Garfield Tan | 2010ff7 | 2016-09-30 14:55:32 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2016 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.sorting; |
| 18 | |
| 19 | import static com.android.documentsui.base.DocumentInfo.getCursorLong; |
| 20 | import static com.android.documentsui.base.DocumentInfo.getCursorString; |
| 21 | |
| 22 | import android.database.AbstractCursor; |
| 23 | import android.database.Cursor; |
Steve McKay | b324dfd | 2016-10-28 12:52:36 -0700 | [diff] [blame] | 24 | import android.os.Bundle; |
Garfield Tan | 2010ff7 | 2016-09-30 14:55:32 -0700 | [diff] [blame] | 25 | import android.provider.DocumentsContract.Document; |
| 26 | |
| 27 | import com.android.documentsui.base.Shared; |
| 28 | import com.android.documentsui.sorting.SortModel.SortDimensionId; |
| 29 | |
| 30 | /** |
| 31 | * Cursor wrapper that presents a sorted view of the underlying cursor. Handles |
| 32 | * common {@link Document} sorting modes, such as ordering directories first. |
| 33 | */ |
| 34 | class SortingCursorWrapper extends AbstractCursor { |
| 35 | private final Cursor mCursor; |
| 36 | |
| 37 | private final int[] mPosition; |
| 38 | |
| 39 | public SortingCursorWrapper(Cursor cursor, SortDimension dimension) { |
| 40 | mCursor = cursor; |
| 41 | |
| 42 | final int count = cursor.getCount(); |
| 43 | mPosition = new int[count]; |
| 44 | boolean[] isDirs = new boolean[count]; |
| 45 | String[] displayNames = null; |
| 46 | long[] longValues = null; |
| 47 | String[] ids = null; |
| 48 | |
| 49 | final @SortDimensionId int id = dimension.getId(); |
| 50 | switch (id) { |
| 51 | case SortModel.SORT_DIMENSION_ID_TITLE: |
| 52 | displayNames = new String[count]; |
| 53 | break; |
| 54 | case SortModel.SORT_DIMENSION_ID_DATE: |
| 55 | case SortModel.SORT_DIMENSION_ID_SIZE: |
| 56 | longValues = new long[count]; |
| 57 | ids = new String[count]; |
| 58 | break; |
| 59 | } |
| 60 | |
| 61 | cursor.moveToPosition(-1); |
| 62 | for (int i = 0; i < count; i++) { |
| 63 | cursor.moveToNext(); |
| 64 | mPosition[i] = i; |
| 65 | |
| 66 | final String mimeType = getCursorString(mCursor, Document.COLUMN_MIME_TYPE); |
| 67 | isDirs[i] = Document.MIME_TYPE_DIR.equals(mimeType); |
| 68 | |
| 69 | switch(id) { |
| 70 | case SortModel.SORT_DIMENSION_ID_TITLE: |
| 71 | final String displayName = getCursorString( |
| 72 | mCursor, Document.COLUMN_DISPLAY_NAME); |
| 73 | displayNames[i] = displayName; |
| 74 | break; |
| 75 | case SortModel.SORT_DIMENSION_ID_DATE: |
| 76 | longValues[i] = getLastModified(mCursor); |
| 77 | ids[i] = getCursorString(mCursor, Document.COLUMN_DOCUMENT_ID); |
| 78 | break; |
| 79 | case SortModel.SORT_DIMENSION_ID_SIZE: |
| 80 | longValues[i] = getCursorLong(mCursor, Document.COLUMN_SIZE); |
| 81 | ids[i] = getCursorString(mCursor, Document.COLUMN_DOCUMENT_ID); |
| 82 | break; |
| 83 | } |
| 84 | |
| 85 | } |
| 86 | |
| 87 | switch (id) { |
| 88 | case SortModel.SORT_DIMENSION_ID_TITLE: |
| 89 | binarySort(displayNames, isDirs, mPosition, dimension.getSortDirection()); |
| 90 | break; |
| 91 | case SortModel.SORT_DIMENSION_ID_DATE: |
| 92 | case SortModel.SORT_DIMENSION_ID_SIZE: |
| 93 | binarySort(longValues, isDirs, mPosition, ids, dimension.getSortDirection()); |
| 94 | break; |
| 95 | } |
| 96 | |
| 97 | } |
| 98 | |
| 99 | @Override |
| 100 | public void close() { |
| 101 | super.close(); |
| 102 | mCursor.close(); |
| 103 | } |
| 104 | |
| 105 | @Override |
| 106 | public boolean onMove(int oldPosition, int newPosition) { |
| 107 | return mCursor.moveToPosition(mPosition[newPosition]); |
| 108 | } |
| 109 | |
| 110 | @Override |
| 111 | public String[] getColumnNames() { |
| 112 | return mCursor.getColumnNames(); |
| 113 | } |
