Jeff Brown | 67b6ab7 | 2010-12-17 18:33:02 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2010 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.text.method; |
| 18 | |
| 19 | import android.text.Layout; |
| 20 | import android.text.Spannable; |
Jeff Brown | 8f34567 | 2011-02-26 13:29:53 -0800 | [diff] [blame] | 21 | import android.view.InputDevice; |
Jeff Brown | 67b6ab7 | 2010-12-17 18:33:02 -0800 | [diff] [blame] | 22 | import android.view.KeyEvent; |
| 23 | import android.view.MotionEvent; |
| 24 | import android.widget.TextView; |
| 25 | |
| 26 | /** |
| 27 | * Base classes for movement methods. |
| 28 | */ |
| 29 | public class BaseMovementMethod implements MovementMethod { |
| 30 | @Override |
| 31 | public boolean canSelectArbitrarily() { |
| 32 | return false; |
| 33 | } |
| 34 | |
| 35 | @Override |
| 36 | public void initialize(TextView widget, Spannable text) { |
| 37 | } |
| 38 | |
| 39 | @Override |
| 40 | public boolean onKeyDown(TextView widget, Spannable text, int keyCode, KeyEvent event) { |
| 41 | final int movementMetaState = getMovementMetaState(text, event); |
| 42 | boolean handled = handleMovementKey(widget, text, keyCode, movementMetaState, event); |
| 43 | if (handled) { |
| 44 | MetaKeyKeyListener.adjustMetaAfterKeypress(text); |
| 45 | MetaKeyKeyListener.resetLockedMeta(text); |
| 46 | } |
| 47 | return handled; |
| 48 | } |
| 49 | |
| 50 | @Override |
| 51 | public boolean onKeyOther(TextView widget, Spannable text, KeyEvent event) { |
| 52 | final int movementMetaState = getMovementMetaState(text, event); |
| 53 | final int keyCode = event.getKeyCode(); |
| 54 | if (keyCode != KeyEvent.KEYCODE_UNKNOWN |
| 55 | && event.getAction() == KeyEvent.ACTION_MULTIPLE) { |
| 56 | final int repeat = event.getRepeatCount(); |
| 57 | boolean handled = false; |
| 58 | for (int i = 0; i < repeat; i++) { |
| 59 | if (!handleMovementKey(widget, text, keyCode, movementMetaState, event)) { |
| 60 | break; |
| 61 | } |
| 62 | handled = true; |
| 63 | } |
| 64 | if (handled) { |
| 65 | MetaKeyKeyListener.adjustMetaAfterKeypress(text); |
| 66 | MetaKeyKeyListener.resetLockedMeta(text); |
| 67 | } |
| 68 | return handled; |
| 69 | } |
| 70 | return false; |
| 71 | } |
| 72 | |
| 73 | @Override |
| 74 | public boolean onKeyUp(TextView widget, Spannable text, int keyCode, KeyEvent event) { |
| 75 | return false; |
| 76 | } |
| 77 | |
| 78 | @Override |
| 79 | public void onTakeFocus(TextView widget, Spannable text, int direction) { |
| 80 | } |
| 81 | |
| 82 | @Override |
| 83 | public boolean onTouchEvent(TextView widget, Spannable text, MotionEvent event) { |
| 84 | return false; |
| 85 | } |
| 86 | |
| 87 | @Override |
| 88 | public boolean onTrackballEvent(TextView widget, Spannable text, MotionEvent event) { |
| 89 | return false; |
| 90 | } |
| 91 | |
Jeff Brown | 8f34567 | 2011-02-26 13:29:53 -0800 | [diff] [blame] | 92 | @Override |
| 93 | public boolean onGenericMotionEvent(TextView widget, Spannable text, MotionEvent event) { |
| 94 | if ((event.getSource() & InputDevice.SOURCE_CLASS_POINTER) != 0) { |
| 95 | switch (event.getAction()) { |
| 96 | case MotionEvent.ACTION_SCROLL: { |
| 97 | final float vscroll; |
| 98 | final float hscroll; |
