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SWT is an open source widget toolkit for Java designed to provide efficient, portable access to the user-interface facilities of the operating systems on which it is implemented.

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/*******************************************************************************
 * Copyright (c) 2000, 2011 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.custom;

import org.eclipse.swt.*;
import org.eclipse.swt.internal.Compatibility;
import org.eclipse.swt.widgets.*;
import java.util.Vector;

class DefaultContent implements StyledTextContent {
	private final static String LineDelimiter = System.getProperty("line.separator");

	Vector textListeners = new Vector(); // stores text listeners for event sending
	char[] textStore = new char[0];	// stores the actual text
	int gapStart = -1;	// the character position start of the gap
	int gapEnd = -1;	// the character position after the end of the gap
	int gapLine = -1;	// the line on which the gap exists, the gap will always be associated with one line
	int highWatermark = 300;	
	int lowWatermark = 50;		
	
	int[][] lines = new int[50][2];	// array of character positions and lengths representing the lines of text
	int lineCount = 0;	// the number of lines of text	
	int expandExp = 1; 	// the expansion exponent, used to increase the lines array exponentially
	int replaceExpandExp = 1; 	// the expansion exponent, used to increase the lines array exponentially

/** 
 * Creates a new DefaultContent and initializes it.  A StyledTextContent will always have
 * at least one empty line.
 */
DefaultContent() {
	super();
	setText("");
}
/** 
 * Adds a line to the end of the line indexes array.  Increases the size of the array if necessary.
 * lineCount is updated to reflect the new entry.
 * 

* * @param start the start of the line * @param length the length of the line */ void addLineIndex(int start, int length) { int size = lines.length; if (lineCount == size) { // expand the lines by powers of 2 int[][] newLines = new int[size+Compatibility.pow2(expandExp)][2]; System.arraycopy(lines, 0, newLines, 0, size); lines = newLines; expandExp++; } int[] range = new int[] {start, length}; lines[lineCount] = range; lineCount++; } /** * Adds a line index to the end of linesArray. Increases the * size of the array if necessary and returns a new array. *

* * @param start the start of the line * @param length the length of the line * @param linesArray the array to which to add the line index * @param count the position at which to add the line * @return a new array of line indexes */ int[][] addLineIndex(int start, int length, int[][] linesArray, int count) { int size = linesArray.length; int[][] newLines = linesArray; if (count == size) { newLines = new int[size+Compatibility.pow2(replaceExpandExp)][2]; replaceExpandExp++; System.arraycopy(linesArray, 0, newLines, 0, size); } int[] range = new int[] {start, length}; newLines[count] = range; return newLines; } /** * Adds a TextChangeListener listening for * TextChangingEvent and TextChangedEvent. A * TextChangingEvent is sent before changes to the text occur. * A TextChangedEvent is sent after changes to the text * occurred. *

* * @param listener the listener * @exception IllegalArgumentException

    *
  • ERROR_NULL_ARGUMENT when listener is null
  • *
*/ public void addTextChangeListener(TextChangeListener listener) { if (listener == null) error(SWT.ERROR_NULL_ARGUMENT); StyledTextListener typedListener = new StyledTextListener(listener); textListeners.addElement(typedListener); } /** * Adjusts the gap to accommodate a text change that is occurring. *

* * @param position the position at which a change is occurring * @param sizeHint the size of the change * @param line the line where the gap will go */ void adjustGap(int position, int sizeHint, int line) { if (position == gapStart) { // text is being inserted at the gap position int size = (gapEnd - gapStart) - sizeHint; if (lowWatermark <= size && size <= highWatermark) return; } else if ((position + sizeHint == gapStart) && (sizeHint < 0)) { // text is being deleted at the gap position int size = (gapEnd - gapStart) - sizeHint; if (lowWatermark <= size && size <= highWatermark) return; } moveAndResizeGap(position, sizeHint, line); } /** * Calculates the indexes of each line in the text store. Assumes no gap exists. * Optimized to do less checking. */ void indexLines(){ int start = 0; lineCount = 0; int textLength = textStore.length; int i; for (i = start; i < textLength; i++) { char ch = textStore[i]; if (ch == SWT.CR) { // see if the next character is a LF if (i + 1 < textLength) { ch = textStore[i+1]; if (ch == SWT.LF) { i++; } } addLineIndex(start, i - start + 1); start = i + 1; } else if (ch == SWT.LF) { addLineIndex(start, i - start + 1); start = i + 1; } } addLineIndex(start, i - start); } /** * Returns whether or not the given character is a line delimiter. Both CR and LF * are valid line delimiters. *

