| 1 | /* |
| 2 | * Copyright (C) 2011 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.support.v2.widget; |
| 18 | |
| 19 | import android.content.Context; |
| 20 | import android.database.Cursor; |
| 21 | import android.net.Uri; |
| 22 | import android.view.View; |
| 23 | import android.widget.ImageView; |
| 24 | import android.widget.TextView; |
| 25 | |
| 26 | /** |
| 27 | * Static library support version of the framework's {@link android.widget.SimpleCursorAdapter}. |
| 28 | * Used to write apps that run on platforms prior to Android 3.0. When running |
| 29 | * on Android 3.0 or above, this implementation is still used; it does not try |
| 30 | * to switch to the framework's implementation. See the framework SDK |
| 31 | * documentation for a class overview. |
| 32 | */ |
| 33 | public class SimpleCursorAdapter extends ResourceCursorAdapter { |
| 34 | /** |
| 35 | * A list of columns containing the data to bind to the UI. |
| 36 | * This field should be made private, so it is hidden from the SDK. |
| 37 | * {@hide} |
| 38 | */ |
| 39 | protected int[] mFrom; |
| 40 | /** |
| 41 | * A list of View ids representing the views to which the data must be bound. |
| 42 | * This field should be made private, so it is hidden from the SDK. |
| 43 | * {@hide} |
| 44 | */ |
| 45 | protected int[] mTo; |
| 46 | |
| 47 | private int mStringConversionColumn = -1; |
| 48 | private CursorToStringConverter mCursorToStringConverter; |
| 49 | private ViewBinder mViewBinder; |
| 50 | |
| 51 | String[] mOriginalFrom; |
| 52 | |
| 53 | /** |
| 54 | * Constructor the enables auto-requery. |
| 55 | * |
| 56 | * @deprecated This option is discouraged, as it results in Cursor queries |
| 57 | * being performed on the application's UI thread and thus can cause poor |
| 58 | * responsiveness or even Application Not Responding errors. As an alternative, |
| 59 | * use {@link android.app.LoaderManager} with a {@link android.content.CursorLoader}. |
| 60 | */ |
| 61 | @Deprecated |
| 62 | public SimpleCursorAdapter(Context context, int layout, Cursor c, String[] from, int[] to) { |
| 63 | super(context, layout, c); |
| 64 | mTo = to; |
| 65 | mOriginalFrom = from; |
| 66 | findColumns(from); |
| 67 | } |
| 68 | |
| 69 | /** |
| 70 | * Standard constructor. |
| 71 | * |
| 72 | * @param context The context where the ListView associated with this |
| 73 | * SimpleListItemFactory is running |
| 74 | * @param layout resource identifier of a layout file that defines the views |
| 75 | * for this list item. The layout file should include at least |
| 76 | * those named views defined in "to" |
| 77 | * @param c The database cursor. Can be null if the cursor is not available yet. |
| 78 | * @param from A list of column names representing the data to bind to the UI. Can be null |
| 79 | * if the cursor is not available yet. |
| 80 | * @param to The views that should display column in the "from" parameter. |
| 81 | * These should all be TextViews. The first N views in this list |
| 82 | * are given the values of the first N columns in the from |
| 83 | * parameter. Can be null if the cursor is not available yet. |
| 84 | * @param flags Flags used to determine the behavior of the adapter, |
| 85 | * as per {@link CursorAdapter#CursorAdapter(Context, Cursor, int)}. |
| 86 | */ |
| 87 | public SimpleCursorAdapter(Context context, int layout, Cursor c, String[] from, |
| 88 | int[] to, int flags) { |
| 89 | super(context, layout, c, flags); |
| 90 | mTo = to; |
| 91 | mOriginalFrom = from; |
| 92 | findColumns(from); |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * Binds all of the field names passed into the "to" parameter of the |
| 97 | * constructor with their corresponding cursor columns as specified in the |
| 98 | * "from" parameter. |
| 99 | * |
| 100 | * Binding occurs in two phases. First, if a |
| 101 | * {@link android.widget.SimpleCursorAdapter.ViewBinder} is available, |
| 102 | * {@link ViewBinder#setViewValue(android.view.View, android.database.Cursor, int)} |
| 103 | * is invoked. If the returned value is true, binding has occured. If the |
