The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2007 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.view; |
| 18 | |
| 19 | import android.graphics.Rect; |
| 20 | |
| 21 | import java.util.ArrayList; |
Jeff Brown | 4e6319b | 2010-12-13 10:36:51 -0800 | [diff] [blame] | 22 | import java.util.Collections; |
| 23 | import java.util.Comparator; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 24 | |
| 25 | /** |
| 26 | * The algorithm used for finding the next focusable view in a given direction |
| 27 | * from a view that currently has focus. |
| 28 | */ |
| 29 | public class FocusFinder { |
| 30 | |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 31 | private static final ThreadLocal<FocusFinder> tlFocusFinder = |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 32 | new ThreadLocal<FocusFinder>() { |
Svetoslav Ganov | 4213804 | 2012-03-20 11:51:39 -0700 | [diff] [blame] | 33 | @Override |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 34 | protected FocusFinder initialValue() { |
| 35 | return new FocusFinder(); |
| 36 | } |
| 37 | }; |
| 38 | |
| 39 | /** |
| 40 | * Get the focus finder for this thread. |
| 41 | */ |
| 42 | public static FocusFinder getInstance() { |
| 43 | return tlFocusFinder.get(); |
| 44 | } |
| 45 | |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 46 | final Rect mFocusedRect = new Rect(); |
| 47 | final Rect mOtherRect = new Rect(); |
| 48 | final Rect mBestCandidateRect = new Rect(); |
| 49 | final SequentialFocusComparator mSequentialFocusComparator = new SequentialFocusComparator(); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 50 | |
Svetoslav Ganov | 4213804 | 2012-03-20 11:51:39 -0700 | [diff] [blame] | 51 | private final ArrayList<View> mTempList = new ArrayList<View>(); |
| 52 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 53 | // enforce thread local access |
| 54 | private FocusFinder() {} |
| 55 | |
| 56 | /** |
| 57 | * Find the next view to take focus in root's descendants, starting from the view |
| 58 | * that currently is focused. |
Fabrice Di Meglio | 7e0a372 | 2012-03-27 16:06:25 -0700 | [diff] [blame] | 59 | * @param root Contains focused. Cannot be null. |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 60 | * @param focused Has focus now. |
| 61 | * @param direction Direction to look. |
| 62 | * @return The next focusable view, or null if none exists. |
| 63 | */ |
| 64 | public final View findNextFocus(ViewGroup root, View focused, int direction) { |
Svetoslav Ganov | 951bb42 | 2012-04-30 13:15:21 -0700 | [diff] [blame] | 65 | return findNextFocus(root, focused, null, direction); |
Svetoslav Ganov | 4213804 | 2012-03-20 11:51:39 -0700 | [diff] [blame] | 66 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 67 | |
Svetoslav Ganov | 4213804 | 2012-03-20 11:51:39 -0700 | [diff] [blame] | 68 | /** |
| 69 | * Find the next view to take focus in root's descendants, searching from |
| 70 | * a particular rectangle in root's coordinates. |
| 71 | * @param root Contains focusedRect. Cannot be null. |
| 72 | * @param focusedRect The starting point of the search. |
| 73 | * @param direction Direction to look. |
| 74 | * @return The next focusable view, or null if none exists. |
| 75 | */ |
| 76 | public View findNextFocusFromRect(ViewGroup root, Rect focusedRect, int direction) { |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 77 | mFocusedRect.set(focusedRect); |
| 78 | return findNextFocus(root, null, mFocusedRect, direction); |
Svetoslav Ganov | 4213804 | 2012-03-20 11:51:39 -0700 | [diff] [blame] | 79 | } |
| 80 | |
| 81 | private View findNextFocus(ViewGroup root, View focused, Rect focusedRect, int direction) { |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 82 | View next = null; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 83 | if (focused != null) { |