* * @param ch the character to test * @return true if ch is a delimiter, false otherwise */ boolean isDelimiter(char ch) { if (ch == SWT.CR) return true; if (ch == SWT.LF) return true; return false; } /** * Determine whether or not the replace operation is valid. DefaultContent will not allow * the /r/n line delimiter to be split or partially deleted. *

* * @param start start offset of text to replace * @param replaceLength start offset of text to replace * @param newText start offset of text to replace * @return a boolean specifying whether or not the replace operation is valid */ protected boolean isValidReplace(int start, int replaceLength, String newText){ if (replaceLength == 0) { // inserting text, see if the \r\n line delimiter is being split if (start == 0) return true; if (start == getCharCount()) return true; char before = getTextRange(start - 1, 1).charAt(0); if (before == '\r') { char after = getTextRange(start, 1).charAt(0); if (after == '\n') return false; } } else { // deleting text, see if part of a \r\n line delimiter is being deleted char startChar = getTextRange(start, 1).charAt(0); if (startChar == '\n') { // see if char before delete position is \r if (start != 0) { char before = getTextRange(start - 1, 1).charAt(0); if (before == '\r') return false; } } char endChar = getTextRange(start + replaceLength - 1, 1).charAt(0); if (endChar == '\r') { // see if char after delete position is \n if (start + replaceLength != getCharCount()) { char after = getTextRange(start + replaceLength, 1).charAt(0); if (after == '\n') return false; } } } return true; } /** * Calculates the indexes of each line of text in the given range. *

* * @param offset the logical start offset of the text lineate * @param length the length of the text to lineate, includes gap * @param numLines the number of lines to initially allocate for the line index array, * passed in for efficiency (the exact number of lines may be known) * @return a line indexes array where each line is identified by a start offset and * a length */ int[][] indexLines(int offset, int length, int numLines){ int[][] indexedLines = new int[numLines][2]; int start = 0; int lineCount = 0; int i; replaceExpandExp = 1; for (i = start; i < length; i++) { int location = i + offset; if ((location >= gapStart) && (location < gapEnd)) { // ignore the gap } else { char ch = textStore[location]; if (ch == SWT.CR) { // see if the next character is a LF if (location+1 < textStore.length) { ch = textStore[location+1]; if (ch == SWT.LF) { i++; } } indexedLines = addLineIndex(start, i - start + 1, indexedLines, lineCount); lineCount++; start = i + 1; } else if (ch == SWT.LF) { indexedLines = addLineIndex(start, i - start + 1, indexedLines, lineCount); lineCount++; start = i + 1; } } } int[][] newLines = new int[lineCount+1][2]; System.arraycopy(indexedLines, 0, newLines, 0, lineCount); int[] range = new int[] {start, i - start}; newLines[lineCount] = range; return newLines; } /** * Inserts text. *

