = cursor.getLong( 77 cursor.getColumnIndex(Document.COLUMN_LAST_MODIFIED)); 78 break; 79 case SORT_ORDER_SIZE: 80 mValueLong[i] = cursor.getLong(cursor.getColumnIndex(Document.COLUMN_SIZE)); 81 break; 82 } 83 } 84 85 switch (sortOrder) { 86 case SORT_ORDER_DISPLAY_NAME: 87 synchronized (SortingCursorWrapper.class) { 88 89 binarySort(mPosition, mValueString); 90 } 91 break; 92 case SORT_ORDER_LAST_MODIFIED: 93 case SORT_ORDER_SIZE: 94 binarySort(mPosition, mValueLong); 95 break; 96 } 97 } 98 99 @Override 100 public Bundle getExtras() { 101 return mCursor.getExtras(); 102 } 103 104 @Override 105 public void close() { 106 super.close(); 107 mCursor.close(); 108 } 109 110 @Override 111 public boolean onMove(int oldPosition, int newPosition) { 112 return mCursor.moveToPosition(mPosition[newPosition]); 113 } 114 115 @Override 116 public String[] getColumnNames() { 117 return mCursor.getColumnNames(); 118 } 119 120 @Override 121 public int getCount() { 122 return mCursor.getCount(); 123 } 124 125 @Override 126 public double getDouble(int column) { 127 return mCursor.getDouble(column); 128 } 129 130 @Override 131 public float getFloat(int column) { 132 return mCursor.getFloat(column); 133 } 134 135 @Override 136 public int getInt(int column) { 137 return mCursor.getInt(column); 138 } 139 140 @Override 141 public long getLong(int column) { 142 return mCursor.getLong(column); 143 } 144 145 @Override 146 public short getShort(int column) { 147 return mCursor.getShort(column); 148 } 149 150 @Override 151 public String getString(int column) { 152 return mCursor.getString(column); 153 } 154 155 @Override 156 public int getType(int column) { 157 return mCursor.getType(column); 158 } 159 160 @Override 161 public boolean isNull(int column) { 162 return mCursor.isNull(column); 163 } 164 165 /** 166 * Borrowed from TimSort.binarySort(), but modified to sort two column 167 * dataset. 168 */ 169 private static void binarySort(int[] position, String[] value) { 170 final int count = position.length; 171 for (int start = 1; start < count; start++) { 172 final int pivotPosition = position[start]; 173 final String pivotValue = value[start]; 174 175 int left = 0; 176 int right = start; 177 178 while (left < right) { 179 int mid = (left + right) >>> 1; 180 181 final String lhs = pivotValue; 182 final String rhs = value[mid]; 183 final int compare; 184 if (lhs == null) { 185 compare = -1; 186 } else if (rhs == null) { 187 compare = 1; 188 } else { 189 compare = lhs.compareToIgnoreCase(rhs); 190 } 191 192 if (compare < 0) { 193 right = mid; 194 } else { 195 left = mid + 1; 196 } 197 } 198 199 int n = start - left; 200 switch (n) { 201 case 2: 202 position[left + 2] = position[left + 1]; 203 value[left + 2] = value[left + 1]; 204 case 1: 205 position[left + 1] = position[left]; 206 value[left + 1] = value[left]; 207 break; 208 default: 209 System.arraycopy(position, left, position, left + 1, n); 210 System.arraycopy(value, left, value, left + 1, n); 211 } 212 213 position[left] = pivotPosition; 214 value[left] = pivotValue; 215 } 216 } 217 218 /** 219 * Borrowed from TimSort.binarySort(), but modified to sort two column 220 * dataset. 221 */ 222 private static void binarySort(int[] position, long[] value) { 223 final int count = position.length; 224 for (int start = 1; start < count; start++) { 225 final int pivotPosition = position[start]; 226 final long pivotValue = value[start]; 227 228 int left = 0; 229 int right = start; 230 231 while (left < right) { 232 int mid = (left + right) >>> 1; 233 234 final long lhs = pivotValue; 235 final long rhs = value[mid]; 236 final int compare = Long.compare(lhs, rhs); 237 if (compare > 0) { 238 right = mid; 239 } else { 240 left = mid + 1; 241 } 242 } 243 244 int n = start - left; 245 switch (n) { 246 case 2: 247 position[left + 2] = position[left + 1]; 248 value[left + 2] = value[left + 1]; 249 case 1: 250 position[left + 1] = position[left]; 251 value[left + 1] = value[left]; 252 break; 253 default: 254 System.arraycopy(position, left, position, left + 1, n); 255 System.arraycopy(value, left, value, left + 1, n); 256 } 257 258 position[left] = pivotPosition; 259 value[left] = pivotValue; 260 } 261 } 262 } 263