Svetoslav Ganov | 27e2da7 | 2012-07-02 18:12:00 -0700 | [diff] [blame] | 84 | next = findNextUserSpecifiedFocus(root, focused, direction); |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 85 | } |
| 86 | if (next != null) { |
| 87 | return next; |
| 88 | } |
| 89 | ArrayList<View> focusables = mTempList; |
| 90 | try { |
| 91 | focusables.clear(); |
| 92 | root.addFocusables(focusables, direction); |
| 93 | if (!focusables.isEmpty()) { |
| 94 | next = findNextFocus(root, focused, focusedRect, direction, focusables); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 95 | } |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 96 | } finally { |
| 97 | focusables.clear(); |
| 98 | } |
| 99 | return next; |
| 100 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 101 | |
Svetoslav Ganov | 27e2da7 | 2012-07-02 18:12:00 -0700 | [diff] [blame] | 102 | private View findNextUserSpecifiedFocus(ViewGroup root, View focused, int direction) { |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 103 | // check for user specified next focus |
| 104 | View userSetNextFocus = focused.findUserSetNextFocus(root, direction); |
| 105 | if (userSetNextFocus != null && userSetNextFocus.isFocusable() |
| 106 | && (!userSetNextFocus.isInTouchMode() |
| 107 | || userSetNextFocus.isFocusableInTouchMode())) { |
| 108 | return userSetNextFocus; |
| 109 | } |
| 110 | return null; |
| 111 | } |
| 112 | |
| 113 | private View findNextFocus(ViewGroup root, View focused, Rect focusedRect, |
| 114 | int direction, ArrayList<View> focusables) { |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 115 | if (focused != null) { |
Svetoslav Ganov | 951bb42 | 2012-04-30 13:15:21 -0700 | [diff] [blame] | 116 | if (focusedRect == null) { |
| 117 | focusedRect = mFocusedRect; |
| 118 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 119 | // fill in interesting rect from focused |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 120 | focused.getFocusedRect(focusedRect); |
| 121 | root.offsetDescendantRectToMyCoords(focused, focusedRect); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 122 | } else { |
Svetoslav Ganov | 951bb42 | 2012-04-30 13:15:21 -0700 | [diff] [blame] | 123 | if (focusedRect == null) { |
| 124 | focusedRect = mFocusedRect; |
| 125 | // make up a rect at top left or bottom right of root |
Svetoslav Ganov | 27e2da7 | 2012-07-02 18:12:00 -0700 | [diff] [blame] | 126 | switch (direction) { |
Svetoslav Ganov | 951bb42 | 2012-04-30 13:15:21 -0700 | [diff] [blame] | 127 | case View.FOCUS_RIGHT: |
| 128 | case View.FOCUS_DOWN: |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 129 | setFocusTopLeft(root, focusedRect); |
Svetoslav Ganov | 951bb42 | 2012-04-30 13:15:21 -0700 | [diff] [blame] | 130 | break; |
| 131 | case View.FOCUS_FORWARD: |
| 132 | if (root.isLayoutRtl()) { |
| 133 | setFocusBottomRight(root, focusedRect); |
| 134 | } else { |
| 135 | setFocusTopLeft(root, focusedRect); |
| 136 | } |
| 137 | break; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 138 | |
Svetoslav Ganov | 951bb42 | 2012-04-30 13:15:21 -0700 | [diff] [blame] | 139 | case View.FOCUS_LEFT: |
| 140 | case View.FOCUS_UP: |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 141 | setFocusBottomRight(root, focusedRect); |
Svetoslav Ganov | 951bb42 | 2012-04-30 13:15:21 -0700 | [diff] [blame] | 142 | break; |
| 143 | case View.FOCUS_BACKWARD: |
| 144 | if (root.isLayoutRtl()) { |
| 145 | setFocusTopLeft(root, focusedRect); |
| 146 | } else { |
| 147 | setFocusBottomRight(root, focusedRect); |
| 148 | break; |
| 149 | } |
Fabrice Di Meglio | 702e8f9 | 2012-03-23 18:09:20 -0700 | [diff] [blame] | 150 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 151 | } |
| 152 | } |
Svetoslav Ganov | 4213804 | 2012-03-20 11:51:39 -0700 | [diff] [blame] | 153 | |
Svetoslav Ganov | 27e2da7 | 2012-07-02 18:12:00 -0700 | [diff] [blame] | 154 | switch (direction) { |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 155 | case View.FOCUS_FORWARD: |
| 156 | case View.FOCUS_BACKWARD: |