* * @param position the position at which to insert the text * @param text the text to insert */ void insert(int position, String text) { if (text.length() == 0) return; int startLine = getLineAtOffset(position); int change = text.length(); boolean endInsert = position == getCharCount(); adjustGap(position, change, startLine); // during an insert the gap will be adjusted to start at // position and it will be associated with startline, the // inserted text will be placed in the gap int startLineOffset = getOffsetAtLine(startLine); // at this point, startLineLength will include the start line // and all of the newly inserted text int startLineLength = getPhysicalLine(startLine).length(); if (change > 0) { // shrink gap gapStart += (change); for (int i = 0; i < text.length(); i++) { textStore[position + i]= text.charAt(i); } } // figure out the number of new lines that have been inserted int [][] newLines = indexLines(startLineOffset, startLineLength, 10); // only insert an empty line if it is the last line in the text int numNewLines = newLines.length - 1; if (newLines[numNewLines][1] == 0) { // last inserted line is a new line if (endInsert) { // insert happening at end of the text, leave numNewLines as // is since the last new line will not be concatenated with another // line numNewLines += 1; } else { numNewLines -= 1; } } // make room for the new lines expandLinesBy(numNewLines); // shift down the lines after the replace line for (int i = lineCount - 1; i > startLine; i--) { lines[i + numNewLines]=lines[i]; } // insert the new lines for (int i = 0; i < numNewLines; i++) { newLines[i][0] += startLineOffset; lines[startLine + i]=newLines[i]; } // update the last inserted line if (numNewLines < newLines.length) { newLines[numNewLines][0] += startLineOffset; lines[startLine + numNewLines] = newLines[numNewLines]; } lineCount += numNewLines; gapLine = getLineAtPhysicalOffset(gapStart); } /** * Moves the gap and adjusts its size in anticipation of a text change. * The gap is resized to actual size + the specified size and moved to the given * position. *

* * @param position the position at which a change is occurring * @param size the size of the change * @param newGapLine the line where the gap should be put */ void moveAndResizeGap(int position, int size, int newGapLine) { char[] content = null; int oldSize = gapEnd - gapStart; int newSize; if (size > 0) { newSize = highWatermark + size; } else { newSize = lowWatermark - size; } // remove the old gap from the lines information if (gapExists()) { // adjust the line length lines[gapLine][1] = lines[gapLine][1] - oldSize; // adjust the offsets of the lines after the gapLine for (int i = gapLine + 1; i < lineCount; i++) { lines[i][0] = lines[i][0] - oldSize; } } if (newSize < 0) { if (oldSize > 0) { // removing the gap content = new char[textStore.length - oldSize]; System.arraycopy(textStore, 0, content, 0, gapStart); System.arraycopy(textStore, gapEnd, content, gapStart, content.length - gapStart); textStore = content; } gapStart = gapEnd = position; return; } content = new char[textStore.length + (newSize - oldSize)]; int newGapStart = position; int newGapEnd = newGapStart + newSize; if (oldSize == 0) { System.arraycopy(textStore, 0, content, 0, newGapStart); System.arraycopy(textStore, newGapStart, content, newGapEnd, content.length - newGapEnd); } else if (newGapStart < gapStart) { int delta = gapStart - newGapStart; System.arraycopy(textStore, 0, content, 0, newGapStart); System.arraycopy(textStore, newGapStart, content, newGapEnd, delta); System.arraycopy(textStore, gapEnd, content, newGapEnd + delta, textStore.length - gapEnd); } else { int delta = newGapStart - gapStart; System.arraycopy(textStore, 0, content, 0, gapStart); System.arraycopy(textStore, gapEnd, content, gapStart, delta); System.arraycopy(textStore, gapEnd + delta, content, newGapEnd, content.length - newGapEnd); } textStore = content; gapStart = newGapStart; gapEnd = newGapEnd; // add the new gap to the lines information if (gapExists()) { gapLine = newGapLine; // adjust the line length int gapLength = gapEnd - gapStart; lines[gapLine][1] = lines[gapLine][1] + (gapLength); // adjust the offsets of the lines after the gapLine for (int i = gapLine + 1; i < lineCount; i++) { lines[i][0] = lines[i][0] + gapLength; } } } /** * Returns the number of lines that are in the specified text. *

