Mercurial > projects > dwt-addons
annotate dwtx/jface/text/GapTextStore.d @ 162:1a5b8f8129df
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| author | Frank Benoit <benoit@tionex.de> |
|---|---|
| date | Mon, 08 Sep 2008 00:51:37 +0200 |
| parents | a9566845f1cb |
| children |
| rev | line source |
|---|---|
| 129 | 1 /******************************************************************************* |
| 2 * Copyright (c) 2000, 2008 IBM Corporation and others. | |
| 3 * All rights reserved. This program and the accompanying materials | |
| 4 * are made available under the terms of the Eclipse Public License v1.0 | |
| 5 * which accompanies this distribution, and is available at | |
| 6 * http://www.eclipse.org/legal/epl-v10.html | |
| 7 * | |
| 8 * Contributors: | |
| 9 * IBM Corporation - initial API and implementation | |
| 10 * Port to the D programming language: | |
| 11 * Frank Benoit <benoit@tionex.de> | |
| 12 *******************************************************************************/ | |
| 13 module dwtx.jface.text.GapTextStore; | |
| 14 | |
| 131 | 15 import dwtx.jface.text.IDocumentPartitioningListener; // packageimport |
| 16 import dwtx.jface.text.DefaultTextHover; // packageimport | |
| 17 import dwtx.jface.text.AbstractInformationControl; // packageimport | |
| 18 import dwtx.jface.text.TextUtilities; // packageimport | |
| 19 import dwtx.jface.text.IInformationControlCreatorExtension; // packageimport | |
| 20 import dwtx.jface.text.AbstractInformationControlManager; // packageimport | |
| 21 import dwtx.jface.text.ITextViewerExtension2; // packageimport | |
| 22 import dwtx.jface.text.IDocumentPartitioner; // packageimport | |
| 23 import dwtx.jface.text.DefaultIndentLineAutoEditStrategy; // packageimport | |
| 24 import dwtx.jface.text.ITextSelection; // packageimport | |
| 25 import dwtx.jface.text.Document; // packageimport | |
| 26 import dwtx.jface.text.FindReplaceDocumentAdapterContentProposalProvider; // packageimport | |
| 27 import dwtx.jface.text.ITextListener; // packageimport | |
| 28 import dwtx.jface.text.BadPartitioningException; // packageimport | |
| 29 import dwtx.jface.text.ITextViewerExtension5; // packageimport | |
| 30 import dwtx.jface.text.IDocumentPartitionerExtension3; // packageimport | |
| 31 import dwtx.jface.text.IUndoManager; // packageimport | |
| 32 import dwtx.jface.text.ITextHoverExtension2; // packageimport | |
| 33 import dwtx.jface.text.IRepairableDocument; // packageimport | |
| 34 import dwtx.jface.text.IRewriteTarget; // packageimport | |
| 35 import dwtx.jface.text.DefaultPositionUpdater; // packageimport | |
| 36 import dwtx.jface.text.RewriteSessionEditProcessor; // packageimport | |
| 37 import dwtx.jface.text.TextViewerHoverManager; // packageimport | |
| 38 import dwtx.jface.text.DocumentRewriteSession; // packageimport | |
| 39 import dwtx.jface.text.TextViewer; // packageimport | |
| 40 import dwtx.jface.text.ITextViewerExtension8; // packageimport | |
| 41 import dwtx.jface.text.RegExMessages; // packageimport | |
| 42 import dwtx.jface.text.IDelayedInputChangeProvider; // packageimport | |
| 43 import dwtx.jface.text.ITextOperationTargetExtension; // packageimport | |
| 44 import dwtx.jface.text.IWidgetTokenOwner; // packageimport | |
| 45 import dwtx.jface.text.IViewportListener; // packageimport | |
| 46 import dwtx.jface.text.MarkSelection; // packageimport | |
| 47 import dwtx.jface.text.IDocumentPartitioningListenerExtension; // packageimport | |