Svetoslav Ganov | 27e2da7 | 2012-07-02 18:12:00 -0700 | [diff] [blame] | 157 | return findNextFocusInRelativeDirection(focusables, root, focused, focusedRect, |
| 158 | direction); |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 159 | case View.FOCUS_UP: |
| 160 | case View.FOCUS_DOWN: |
| 161 | case View.FOCUS_LEFT: |
| 162 | case View.FOCUS_RIGHT: |
Svetoslav Ganov | 27e2da7 | 2012-07-02 18:12:00 -0700 | [diff] [blame] | 163 | return findNextFocusInAbsoluteDirection(focusables, root, focused, |
| 164 | focusedRect, direction); |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 165 | default: |
Svetoslav Ganov | 27e2da7 | 2012-07-02 18:12:00 -0700 | [diff] [blame] | 166 | throw new IllegalArgumentException("Unknown direction: " + direction); |
Svetoslav Ganov | 4213804 | 2012-03-20 11:51:39 -0700 | [diff] [blame] | 167 | } |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 168 | } |
Svetoslav Ganov | 4213804 | 2012-03-20 11:51:39 -0700 | [diff] [blame] | 169 | |
Svetoslav Ganov | 27e2da7 | 2012-07-02 18:12:00 -0700 | [diff] [blame] | 170 | private View findNextFocusInRelativeDirection(ArrayList<View> focusables, ViewGroup root, |
Svetoslav Ganov | 4213804 | 2012-03-20 11:51:39 -0700 | [diff] [blame] | 171 | View focused, Rect focusedRect, int direction) { |
| 172 | try { |
| 173 | // Note: This sort is stable. |
| 174 | mSequentialFocusComparator.setRoot(root); |
| 175 | Collections.sort(focusables, mSequentialFocusComparator); |
| 176 | } finally { |
| 177 | mSequentialFocusComparator.recycle(); |
| 178 | } |
| 179 | |
| 180 | final int count = focusables.size(); |
| 181 | switch (direction) { |
| 182 | case View.FOCUS_FORWARD: |
| 183 | return getForwardFocusable(root, focused, focusables, count); |
| 184 | case View.FOCUS_BACKWARD: |
| 185 | return getBackwardFocusable(root, focused, focusables, count); |
| 186 | } |
| 187 | return focusables.get(count - 1); |
| 188 | } |
| 189 | |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 190 | private void setFocusBottomRight(ViewGroup root, Rect focusedRect) { |
Fabrice Di Meglio | 702e8f9 | 2012-03-23 18:09:20 -0700 | [diff] [blame] | 191 | final int rootBottom = root.getScrollY() + root.getHeight(); |
| 192 | final int rootRight = root.getScrollX() + root.getWidth(); |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 193 | focusedRect.set(rootRight, rootBottom, rootRight, rootBottom); |
Fabrice Di Meglio | 702e8f9 | 2012-03-23 18:09:20 -0700 | [diff] [blame] | 194 | } |
| 195 | |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 196 | private void setFocusTopLeft(ViewGroup root, Rect focusedRect) { |
Fabrice Di Meglio | 702e8f9 | 2012-03-23 18:09:20 -0700 | [diff] [blame] | 197 | final int rootTop = root.getScrollY(); |
| 198 | final int rootLeft = root.getScrollX(); |
Svetoslav Ganov | 76f287e | 2012-04-23 11:02:36 -0700 | [diff] [blame] | 199 | focusedRect.set(rootLeft, rootTop, rootLeft, rootTop); |
Fabrice Di Meglio | 702e8f9 | 2012-03-23 18:09:20 -0700 | [diff] [blame] | 200 | } |
| 201 | |
Svetoslav Ganov | 27e2da7 | 2012-07-02 18:12:00 -0700 | [diff] [blame] | 202 | View findNextFocusInAbsoluteDirection(ArrayList<View> focusables, ViewGroup root, View focused, |
Svetoslav Ganov | 4213804 | 2012-03-20 11:51:39 -0700 | [diff] [blame] | 203 | Rect focusedRect, int direction) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 204 | // initialize the best candidate to something impossible |
| 205 | // (so the first plausible view will become the best choice) |
| 206 | mBestCandidateRect.set(focusedRect); |
| 207 | switch(direction) { |
| 208 | case View.FOCUS_LEFT: |
| 209 | mBestCandidateRect.offset(focusedRect.width() + 1, 0); |
| 210 | break; |
| 211 | case View.FOCUS_RIGHT: |
| 212 | mBestCandidateRect.offset(-(focusedRect.width() + 1), 0); |
| 213 | break; |
| 214 | case View.FOCUS_UP: |
| 215 | mBestCandidateRect.offset(0, focusedRect.height() + 1); |
| 216 | break; |
| 217 | case View.FOCUS_DOWN: |
