defaultcontent.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

 */
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 <code>index</code> without delimiters.
 * <p>
 *
 * @param index	the index of the line to return
 * @return the logical line text (i.e., without the gap)
 * @exception IllegalArgumentException <ul>
 *   <li>ERROR_INVALID_ARGUMENT when index is out of range</li>
 * </ul>
 */
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 <code>StyledTextContent</code> interface.
 * <p>
 *
 * @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.
 * <p>
 * @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 buf = new StringBuffer();
		int gapLength = gapEnd - gapStart;
		buf.append(textStore, start, gapStart - start);
		buf.append(textStore, gapEnd, length - gapLength - (gapStart - start));
		return buf.toString();
	}
}
/**
 * Returns the physical line at the given index (i.e., with delimiters and the gap).
 * <p>
 *
 * @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.
 * <p>
 *
 * @param charPosition logical character offset (i.e., does not include gap)
 * @return the line index
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT when charPosition is out of range</li>
 * </ul>
 */
public int getLineAtOffset(int charPosition){
	int position;
	if ((charPosition > getCharCount()) || (charPosition < 0)) error(SWT.ERROR_INVALID_ARGUMENT);
	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.
 * <p>
 *
 * @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.
 * <p>
 *
 * @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 <ul>
 *   <li>ERROR_INVALID_ARGUMENT when lineIndex is out of range</li>
 * </ul>
 */
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 accomodate more lines.
 * <p>
 *
 * @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.
 * <p>
 *
 * @param code the error code
 */
void error (int code) {
	SWT.error(code);
}
/** 
 * Returns whether or not a gap exists in the text store.
 * <p>
 *
 * @return true if gap exists, false otherwise
 */
boolean gapExists() {
	return gapStart != gapEnd;
}	

/**
 * Returns a string representing the continous content of
 * the text store.
 * <p>
 *
 * @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).
 * <p>
 *
 * @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 <code>TextChangeListener</code>.
 * <p>
 *
 * @param listener the listener
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT when listener is null</li>
 * </ul>
 */
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 <code>newText</code> starting at position <code>start</code> 
 * for a length of <code>replaceLength</code>.  Notifies the appropriate listeners.
 * <p>
 *
 * When sending the TextChangingEvent, <code>newLineCount</code> is the number of 
 * lines that are going to be inserted and <code>replaceLineCount</code> is 
 * the number of lines that are going to be deleted, based on the change 
 * that occurs visually.  For example:
 * <ul>
 * <li>(replaceText,newText) ==> (replaceLineCount,newLineCount)
 * <li>("","\n") ==> (0,1)
 * <li>("\n\n","a") ==> (2,0)
 * </ul>
 * </p>
 *
 * @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 <ul>
 *   <li>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</li>
 * </ul>
 */
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 = StyledText.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 = StyledText.TextChanged;
	sendTextEvent(event);		
	// printLines();
}
/**
 * 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.
 * <p>
 *
 * @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 = StyledText.TextSet;
	event.text = "";
	sendTextEvent(event);
}
/**
 * Deletes text.
 * <p>
 * @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 delmiter 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);		
}
}