The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2006 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; |
| 18 | |
| 19 | import android.graphics.Canvas; |
| 20 | import android.graphics.Paint; |
| 21 | import android.graphics.Path; |
Eric Fischer | 86fcef8 | 2009-08-17 17:16:44 -0700 | [diff] [blame] | 22 | import android.text.style.ParagraphStyle; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 23 | import android.util.FloatMath; |
| 24 | |
| 25 | /** |
| 26 | * A BoringLayout is a very simple Layout implementation for text that |
| 27 | * fits on a single line and is all left-to-right characters. |
| 28 | * You will probably never want to make one of these yourself; |
| 29 | * if you do, be sure to call {@link #isBoring} first to make sure |
| 30 | * the text meets the criteria. |
| 31 | * <p>This class is used by widgets to control text layout. You should not need |
| 32 | * to use this class directly unless you are implementing your own widget |
| 33 | * or custom display object, in which case |
| 34 | * you are encouraged to use a Layout instead of calling |
| 35 | * {@link android.graphics.Canvas#drawText(java.lang.CharSequence, int, int, float, float, android.graphics.Paint) |
| 36 | * Canvas.drawText()} directly.</p> |
| 37 | */ |
| 38 | public class BoringLayout extends Layout implements TextUtils.EllipsizeCallback { |
| 39 | public static BoringLayout make(CharSequence source, |
| 40 | TextPaint paint, int outerwidth, |
| 41 | Alignment align, |
| 42 | float spacingmult, float spacingadd, |
| 43 | BoringLayout.Metrics metrics, boolean includepad) { |
| 44 | return new BoringLayout(source, paint, outerwidth, align, |
| 45 | spacingmult, spacingadd, metrics, |
| 46 | includepad); |
| 47 | } |
| 48 | |
| 49 | public static BoringLayout make(CharSequence source, |
| 50 | TextPaint paint, int outerwidth, |
| 51 | Alignment align, |
| 52 | float spacingmult, float spacingadd, |
| 53 | BoringLayout.Metrics metrics, boolean includepad, |
| 54 | TextUtils.TruncateAt ellipsize, int ellipsizedWidth) { |
| 55 | return new BoringLayout(source, paint, outerwidth, align, |
| 56 | spacingmult, spacingadd, metrics, |
| 57 | includepad, ellipsize, ellipsizedWidth); |
| 58 | } |
| 59 | |
| 60 | /** |
| 61 | * Returns a BoringLayout for the specified text, potentially reusing |
| 62 | * this one if it is already suitable. The caller must make sure that |
| 63 | * no one is still using this Layout. |
| 64 | */ |
| 65 | public BoringLayout replaceOrMake(CharSequence source, TextPaint paint, |
| 66 | int outerwidth, Alignment align, |
| 67 | float spacingmult, float spacingadd, |
| 68 | BoringLayout.Metrics metrics, |
| 69 | boolean includepad) { |
| 70 | replaceWith(source, paint, outerwidth, align, spacingmult, |
| 71 | spacingadd); |
| 72 | |
| 73 | mEllipsizedWidth = outerwidth; |
| 74 | mEllipsizedStart = 0; |
| 75 | mEllipsizedCount = 0; |
| 76 | |
| 77 | init(source, paint, outerwidth, align, spacingmult, spacingadd, |
| 78 | metrics, includepad, true); |
| 79 | return this; |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Returns a BoringLayout for the specified text, potentially reusing |
| 84 | * this one if it is already suitable. The caller must make sure that |
| 85 | * no one is still using this Layout. |
| 86 | */ |
| 87 | public BoringLayout replaceOrMake(CharSequence source, TextPaint paint, |
| 88 | int outerwidth, Alignment align, |