| 218 | mBestCandidateRect.offset(0, -(focusedRect.height() + 1)); |
| 219 | } |
| 220 | |
| 221 | View closest = null; |
| 222 | |
| 223 | int numFocusables = focusables.size(); |
| 224 | for (int i = 0; i < numFocusables; i++) { |
| 225 | View focusable = focusables.get(i); |
| 226 | |
| 227 | // only interested in other non-root views |
| 228 | if (focusable == focused || focusable == root) continue; |
| 229 | |
Tobias Dubois | defdb1e | 2010-12-15 11:35:30 +0100 | [diff] [blame] | 230 | // get focus bounds of other view in same coordinate system |
Fabrice Di Meglio | c11f77f | 2012-09-18 15:33:07 -0700 | [diff] [blame] | 231 | focusable.getFocusedRect(mOtherRect); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 232 | root.offsetDescendantRectToMyCoords(focusable, mOtherRect); |
| 233 | |
| 234 | if (isBetterCandidate(direction, focusedRect, mOtherRect, mBestCandidateRect)) { |
| 235 | mBestCandidateRect.set(mOtherRect); |
| 236 | closest = focusable; |
| 237 | } |
| 238 | } |
| 239 | return closest; |
| 240 | } |
| 241 | |
Fabrice Di Meglio | 7e0a372 | 2012-03-27 16:06:25 -0700 | [diff] [blame] | 242 | private static View getForwardFocusable(ViewGroup root, View focused, |
| 243 | ArrayList<View> focusables, int count) { |
| 244 | return (root.isLayoutRtl()) ? |
Fabrice Di Meglio | 702e8f9 | 2012-03-23 18:09:20 -0700 | [diff] [blame] | 245 | getPreviousFocusable(focused, focusables, count) : |
| 246 | getNextFocusable(focused, focusables, count); |
| 247 | } |
| 248 | |
Fabrice Di Meglio | 7e0a372 | 2012-03-27 16:06:25 -0700 | [diff] [blame] | 249 | private static View getNextFocusable(View focused, ArrayList<View> focusables, int count) { |
Fabrice Di Meglio | 702e8f9 | 2012-03-23 18:09:20 -0700 | [diff] [blame] | 250 | if (focused != null) { |
| 251 | int position = focusables.lastIndexOf(focused); |
| 252 | if (position >= 0 && position + 1 < count) { |
| 253 | return focusables.get(position + 1); |
| 254 | } |
| 255 | } |
Svetoslav Ganov | e5dfa47d | 2012-05-08 15:58:32 -0700 | [diff] [blame] | 256 | if (!focusables.isEmpty()) { |
| 257 | return focusables.get(0); |
| 258 | } |
| 259 | return null; |
Fabrice Di Meglio | 702e8f9 | 2012-03-23 18:09:20 -0700 | [diff] [blame] | 260 | } |
| 261 | |
Fabrice Di Meglio | 7e0a372 | 2012-03-27 16:06:25 -0700 | [diff] [blame] | 262 | private static View getBackwardFocusable(ViewGroup root, View focused, |
| 263 | ArrayList<View> focusables, int count) { |
| 264 | return (root.isLayoutRtl()) ? |
Fabrice Di Meglio | 702e8f9 | 2012-03-23 18:09:20 -0700 | [diff] [blame] | 265 | getNextFocusable(focused, focusables, count) : |
| 266 | getPreviousFocusable(focused, focusables, count); |
| 267 | } |
| 268 | |
Fabrice Di Meglio | 7e0a372 | 2012-03-27 16:06:25 -0700 | [diff] [blame] | 269 | private static View getPreviousFocusable(View focused, ArrayList<View> focusables, int count) { |
Fabrice Di Meglio | 702e8f9 | 2012-03-23 18:09:20 -0700 | [diff] [blame] | 270 | if (focused != null) { |
| 271 | int position = focusables.indexOf(focused); |
| 272 | if (position > 0) { |
| 273 | return focusables.get(position - 1); |
| 274 | } |
| 275 | } |
Svetoslav Ganov | e5dfa47d | 2012-05-08 15:58:32 -0700 | [diff] [blame] | 276 | if (!focusables.isEmpty()) { |
| 277 | return focusables.get(count - 1); |
| 278 | } |
| 279 | return null; |
Fabrice Di Meglio | 702e8f9 | 2012-03-23 18:09:20 -0700 | [diff] [blame] | 280 | } |
| 281 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 282 | /** |
| 283 | * Is rect1 a better candidate than rect2 for a focus search in a particular |
| 284 | * direction from a source rect? This is the core routine that determines |
| 285 | * the order of focus searching. |
| 286 | * @param direction the direction (up, down, left, right) |
| 287 | * @param source The source we are searching from |
| 288 | * @param rect1 The candidate rectangle |
| 289 | * @param rect2 The current best candidate. |