| 48 import dwtx.jface.text.IDocumentAdapterExtension; // packageimport | |
| 49 import dwtx.jface.text.IInformationControlExtension; // packageimport | |
| 50 import dwtx.jface.text.IDocumentPartitioningListenerExtension2; // packageimport | |
| 51 import dwtx.jface.text.DefaultDocumentAdapter; // packageimport | |
| 52 import dwtx.jface.text.ITextViewerExtension3; // packageimport | |
| 53 import dwtx.jface.text.IInformationControlCreator; // packageimport | |
| 54 import dwtx.jface.text.TypedRegion; // packageimport | |
| 55 import dwtx.jface.text.ISynchronizable; // packageimport | |
| 56 import dwtx.jface.text.IMarkRegionTarget; // packageimport | |
| 57 import dwtx.jface.text.TextViewerUndoManager; // packageimport | |
| 58 import dwtx.jface.text.IRegion; // packageimport | |
| 59 import dwtx.jface.text.IInformationControlExtension2; // packageimport | |
| 60 import dwtx.jface.text.IDocumentExtension4; // packageimport | |
| 61 import dwtx.jface.text.IDocumentExtension2; // packageimport | |
| 62 import dwtx.jface.text.IDocumentPartitionerExtension2; // packageimport | |
| 63 import dwtx.jface.text.DefaultInformationControl; // packageimport | |
| 64 import dwtx.jface.text.IWidgetTokenOwnerExtension; // packageimport | |
| 65 import dwtx.jface.text.DocumentClone; // packageimport | |
| 66 import dwtx.jface.text.DefaultUndoManager; // packageimport | |
| 67 import dwtx.jface.text.IFindReplaceTarget; // packageimport | |
| 68 import dwtx.jface.text.IAutoEditStrategy; // packageimport | |
| 69 import dwtx.jface.text.ILineTrackerExtension; // packageimport | |
| 70 import dwtx.jface.text.IUndoManagerExtension; // packageimport | |
| 71 import dwtx.jface.text.TextSelection; // packageimport | |
| 72 import dwtx.jface.text.DefaultAutoIndentStrategy; // packageimport | |
| 73 import dwtx.jface.text.IAutoIndentStrategy; // packageimport | |
| 74 import dwtx.jface.text.IPainter; // packageimport | |
| 75 import dwtx.jface.text.IInformationControl; // packageimport | |
| 76 import dwtx.jface.text.IInformationControlExtension3; // packageimport | |
| 77 import dwtx.jface.text.ITextViewerExtension6; // packageimport | |
| 78 import dwtx.jface.text.IInformationControlExtension4; // packageimport | |
| 79 import dwtx.jface.text.DefaultLineTracker; // packageimport | |
| 80 import dwtx.jface.text.IDocumentInformationMappingExtension; // packageimport | |
| 81 import dwtx.jface.text.IRepairableDocumentExtension; // packageimport | |
| 82 import dwtx.jface.text.ITextHover; // packageimport | |
| 83 import dwtx.jface.text.FindReplaceDocumentAdapter; // packageimport | |
| 84 import dwtx.jface.text.ILineTracker; // packageimport | |
| 85 import dwtx.jface.text.Line; // packageimport | |
| 86 import dwtx.jface.text.ITextViewerExtension; // packageimport | |
| 87 import dwtx.jface.text.IDocumentAdapter; // packageimport | |
| 88 import dwtx.jface.text.TextEvent; // packageimport | |
| 89 import dwtx.jface.text.BadLocationException; // packageimport | |
| 90 import dwtx.jface.text.AbstractDocument; // packageimport | |
| 91 import dwtx.jface.text.AbstractLineTracker; // packageimport | |
| 92 import dwtx.jface.text.TreeLineTracker; // packageimport | |
| 93 import dwtx.jface.text.ITextPresentationListener; // packageimport | |
| 94 import dwtx.jface.text.Region; // packageimport | |
| 95 import dwtx.jface.text.ITextViewer; // packageimport | |
| 96 import dwtx.jface.text.IDocumentInformationMapping; // packageimport | |
| 97 import dwtx.jface.text.MarginPainter; // packageimport | |