| 99 | if ((event.getMetaState() & KeyEvent.META_SHIFT_ON) != 0) { |
| 100 | vscroll = 0; |
| 101 | hscroll = event.getAxisValue(MotionEvent.AXIS_VSCROLL); |
| 102 | } else { |
| 103 | vscroll = -event.getAxisValue(MotionEvent.AXIS_VSCROLL); |
| 104 | hscroll = event.getAxisValue(MotionEvent.AXIS_HSCROLL); |
| 105 | } |
| 106 | |
| 107 | boolean handled = false; |
| 108 | if (hscroll < 0) { |
| 109 | handled |= scrollLeft(widget, text, (int)Math.ceil(-hscroll)); |
| 110 | } else if (hscroll > 0) { |
| 111 | handled |= scrollRight(widget, text, (int)Math.ceil(hscroll)); |
| 112 | } |
| 113 | if (vscroll < 0) { |
| 114 | handled |= scrollUp(widget, text, (int)Math.ceil(-vscroll)); |
| 115 | } else if (vscroll > 0) { |
| 116 | handled |= scrollDown(widget, text, (int)Math.ceil(vscroll)); |
| 117 | } |
| 118 | return handled; |
| 119 | } |
| 120 | } |
| 121 | } |
| 122 | return false; |
| 123 | } |
| 124 | |
Jeff Brown | 67b6ab7 | 2010-12-17 18:33:02 -0800 | [diff] [blame] | 125 | /** |
| 126 | * Gets the meta state used for movement using the modifiers tracked by the text |
| 127 | * buffer as well as those present in the key event. |
| 128 | * |
| 129 | * The movement meta state excludes the state of locked modifiers or the SHIFT key |
| 130 | * since they are not used by movement actions (but they may be used for selection). |
| 131 | * |
| 132 | * @param buffer The text buffer. |
| 133 | * @param event The key event. |
| 134 | * @return The keyboard meta states used for movement. |
| 135 | */ |
| 136 | protected int getMovementMetaState(Spannable buffer, KeyEvent event) { |
| 137 | // We ignore locked modifiers and SHIFT. |
| 138 | int metaState = (event.getMetaState() | MetaKeyKeyListener.getMetaState(buffer)) |
| 139 | & ~(MetaKeyKeyListener.META_ALT_LOCKED | MetaKeyKeyListener.META_SYM_LOCKED); |
| 140 | return KeyEvent.normalizeMetaState(metaState) & ~KeyEvent.META_SHIFT_MASK; |
| 141 | } |
| 142 | |
| 143 | /** |
| 144 | * Performs a movement key action. |
| 145 | * The default implementation decodes the key down and invokes movement actions |
| 146 | * such as {@link #down} and {@link #up}. |
| 147 | * {@link #onKeyDown(TextView, Spannable, int, KeyEvent)} calls this method once |
| 148 | * to handle an {@link KeyEvent#ACTION_DOWN}. |
| 149 | * {@link #onKeyOther(TextView, Spannable, KeyEvent)} calls this method repeatedly |
| 150 | * to handle each repetition of an {@link KeyEvent#ACTION_MULTIPLE}. |
| 151 | * |
| 152 | * @param widget The text view. |
| 153 | * @param buffer The text buffer. |
| 154 | * @param event The key event. |
| 155 | * @param keyCode The key code. |
| 156 | * @param movementMetaState The keyboard meta states used for movement. |
| 157 | * @param event The key event. |
| 158 | * @return True if the event was handled. |
| 159 | */ |
| 160 | protected boolean handleMovementKey(TextView widget, Spannable buffer, |
| 161 | int keyCode, int movementMetaState, KeyEvent event) { |
| 162 | switch (keyCode) { |
| 163 | case KeyEvent.KEYCODE_DPAD_LEFT: |
| 164 | if (KeyEvent.metaStateHasNoModifiers(movementMetaState)) { |
| 165 | return left(widget, buffer); |
| 166 | } else if (KeyEvent.metaStateHasModifiers(movementMetaState, |
Jeff Sharkey | e982dfc1 | 2011-03-21 16:40:23 -0700 | [diff] [blame] | 167 | KeyEvent.META_CTRL_ON)) { |