| 104 | * returned value is false and the view to bind is a TextView, |
| 105 | * {@link #setViewText(TextView, String)} is invoked. If the returned value is |
| 106 | * false and the view to bind is an ImageView, |
| 107 | * {@link #setViewImage(ImageView, String)} is invoked. If no appropriate |
| 108 | * binding can be found, an {@link IllegalStateException} is thrown. |
| 109 | * |
| 110 | * @throws IllegalStateException if binding cannot occur |
| 111 | * |
| 112 | * @see android.widget.CursorAdapter#bindView(android.view.View, |
| 113 | * android.content.Context, android.database.Cursor) |
| 114 | * @see #getViewBinder() |
| 115 | * @see #setViewBinder(android.widget.SimpleCursorAdapter.ViewBinder) |
| 116 | * @see #setViewImage(ImageView, String) |
| 117 | * @see #setViewText(TextView, String) |
| 118 | */ |
| 119 | @Override |
| 120 | public void bindView(View view, Context context, Cursor cursor) { |
| 121 | final ViewBinder binder = mViewBinder; |
| 122 | final int count = mTo.length; |
| 123 | final int[] from = mFrom; |
| 124 | final int[] to = mTo; |
| 125 | |
| 126 | for (int i = 0; i < count; i++) { |
| 127 | final View v = view.findViewById(to[i]); |
| 128 | if (v != null) { |
| 129 | boolean bound = false; |
| 130 | if (binder != null) { |
| 131 | bound = binder.setViewValue(v, cursor, from[i]); |
| 132 | } |
| 133 | |
| 134 | if (!bound) { |
| 135 | String text = cursor.getString(from[i]); |
| 136 | if (text == null) { |
| 137 | text = ""; |
| 138 | } |
| 139 | |
| 140 | if (v instanceof TextView) { |
| 141 | setViewText((TextView) v, text); |
| 142 | } else if (v instanceof ImageView) { |
| 143 | setViewImage((ImageView) v, text); |
| 144 | } else { |
| 145 | throw new IllegalStateException(v.getClass().getName() + " is not a " + |
| 146 | " view that can be bounds by this SimpleCursorAdapter"); |
| 147 | } |
| 148 | } |
| 149 | } |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * Returns the {@link ViewBinder} used to bind data to views. |
| 155 | * |
| 156 | * @return a ViewBinder or null if the binder does not exist |
| 157 | * |
| 158 | * @see #bindView(android.view.View, android.content.Context, android.database.Cursor) |
| 159 | * @see #setViewBinder(android.widget.SimpleCursorAdapter.ViewBinder) |
| 160 | */ |
| 161 | public ViewBinder getViewBinder() { |
| 162 | return mViewBinder; |
| 163 | } |
| 164 | |
| 165 | /** |
| 166 | * Sets the binder used to bind data to views. |
| 167 | * |
| 168 | * @param viewBinder the binder used to bind data to views, can be null to |
| 169 | * remove the existing binder |
| 170 | * |
| 171 | * @see #bindView(android.view.View, android.content.Context, android.database.Cursor) |
| 172 | * @see #getViewBinder() |
| 173 | */ |
| 174 | public void setViewBinder(ViewBinder viewBinder) { |
| 175 | mViewBinder = viewBinder; |
| 176 | } |
| 177 | |
| 178 | /** |
| 179 | * Called by bindView() to set the image for an ImageView but only if |
| 180 | * there is no existing ViewBinder or if the existing ViewBinder cannot |
| 181 | * handle binding to an ImageView. |
| 182 | * |
| 183 | * By default, the value will be treated as an image resource. If the |
| 184 | * value cannot be used as an image resource, the value is used as an |
| 185 | * image Uri. |
| 186 | * |
| 187 | * Intended to be overridden by Adapters that need to filter strings |
| 188 | * retrieved from the database. |
| 189 | * |
| 190 | * @param v ImageView to receive an image |
| 191 | * @param value the value retrieved from the cursor |
| 192 | */ |
| 193 | public void setViewImage(ImageView v, String value) { |
| 194 | try { |
| 195 | v.setImageResource(Integer.parseInt(value)); |
| 196 | } catch (NumberFormatException nfe) { |
| 197 | v.setImageURI(Uri.parse(value)); |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | /** |
| 202 | * Called by bindView() to set the text for a TextView but only if |
| 203 | * there is no existing ViewBinder or if the existing ViewBinder cannot |
| 204 | * handle binding to an TextView. |
| 205 | * |
| 206 | * Intended to be overridden by Adapters that need to filter strings |