| 98 import dwtx.jface.text.IPaintPositionManager; // packageimport | |
| 99 import dwtx.jface.text.TextPresentation; // packageimport | |
| 100 import dwtx.jface.text.IFindReplaceTargetExtension; // packageimport | |
| 101 import dwtx.jface.text.ISlaveDocumentManagerExtension; // packageimport | |
| 102 import dwtx.jface.text.ISelectionValidator; // packageimport | |
| 103 import dwtx.jface.text.IDocumentExtension; // packageimport | |
| 104 import dwtx.jface.text.PropagatingFontFieldEditor; // packageimport | |
| 105 import dwtx.jface.text.ConfigurableLineTracker; // packageimport | |
| 106 import dwtx.jface.text.SlaveDocumentEvent; // packageimport | |
| 107 import dwtx.jface.text.IDocumentListener; // packageimport | |
| 108 import dwtx.jface.text.PaintManager; // packageimport | |
| 109 import dwtx.jface.text.IFindReplaceTargetExtension3; // packageimport | |
| 110 import dwtx.jface.text.ITextDoubleClickStrategy; // packageimport | |
| 111 import dwtx.jface.text.IDocumentExtension3; // packageimport | |
| 112 import dwtx.jface.text.Position; // packageimport | |
| 113 import dwtx.jface.text.TextMessages; // packageimport | |
| 114 import dwtx.jface.text.CopyOnWriteTextStore; // packageimport | |
| 115 import dwtx.jface.text.WhitespaceCharacterPainter; // packageimport | |
| 116 import dwtx.jface.text.IPositionUpdater; // packageimport | |
| 117 import dwtx.jface.text.DefaultTextDoubleClickStrategy; // packageimport | |
| 118 import dwtx.jface.text.ListLineTracker; // packageimport | |
| 119 import dwtx.jface.text.ITextInputListener; // packageimport | |
| 120 import dwtx.jface.text.BadPositionCategoryException; // packageimport | |
| 121 import dwtx.jface.text.IWidgetTokenKeeperExtension; // packageimport | |
| 122 import dwtx.jface.text.IInputChangedListener; // packageimport | |
| 123 import dwtx.jface.text.ITextOperationTarget; // packageimport | |
| 124 import dwtx.jface.text.IDocumentInformationMappingExtension2; // packageimport | |
| 125 import dwtx.jface.text.ITextViewerExtension7; // packageimport | |
| 126 import dwtx.jface.text.IInformationControlExtension5; // packageimport | |
| 127 import dwtx.jface.text.IDocumentRewriteSessionListener; // packageimport | |
| 128 import dwtx.jface.text.JFaceTextUtil; // packageimport | |
| 129 import dwtx.jface.text.AbstractReusableInformationControlCreator; // packageimport | |
| 130 import dwtx.jface.text.TabsToSpacesConverter; // packageimport | |
| 131 import dwtx.jface.text.CursorLinePainter; // packageimport | |
| 132 import dwtx.jface.text.ITextHoverExtension; // packageimport | |
| 133 import dwtx.jface.text.IEventConsumer; // packageimport | |
| 134 import dwtx.jface.text.IDocument; // packageimport | |
| 135 import dwtx.jface.text.IWidgetTokenKeeper; // packageimport | |
| 136 import dwtx.jface.text.DocumentCommand; // packageimport | |
| 137 import dwtx.jface.text.TypedPosition; // packageimport | |
| 138 import dwtx.jface.text.IEditingSupportRegistry; // packageimport | |
| 139 import dwtx.jface.text.IDocumentPartitionerExtension; // packageimport | |
| 140 import dwtx.jface.text.AbstractHoverInformationControlManager; // packageimport | |
| 141 import dwtx.jface.text.IEditingSupport; // packageimport | |
| 142 import dwtx.jface.text.IMarkSelection; // packageimport | |
| 143 import dwtx.jface.text.ISlaveDocumentManager; // packageimport | |
| 144 import dwtx.jface.text.DocumentEvent; // packageimport | |
| 145 import dwtx.jface.text.DocumentPartitioningChangedEvent; // packageimport | |