| 168 | return leftWord(widget, buffer); |
| 169 | } else if (KeyEvent.metaStateHasModifiers(movementMetaState, |
Jeff Brown | 67b6ab7 | 2010-12-17 18:33:02 -0800 | [diff] [blame] | 170 | KeyEvent.META_ALT_ON)) { |
| 171 | return lineStart(widget, buffer); |
| 172 | } |
| 173 | break; |
| 174 | |
| 175 | case KeyEvent.KEYCODE_DPAD_RIGHT: |
| 176 | if (KeyEvent.metaStateHasNoModifiers(movementMetaState)) { |
| 177 | return right(widget, buffer); |
| 178 | } else if (KeyEvent.metaStateHasModifiers(movementMetaState, |
Jeff Sharkey | e982dfc1 | 2011-03-21 16:40:23 -0700 | [diff] [blame] | 179 | KeyEvent.META_CTRL_ON)) { |
| 180 | return rightWord(widget, buffer); |
| 181 | } else if (KeyEvent.metaStateHasModifiers(movementMetaState, |
Jeff Brown | 67b6ab7 | 2010-12-17 18:33:02 -0800 | [diff] [blame] | 182 | KeyEvent.META_ALT_ON)) { |
| 183 | return lineEnd(widget, buffer); |
| 184 | } |
| 185 | break; |
| 186 | |
| 187 | case KeyEvent.KEYCODE_DPAD_UP: |
| 188 | if (KeyEvent.metaStateHasNoModifiers(movementMetaState)) { |
| 189 | return up(widget, buffer); |
| 190 | } else if (KeyEvent.metaStateHasModifiers(movementMetaState, |
| 191 | KeyEvent.META_ALT_ON)) { |
| 192 | return top(widget, buffer); |
| 193 | } |
| 194 | break; |
| 195 | |
| 196 | case KeyEvent.KEYCODE_DPAD_DOWN: |
| 197 | if (KeyEvent.metaStateHasNoModifiers(movementMetaState)) { |
| 198 | return down(widget, buffer); |
| 199 | } else if (KeyEvent.metaStateHasModifiers(movementMetaState, |
| 200 | KeyEvent.META_ALT_ON)) { |
| 201 | return bottom(widget, buffer); |
| 202 | } |
| 203 | break; |
| 204 | |
| 205 | case KeyEvent.KEYCODE_PAGE_UP: |
| 206 | if (KeyEvent.metaStateHasNoModifiers(movementMetaState)) { |
| 207 | return pageUp(widget, buffer); |
| 208 | } else if (KeyEvent.metaStateHasModifiers(movementMetaState, |
| 209 | KeyEvent.META_ALT_ON)) { |
| 210 | return top(widget, buffer); |
| 211 | } |
| 212 | break; |
| 213 | |
| 214 | case KeyEvent.KEYCODE_PAGE_DOWN: |
| 215 | if (KeyEvent.metaStateHasNoModifiers(movementMetaState)) { |
| 216 | return pageDown(widget, buffer); |
| 217 | } else if (KeyEvent.metaStateHasModifiers(movementMetaState, |
| 218 | KeyEvent.META_ALT_ON)) { |
| 219 | return bottom(widget, buffer); |
| 220 | } |
| 221 | break; |
| 222 | |
| 223 | case KeyEvent.KEYCODE_MOVE_HOME: |
| 224 | if (KeyEvent.metaStateHasNoModifiers(movementMetaState)) { |
| 225 | return home(widget, buffer); |
Jeff Sharkey | e982dfc1 | 2011-03-21 16:40:23 -0700 | [diff] [blame] | 226 | } else if (KeyEvent.metaStateHasModifiers(movementMetaState, |
| 227 | KeyEvent.META_CTRL_ON)) { |
| 228 | return top(widget, buffer); |
Jeff Brown | 67b6ab7 | 2010-12-17 18:33:02 -0800 | [diff] [blame] | 229 | } |
| 230 | break; |
| 231 | |
| 232 | case KeyEvent.KEYCODE_MOVE_END: |
| 233 | if (KeyEvent.metaStateHasNoModifiers(movementMetaState)) { |
| 234 | return end(widget, buffer); |
Jeff Sharkey | e982dfc1 | 2011-03-21 16:40:23 -0700 | [diff] [blame] | 235 | } else if (KeyEvent.metaStateHasModifiers(movementMetaState, |
| 236 | KeyEvent.META_CTRL_ON)) { |
| 237 | return bottom(widget, buffer); |
Jeff Brown | 67b6ab7 | 2010-12-17 18:33:02 -0800 | [diff] [blame] | 238 | } |
| 239 | break; |