| 290 | * @return Whether the candidate is the new best. |
| 291 | */ |
| 292 | boolean isBetterCandidate(int direction, Rect source, Rect rect1, Rect rect2) { |
| 293 | |
| 294 | // to be a better candidate, need to at least be a candidate in the first |
| 295 | // place :) |
| 296 | if (!isCandidate(source, rect1, direction)) { |
| 297 | return false; |
| 298 | } |
| 299 | |
| 300 | // we know that rect1 is a candidate.. if rect2 is not a candidate, |
| 301 | // rect1 is better |
| 302 | if (!isCandidate(source, rect2, direction)) { |
| 303 | return true; |
| 304 | } |
| 305 | |
| 306 | // if rect1 is better by beam, it wins |
| 307 | if (beamBeats(direction, source, rect1, rect2)) { |
| 308 | return true; |
| 309 | } |
| 310 | |
| 311 | // if rect2 is better, then rect1 cant' be :) |
| 312 | if (beamBeats(direction, source, rect2, rect1)) { |
| 313 | return false; |
| 314 | } |
| 315 | |
| 316 | // otherwise, do fudge-tastic comparison of the major and minor axis |
| 317 | return (getWeightedDistanceFor( |
| 318 | majorAxisDistance(direction, source, rect1), |
| 319 | minorAxisDistance(direction, source, rect1)) |
| 320 | < getWeightedDistanceFor( |
| 321 | majorAxisDistance(direction, source, rect2), |
| 322 | minorAxisDistance(direction, source, rect2))); |
| 323 | } |
| 324 | |
| 325 | /** |
| 326 | * One rectangle may be another candidate than another by virtue of being |
| 327 | * exclusively in the beam of the source rect. |
| 328 | * @return Whether rect1 is a better candidate than rect2 by virtue of it being in src's |
| 329 | * beam |
| 330 | */ |
| 331 | boolean beamBeats(int direction, Rect source, Rect rect1, Rect rect2) { |
| 332 | final boolean rect1InSrcBeam = beamsOverlap(direction, source, rect1); |
| 333 | final boolean rect2InSrcBeam = beamsOverlap(direction, source, rect2); |
| 334 | |
| 335 | // if rect1 isn't exclusively in the src beam, it doesn't win |
| 336 | if (rect2InSrcBeam || !rect1InSrcBeam) { |
| 337 | return false; |
| 338 | } |
| 339 | |
| 340 | // we know rect1 is in the beam, and rect2 is not |
| 341 | |
| 342 | // if rect1 is to the direction of, and rect2 is not, rect1 wins. |
| 343 | // for example, for direction left, if rect1 is to the left of the source |
| 344 | // and rect2 is below, then we always prefer the in beam rect1, since rect2 |
| 345 | // could be reached by going down. |
| 346 | if (!isToDirectionOf(direction, source, rect2)) { |
| 347 | return true; |
| 348 | } |
| 349 | |
| 350 | // for horizontal directions, being exclusively in beam always wins |
| 351 | if ((direction == View.FOCUS_LEFT || direction == View.FOCUS_RIGHT)) { |
| 352 | return true; |
| 353 | } |
| 354 | |
| 355 | // for vertical directions, beams only beat up to a point: |
| 356 | // now, as long as rect2 isn't completely closer, rect1 wins |
| 357 | // e.g for direction down, completely closer means for rect2's top |
| 358 | // edge to be closer to the source's top edge than rect1's bottom edge. |
| 359 | return (majorAxisDistance(direction, source, rect1) |
| 360 | < majorAxisDistanceToFarEdge(direction, source, rect2)); |
| 361 | } |
| 362 | |
| 363 | /** |
| 364 | * Fudge-factor opportunity: how to calculate distance given major and minor |
| 365 | * axis distances. Warning: this fudge factor is finely tuned, be sure to |
| 366 | * run all focus tests if you dare tweak it. |
| 367 | */ |
| 368 | int getWeightedDistanceFor(int majorAxisDistance, int minorAxisDistance) { |
| 369 | return 13 * majorAxisDistance * majorAxisDistance |
| 370 | + minorAxisDistance * minorAxisDistance; |
| 371 | } |
| 372 | |
| 373 | /** |
| 374 | * Is destRect a candidate for the next focus given the direction? This |
| 375 | * checks whether the dest is at least partially to the direction of (e.g left of) |
| 376 | * from source. |
| 377 | * |
| 378 | * Includes an edge case for an empty rect (which is used in some cases when |
| 379 | * searching from a point on the screen). |