| 114 | |
| 115 | @Override |
| 116 | public int getCount() { |
| 117 | return mCursor.getCount(); |
| 118 | } |
| 119 | |
| 120 | @Override |
| 121 | public double getDouble(int column) { |
| 122 | return mCursor.getDouble(column); |
| 123 | } |
| 124 | |
| 125 | @Override |
| 126 | public float getFloat(int column) { |
| 127 | return mCursor.getFloat(column); |
| 128 | } |
| 129 | |
| 130 | @Override |
| 131 | public int getInt(int column) { |
| 132 | return mCursor.getInt(column); |
| 133 | } |
| 134 | |
| 135 | @Override |
| 136 | public long getLong(int column) { |
| 137 | return mCursor.getLong(column); |
| 138 | } |
| 139 | |
| 140 | @Override |
| 141 | public short getShort(int column) { |
| 142 | return mCursor.getShort(column); |
| 143 | } |
| 144 | |
| 145 | @Override |
| 146 | public String getString(int column) { |
| 147 | return mCursor.getString(column); |
| 148 | } |
| 149 | |
| 150 | @Override |
| 151 | public int getType(int column) { |
| 152 | return mCursor.getType(column); |
| 153 | } |
| 154 | |
| 155 | @Override |
| 156 | public boolean isNull(int column) { |
| 157 | return mCursor.isNull(column); |
| 158 | } |
| 159 | |
Steve McKay | b324dfd | 2016-10-28 12:52:36 -0700 | [diff] [blame] | 160 | @Override |
| 161 | public Bundle getExtras() { |
| 162 | return mCursor.getExtras(); |
| 163 | } |
| 164 | |
Garfield Tan | 2010ff7 | 2016-09-30 14:55:32 -0700 | [diff] [blame] | 165 | /** |
| 166 | * @return Timestamp for the given document. Some docs (e.g. active downloads) have a null |
| 167 | * timestamp - these will be replaced with MAX_LONG so that such files get sorted to the top |
| 168 | * when sorting descending by date. |
| 169 | */ |
| 170 | private static long getLastModified(Cursor cursor) { |
| 171 | long l = getCursorLong(cursor, Document.COLUMN_LAST_MODIFIED); |
| 172 | return (l == -1) ? Long.MAX_VALUE : l; |
| 173 | } |
| 174 | |
| 175 | /** |
| 176 | * Borrowed from TimSort.binarySort(), but modified to sort two column |
| 177 | * dataset. |
| 178 | */ |
| 179 | private static void binarySort( |
| 180 | String[] sortKey, |
| 181 | boolean[] isDirs, |
| 182 | int[] positions, |
| 183 | @SortDimension.SortDirection int direction) { |
| 184 | final int count = positions.length; |
| 185 | for (int start = 1; start < count; start++) { |
| 186 | final int pivotPosition = positions[start]; |
| 187 | final String pivotValue = sortKey[start]; |
| 188 | final boolean pivotIsDir = isDirs[start]; |
| 189 | |
| 190 | int left = 0; |
| 191 | int right = start; |
| 192 | |
| 193 | while (left < right) { |
| 194 | int mid = (left + right) >>> 1; |
| 195 | |
| 196 | // Directories always go in front. |
| 197 | int compare = 0; |
| 198 | final boolean rhsIsDir = isDirs[mid]; |
| 199 | if (pivotIsDir && !rhsIsDir) { |
| 200 | compare = -1; |
| 201 | } else if (!pivotIsDir && rhsIsDir) { |
| 202 | compare = 1; |
| 203 | } else { |
| 204 | final String lhs = pivotValue; |
| 205 | final String rhs = sortKey[mid]; |
| 206 | switch (direction) { |
| 207 | case SortDimension.SORT_DIRECTION_ASCENDING: |
| 208 | compare = Shared.compareToIgnoreCaseNullable(lhs, rhs); |
| 209 | break; |
| 210 | case SortDimension.SORT_DIRECTION_DESCENDING: |
| 211 | compare = -Shared.compareToIgnoreCaseNullable(lhs, rhs); |
| 212 | break; |
| 213 | default: |
| 214 | throw new IllegalArgumentException( |
| 215 | "Unknown sorting direction: " + direction); |
| 216 | } |
| 217 | } |
| 218 | |
| 219 | if (compare < 0) { |
| 220 | right = mid; |
| 221 | } else { |
| 222 | left = mid + 1; |
| 223 | } |
| 224 | } |
| 225 | |
| 226 | int n = start - left; |
| 227 | switch (n) { |
| 228 | case 2: |
| 229 | positions[left + 2] = positions[left + 1]; |
| 230 | sortKey[left + 2] = sortKey[left + 1]; |