| 240 | } |
| 241 | return false; |
| 242 | } |
| 243 | |
| 244 | /** |
| 245 | * Performs a left movement action. |
| 246 | * Moves the cursor or scrolls left by one character. |
| 247 | * |
| 248 | * @param widget The text view. |
| 249 | * @param buffer The text buffer. |
| 250 | * @return True if the event was handled. |
| 251 | */ |
| 252 | protected boolean left(TextView widget, Spannable buffer) { |
| 253 | return false; |
| 254 | } |
| 255 | |
| 256 | /** |
| 257 | * Performs a right movement action. |
| 258 | * Moves the cursor or scrolls right by one character. |
| 259 | * |
| 260 | * @param widget The text view. |
| 261 | * @param buffer The text buffer. |
| 262 | * @return True if the event was handled. |
| 263 | */ |
| 264 | protected boolean right(TextView widget, Spannable buffer) { |
| 265 | return false; |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * Performs an up movement action. |
| 270 | * Moves the cursor or scrolls up by one line. |
| 271 | * |
| 272 | * @param widget The text view. |
| 273 | * @param buffer The text buffer. |
| 274 | * @return True if the event was handled. |
| 275 | */ |
| 276 | protected boolean up(TextView widget, Spannable buffer) { |
| 277 | return false; |
| 278 | } |
| 279 | |
| 280 | /** |
| 281 | * Performs a down movement action. |
| 282 | * Moves the cursor or scrolls down by one line. |
| 283 | * |
| 284 | * @param widget The text view. |
| 285 | * @param buffer The text buffer. |
| 286 | * @return True if the event was handled. |
| 287 | */ |
| 288 | protected boolean down(TextView widget, Spannable buffer) { |
| 289 | return false; |
| 290 | } |
| 291 | |
| 292 | /** |
| 293 | * Performs a page-up movement action. |
| 294 | * Moves the cursor or scrolls up by one page. |
| 295 | * |
| 296 | * @param widget The text view. |
| 297 | * @param buffer The text buffer. |
| 298 | * @return True if the event was handled. |
| 299 | */ |
| 300 | protected boolean pageUp(TextView widget, Spannable buffer) { |
| 301 | return false; |
| 302 | } |
| 303 | |
| 304 | /** |
| 305 | * Performs a page-down movement action. |
| 306 | * Moves the cursor or scrolls down by one page. |
| 307 | * |
| 308 | * @param widget The text view. |
| 309 | * @param buffer The text buffer. |
| 310 | * @return True if the event was handled. |
| 311 | */ |
| 312 | protected boolean pageDown(TextView widget, Spannable buffer) { |
| 313 | return false; |
| 314 | } |
| 315 | |
| 316 | /** |
| 317 | * Performs a top movement action. |
| 318 | * Moves the cursor or scrolls to the top of the buffer. |
| 319 | * |
| 320 | * @param widget The text view. |
| 321 | * @param buffer The text buffer. |
| 322 | * @return True if the event was handled. |
| 323 | */ |
| 324 | protected boolean top(TextView widget, Spannable buffer) { |
| 325 | return false; |
| 326 | } |
| 327 | |
| 328 | /** |
| 329 | * Performs a bottom movement action. |
| 330 | * Moves the cursor or scrolls to the bottom of the buffer. |
| 331 | * |
| 332 | * @param widget The text view. |
| 333 | * @param buffer The text buffer. |
| 334 | * @return True if the event was handled. |
| 335 | */ |
| 336 | protected boolean bottom(TextView widget, Spannable buffer) { |
| 337 | return false; |
| 338 | } |