| 380 | */ |
| 381 | boolean isCandidate(Rect srcRect, Rect destRect, int direction) { |
| 382 | switch (direction) { |
| 383 | case View.FOCUS_LEFT: |
| 384 | return (srcRect.right > destRect.right || srcRect.left >= destRect.right) |
| 385 | && srcRect.left > destRect.left; |
| 386 | case View.FOCUS_RIGHT: |
| 387 | return (srcRect.left < destRect.left || srcRect.right <= destRect.left) |
| 388 | && srcRect.right < destRect.right; |
| 389 | case View.FOCUS_UP: |
| 390 | return (srcRect.bottom > destRect.bottom || srcRect.top >= destRect.bottom) |
| 391 | && srcRect.top > destRect.top; |
| 392 | case View.FOCUS_DOWN: |
| 393 | return (srcRect.top < destRect.top || srcRect.bottom <= destRect.top) |
| 394 | && srcRect.bottom < destRect.bottom; |
| 395 | } |
| 396 | throw new IllegalArgumentException("direction must be one of " |
| 397 | + "{FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, FOCUS_RIGHT}."); |
| 398 | } |
| 399 | |
| 400 | |
| 401 | /** |
Fabrice Di Meglio | 7e0a372 | 2012-03-27 16:06:25 -0700 | [diff] [blame] | 402 | * Do the "beams" w.r.t the given direction's axis of rect1 and rect2 overlap? |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 403 | * @param direction the direction (up, down, left, right) |
| 404 | * @param rect1 The first rectangle |
| 405 | * @param rect2 The second rectangle |
| 406 | * @return whether the beams overlap |
| 407 | */ |
| 408 | boolean beamsOverlap(int direction, Rect rect1, Rect rect2) { |
| 409 | switch (direction) { |
| 410 | case View.FOCUS_LEFT: |
| 411 | case View.FOCUS_RIGHT: |
| 412 | return (rect2.bottom >= rect1.top) && (rect2.top <= rect1.bottom); |
| 413 | case View.FOCUS_UP: |
| 414 | case View.FOCUS_DOWN: |
| 415 | return (rect2.right >= rect1.left) && (rect2.left <= rect1.right); |
| 416 | } |
| 417 | throw new IllegalArgumentException("direction must be one of " |
| 418 | + "{FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, FOCUS_RIGHT}."); |
| 419 | } |
| 420 | |
| 421 | /** |
| 422 | * e.g for left, is 'to left of' |
| 423 | */ |
| 424 | boolean isToDirectionOf(int direction, Rect src, Rect dest) { |
| 425 | switch (direction) { |
| 426 | case View.FOCUS_LEFT: |
| 427 | return src.left >= dest.right; |
| 428 | case View.FOCUS_RIGHT: |
| 429 | return src.right <= dest.left; |
| 430 | case View.FOCUS_UP: |
| 431 | return src.top >= dest.bottom; |
| 432 | case View.FOCUS_DOWN: |
| 433 | return src.bottom <= dest.top; |
| 434 | } |
| 435 | throw new IllegalArgumentException("direction must be one of " |
| 436 | + "{FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, FOCUS_RIGHT}."); |
| 437 | } |
| 438 | |
| 439 | /** |
| 440 | * @return The distance from the edge furthest in the given direction |
| 441 | * of source to the edge nearest in the given direction of dest. If the |
| 442 | * dest is not in the direction from source, return 0. |
| 443 | */ |
| 444 | static int majorAxisDistance(int direction, Rect source, Rect dest) { |
| 445 | return Math.max(0, majorAxisDistanceRaw(direction, source, dest)); |
| 446 | } |
| 447 | |
| 448 | static int majorAxisDistanceRaw(int direction, Rect source, Rect dest) { |
| 449 | switch (direction) { |
| 450 | case View.FOCUS_LEFT: |
| 451 | return source.left - dest.right; |
| 452 | case View.FOCUS_RIGHT: |
| 453 | return dest.left - source.right; |
| 454 | case View.FOCUS_UP: |
| 455 | return source.top - dest.bottom; |
| 456 | case View.FOCUS_DOWN: |
| 457 | return dest.top - source.bottom; |
| 458 | } |
| 459 | throw new IllegalArgumentException("direction must be one of " |
| 460 | + "{FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, FOCUS_RIGHT}."); |
| 461 | } |
| 462 | |
| 463 | /** |
| 464 | * @return The distance along the major axis w.r.t the direction from the |
| 465 | * edge of source to the far edge of dest. If the |
| 466 | * dest is not in the direction from source, return 1 (to break ties with |