| 231 | isDirs[left + 2] = isDirs[left + 1]; |
| 232 | case 1: |
| 233 | positions[left + 1] = positions[left]; |
| 234 | sortKey[left + 1] = sortKey[left]; |
| 235 | isDirs[left + 1] = isDirs[left]; |
| 236 | break; |
| 237 | default: |
| 238 | System.arraycopy(positions, left, positions, left + 1, n); |
| 239 | System.arraycopy(sortKey, left, sortKey, left + 1, n); |
| 240 | System.arraycopy(isDirs, left, isDirs, left + 1, n); |
| 241 | } |
| 242 | |
| 243 | positions[left] = pivotPosition; |
| 244 | sortKey[left] = pivotValue; |
| 245 | isDirs[left] = pivotIsDir; |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | /** |
| 250 | * Borrowed from TimSort.binarySort(), but modified to sort two column |
| 251 | * dataset. |
| 252 | */ |
| 253 | private static void binarySort( |
| 254 | long[] sortKey, |
| 255 | boolean[] isDirs, |
| 256 | int[] positions, |
| 257 | String[] ids, |
| 258 | @SortDimension.SortDirection int direction) { |
| 259 | final int count = positions.length; |
| 260 | for (int start = 1; start < count; start++) { |
| 261 | final int pivotPosition = positions[start]; |
| 262 | final long pivotValue = sortKey[start]; |
| 263 | final boolean pivotIsDir = isDirs[start]; |
| 264 | final String pivotId = ids[start]; |
| 265 | |
| 266 | int left = 0; |
| 267 | int right = start; |
| 268 | |
| 269 | while (left < right) { |
| 270 | int mid = ((left + right) >>> 1); |
| 271 | |
| 272 | // Directories always go in front. |
| 273 | int compare = 0; |
| 274 | final boolean rhsIsDir = isDirs[mid]; |
| 275 | if (pivotIsDir && !rhsIsDir) { |
| 276 | compare = -1; |
| 277 | } else if (!pivotIsDir && rhsIsDir) { |
| 278 | compare = 1; |
| 279 | } else { |
| 280 | final long lhs = pivotValue; |
| 281 | final long rhs = sortKey[mid]; |
| 282 | switch (direction) { |
| 283 | case SortDimension.SORT_DIRECTION_ASCENDING: |
| 284 | compare = Long.compare(lhs, rhs); |
| 285 | break; |
| 286 | case SortDimension.SORT_DIRECTION_DESCENDING: |
| 287 | compare = -Long.compare(lhs, rhs); |
| 288 | break; |
| 289 | default: |
| 290 | throw new IllegalArgumentException( |
| 291 | "Unknown sorting direction: " + direction); |
| 292 | } |
| 293 | } |
| 294 | |
| 295 | // If numerical comparison yields a tie, use document ID as a tie breaker. This |
| 296 | // will yield stable results even if incoming items are continually shuffling and |
| 297 | // have identical numerical sort keys. One common example of this scenario is seen |
| 298 | // when sorting a set of active downloads by mod time. |
| 299 | if (compare == 0) { |
| 300 | compare = pivotId.compareTo(ids[mid]); |
| 301 | } |
| 302 | |
| 303 | if (compare < 0) { |
| 304 | right = mid; |
| 305 | } else { |
| 306 | left = mid + 1; |
| 307 | } |
| 308 | } |
| 309 | |
| 310 | int n = start - left; |
| 311 | switch (n) { |
| 312 | case 2: |
| 313 | positions[left + 2] = positions[left + 1]; |
| 314 | sortKey[left + 2] = sortKey[left + 1]; |
| 315 | isDirs[left + 2] = isDirs[left + 1]; |
| 316 | ids[left + 2] = ids[left + 1]; |
| 317 | case 1: |
| 318 | positions[left + 1] = positions[left]; |
| 319 | sortKey[left + 1] = sortKey[left]; |
| 320 | isDirs[left + 1] = isDirs[left]; |
| 321 | ids[left + 1] = ids[left]; |
| 322 | break; |
| 323 | default: |
| 324 | System.arraycopy(positions, left, positions, left + 1, n); |
| 325 | System.arraycopy(sortKey, left, sortKey, left + 1, n); |
| 326 | System.arraycopy(isDirs, left, isDirs, left + 1, n); |
| 327 | System.arraycopy(ids, left, ids, left + 1, n); |
| 328 | } |
| 329 | |
| 330 | positions[left] = pivotPosition; |
| 331 | sortKey[left] = pivotValue; |
| 332 | isDirs[left] = pivotIsDir; |
| 333 | ids[left] = pivotId; |
| 334 | } |
| 335 | } |
| 336 | } |