/*******************************************************************************
* Copyright (c) 2002, 2009 Innoopract Informationssysteme GmbH.
* 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:
* Innoopract Informationssysteme GmbH - initial API and implementation
* EclipseSource - ongoing development
******************************************************************************/
package org.eclipse.swt.widgets;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.internal.graphics.TextSizeDetermination;
import org.eclipse.swt.internal.widgets.ILinkAdapter;
/**
* Instances of this class represent a selectable
* user interface object that displays a text with
* links.
* <p>
* <dl>
* <dt><b>Styles:</b></dt>
* <dd>(none)</dd>
* <dt><b>Events:</b></dt>
* <dd>Selection</dd>
* </dl>
* <p>
* IMPORTANT: This class is <em>not</em> intended to be subclassed.
* </p>
*
* @since 1.0
*/
public class Link extends Control {
// Must be kept in sync with appearance value in AppearancesBase.js
private final static int PADDING = 2;
private String text = "";
private String displayText = "";
private Point[] offsets;
private String[] ids;
private int[] mnemonics;
private ILinkAdapter linkAdapter;
/**
* Constructs a new instance of this class given its parent
* and a style value describing its behavior and appearance.
* <p>
* The style value is either one of the style constants defined in
* class <code>SWT</code> which is applicable to instances of this
* class, or must be built by <em>bitwise OR</em>'ing together
* (that is, using the <code>int</code> "|" operator) two or more
* of those <code>SWT</code> style constants. The class description
* lists the style constants that are applicable to the class.
* Style bits are also inherited from superclasses.
* </p>
*
* @param parent a composite control which will be the parent of the new instance (cannot be null)
* @param style the style of control to construct
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
* <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
* </ul>
*
* @see Widget#checkSubclass
* @see Widget#getStyle
*/
public Link( final Composite parent, final int style ) {
super( parent, style );
}
void initState() {
state |= THEME_BACKGROUND;
}
/**
* Sets the receiver's text.
* <p>
* The string can contain both regular text and hyperlinks. A hyperlink
* is delimited by an anchor tag, <A> and </A>. Within an
* anchor, a single HREF attribute is supported. When a hyperlink is
* selected, the text field of the selection event contains either the
* text of the hyperlink or the value of its HREF, if one was specified.
* In the rare case of identical hyperlinks within the same string, the
* HREF tag can be used to distinguish between them. The string may
* include the mnemonic character and line delimiters.
* </p>
*
* @param string the new text
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if the text is null</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
* </ul>
*/
public void setText( final String string ) {
checkWidget();
if( string == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
if( !string.equals( text ) ) {
displayText = parse( string );
text = string;
}
}
/**
* Returns the receiver's text, which will be an empty
* string if it has never been set.
*
* @return the receiver's text
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
* </ul>
*/
public String getText() {
checkWidget();
return text;
}
///////////////////////////////////////
// Listener registration/deregistration
/**
* Adds the listener to the collection of listeners who will
* be notified when the control is selected, by sending
* it one of the messages defined in the <code>SelectionListener</code>
* interface.
* <p>
* <code>widgetSelected</code> is called when the control is selected.
* <code>widgetDefaultSelected</code> is not called.
* </p>
*
* @param listener the listener which should be notified
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
* </ul>
*
* @see SelectionListener
* @see #removeSelectionListener
* @see SelectionEvent
*/
public void addSelectionListener( final SelectionListener listener ) {
checkWidget();
SelectionEvent.addListener( this, listener );
}
/**
* Removes the listener from the collection of listeners who will
* be notified when the control is selected.