| 207 | * retrieved from the database. |
| 208 | * |
| 209 | * @param v TextView to receive text |
| 210 | * @param text the text to be set for the TextView |
| 211 | */ |
| 212 | public void setViewText(TextView v, String text) { |
| 213 | v.setText(text); |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * Return the index of the column used to get a String representation |
| 218 | * of the Cursor. |
| 219 | * |
| 220 | * @return a valid index in the current Cursor or -1 |
| 221 | * |
| 222 | * @see android.widget.CursorAdapter#convertToString(android.database.Cursor) |
| 223 | * @see #setStringConversionColumn(int) |
| 224 | * @see #setCursorToStringConverter(android.widget.SimpleCursorAdapter.CursorToStringConverter) |
| 225 | * @see #getCursorToStringConverter() |
| 226 | */ |
| 227 | public int getStringConversionColumn() { |
| 228 | return mStringConversionColumn; |
| 229 | } |
| 230 | |
| 231 | /** |
| 232 | * Defines the index of the column in the Cursor used to get a String |
| 233 | * representation of that Cursor. The column is used to convert the |
| 234 | * Cursor to a String only when the current CursorToStringConverter |
| 235 | * is null. |
| 236 | * |
| 237 | * @param stringConversionColumn a valid index in the current Cursor or -1 to use the default |
| 238 | * conversion mechanism |
| 239 | * |
| 240 | * @see android.widget.CursorAdapter#convertToString(android.database.Cursor) |
| 241 | * @see #getStringConversionColumn() |
| 242 | * @see #setCursorToStringConverter(android.widget.SimpleCursorAdapter.CursorToStringConverter) |
| 243 | * @see #getCursorToStringConverter() |
| 244 | */ |
| 245 | public void setStringConversionColumn(int stringConversionColumn) { |
| 246 | mStringConversionColumn = stringConversionColumn; |
| 247 | } |
| 248 | |
| 249 | /** |
| 250 | * Returns the converter used to convert the filtering Cursor |
| 251 | * into a String. |
| 252 | * |
| 253 | * @return null if the converter does not exist or an instance of |
| 254 | * {@link android.widget.SimpleCursorAdapter.CursorToStringConverter} |
| 255 | * |
| 256 | * @see #setCursorToStringConverter(android.widget.SimpleCursorAdapter.CursorToStringConverter) |
| 257 | * @see #getStringConversionColumn() |
| 258 | * @see #setStringConversionColumn(int) |
| 259 | * @see android.widget.CursorAdapter#convertToString(android.database.Cursor) |
| 260 | */ |
| 261 | public CursorToStringConverter getCursorToStringConverter() { |
| 262 | return mCursorToStringConverter; |
| 263 | } |
| 264 | |
| 265 | /** |
| 266 | * Sets the converter used to convert the filtering Cursor |
| 267 | * into a String. |
| 268 | * |
| 269 | * @param cursorToStringConverter the Cursor to String converter, or |
| 270 | * null to remove the converter |
| 271 | * |
| 272 | * @see #setCursorToStringConverter(android.widget.SimpleCursorAdapter.CursorToStringConverter) |
| 273 | * @see #getStringConversionColumn() |
| 274 | * @see #setStringConversionColumn(int) |
| 275 | * @see android.widget.CursorAdapter#convertToString(android.database.Cursor) |
| 276 | */ |
| 277 | public void setCursorToStringConverter(CursorToStringConverter cursorToStringConverter) { |
| 278 | mCursorToStringConverter = cursorToStringConverter; |
| 279 | } |
| 280 | |
| 281 | /** |
| 282 | * Returns a CharSequence representation of the specified Cursor as defined |
| 283 | * by the current CursorToStringConverter. If no CursorToStringConverter |
| 284 | * has been set, the String conversion column is used instead. If the |
| 285 | * conversion column is -1, the returned String is empty if the cursor |
| 286 | * is null or Cursor.toString(). |
| 287 | * |
| 288 | * @param cursor the Cursor to convert to a CharSequence |
| 289 | * |
| 290 | * @return a non-null CharSequence representing the cursor |
| 291 | */ |
| 292 | @Override |
| 293 | public CharSequence convertToString(Cursor cursor) { |
| 294 | if (mCursorToStringConverter != null) { |
| 295 | return mCursorToStringConverter.convertToString(cursor); |
| 296 | } else if (mStringConversionColumn > -1) { |
| 297 | return cursor.getString(mStringConversionColumn); |