| 146 import dwtx.jface.text.ITextStore; // packageimport | |
| 147 import dwtx.jface.text.JFaceTextMessages; // packageimport | |
| 148 import dwtx.jface.text.DocumentRewriteSessionEvent; // packageimport | |
| 149 import dwtx.jface.text.SequentialRewriteTextStore; // packageimport | |
| 150 import dwtx.jface.text.DocumentRewriteSessionType; // packageimport | |
| 151 import dwtx.jface.text.TextAttribute; // packageimport | |
| 152 import dwtx.jface.text.ITextViewerExtension4; // packageimport | |
| 153 import dwtx.jface.text.ITypedRegion; // packageimport | |
| 154 | |
| 155 | |
| 129 | 156 import dwt.dwthelper.utils; |
| 157 | |
| 158 import dwtx.core.runtime.Assert; | |
| 159 | |
| 160 | |
| 161 /** | |
| 162 * Implements a gap managing text store. The gap text store relies on the assumption that | |
| 163 * consecutive changes to a document are co-located. The start of the gap is always moved to the | |
| 164 * location of the last change. | |
| 165 * <p> | |
| 166 * <strong>Performance:</strong> Typing-style changes perform in constant time unless re-allocation | |
| 167 * becomes necessary. Generally, a change that does not cause re-allocation will cause at most one | |
| 168 * {@linkplain System#arraycopy(Object, int, Object, int, int) arraycopy} operation of a length of | |
| 169 * about <var>d</var>, where <var>d</var> is the distance from the previous change. Let <var>a(x)</var> | |
| 170 * be the algorithmic performance of an <code>arraycopy</code> operation of the length <var>x</var>, | |
| 171 * then such a change then performs in <i>O(a(x))</i>, | |
| 172 * {@linkplain #get(int, int) get(int, <var>length</var>)} performs in <i>O(a(length))</i>, | |
| 173 * {@link #get(int)} in <i>O(1)</i>. | |
| 174 * <p> | |
| 175 * How frequently the array needs re-allocation is controlled by the constructor parameters. | |
| 176 * </p> | |
| 177 * <p> | |
| 178 * This class is not intended to be subclassed. | |
| 179 * </p> | |
| 156 | 180 * |
| 129 | 181 * @see CopyOnWriteTextStore for a copy-on-write text store wrapper |
| 182 * @noextend This class is not intended to be subclassed by clients. | |
| 183 */ | |
| 184 public class GapTextStore : ITextStore { | |
| 185 /** | |
| 186 * The minimum gap size allocated when re-allocation occurs. | |
| 187 * @since 3.3 | |
| 188 */ | |
| 146 | 189 private const int fMinGapSize; |
| 129 | 190 /** |
| 191 * The maximum gap size allocated when re-allocation occurs. | |
| 192 * @since 3.3 | |
| 193 */ | |
| 146 | 194 private const int fMaxGapSize; |
| 129 | 195 /** |
| 196 * The multiplier to compute the array size from the content length | |
| 197 * (1 <= fSizeMultiplier <= 2). | |
| 156 | 198 * |
| 129 | 199 * @since 3.3 |
| 200 */ | |
| 146 | 201 private const float fSizeMultiplier; |
| 129 | 202 |
| 203 /** The store's content */ | |
| 162 | 204 private char[] fContent; |
| 129 | 205 /** Starting index of the gap */ |
| 206 private int fGapStart= 0; | |
| 207 /** End index of the gap */ | |
| 208 private int fGapEnd= 0; | |
| 209 /** | |
| 210 * The current high water mark. If a change would cause the gap to grow larger than this, the | |
| 211 * array is re-allocated. | |
| 212 * @since 3.3 | |
| 213 */ | |
| 214 private int fThreshold= 0; | |
| 215 | |
| 216 /** | |
| 217 * Creates a new empty text store using the specified low and high watermarks. | |
| 156 | 218 * |
| 129 | 219 * @param lowWatermark unused - at the lower bound, the array is only resized when the content |