| 339 | |
| 340 | /** |
| 341 | * Performs a line-start movement action. |
| 342 | * Moves the cursor or scrolls to the start of the line. |
| 343 | * |
| 344 | * @param widget The text view. |
| 345 | * @param buffer The text buffer. |
| 346 | * @return True if the event was handled. |
| 347 | */ |
| 348 | protected boolean lineStart(TextView widget, Spannable buffer) { |
| 349 | return false; |
| 350 | } |
| 351 | |
| 352 | /** |
| 353 | * Performs an line-end movement action. |
| 354 | * Moves the cursor or scrolls to the end of the line. |
| 355 | * |
| 356 | * @param widget The text view. |
| 357 | * @param buffer The text buffer. |
| 358 | * @return True if the event was handled. |
| 359 | */ |
| 360 | protected boolean lineEnd(TextView widget, Spannable buffer) { |
| 361 | return false; |
| 362 | } |
| 363 | |
Jeff Sharkey | e982dfc1 | 2011-03-21 16:40:23 -0700 | [diff] [blame] | 364 | /** {@hide} */ |
| 365 | protected boolean leftWord(TextView widget, Spannable buffer) { |
| 366 | return false; |
| 367 | } |
| 368 | |
| 369 | /** {@hide} */ |
| 370 | protected boolean rightWord(TextView widget, Spannable buffer) { |
| 371 | return false; |
| 372 | } |
| 373 | |
Jeff Brown | 67b6ab7 | 2010-12-17 18:33:02 -0800 | [diff] [blame] | 374 | /** |
| 375 | * Performs a home movement action. |
| 376 | * Moves the cursor or scrolls to the start of the line or to the top of the |
| 377 | * document depending on whether the insertion point is being moved or |
| 378 | * the document is being scrolled. |
| 379 | * |
| 380 | * @param widget The text view. |
| 381 | * @param buffer The text buffer. |
| 382 | * @return True if the event was handled. |
| 383 | */ |
| 384 | protected boolean home(TextView widget, Spannable buffer) { |
| 385 | return false; |
| 386 | } |
| 387 | |
| 388 | /** |
| 389 | * Performs an end movement action. |
| 390 | * Moves the cursor or scrolls to the start of the line or to the top of the |
| 391 | * document depending on whether the insertion point is being moved or |
| 392 | * the document is being scrolled. |
| 393 | * |
| 394 | * @param widget The text view. |
| 395 | * @param buffer The text buffer. |
| 396 | * @return True if the event was handled. |
| 397 | */ |
| 398 | protected boolean end(TextView widget, Spannable buffer) { |
| 399 | return false; |
| 400 | } |
Jeff Brown | 8f34567 | 2011-02-26 13:29:53 -0800 | [diff] [blame] | 401 | |
| 402 | private int getTopLine(TextView widget) { |
| 403 | return widget.getLayout().getLineForVertical(widget.getScrollY()); |
| 404 | } |
| 405 | |
| 406 | private int getBottomLine(TextView widget) { |
| 407 | return widget.getLayout().getLineForVertical(widget.getScrollY() + getInnerHeight(widget)); |
| 408 | } |
| 409 | |
| 410 | private int getInnerWidth(TextView widget) { |
| 411 | return widget.getWidth() - widget.getTotalPaddingLeft() - widget.getTotalPaddingRight(); |
| 412 | } |
| 413 | |
| 414 | private int getInnerHeight(TextView widget) { |
| 415 | return widget.getHeight() - widget.getTotalPaddingTop() - widget.getTotalPaddingBottom(); |
| 416 | } |
| 417 | |
| 418 | private int getCharacterWidth(TextView widget) { |
| 419 | return (int) Math.ceil(widget.getPaint().getFontSpacing()); |
| 420 | } |