| 89 | float spacingmult, float spacingadd, |
| 90 | BoringLayout.Metrics metrics, |
| 91 | boolean includepad, |
| 92 | TextUtils.TruncateAt ellipsize, |
| 93 | int ellipsizedWidth) { |
| 94 | boolean trust; |
| 95 | |
| 96 | if (ellipsize == null || ellipsize == TextUtils.TruncateAt.MARQUEE) { |
| 97 | replaceWith(source, paint, outerwidth, align, spacingmult, |
| 98 | spacingadd); |
| 99 | |
| 100 | mEllipsizedWidth = outerwidth; |
| 101 | mEllipsizedStart = 0; |
| 102 | mEllipsizedCount = 0; |
| 103 | trust = true; |
| 104 | } else { |
| 105 | replaceWith(TextUtils.ellipsize(source, paint, ellipsizedWidth, |
| 106 | ellipsize, true, this), |
| 107 | paint, outerwidth, align, spacingmult, |
| 108 | spacingadd); |
| 109 | |
| 110 | mEllipsizedWidth = ellipsizedWidth; |
| 111 | trust = false; |
| 112 | } |
| 113 | |
| 114 | init(getText(), paint, outerwidth, align, spacingmult, spacingadd, |
| 115 | metrics, includepad, trust); |
| 116 | return this; |
| 117 | } |
| 118 | |
| 119 | public BoringLayout(CharSequence source, |
| 120 | TextPaint paint, int outerwidth, |
| 121 | Alignment align, |
| 122 | float spacingmult, float spacingadd, |
| 123 | BoringLayout.Metrics metrics, boolean includepad) { |
| 124 | super(source, paint, outerwidth, align, spacingmult, spacingadd); |
| 125 | |
| 126 | mEllipsizedWidth = outerwidth; |
| 127 | mEllipsizedStart = 0; |
| 128 | mEllipsizedCount = 0; |
| 129 | |
| 130 | init(source, paint, outerwidth, align, spacingmult, spacingadd, |
| 131 | metrics, includepad, true); |
| 132 | } |
| 133 | |
| 134 | public BoringLayout(CharSequence source, |
| 135 | TextPaint paint, int outerwidth, |
| 136 | Alignment align, |
| 137 | float spacingmult, float spacingadd, |
| 138 | BoringLayout.Metrics metrics, boolean includepad, |
| 139 | TextUtils.TruncateAt ellipsize, int ellipsizedWidth) { |
| 140 | /* |
| 141 | * It is silly to have to call super() and then replaceWith(), |
| 142 | * but we can't use "this" for the callback until the call to |
| 143 | * super() finishes. |
| 144 | */ |
| 145 | super(source, paint, outerwidth, align, spacingmult, spacingadd); |
| 146 | |
| 147 | boolean trust; |
| 148 | |
| 149 | if (ellipsize == null || ellipsize == TextUtils.TruncateAt.MARQUEE) { |
| 150 | mEllipsizedWidth = outerwidth; |
| 151 | mEllipsizedStart = 0; |
| 152 | mEllipsizedCount = 0; |
| 153 | trust = true; |
| 154 | } else { |
| 155 | replaceWith(TextUtils.ellipsize(source, paint, ellipsizedWidth, |
| 156 | ellipsize, true, this), |
| 157 | paint, outerwidth, align, spacingmult, |
| 158 | spacingadd); |
| 159 | |
| 160 | |
| 161 | mEllipsizedWidth = ellipsizedWidth; |
| 162 | trust = false; |
| 163 | } |
| 164 | |
| 165 | init(getText(), paint, outerwidth, align, spacingmult, spacingadd, |
| 166 | metrics, includepad, trust); |
| 167 | } |
| 168 | |
| 169 | /* package */ void init(CharSequence source, |
| 170 | TextPaint paint, int outerwidth, |
| 171 | Alignment align, |
| 172 | float spacingmult, float spacingadd, |
| 173 | BoringLayout.Metrics metrics, boolean includepad, |
| 174 | boolean trustWidth) { |
| 175 | int spacing; |
| 176 | |
| 177 | if (source instanceof String && align == Layout.Alignment.ALIGN_NORMAL) { |
| 178 | mDirect = source.toString(); |
| 179 | } else { |
| 180 | mDirect = null; |
| 181 | } |
| 182 | |
| 183 | mPaint = paint; |
| 184 | |
| 185 | if (includepad) { |