* * @param startOffset the start of the text to lineate * @param length the length of the text to lineate * @return number of lines */ int lineCount(int startOffset, int length){ if (length == 0) { return 0; } int lineCount = 0; int count = 0; int i = startOffset; if (i >= gapStart) { i += gapEnd - gapStart; } while (count < length) { if ((i >= gapStart) && (i < gapEnd)) { // ignore the gap } else { char ch = textStore[i]; if (ch == SWT.CR) { // see if the next character is a LF if (i + 1 < textStore.length) { ch = textStore[i+1]; if (ch == SWT.LF) { i++; count++; } } lineCount++; } else if (ch == SWT.LF) { lineCount++; } count++; } i++; } return lineCount; } /** * Returns the number of lines that are in the specified text. *

* * @param text the text to lineate * @return number of lines in the text */ int lineCount(String text){ int lineCount = 0; int length = text.length(); for (int i = 0; i < length; i++) { char ch = text.charAt(i); if (ch == SWT.CR) { if (i + 1 < length && text.charAt(i + 1) == SWT.LF) { i++; } lineCount++; } else if (ch == SWT.LF) { lineCount++; } } return lineCount; } /** * @return the logical length of the text store */ public int getCharCount() { int length = gapEnd - gapStart; return (textStore.length - length); } /** * Returns the line at index without delimiters. *

* * @param index the index of the line to return * @return the logical line text (i.e., without the gap) * @exception IllegalArgumentException

    *
  • ERROR_INVALID_ARGUMENT when index is out of range
  • *
*/ public String getLine(int index) { if ((index >= lineCount) || (index < 0)) error(SWT.ERROR_INVALID_ARGUMENT); int start = lines[index][0]; int length = lines[index][1]; int end = start + length - 1; if (!gapExists() || (end < gapStart) || (start >= gapEnd)) { // line is before or after the gap while ((length - 1 >= 0) && isDelimiter(textStore[start+length-1])) { length--; } return new String(textStore, start, length); } else { // gap is in the specified range, strip out the gap StringBuffer buf = new StringBuffer(); int gapLength = gapEnd - gapStart; buf.append(textStore, start, gapStart - start); buf.append(textStore, gapEnd, length - gapLength - (gapStart - start)); length = buf.length(); while ((length - 1 >=0) && isDelimiter(buf.charAt(length - 1))) { length--; } return buf.toString().substring(0, length); } } /** * Returns the line delimiter that should be used by the StyledText * widget when inserting new lines. This delimiter may be different than the * delimiter that is used by the StyledTextContent interface. *

* * @return the platform line delimiter as specified in the line.separator * system property. */ public String getLineDelimiter() { return LineDelimiter; } /** * Returns the line at the given index with delimiters. *

* @param index the index of the line to return * @return the logical line text (i.e., without the gap) with delimiters */ String getFullLine(int index) { int start = lines[index][0]; int length = lines[index][1]; int end = start + length - 1; if (!gapExists() || (end < gapStart) || (start >= gapEnd)) { // line is before or after the gap return new String(textStore, start, length); } else { // gap is in the specified range, strip out the gap StringBuffer buffer = new StringBuffer(); int gapLength = gapEnd - gapStart; buffer.append(textStore, start, gapStart - start); buffer.append(textStore, gapEnd, length - gapLength - (gapStart - start)); return buffer.toString(); } } /** * Returns the physical line at the given index (i.e., with delimiters and the gap). *

* * @param index the line index * @return the physical line */ String getPhysicalLine(int index) { int start = lines[index][0]; int length = lines[index][1]; return getPhysicalText(start, length); } /** * @return the number of lines in the text store */ public int getLineCount(){ return lineCount; } /** * Returns the line at the given offset. *

* * @param charPosition logical character offset (i.e., does not include gap) * @return the line index * @exception IllegalArgumentException