| 298 | } |
| 299 | |
| 300 | return super.convertToString(cursor); |
| 301 | } |
| 302 | |
| 303 | /** |
| 304 | * Create a map from an array of strings to an array of column-id integers in mCursor. |
| 305 | * If mCursor is null, the array will be discarded. |
| 306 | * |
| 307 | * @param from the Strings naming the columns of interest |
| 308 | */ |
| 309 | private void findColumns(String[] from) { |
| 310 | if (mCursor != null) { |
| 311 | int i; |
| 312 | int count = from.length; |
| 313 | if (mFrom == null || mFrom.length != count) { |
| 314 | mFrom = new int[count]; |
| 315 | } |
| 316 | for (i = 0; i < count; i++) { |
| 317 | mFrom[i] = mCursor.getColumnIndexOrThrow(from[i]); |
| 318 | } |
| 319 | } else { |
| 320 | mFrom = null; |
| 321 | } |
| 322 | } |
| 323 | |
| 324 | @Override |
| 325 | public Cursor swapCursor(Cursor c) { |
| 326 | Cursor res = super.swapCursor(c); |
| 327 | // rescan columns in case cursor layout is different |
| 328 | findColumns(mOriginalFrom); |
| 329 | return res; |
| 330 | } |
| 331 | |
| 332 | /** |
| 333 | * Change the cursor and change the column-to-view mappings at the same time. |
| 334 | * |
| 335 | * @param c The database cursor. Can be null if the cursor is not available yet. |
| 336 | * @param from A list of column names representing the data to bind to the UI. Can be null |
| 337 | * if the cursor is not available yet. |
| 338 | * @param to The views that should display column in the "from" parameter. |
| 339 | * These should all be TextViews. The first N views in this list |
| 340 | * are given the values of the first N columns in the from |
| 341 | * parameter. Can be null if the cursor is not available yet. |
| 342 | */ |
| 343 | public void changeCursorAndColumns(Cursor c, String[] from, int[] to) { |
| 344 | mOriginalFrom = from; |
| 345 | mTo = to; |
| 346 | super.changeCursor(c); |
| 347 | findColumns(mOriginalFrom); |
| 348 | } |
| 349 | |
| 350 | /** |
| 351 | * This class can be used by external clients of SimpleCursorAdapter |
| 352 | * to bind values fom the Cursor to views. |
| 353 | * |
| 354 | * You should use this class to bind values from the Cursor to views |
| 355 | * that are not directly supported by SimpleCursorAdapter or to |
| 356 | * change the way binding occurs for views supported by |
| 357 | * SimpleCursorAdapter. |
| 358 | * |
| 359 | * @see SimpleCursorAdapter#bindView(android.view.View, android.content.Context, android.database.Cursor) |
| 360 | * @see SimpleCursorAdapter#setViewImage(ImageView, String) |
| 361 | * @see SimpleCursorAdapter#setViewText(TextView, String) |
| 362 | */ |
| 363 | public static interface ViewBinder { |
| 364 | /** |
| 365 | * Binds the Cursor column defined by the specified index to the specified view. |
| 366 | * |
| 367 | * When binding is handled by this ViewBinder, this method must return true. |
| 368 | * If this method returns false, SimpleCursorAdapter will attempts to handle |
| 369 | * the binding on its own. |
| 370 | * |
| 371 | * @param view the view to bind the data to |
| 372 | * @param cursor the cursor to get the data from |
| 373 | * @param columnIndex the column at which the data can be found in the cursor |
| 374 | * |
| 375 | * @return true if the data was bound to the view, false otherwise |
| 376 | */ |
| 377 | boolean setViewValue(View view, Cursor cursor, int columnIndex); |
| 378 | } |
| 379 | |
| 380 | /** |
| 381 | * This class can be used by external clients of SimpleCursorAdapter |
| 382 | * to define how the Cursor should be converted to a String. |
| 383 | * |
| 384 | * @see android.widget.CursorAdapter#convertToString(android.database.Cursor) |
| 385 | */ |
| 386 | public static interface CursorToStringConverter { |
| 387 | /** |
| 388 | * Returns a CharSequence representing the specified Cursor. |
| 389 | * |
| 390 | * @param cursor the cursor for which a CharSequence representation |
| 391 | * is requested |
| 392 | * |
| 393 | * @return a non-null CharSequence representing the cursor |
| 394 | */ |
| 395 | CharSequence convertToString(Cursor cursor); |
| 396 | } |
| 397 | |
| 398 | } |