| 186 | spacing = metrics.bottom - metrics.top; |
| 187 | } else { |
| 188 | spacing = metrics.descent - metrics.ascent; |
| 189 | } |
| 190 | |
| 191 | if (spacingmult != 1 || spacingadd != 0) { |
| 192 | spacing = (int)(spacing * spacingmult + spacingadd + 0.5f); |
| 193 | } |
| 194 | |
| 195 | mBottom = spacing; |
| 196 | |
| 197 | if (includepad) { |
| 198 | mDesc = spacing + metrics.top; |
| 199 | } else { |
| 200 | mDesc = spacing + metrics.ascent; |
| 201 | } |
| 202 | |
| 203 | if (trustWidth) { |
| 204 | mMax = metrics.width; |
| 205 | } else { |
| 206 | /* |
| 207 | * If we have ellipsized, we have to actually calculate the |
| 208 | * width because the width that was passed in was for the |
| 209 | * full text, not the ellipsized form. |
| 210 | */ |
Doug Felt | e8e45f2 | 2010-03-29 14:58:40 -0700 | [diff] [blame] | 211 | TextLine line = TextLine.obtain(); |
| 212 | line.set(paint, source, 0, source.length(), Layout.DIR_LEFT_TO_RIGHT, |
| 213 | Layout.DIRS_ALL_LEFT_TO_RIGHT, false, null); |
| 214 | mMax = (int) FloatMath.ceil(line.metrics(null)); |
| 215 | TextLine.recycle(line); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 216 | } |
| 217 | |
| 218 | if (includepad) { |
| 219 | mTopPadding = metrics.top - metrics.ascent; |
| 220 | mBottomPadding = metrics.bottom - metrics.descent; |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | /** |
| 225 | * Returns null if not boring; the width, ascent, and descent if boring. |
| 226 | */ |
| 227 | public static Metrics isBoring(CharSequence text, |
| 228 | TextPaint paint) { |
| 229 | return isBoring(text, paint, null); |
| 230 | } |
| 231 | |
| 232 | /** |
| 233 | * Returns null if not boring; the width, ascent, and descent in the |
| 234 | * provided Metrics object (or a new one if the provided one was null) |
| 235 | * if boring. |
| 236 | */ |
| 237 | public static Metrics isBoring(CharSequence text, TextPaint paint, |
| 238 | Metrics metrics) { |
| 239 | char[] temp = TextUtils.obtain(500); |
| 240 | int len = text.length(); |
| 241 | boolean boring = true; |
| 242 | |
| 243 | outer: |
| 244 | for (int i = 0; i < len; i += 500) { |
| 245 | int j = i + 500; |
| 246 | |
| 247 | if (j > len) |
| 248 | j = len; |
| 249 | |
| 250 | TextUtils.getChars(text, i, j, temp, 0); |
| 251 | |
| 252 | int n = j - i; |
| 253 | |
| 254 | for (int a = 0; a < n; a++) { |
| 255 | char c = temp[a]; |
| 256 | |
| 257 | if (c == '\n' || c == '\t' || c >= FIRST_RIGHT_TO_LEFT) { |
| 258 | boring = false; |
| 259 | break outer; |
| 260 | } |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | TextUtils.recycle(temp); |
| 265 | |
Eric Fischer | 86fcef8 | 2009-08-17 17:16:44 -0700 | [diff] [blame] | 266 | if (boring && text instanceof Spanned) { |
| 267 | Spanned sp = (Spanned) text; |
| 268 | Object[] styles = sp.getSpans(0, text.length(), ParagraphStyle.class); |
| 269 | if (styles.length > 0) { |
| 270 | boring = false; |
| 271 | } |
| 272 | } |
| 273 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 274 | if (boring) { |
| 275 | Metrics fm = metrics; |
| 276 | if (fm == null) { |
| 277 | fm = new Metrics(); |
| 278 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 279 | |
Doug Felt | e8e45f2 | 2010-03-29 14:58:40 -0700 | [diff] [blame] | 280 | TextLine line = TextLine.obtain(); |
| 281 | line.set(paint, text, 0, text.length(), Layout.DIR_LEFT_TO_RIGHT, |
| 282 | Layout.DIRS_ALL_LEFT_TO_RIGHT, false, null); |