    *
  • ERROR_INVALID_ARGUMENT when charPosition is out of range
  • *
*/ public int getLineAtOffset(int charPosition){ if ((charPosition > getCharCount()) || (charPosition < 0)) error(SWT.ERROR_INVALID_ARGUMENT); int position; if (charPosition < gapStart) { // position is before the gap position = charPosition; } else { // position includes the gap position = charPosition + (gapEnd - gapStart); } // if last line and the line is not empty you can ask for // a position that doesn't exist (the one to the right of the // last character) - for inserting if (lineCount > 0) { int lastLine = lineCount - 1; if (position == lines[lastLine][0] + lines[lastLine][1]) return lastLine; } int high = lineCount; int low = -1; int index = lineCount; while (high - low > 1) { index = (high + low) / 2; int lineStart = lines[index][0]; int lineEnd = lineStart + lines[index][1] - 1; if (position <= lineStart) { high = index; } else if (position <= lineEnd) { high = index; break; } else { low = index; } } return high; } /** * Returns the line index at the given physical offset. *

* * @param position physical character offset (i.e., includes gap) * @return the line index */ int getLineAtPhysicalOffset(int position){ int high = lineCount; int low = -1; int index = lineCount; while (high - low > 1) { index = (high + low) / 2; int lineStart = lines[index][0]; int lineEnd = lineStart + lines[index][1] - 1; if (position <= lineStart) { high = index; } else if (position <= lineEnd) { high = index; break; } else { low = index; } } return high; } /** * Returns the logical offset of the given line. *

* * @param lineIndex index of line * @return the logical starting offset of the line. When there are not any lines, * getOffsetAtLine(0) is a valid call that should answer 0. * @exception IllegalArgumentException

    *
  • ERROR_INVALID_ARGUMENT when lineIndex is out of range
  • *
*/ public int getOffsetAtLine(int lineIndex) { if (lineIndex == 0) return 0; if ((lineIndex >= lineCount) || (lineIndex < 0)) error(SWT.ERROR_INVALID_ARGUMENT); int start = lines[lineIndex][0]; if (start > gapEnd) { return start - (gapEnd - gapStart); } else { return start; } } /** * Increases the line indexes array to accommodate more lines. *

* * @param numLines the number to increase the array by */ void expandLinesBy(int numLines) { int size = lines.length; if (size - lineCount >= numLines) { return; } int[][] newLines = new int[size+Math.max(10, numLines)][2]; System.arraycopy(lines, 0, newLines, 0, size); lines = newLines; } /** * Reports an SWT error. *

* * @param code the error code */ void error (int code) { SWT.error(code); } /** * Returns whether or not a gap exists in the text store. *

* * @return true if gap exists, false otherwise */ boolean gapExists() { return gapStart != gapEnd; } /** * Returns a string representing the continuous content of * the text store. *

* * @param start the physical start offset of the text to return * @param length the physical length of the text to return * @return the text */ String getPhysicalText(int start, int length) { return new String(textStore, start, length); } /** * Returns a string representing the logical content of * the text store (i.e., gap stripped out). *

* * @param start the logical start offset of the text to return * @param length the logical length of the text to return * @return the text */ public String getTextRange(int start, int length) { if (textStore == null) return ""; if (length == 0) return ""; int end= start + length; if (!gapExists() || (end < gapStart)) return new String(textStore, start, length); if (gapStart < start) { int gapLength= gapEnd - gapStart; return new String(textStore, start + gapLength , length); } StringBuffer buf = new StringBuffer(); buf.append(textStore, start, gapStart - start); buf.append(textStore, gapEnd, end - gapStart); return buf.toString(); } /** * Removes the specified TextChangeListener. *

* * @param listener the listener which should no longer be notified * * @exception IllegalArgumentException

    *
  • ERROR_NULL_ARGUMENT when listener is null
  • *
*/ public void removeTextChangeListener(TextChangeListener listener){ if (listener == null) error(SWT.ERROR_NULL_ARGUMENT); for (int i = 0; i < textListeners.size(); i++) { TypedListener typedListener = (TypedListener) textListeners.elementAt(i); if (typedListener.getEventListener () == listener) { textListeners.removeElementAt(i); break; } } } /** * Replaces the text with newText starting at position start * for a length of replaceLength. Notifies the appropriate listeners. *