| 220 * does not fit | |
| 221 * @param highWatermark if the gap is ever larger than this, it will automatically be shrunken | |
| 222 * (>= 0) | |
| 223 * @deprecated use {@link GapTextStore#GapTextStore(int, int, float)} instead | |
| 224 */ | |
|
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225 public this(int lowWatermark, int highWatermark) { |
| 129 | 226 /* |
| 227 * Legacy constructor. The API contract states that highWatermark is the upper bound for the | |
| 228 * gap size. Albeit this contract was not previously adhered to, it is now: The allocated | |
| 229 * gap size is fixed at half the highWatermark. Since the threshold is always twice the | |
| 230 * allocated gap size, the gap will never grow larger than highWatermark. Previously, the | |
| 231 * gap size was initialized to highWatermark, causing re-allocation if the content length | |
| 232 * shrunk right after allocation. The fixed gap size is now only half of the previous value, | |
| 233 * circumventing that problem (there was no API contract specifying the initial gap size). | |
| 234 * | |
| 235 * The previous implementation did not allow the gap size to become smaller than | |
| 236 * lowWatermark, which doesn't make any sense: that area of the gap was simply never ever | |
| 237 * used. | |
| 238 */ | |
| 239 this(highWatermark / 2, highWatermark / 2, 0f); | |
| 240 } | |
| 156 | 241 |
| 129 | 242 /** |
| 243 * Equivalent to | |
| 244 * {@linkplain GapTextStore#GapTextStore(int, int, float) new GapTextStore(256, 4096, 0.1f)}. | |
| 156 | 245 * |
| 129 | 246 * @since 3.3 |
| 247 */ | |
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248 public this() { |
| 129 | 249 this(256, 4096, 0.1f); |
| 250 } | |
| 251 | |
| 252 /** | |
| 253 * Creates an empty text store that uses re-allocation thresholds relative to the content | |
| 254 * length. Re-allocation is controlled by the <em>gap factor</em>, which is the quotient of | |
| 255 * the gap size and the array size. Re-allocation occurs if a change causes the gap factor to go | |
| 256 * outside <code>[0, maxGapFactor]</code>. When re-allocation occurs, the array is sized | |
| 257 * such that the gap factor is <code>0.5 * maxGapFactor</code>. The gap size computed in this | |
| 258 * manner is bounded by the <code>minSize</code> and <code>maxSize</code> parameters. | |
| 259 * <p> | |
| 260 * A <code>maxGapFactor</code> of <code>0</code> creates a text store that never has a gap | |
| 261 * at all (if <code>minSize</code> is 0); a <code>maxGapFactor</code> of <code>1</code> | |
| 262 * creates a text store that doubles its size with every re-allocation and that never shrinks. | |
| 263 * </p> | |
| 264 * <p> | |
| 265 * The <code>minSize</code> and <code>maxSize</code> parameters are absolute bounds to the | |
| 266 * allocated gap size. Use <code>minSize</code> to avoid frequent re-allocation for small | |
| 267 * documents. Use <code>maxSize</code> to avoid a huge gap being allocated for large | |
| 268 * documents. | |
| 269 * </p> | |
| 156 | 270 * |
| 129 | 271 * @param minSize the minimum gap size to allocate (>= 0; use 0 for no minimum) |
| 272 * @param maxSize the maximum gap size to allocate (>= minSize; use | |
| 273 * {@link Integer#MAX_VALUE} for no maximum) | |
| 274 * @param maxGapFactor is the maximum fraction of the array that is occupied by the gap (<code>0 <= maxGapFactor <= 1</code>) | |
| 275 * @since 3.3 | |
| 276 */ | |