| 283 | fm.width = (int) FloatMath.ceil(line.metrics(fm)); |
| 284 | TextLine.recycle(line); |
| 285 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 286 | return fm; |
| 287 | } else { |
| 288 | return null; |
| 289 | } |
| 290 | } |
| 291 | |
| 292 | @Override public int getHeight() { |
| 293 | return mBottom; |
| 294 | } |
| 295 | |
| 296 | @Override public int getLineCount() { |
| 297 | return 1; |
| 298 | } |
| 299 | |
| 300 | @Override public int getLineTop(int line) { |
| 301 | if (line == 0) |
| 302 | return 0; |
| 303 | else |
| 304 | return mBottom; |
| 305 | } |
| 306 | |
| 307 | @Override public int getLineDescent(int line) { |
| 308 | return mDesc; |
| 309 | } |
| 310 | |
| 311 | @Override public int getLineStart(int line) { |
| 312 | if (line == 0) |
| 313 | return 0; |
| 314 | else |
| 315 | return getText().length(); |
| 316 | } |
| 317 | |
| 318 | @Override public int getParagraphDirection(int line) { |
| 319 | return DIR_LEFT_TO_RIGHT; |
| 320 | } |
| 321 | |
| 322 | @Override public boolean getLineContainsTab(int line) { |
| 323 | return false; |
| 324 | } |
| 325 | |
| 326 | @Override public float getLineMax(int line) { |
| 327 | return mMax; |
| 328 | } |
| 329 | |
| 330 | @Override public final Directions getLineDirections(int line) { |
| 331 | return Layout.DIRS_ALL_LEFT_TO_RIGHT; |
| 332 | } |
| 333 | |
| 334 | public int getTopPadding() { |
| 335 | return mTopPadding; |
| 336 | } |
| 337 | |
| 338 | public int getBottomPadding() { |
| 339 | return mBottomPadding; |
| 340 | } |
| 341 | |
| 342 | @Override |
| 343 | public int getEllipsisCount(int line) { |
| 344 | return mEllipsizedCount; |
| 345 | } |
| 346 | |
| 347 | @Override |
| 348 | public int getEllipsisStart(int line) { |
| 349 | return mEllipsizedStart; |
| 350 | } |
| 351 | |
| 352 | @Override |
| 353 | public int getEllipsizedWidth() { |
| 354 | return mEllipsizedWidth; |
| 355 | } |
| 356 | |
| 357 | // Override draw so it will be faster. |
| 358 | @Override |
| 359 | public void draw(Canvas c, Path highlight, Paint highlightpaint, |
| 360 | int cursorOffset) { |
| 361 | if (mDirect != null && highlight == null) { |
| 362 | c.drawText(mDirect, 0, mBottom - mDesc, mPaint); |
| 363 | } else { |
| 364 | super.draw(c, highlight, highlightpaint, cursorOffset); |
| 365 | } |
| 366 | } |
| 367 | |
| 368 | /** |
| 369 | * Callback for the ellipsizer to report what region it ellipsized. |
| 370 | */ |
| 371 | public void ellipsized(int start, int end) { |
| 372 | mEllipsizedStart = start; |
| 373 | mEllipsizedCount = end - start; |
| 374 | } |
| 375 | |
| 376 | private static final char FIRST_RIGHT_TO_LEFT = '\u0590'; |
| 377 | |
| 378 | private String mDirect; |
| 379 | private Paint mPaint; |
| 380 | |
| 381 | /* package */ int mBottom, mDesc; // for Direct |
| 382 | private int mTopPadding, mBottomPadding; |
| 383 | private float mMax; |
| 384 | private int mEllipsizedWidth, mEllipsizedStart, mEllipsizedCount; |
| 385 | |
| 386 | private static final TextPaint sTemp = |
| 387 | new TextPaint(); |
| 388 | |
| 389 | public static class Metrics extends Paint.FontMetricsInt { |
| 390 | public int width; |
Doug Felt | e8e45f2 | 2010-03-29 14:58:40 -0700 | [diff] [blame] | 391 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 392 | @Override public String toString() { |
| 393 | return super.toString() + " width=" + width; |
| 394 | } |
| 395 | } |
| 396 | } |