| 421 | |
| 422 | private int getScrollBoundsLeft(TextView widget) { |
| 423 | final Layout layout = widget.getLayout(); |
| 424 | final int topLine = getTopLine(widget); |
| 425 | final int bottomLine = getBottomLine(widget); |
| 426 | if (topLine > bottomLine) { |
| 427 | return 0; |
| 428 | } |
| 429 | int left = Integer.MAX_VALUE; |
| 430 | for (int line = topLine; line <= bottomLine; line++) { |
| 431 | final int lineLeft = (int) Math.floor(layout.getLineLeft(line)); |
| 432 | if (lineLeft < left) { |
| 433 | left = lineLeft; |
| 434 | } |
| 435 | } |
| 436 | return left; |
| 437 | } |
| 438 | |
| 439 | private int getScrollBoundsRight(TextView widget) { |
| 440 | final Layout layout = widget.getLayout(); |
| 441 | final int topLine = getTopLine(widget); |
| 442 | final int bottomLine = getBottomLine(widget); |
| 443 | if (topLine > bottomLine) { |
| 444 | return 0; |
| 445 | } |
| 446 | int right = Integer.MIN_VALUE; |
| 447 | for (int line = topLine; line <= bottomLine; line++) { |
| 448 | final int lineRight = (int) Math.ceil(layout.getLineRight(line)); |
| 449 | if (lineRight > right) { |
| 450 | right = lineRight; |
| 451 | } |
| 452 | } |
| 453 | return right; |
| 454 | } |
| 455 | |
| 456 | /** |
| 457 | * Performs a scroll left action. |
| 458 | * Scrolls left by the specified number of characters. |
| 459 | * |
| 460 | * @param widget The text view. |
| 461 | * @param buffer The text buffer. |
| 462 | * @param amount The number of characters to scroll by. Must be at least 1. |
| 463 | * @return True if the event was handled. |
| 464 | * @hide |
| 465 | */ |
| 466 | protected boolean scrollLeft(TextView widget, Spannable buffer, int amount) { |
| 467 | final int minScrollX = getScrollBoundsLeft(widget); |
| 468 | int scrollX = widget.getScrollX(); |
| 469 | if (scrollX > minScrollX) { |
| 470 | scrollX = Math.max(scrollX - getCharacterWidth(widget) * amount, minScrollX); |
| 471 | widget.scrollTo(scrollX, widget.getScrollY()); |
| 472 | return true; |
| 473 | } |
| 474 | return false; |
| 475 | } |
| 476 | |
| 477 | /** |
| 478 | * Performs a scroll right action. |
| 479 | * Scrolls right by the specified number of characters. |
| 480 | * |
| 481 | * @param widget The text view. |
| 482 | * @param buffer The text buffer. |
| 483 | * @param amount The number of characters to scroll by. Must be at least 1. |
| 484 | * @return True if the event was handled. |
| 485 | * @hide |
| 486 | */ |
| 487 | protected boolean scrollRight(TextView widget, Spannable buffer, int amount) { |
| 488 | final int maxScrollX = getScrollBoundsRight(widget) - getInnerWidth(widget); |
| 489 | int scrollX = widget.getScrollX(); |
| 490 | if (scrollX < maxScrollX) { |
| 491 | scrollX = Math.min(scrollX + getCharacterWidth(widget) * amount, maxScrollX); |
| 492 | widget.scrollTo(scrollX, widget.getScrollY()); |
| 493 | return true; |
| 494 | } |
| 495 | return false; |
| 496 | } |
| 497 | |
| 498 | /** |
| 499 | * Performs a scroll up action. |
| 500 | * Scrolls up by the specified number of lines. |
| 501 | * |
| 502 | * @param widget The text view. |
| 503 | * @param buffer The text buffer. |
| 504 | * @param amount The number of lines to scroll by. Must be at least 1. |
| 505 | * @return True if the event was handled. |