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277 public this(int minSize, int maxSize, float maxGapFactor) { |
| 129 | 278 Assert.isLegal(0f <= maxGapFactor && maxGapFactor <= 1f); |
| 279 Assert.isLegal(0 <= minSize && minSize <= maxSize); | |
| 280 fMinGapSize= minSize; | |
| 281 fMaxGapSize= maxSize; | |
| 282 fSizeMultiplier= 1 / (1 - maxGapFactor / 2); | |
| 283 } | |
| 284 | |
| 285 /* | |
| 286 * @see dwtx.jface.text.ITextStore#get(int) | |
| 287 */ | |
| 288 public final char get(int offset) { | |
| 289 if (offset < fGapStart) | |
| 290 return fContent[offset]; | |
| 291 | |
| 292 return fContent[offset + gapSize()]; | |
| 293 } | |
| 294 | |
| 295 /* | |
| 296 * @see dwtx.jface.text.ITextStore#get(int, int) | |
| 297 */ | |
| 298 public final String get(int offset, int length) { | |
| 299 if (fGapStart <= offset) | |
| 162 | 300 return new_String(fContent, offset + gapSize() , length); |
| 129 | 301 |
| 302 final int end= offset + length; | |
| 303 | |
| 304 if (end <= fGapStart) | |
| 162 | 305 return new_String(fContent, offset, length); |
| 129 | 306 |
| 307 StringBuffer buf= new StringBuffer(length); | |
| 162 | 308 buf.append(fContent[ offset .. fGapStart ]); |
| 309 buf.append(fContent[ fGapEnd .. end - fGapStart + fGapEnd ]); | |
| 129 | 310 return buf.toString(); |
| 311 } | |
| 312 | |
| 313 /* | |
| 314 * @see dwtx.jface.text.ITextStore#getLength() | |
| 315 */ | |
| 316 public final int getLength() { | |
| 317 return fContent.length - gapSize(); | |
| 318 } | |
| 319 | |
| 320 /* | |
| 321 * @see dwtx.jface.text.ITextStore#set(java.lang.String) | |
| 322 */ | |
| 323 public final void set(String text) { | |
| 324 /* | |
| 325 * Moves the gap to the end of the content. There is no sensible prediction of where the | |
| 326 * next change will occur, but at least the next change will not trigger re-allocation. This | |
| 327 * is especially important when using the GapTextStore within a CopyOnWriteTextStore, where | |
| 328 * the GTS is only initialized right before a modification. | |
| 329 */ | |
| 330 replace(0, getLength(), text); | |
| 331 } | |
| 332 | |
| 333 /* | |
| 334 * @see dwtx.jface.text.ITextStore#replace(int, int, java.lang.String) | |
| 335 */ | |
| 336 public final void replace(int offset, int length, String text) { | |
| 337 if (text is null) { | |
| 338 adjustGap(offset, length, 0); | |
| 339 } else { | |
| 162 | 340 int textLength= text.length; |
| 129 | 341 adjustGap(offset, length, textLength); |
| 342 if (textLength !is 0) | |
| 343 text.getChars(0, textLength, fContent, offset); | |
| 344 } | |
| 345 } | |
| 346 | |
| 347 /** | |
| 348 * Moves the gap to <code>offset + add</code>, moving any content after | |
| 349 * <code>offset + remove</code> behind the gap. The gap size is kept between 0 and | |
| 350 * {@link #fThreshold}, leading to re-allocation if needed. The content between | |
| 351 * <code>offset</code> and <code>offset + add</code> is undefined after this operation. | |
| 156 | 352 * |
| 129 | 353 * @param offset the offset at which a change happens |
| 354 * @param remove the number of character which are removed or overwritten at <code>offset</code> | |
| 355 * @param add the number of character which are inserted or overwriting at <code>offset</code> | |
| 356 */ | |
| 357 private void adjustGap(int offset, int remove, int add) { | |
| 358 final int oldGapSize= gapSize(); | |
| 359 final int newGapSize= oldGapSize - add + remove; | |
| 360 final bool reuseArray= 0 <= newGapSize && newGapSize <= fThreshold; | |