| 467 | * {@link #majorAxisDistance}). |
| 468 | */ |
| 469 | static int majorAxisDistanceToFarEdge(int direction, Rect source, Rect dest) { |
| 470 | return Math.max(1, majorAxisDistanceToFarEdgeRaw(direction, source, dest)); |
| 471 | } |
| 472 | |
| 473 | static int majorAxisDistanceToFarEdgeRaw(int direction, Rect source, Rect dest) { |
| 474 | switch (direction) { |
| 475 | case View.FOCUS_LEFT: |
| 476 | return source.left - dest.left; |
| 477 | case View.FOCUS_RIGHT: |
| 478 | return dest.right - source.right; |
| 479 | case View.FOCUS_UP: |
| 480 | return source.top - dest.top; |
| 481 | case View.FOCUS_DOWN: |
| 482 | return dest.bottom - source.bottom; |
| 483 | } |
| 484 | throw new IllegalArgumentException("direction must be one of " |
| 485 | + "{FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, FOCUS_RIGHT}."); |
| 486 | } |
| 487 | |
| 488 | /** |
| 489 | * Find the distance on the minor axis w.r.t the direction to the nearest |
Fabrice Di Meglio | 7e0a372 | 2012-03-27 16:06:25 -0700 | [diff] [blame] | 490 | * edge of the destination rectangle. |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 491 | * @param direction the direction (up, down, left, right) |
| 492 | * @param source The source rect. |
| 493 | * @param dest The destination rect. |
| 494 | * @return The distance. |
| 495 | */ |
| 496 | static int minorAxisDistance(int direction, Rect source, Rect dest) { |
| 497 | switch (direction) { |
| 498 | case View.FOCUS_LEFT: |
| 499 | case View.FOCUS_RIGHT: |
| 500 | // the distance between the center verticals |
| 501 | return Math.abs( |
| 502 | ((source.top + source.height() / 2) - |
| 503 | ((dest.top + dest.height() / 2)))); |
| 504 | case View.FOCUS_UP: |
| 505 | case View.FOCUS_DOWN: |
| 506 | // the distance between the center horizontals |
| 507 | return Math.abs( |
| 508 | ((source.left + source.width() / 2) - |
| 509 | ((dest.left + dest.width() / 2)))); |
| 510 | } |
| 511 | throw new IllegalArgumentException("direction must be one of " |
| 512 | + "{FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, FOCUS_RIGHT}."); |
| 513 | } |
| 514 | |
| 515 | /** |
| 516 | * Find the nearest touchable view to the specified view. |
| 517 | * |
| 518 | * @param root The root of the tree in which to search |
| 519 | * @param x X coordinate from which to start the search |
| 520 | * @param y Y coordinate from which to start the search |
| 521 | * @param direction Direction to look |
| 522 | * @param deltas Offset from the <x, y> to the edge of the nearest view. Note that this array |
| 523 | * may already be populated with values. |
| 524 | * @return The nearest touchable view, or null if none exists. |
| 525 | */ |
| 526 | public View findNearestTouchable(ViewGroup root, int x, int y, int direction, int[] deltas) { |
| 527 | ArrayList<View> touchables = root.getTouchables(); |
| 528 | int minDistance = Integer.MAX_VALUE; |
| 529 | View closest = null; |
| 530 | |
| 531 | int numTouchables = touchables.size(); |
| 532 | |
| 533 | int edgeSlop = ViewConfiguration.get(root.mContext).getScaledEdgeSlop(); |
| 534 | |
| 535 | Rect closestBounds = new Rect(); |
| 536 | Rect touchableBounds = mOtherRect; |
| 537 | |
| 538 | for (int i = 0; i < numTouchables; i++) { |
| 539 | View touchable = touchables.get(i); |
| 540 | |
| 541 | // get visible bounds of other view in same coordinate system |
| 542 | touchable.getDrawingRect(touchableBounds); |
| 543 | |
| 544 | root.offsetRectBetweenParentAndChild(touchable, touchableBounds, true, true); |
| 545 | |
| 546 | if (!isTouchCandidate(x, y, touchableBounds, direction)) { |
| 547 | continue; |
| 548 | } |
| 549 | |
| 550 | int distance = Integer.MAX_VALUE; |
| 551 | |
| 552 | switch (direction) { |
| 553 | case View.FOCUS_LEFT: |
| 554 | distance = x - touchableBounds.right + 1; |
| 555 | break; |
| 556 | case View.FOCUS_RIGHT: |
| 557 | distance = touchableBounds.left; |
| 558 | break; |
| 559 | case View.FOCUS_UP: |