* * When sending the TextChangingEvent, newLineCount is the number of * lines that are going to be inserted and replaceLineCount is * the number of lines that are going to be deleted, based on the change * that occurs visually. For example: *

    *
  • (replaceText,newText) ==> (replaceLineCount,newLineCount) *
  • ("","\n") ==> (0,1) *
  • ("\n\n","a") ==> (2,0) *
*

* * @param start start offset of text to replace * @param replaceLength start offset of text to replace * @param newText start offset of text to replace * * @exception SWTException
    *
  • ERROR_INVALID_ARGUMENT when the text change results in a multi byte * line delimiter being split or partially deleted. Splitting a line * delimiter by inserting text between the CR and LF characters of the * \r\n delimiter or deleting part of this line delimiter is not supported
  • *
*/ public void replaceTextRange(int start, int replaceLength, String newText){ // check for invalid replace operations if (!isValidReplace(start, replaceLength, newText)) SWT.error(SWT.ERROR_INVALID_ARGUMENT); // inform listeners StyledTextEvent event = new StyledTextEvent(this); event.type = ST.TextChanging; event.start = start; event.replaceLineCount = lineCount(start, replaceLength); event.text = newText; event.newLineCount = lineCount(newText); event.replaceCharCount = replaceLength; event.newCharCount = newText.length(); sendTextEvent(event); // first delete the text to be replaced delete(start, replaceLength, event.replaceLineCount + 1); // then insert the new text insert(start, newText); // inform listeners event = new StyledTextEvent(this); event.type = ST.TextChanged; sendTextEvent(event); } /** * Sends the text listeners the TextChanged event. */ void sendTextEvent(StyledTextEvent event) { for (int i = 0; i < textListeners.size(); i++) { ((StyledTextListener)textListeners.elementAt(i)).handleEvent(event); } } /** * Sets the content to text and removes the gap since there are no sensible predictions * about where the next change will occur. *

* * @param text the text */ public void setText (String text){ textStore = text.toCharArray(); gapStart = -1; gapEnd = -1; expandExp = 1; indexLines(); StyledTextEvent event = new StyledTextEvent(this); event.type = ST.TextSet; event.text = ""; sendTextEvent(event); } /** * Deletes text. *

* @param position the position at which the text to delete starts * @param length the length of the text to delete * @param numLines the number of lines that are being deleted */ void delete(int position, int length, int numLines) { if (length == 0) return; int startLine = getLineAtOffset(position); int startLineOffset = getOffsetAtLine(startLine); int endLine = getLineAtOffset(position + length); String endText = ""; boolean splittingDelimiter = false; if (position + length < getCharCount()) { endText = getTextRange(position + length - 1, 2); if ((endText.charAt(0) == SWT.CR) && (endText.charAt(1) == SWT.LF)) { splittingDelimiter = true; } } adjustGap(position + length, -length, startLine); int [][] oldLines = indexLines(position, length + (gapEnd - gapStart), numLines); // enlarge the gap - the gap can be enlarged either to the // right or left if (position + length == gapStart) { gapStart -= length; } else { gapEnd += length; } // figure out the length of the new concatenated line, do so by // finding the first line delimiter after position int j = position; boolean eol = false; while (j < textStore.length && !eol) { if (j < gapStart || j >= gapEnd) { char ch = textStore[j]; if (isDelimiter(ch)) { if (j + 1 < textStore.length) { if (ch == SWT.CR && (textStore[j+1] == SWT.LF)) { j++; } } eol = true; } } j++; } // update the line where the deletion started lines[startLine][1] = (position - startLineOffset) + (j - position); // figure out the number of lines that have been deleted int numOldLines = oldLines.length - 1; if (splittingDelimiter) numOldLines -= 1; // shift up the lines after the last deleted line, no need to update // the offset or length of the lines for (int i = endLine + 1; i < lineCount; i++) { lines[i - numOldLines] = lines[i]; } lineCount -= numOldLines; gapLine = getLineAtPhysicalOffset(gapStart); } }





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