| 506 | * @hide |
| 507 | */ |
| 508 | protected boolean scrollUp(TextView widget, Spannable buffer, int amount) { |
| 509 | final Layout layout = widget.getLayout(); |
| 510 | final int top = widget.getScrollY(); |
| 511 | int topLine = layout.getLineForVertical(top); |
| 512 | if (layout.getLineTop(topLine) == top) { |
| 513 | // If the top line is partially visible, bring it all the way |
| 514 | // into view; otherwise, bring the previous line into view. |
| 515 | topLine -= 1; |
| 516 | } |
| 517 | if (topLine >= 0) { |
| 518 | topLine = Math.max(topLine - amount + 1, 0); |
| 519 | Touch.scrollTo(widget, layout, widget.getScrollX(), layout.getLineTop(topLine)); |
| 520 | return true; |
| 521 | } |
| 522 | return false; |
| 523 | } |
| 524 | |
| 525 | /** |
| 526 | * Performs a scroll down action. |
| 527 | * Scrolls down by the specified number of lines. |
| 528 | * |
| 529 | * @param widget The text view. |
| 530 | * @param buffer The text buffer. |
| 531 | * @param amount The number of lines to scroll by. Must be at least 1. |
| 532 | * @return True if the event was handled. |
| 533 | * @hide |
| 534 | */ |
| 535 | protected boolean scrollDown(TextView widget, Spannable buffer, int amount) { |
| 536 | final Layout layout = widget.getLayout(); |
| 537 | final int innerHeight = getInnerHeight(widget); |
| 538 | final int bottom = widget.getScrollY() + innerHeight; |
| 539 | int bottomLine = layout.getLineForVertical(bottom); |
| 540 | if (layout.getLineTop(bottomLine + 1) < bottom + 1) { |
| 541 | // Less than a pixel of this line is out of view, |
| 542 | // so we must have tried to make it entirely in view |
| 543 | // and now want the next line to be in view instead. |
| 544 | bottomLine += 1; |
| 545 | } |
| 546 | final int limit = layout.getLineCount() - 1; |
| 547 | if (bottomLine <= limit) { |
| 548 | bottomLine = Math.min(bottomLine + amount - 1, limit); |
| 549 | Touch.scrollTo(widget, layout, widget.getScrollX(), |
| 550 | layout.getLineTop(bottomLine + 1) - innerHeight); |
| 551 | return true; |
| 552 | } |
| 553 | return false; |
| 554 | } |
| 555 | |
| 556 | /** |
| 557 | * Performs a scroll page up action. |
| 558 | * Scrolls up by one page. |
| 559 | * |
| 560 | * @param widget The text view. |
| 561 | * @param buffer The text buffer. |
| 562 | * @return True if the event was handled. |
| 563 | * @hide |
| 564 | */ |
| 565 | protected boolean scrollPageUp(TextView widget, Spannable buffer) { |
| 566 | final Layout layout = widget.getLayout(); |
| 567 | final int top = widget.getScrollY() - getInnerHeight(widget); |
| 568 | int topLine = layout.getLineForVertical(top); |
| 569 | if (topLine >= 0) { |
| 570 | Touch.scrollTo(widget, layout, widget.getScrollX(), layout.getLineTop(topLine)); |
| 571 | return true; |
| 572 | } |
| 573 | return false; |
| 574 | } |
| 575 | |
| 576 | /** |
| 577 | * Performs a scroll page up action. |
| 578 | * Scrolls down by one page. |
| 579 | * |
| 580 | * @param widget The text view. |
| 581 | * @param buffer The text buffer. |
| 582 | * @return True if the event was handled. |
| 583 | * @hide |
| 584 | */ |
| 585 | protected boolean scrollPageDown(TextView widget, Spannable buffer) { |
| 586 | final Layout layout = widget.getLayout(); |