| 361 | |
| 362 final int newGapStart= offset + add; | |
| 162 | 363 int newGapEnd; |
| 129 | 364 |
| 365 if (reuseArray) | |
| 366 newGapEnd= moveGap(offset, remove, oldGapSize, newGapSize, newGapStart); | |
| 367 else | |
| 368 newGapEnd= reallocate(offset, remove, oldGapSize, newGapSize, newGapStart); | |
| 369 | |
| 370 fGapStart= newGapStart; | |
| 371 fGapEnd= newGapEnd; | |
| 372 } | |
| 373 | |
| 374 /** | |
| 375 * Moves the gap to <code>newGapStart</code>. | |
| 156 | 376 * |
| 129 | 377 * @param offset the change offset |
| 378 * @param remove the number of removed / overwritten characters | |
| 379 * @param oldGapSize the old gap size | |
| 380 * @param newGapSize the gap size after the change | |
| 381 * @param newGapStart the offset in the array to move the gap to | |
| 382 * @return the new gap end | |
| 383 * @since 3.3 | |
| 384 */ | |
| 385 private int moveGap(int offset, int remove, int oldGapSize, int newGapSize, int newGapStart) { | |
| 386 /* | |
| 387 * No re-allocation necessary. The area between the change offset and gap can be copied | |
| 388 * in at most one operation. Don't copy parts that will be overwritten anyway. | |
| 389 */ | |
| 390 final int newGapEnd= newGapStart + newGapSize; | |
| 391 if (offset < fGapStart) { | |
| 392 int afterRemove= offset + remove; | |
| 393 if (afterRemove < fGapStart) { | |
| 394 final int betweenSize= fGapStart - afterRemove; | |
| 395 arrayCopy(afterRemove, fContent, newGapEnd, betweenSize); | |
| 396 } | |
| 397 // otherwise, only the gap gets enlarged | |
| 398 } else { | |
| 399 final int offsetShifted= offset + oldGapSize; | |
| 400 final int betweenSize= offsetShifted - fGapEnd; // in the typing case, betweenSize is 0 | |
| 401 arrayCopy(fGapEnd, fContent, fGapStart, betweenSize); | |
| 402 } | |
| 403 return newGapEnd; | |
| 404 } | |
| 405 | |
| 406 /** | |
| 407 * Reallocates a new array and copies the data from the previous one. | |
| 156 | 408 * |
| 129 | 409 * @param offset the change offset |
| 410 * @param remove the number of removed / overwritten characters | |
| 411 * @param oldGapSize the old gap size | |
| 412 * @param newGapSize the gap size after the change if no re-allocation would occur (can be negative) | |
| 413 * @param newGapStart the offset in the array to move the gap to | |
| 414 * @return the new gap end | |
| 415 * @since 3.3 | |
| 416 */ | |
| 156 | 417 private int reallocate(int offset, int remove, int oldGapSize, int newGapSize, int newGapStart) { |
| 129 | 418 // the new content length (without any gap) |
| 419 final int newLength= fContent.length - newGapSize; | |
| 420 // the new array size based on the gap factor | |
| 134 | 421 int newArraySize= cast(int) (newLength * fSizeMultiplier); |
| 129 | 422 newGapSize= newArraySize - newLength; |
| 423 | |
| 424 // bound the gap size within min/max | |
| 425 if (newGapSize < fMinGapSize) { | |
| 426 newGapSize= fMinGapSize; | |
| 427 newArraySize= newLength + newGapSize; | |
| 428 } else if (newGapSize > fMaxGapSize) { | |
| 429 newGapSize= fMaxGapSize; | |
| 430 newArraySize= newLength + newGapSize; | |
| 431 } | |
| 432 | |
| 433 // the upper threshold is always twice the gapsize | |
| 434 fThreshold= newGapSize * 2; | |
| 435 final char[] newContent= allocate(newArraySize); | |
| 436 final int newGapEnd= newGapStart + newGapSize; | |
| 437 | |
| 438 /* | |
| 439 * Re-allocation: The old content can be copied in at most 3 operations to the newly allocated | |