*
* @param listener the listener which should no longer be notified
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
* </ul>
*
* @see SelectionListener
* @see #addSelectionListener
*/
public void removeSelectionListener( final SelectionListener listener ) {
checkWidget();
SelectionEvent.removeListener( this, listener );
}
public Point computeSize( final int wHint,
final int hHint,
final boolean changed )
{
checkWidget();
int width = 0;
int height = 0;
int border = getBorderWidth();
if( ( displayText.length() > 0 ) ) {
// Replace '&' with '&&' to ensure proper size calculation with one '&',
// because the other will be escaped in
// TextSizeDetermination#createMeasureString()
String string = escapeAmpersand( displayText );
Point extent
= TextSizeDetermination.textExtent( getFont(), string, wHint );
width = extent.x;
height = extent.y;
}
if( wHint != SWT.DEFAULT ) {
width = wHint;
}
if( hHint != SWT.DEFAULT ) {
height = hHint;
}
width += border * 2 + PADDING * 2;
height += border * 2 + PADDING * 2;
return new Point( width, height );
}
private static String escapeAmpersand( final String string ) {
StringBuffer result = new StringBuffer();
for( int i = 0; i < string.length(); i++ ) {
if( string.charAt( i ) == '&' ) {
result.append( "&&" );
} else {
result.append( string.charAt( i ) );
}
}
return result.toString();
}
public Object getAdapter( final Class adapter ) {
Object result;
if( adapter == ILinkAdapter.class ) {
if( linkAdapter == null ) {
linkAdapter = new ILinkAdapter() {
public String getDisplayText() {
return displayText;
}
public Point[] getOffsets() {
return offsets;
}
public String[] getIds() {
return ids;
}
};
}
result = linkAdapter;
} else {
result = super.getAdapter( adapter );
}
return result;
}
boolean isTabGroup() {
return true;
}
String getNameText() {
return getText();
}
/* verbatim copy from SWT */
String parse( String string ) {
int length = string.length();
offsets = new Point[ length / 4 ];
ids = new String[ length / 4 ];
mnemonics = new int[ length / 4 + 1 ];
StringBuffer result = new StringBuffer();
char[] buffer = new char[ length ];
string.getChars( 0, string.length(), buffer, 0 );
int index = 0, state = 0, linkIndex = 0;
int start = 0, tagStart = 0, linkStart = 0, endtagStart = 0, refStart = 0;
while( index < length ) {
char c = Character.toLowerCase( buffer[ index ] );
switch( state ) {
case 0:
if( c == '<' ) {
tagStart = index;
state++;
}
break;
case 1:
if( c == 'a' )
state++;
break;
case 2:
switch( c ) {
case 'h':
state = 7;
break;
case '>':
linkStart = index + 1;
state++;
break;
default:
if( Character.isWhitespace( c ) )
break;
else
state = 13;
}
break;
case 3:
if( c == '<' ) {
endtagStart = index;
state++;
}
break;
case 4:
state = c == '/'
? state + 1
: 3;
break;
case 5:
state = c == 'a'
? state + 1
: 3;
break;
case 6:
if( c == '>' ) {
mnemonics[ linkIndex ] = parseMnemonics( buffer,
start,
tagStart,
result );
int offset = result.length();
parseMnemonics( buffer, linkStart, endtagStart, result );
offsets[ linkIndex ] = new Point( offset, result.length() - 1 );
if( ids[ linkIndex ] == null ) {
ids[ linkIndex ] = new String( buffer, linkStart, endtagStart
- linkStart );
}
linkIndex++;
start = tagStart = linkStart = endtagStart = refStart = index + 1;
state = 0;
} else {
state = 3;
}
break;
case 7:
state = c == 'r'
? state + 1
: 0;
break;
case 8:
state = c == 'e'
? state + 1
: 0;
break;
case 9:
state = c == 'f'
? state + 1
: 0;
break;
case 10:
state = c == '='
? state + 1
: 0;
break;
case 11:
if( c == '"' ) {
state++;
refStart = index + 1;
} else {
state = 0;
}
break;
case 12:
if( c == '"' ) {
ids[ linkIndex ] = new String( buffer, refStart, index - refStart );
state = 2;
}
break;
case 13:
if( Character.isWhitespace( c ) ) {
state = 0;
} else if( c == '=' ) {
state++;
}
break;
case 14:
state = c == '"'
? state + 1
: 0;
break;
case 15:
if( c == '"' )
state = 2;
break;
default:
state = 0;
break;
}
index++;
}
if( start < length ) {
int tmp = parseMnemonics( buffer, start, tagStart, result );
int mnemonic = parseMnemonics( buffer,
Math.max( tagStart, linkStart ),
length,
result );
if( mnemonic == -1 )
mnemonic = tmp;
mnemonics[ linkIndex ] = mnemonic;
} else {
mnemonics[ linkIndex ] = -1;
}
if( offsets.length != linkIndex ) {
Point[] newOffsets = new Point[ linkIndex ];
System.arraycopy( offsets, 0, newOffsets, 0, linkIndex );
offsets = newOffsets;
String[] newIDs = new String[ linkIndex ];
System.arraycopy( ids, 0, newIDs, 0, linkIndex );
ids = newIDs;
int[] newMnemonics = new int[ linkIndex + 1 ];
System.arraycopy( mnemonics, 0, newMnemonics, 0, linkIndex + 1 );
mnemonics = newMnemonics;
}
return result.toString();
}
/* verbatim copy from SWT */
int parseMnemonics( char[] buffer, int start, int end, StringBuffer result ) {
int mnemonic = -1, index = start;
while( index < end ) {
if( buffer[ index ] == '&' ) {
if( index + 1 < end && buffer[ index + 1 ] == '&' ) {
result.append( buffer[ index ] );
index++;
} else {
mnemonic = result.length();
}
} else {
result.append( buffer[ index ] );
}
index++;
}
return mnemonic;
}
}