| 560 | distance = y - touchableBounds.bottom + 1; |
| 561 | break; |
| 562 | case View.FOCUS_DOWN: |
| 563 | distance = touchableBounds.top; |
| 564 | break; |
| 565 | } |
| 566 | |
| 567 | if (distance < edgeSlop) { |
| 568 | // Give preference to innermost views |
| 569 | if (closest == null || |
| 570 | closestBounds.contains(touchableBounds) || |
| 571 | (!touchableBounds.contains(closestBounds) && distance < minDistance)) { |
| 572 | minDistance = distance; |
| 573 | closest = touchable; |
| 574 | closestBounds.set(touchableBounds); |
| 575 | switch (direction) { |
| 576 | case View.FOCUS_LEFT: |
| 577 | deltas[0] = -distance; |
| 578 | break; |
| 579 | case View.FOCUS_RIGHT: |
| 580 | deltas[0] = distance; |
| 581 | break; |
| 582 | case View.FOCUS_UP: |
| 583 | deltas[1] = -distance; |
| 584 | break; |
| 585 | case View.FOCUS_DOWN: |
| 586 | deltas[1] = distance; |
| 587 | break; |
| 588 | } |
| 589 | } |
| 590 | } |
| 591 | } |
| 592 | return closest; |
| 593 | } |
| 594 | |
| 595 | |
| 596 | /** |
| 597 | * Is destRect a candidate for the next touch given the direction? |
| 598 | */ |
| 599 | private boolean isTouchCandidate(int x, int y, Rect destRect, int direction) { |
| 600 | switch (direction) { |
| 601 | case View.FOCUS_LEFT: |
| 602 | return destRect.left <= x && destRect.top <= y && y <= destRect.bottom; |
| 603 | case View.FOCUS_RIGHT: |
| 604 | return destRect.left >= x && destRect.top <= y && y <= destRect.bottom; |
| 605 | case View.FOCUS_UP: |
| 606 | return destRect.top <= y && destRect.left <= x && x <= destRect.right; |
| 607 | case View.FOCUS_DOWN: |
| 608 | return destRect.top >= y && destRect.left <= x && x <= destRect.right; |
| 609 | } |
| 610 | throw new IllegalArgumentException("direction must be one of " |
| 611 | + "{FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, FOCUS_RIGHT}."); |
| 612 | } |
Jeff Brown | 4e6319b | 2010-12-13 10:36:51 -0800 | [diff] [blame] | 613 | |
| 614 | /** |
| 615 | * Sorts views according to their visual layout and geometry for default tab order. |
| 616 | * This is used for sequential focus traversal. |
| 617 | */ |
| 618 | private static final class SequentialFocusComparator implements Comparator<View> { |
| 619 | private final Rect mFirstRect = new Rect(); |
| 620 | private final Rect mSecondRect = new Rect(); |
| 621 | private ViewGroup mRoot; |
| 622 | |
| 623 | public void recycle() { |
| 624 | mRoot = null; |
| 625 | } |
| 626 | |
| 627 | public void setRoot(ViewGroup root) { |
| 628 | mRoot = root; |
| 629 | } |
| 630 | |
| 631 | public int compare(View first, View second) { |
| 632 | if (first == second) { |
| 633 | return 0; |
| 634 | } |
| 635 | |
| 636 | getRect(first, mFirstRect); |
| 637 | getRect(second, mSecondRect); |
| 638 | |
| 639 | if (mFirstRect.top < mSecondRect.top) { |
| 640 | return -1; |
| 641 | } else if (mFirstRect.top > mSecondRect.top) { |
| 642 | return 1; |
| 643 | } else if (mFirstRect.left < mSecondRect.left) { |
| 644 | return -1; |
| 645 | } else if (mFirstRect.left > mSecondRect.left) { |
| 646 | return 1; |
| 647 | } else if (mFirstRect.bottom < mSecondRect.bottom) { |
| 648 | return -1; |
| 649 | } else if (mFirstRect.bottom > mSecondRect.bottom) { |
| 650 | return 1; |
| 651 | } else if (mFirstRect.right < mSecondRect.right) { |
| 652 | return -1; |
| 653 | } else if (mFirstRect.right > mSecondRect.right) { |
| 654 | return 1; |
| 655 | } else { |
| 656 | // The view are distinct but completely coincident so we consider |
| 657 | // them equal for our purposes. Since the sort is stable, this |
| 658 | // means that the views will retain their layout order relative to one another. |
| 659 | return 0; |
| 660 | } |
| 661 | } |
| 662 | |
| 663 | private void getRect(View view, Rect rect) { |
| 664 | view.getDrawingRect(rect); |
| 665 | mRoot.offsetDescendantRectToMyCoords(view, rect); |
| 666 | } |
| 667 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 668 | } |