| 587 | final int innerHeight = getInnerHeight(widget); |
| 588 | final int bottom = widget.getScrollY() + innerHeight + innerHeight; |
| 589 | int bottomLine = layout.getLineForVertical(bottom); |
| 590 | if (bottomLine <= layout.getLineCount() - 1) { |
| 591 | Touch.scrollTo(widget, layout, widget.getScrollX(), |
| 592 | layout.getLineTop(bottomLine + 1) - innerHeight); |
| 593 | return true; |
| 594 | } |
| 595 | return false; |
| 596 | } |
| 597 | |
| 598 | /** |
| 599 | * Performs a scroll to top action. |
| 600 | * Scrolls to the top of the document. |
| 601 | * |
| 602 | * @param widget The text view. |
| 603 | * @param buffer The text buffer. |
| 604 | * @return True if the event was handled. |
| 605 | * @hide |
| 606 | */ |
| 607 | protected boolean scrollTop(TextView widget, Spannable buffer) { |
| 608 | final Layout layout = widget.getLayout(); |
| 609 | if (getTopLine(widget) >= 0) { |
| 610 | Touch.scrollTo(widget, layout, widget.getScrollX(), layout.getLineTop(0)); |
| 611 | return true; |
| 612 | } |
| 613 | return false; |
| 614 | } |
| 615 | |
| 616 | /** |
| 617 | * Performs a scroll to bottom action. |
| 618 | * Scrolls to the bottom of the document. |
| 619 | * |
| 620 | * @param widget The text view. |
| 621 | * @param buffer The text buffer. |
| 622 | * @return True if the event was handled. |
| 623 | * @hide |
| 624 | */ |
| 625 | protected boolean scrollBottom(TextView widget, Spannable buffer) { |
| 626 | final Layout layout = widget.getLayout(); |
| 627 | final int lineCount = layout.getLineCount(); |
| 628 | if (getBottomLine(widget) <= lineCount - 1) { |
| 629 | Touch.scrollTo(widget, layout, widget.getScrollX(), |
| 630 | layout.getLineTop(lineCount) - getInnerHeight(widget)); |
| 631 | return true; |
| 632 | } |
| 633 | return false; |
| 634 | } |
| 635 | |
| 636 | /** |
| 637 | * Performs a scroll to line start action. |
| 638 | * Scrolls to the start of the line. |
| 639 | * |
| 640 | * @param widget The text view. |
| 641 | * @param buffer The text buffer. |
| 642 | * @return True if the event was handled. |
| 643 | * @hide |
| 644 | */ |
| 645 | protected boolean scrollLineStart(TextView widget, Spannable buffer) { |
| 646 | final int minScrollX = getScrollBoundsLeft(widget); |
| 647 | int scrollX = widget.getScrollX(); |
| 648 | if (scrollX > minScrollX) { |
| 649 | widget.scrollTo(minScrollX, widget.getScrollY()); |
| 650 | return true; |
| 651 | } |
| 652 | return false; |
| 653 | } |
| 654 | |
| 655 | /** |
| 656 | * Performs a scroll to line end action. |
| 657 | * Scrolls to the end of the line. |
| 658 | * |
| 659 | * @param widget The text view. |
| 660 | * @param buffer The text buffer. |
| 661 | * @return True if the event was handled. |
| 662 | * @hide |
| 663 | */ |
| 664 | protected boolean scrollLineEnd(TextView widget, Spannable buffer) { |
| 665 | final int maxScrollX = getScrollBoundsRight(widget) - getInnerWidth(widget); |
| 666 | int scrollX = widget.getScrollX(); |
| 667 | if (scrollX < maxScrollX) { |
| 668 | widget.scrollTo(maxScrollX, widget.getScrollY()); |
| 669 | return true; |
| 670 | } |
| 671 | return false; |
| 672 | } |
Jeff Brown | 67b6ab7 | 2010-12-17 18:33:02 -0800 | [diff] [blame] | 673 | } |