| 440 * array. Either one of change offset and the gap may come first. | |
| 441 * - unchanged area before the change offset / gap | |
| 442 * - area between the change offset and the gap (either one may be first) | |
| 443 * - rest area after the change offset / after the gap | |
| 444 */ | |
| 445 if (offset < fGapStart) { | |
| 446 // change comes before gap | |
| 447 arrayCopy(0, newContent, 0, offset); | |
| 448 int afterRemove= offset + remove; | |
| 449 if (afterRemove < fGapStart) { | |
| 450 // removal is completely before the gap | |
| 451 final int betweenSize= fGapStart - afterRemove; | |
| 452 arrayCopy(afterRemove, newContent, newGapEnd, betweenSize); | |
| 453 final int restSize= fContent.length - fGapEnd; | |
| 454 arrayCopy(fGapEnd, newContent, newGapEnd + betweenSize, restSize); | |
| 455 } else { | |
| 456 // removal encompasses the gap | |
| 457 afterRemove += oldGapSize; | |
| 458 final int restSize= fContent.length - afterRemove; | |
| 459 arrayCopy(afterRemove, newContent, newGapEnd, restSize); | |
| 460 } | |
| 461 } else { | |
| 462 // gap comes before change | |
| 463 arrayCopy(0, newContent, 0, fGapStart); | |
| 464 final int offsetShifted= offset + oldGapSize; | |
| 465 final int betweenSize= offsetShifted - fGapEnd; | |
| 466 arrayCopy(fGapEnd, newContent, fGapStart, betweenSize); | |
| 467 final int afterRemove= offsetShifted + remove; | |
| 468 final int restSize= fContent.length - afterRemove; | |
| 469 arrayCopy(afterRemove, newContent, newGapEnd, restSize); | |
| 470 } | |
| 471 | |
| 472 fContent= newContent; | |
| 473 return newGapEnd; | |
| 474 } | |
| 475 | |
| 476 /** | |
| 477 * Allocates a new <code>char[size]</code>. | |
| 156 | 478 * |
| 129 | 479 * @param size the length of the new array. |
| 480 * @return a newly allocated char array | |
| 481 * @since 3.3 | |
| 482 */ | |
| 483 private char[] allocate(int size) { | |
| 484 return new char[size]; | |
| 485 } | |
| 486 | |
| 487 /* | |
| 488 * Executes System.arraycopy if length !is 0. A length < 0 cannot happen -> don't hide coding | |
| 489 * errors by checking for negative lengths. | |
| 490 * @since 3.3 | |
| 491 */ | |
| 492 private void arrayCopy(int srcPos, char[] dest, int destPos, int length) { | |
| 493 if (length !is 0) | |
| 494 System.arraycopy(fContent, srcPos, dest, destPos, length); | |
| 495 } | |
| 496 | |
| 497 /** | |
| 498 * Returns the gap size. | |
| 156 | 499 * |
| 129 | 500 * @return the gap size |
| 501 * @since 3.3 | |
| 502 */ | |
| 503 private int gapSize() { | |
| 504 return fGapEnd - fGapStart; | |
| 505 } | |
| 506 | |
| 507 /** | |
| 508 * Returns a copy of the content of this text store. | |
| 509 * For internal use only. | |
| 510 * | |
| 511 * @return a copy of the content of this text store | |
| 512 */ | |
| 513 protected String getContentAsString() { | |
| 162 | 514 return new_String(fContent); |
| 129 | 515 } |
| 516 | |
| 517 /** | |
| 518 * Returns the start index of the gap managed by this text store. | |
| 519 * For internal use only. | |
| 520 * | |
| 521 * @return the start index of the gap managed by this text store | |
| 522 */ | |
| 523 protected int getGapStartIndex() { | |
| 524 return fGapStart; | |
| 525 } | |
| 526 | |
| 527 /** | |
| 528 * Returns the end index of the gap managed by this text store. | |
| 529 * For internal use only. | |
| 530 * | |
| 531 * @return the end index of the gap managed by this text store | |
| 532 */ | |
| 533 protected int getGapEndIndex() { | |
| 534 return fGapEnd; | |
| 535 } | |
| 536 } |