/*******************************************************************************
* 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;
/**
* Clients may implement the StyledTextContent interface to provide a
* custom store for the StyledText widget content. The StyledText widget
* interacts with its StyledTextContent in order to access and update
* the text that is being displayed and edited in the widget.
* A custom content implementation can be set in the widget using the
* StyledText.setContent API.
*/
public interface StyledTextContent {
/**
* Called by StyledText to add itself as an Observer to content changes.
* See TextChangeListener for a description of the listener methods that
* are called when text changes occur.
* <p>
*
* @param listener the listener
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT when listener is null</li>
* </ul>
*/
public void addTextChangeListener(TextChangeListener listener);
/**
* Return the number of characters in the content.
* <p>
*
* @return the number of characters in the content.
*/
public int getCharCount();
/**
* Return the line at the given line index without delimiters.
* <p>
*
* @param lineIndex index of the line to return. Does not include
* delimiters of preceding lines. Index 0 is the first line of the
* content.
* @return the line text without delimiters
*/
public String getLine(int lineIndex);
/**
* Return the line index at the given character offset.
* <p>
*
* @param offset offset of the line to return. The first character of the
* document is at offset 0. An offset of getLength() is valid and should
* answer the number of lines.
* @return the line index. The first line is at index 0. If the character
* at offset is a delimiter character, answer the line index of the line
* that is delimited.
* For example, if text = "\r\n\r\n", and delimiter = "\r\n", then:
* <ul>
* <li>getLineAtOffset(0) == 0
* <li>getLineAtOffset(1) == 0
* <li>getLineAtOffset(2) == 1
* <li>getLineAtOffset(3) == 1
* <li>getLineAtOffset(4) == 2
* </ul>
*/
public int getLineAtOffset(int offset);
/**
* Return the number of lines. Should answer 1 when no text is specified.
* The StyledText widget relies on this behavior for drawing the cursor.
* <p>
*
* @return the number of lines. For example:
* <ul>
* <li> text value ==> getLineCount
* <li> null ==> 1
* <li> "" ==> 1
* <li> "a\n" ==> 2
* <li> "\n\n" ==> 3
* </ul>
*/
public int getLineCount();
/**
* Return the line delimiter that should be used by the StyledText
* widget when inserting new lines. New lines entered using key strokes
* and paste operations use this line delimiter.
* Implementors may use System.getProperty("line.separator") to return
* the platform line delimiter.
* <p>
*
* @return the line delimiter that should be used by the StyledText widget
* when inserting new lines.
*/
public String getLineDelimiter();
/**
* Return the character offset of the first character of the given line.
* <p>
* <b>NOTE:</b> When there is no text (i.e., no lines), getOffsetAtLine(0)
* is a valid call that should return 0.
* </p>
*
* @param lineIndex index of the line. The first line is at index 0.
* @return offset offset of the first character of the line. The first
* character of the document is at offset 0. The return value should
* include line delimiters.
* For example, if text = "\r\ntest\r\n" and delimiter = "\r\n", then:
* <ul>
* <li>getOffsetAtLine(0) == 0
* <li>getOffsetAtLine(1) == 2
* <li>getOffsetAtLine(2) == 8
* </ul>
*/
public int getOffsetAtLine(int lineIndex);
/**
* Returns a string representing the content at the given range.
* <p>
*
* @param start the start offset of the text to return. Offset 0 is the
* first character of the document.
* @param length the length of the text to return
* @return the text at the given range
*/
public String getTextRange(int start, int length);
/**
* Remove the specified text changed listener.
* <p>
*
* @param listener the listener which should no longer be notified
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT when listener is null</li>
* </ul>
*/
public void removeTextChangeListener(TextChangeListener listener);
/**
* Replace the text with "newText" starting at position "start"
* for a length of "replaceLength".
* <p>
* Implementors have to notify the TextChangeListeners that were added
* using <code>addTextChangeListener</code> before and after the content
* is changed. A <code>TextChangingEvent</code> has to be sent to the
* textChanging method before the content is changed and a
* <code>TextChangedEvent</code> has to be sent to the textChanged method
* after the content has changed.
* The text change that occurs after the <code>TextChangingEvent</code>
* has been sent has to be consistent with the data provided in the
* <code>TextChangingEvent</code>.
* This data will be cached by the widget and will be used when the
* <code>TextChangedEvent</code> is received.
* <p>
* The <code>TextChangingEvent</code> should be set as follows:
* <ul>
* <li>event.start = start of the replaced text
* <li>event.newText = text that is going to be inserted or empty String
* if no text will be inserted
* <li>event.replaceCharCount = length of text that is going to be replaced
* <li>event.newCharCount = length of text that is going to be inserted
* <li>event.replaceLineCount = number of lines that are going to be replaced
* <li>event.newLineCount = number of new lines that are going to be inserted
* </ul>
* <b>NOTE:</b> newLineCount is the number of inserted lines and replaceLineCount
* is the number of deleted lines 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)
* <li>("a", "\n\n") ==> (0, 2)
* <li>("\n", "") ==> (1, 0)
* </ul>
* </p>
*
* @param start start offset of text to replace, none of the offsets include
* delimiters of preceding lines, offset 0 is the first character of the
* document
* @param replaceLength length of text to replace
* @param text text to replace
* @see TextChangeListener
*/
public void replaceTextRange(int start, int replaceLength, String text);
/**
* Set text to "text".
* Implementors have to send a <code>TextChangedEvent</code> to the
* textSet method of the TextChangeListeners that were added using
* <code>addTextChangeListener</code>.
* <p>
*
* @param text the new text
* @see TextChangeListener
*/
public void setText(String text);
}