/*******************************************************************************
* Copyright (c) 2007, 2011, 2012 IBM Corporation, Gerhardt Informatics Kft. 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
* Gerhardt Informatics Kft. - GEFGWT port
*******************************************************************************/
package org.eclipse.swt.widgets;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.graphics.TextStyle;
/**
* Instances of this class represent input method editors. These are typically
* in-line pre-edit text areas that allow the user to compose characters from
* Far Eastern languages such as Japanese, Chinese or Korean.
*
* <dl>
* <dt><b>Styles:</b></dt>
* <dd>(none)</dd>
* <dt><b>Events:</b></dt>
* <dd>ImeComposition</dd>
* </dl>
* <p>
* IMPORTANT: This class is <em>not</em> intended to be subclassed.
* </p>
*
* @see <a href="http://www.eclipse.org/swt/">Sample code and further
* information</a>
*
* @since 3.4
* @noextend This class is not intended to be subclassed by clients.
*/
public class IME extends Widget {
Canvas parent;
int caretOffset;
int startOffset;
int commitCount;
String text;
int[] ranges;
TextStyle[] styles;
boolean inComposition;
/**
* Prevents uninitialized instances from being created outside the package.
*/
IME() {
}
/**
* 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 canvas 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 IME(Canvas parent, int style) {
super(parent, style);
this.parent = parent;
createWidget();
}
void createWidget() {
text = "";
startOffset = -1;
if (parent.getIME() == null) {
parent.setIME(this);
}
}
/**
* Returns the offset of the caret from the start of the document. The caret
* is within the current composition.
*
* @return the caret offset
*
* @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 int getCaretOffset() {
checkWidget();
return startOffset + caretOffset;
}
/**
* Returns the commit count of the composition. This is the number of
* characters that have been composed. When the commit count is equal to the
* length of the composition text, then the in-line edit operation is
* complete.
*
* @return the commit count
*
* @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 IME#getText
*/
public int getCommitCount() {
checkWidget();
return commitCount;
}
/**
* Returns the offset of the composition from the start of the document.
* This is the start offset of the composition within the document and in
* not changed by the input method editor itself during the in-line edit
* session.
*
* @return the offset of the composition
*
* @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 int getCompositionOffset() {
checkWidget();
return startOffset;
}
/**
* Returns the ranges for the style that should be applied during the
* in-line edit session.
* <p>
* The ranges array contains start and end pairs. Each pair refers to the
* corresponding style in the styles array. For example, the pair that
* starts at ranges[n] and ends at ranges[n+1] uses the style at styles[n/2]
* returned by <code>getStyles()</code>.
* </p>
*
* @return the ranges for the styles
*
* @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 IME#getStyles
*/
public int[] getRanges() {
checkWidget();
if (ranges == null)
return new int[0];
int[] result = new int[ranges.length];
for (int i = 0; i < result.length; i++) {
result[i] = ranges[i] + startOffset;
}
return result;
}
/**
* Returns the styles for the ranges.
* <p>
* The ranges array contains start and end pairs. Each pair refers to the
* corresponding style in the styles array. For example, the pair that
* starts at ranges[n] and ends at ranges[n+1] uses the style at
* styles[n/2].
* </p>
*
* @return the ranges for the styles
*
* @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 IME#getRanges
*/
public TextStyle[] getStyles() {
checkWidget();
if (styles == null)
return new TextStyle[0];
TextStyle[] result = new TextStyle[styles.length];
System.arraycopy(styles, 0, result, 0, styles.length);
return result;
}
/**
* Returns the composition text.
* <p>
* The text for an IME is the characters in the widget that are in the
* current composition. When the commit count is equal to the length of the
* composition text, then the in-line edit operation is complete.
* </p>
*
* @return the widget 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;
}
/**
* Returns <code>true</code> if the caret should be wide, and
* <code>false</code> otherwise. In some languages, for example Korean, the
* caret is typically widened to the width of the current character in the
* in-line edit session.
*
* @return the wide caret state
*
* @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 boolean getWideCaret() {
checkWidget();
return false;
}
void releaseParent() {
super.releaseParent();
if (this == parent.getIME())
parent.setIME(null);
}
void releaseWidget() {
super.releaseWidget();
parent = null;
text = null;
styles = null;
ranges = null;
}
/**
* Sets the offset of the composition from the start of the document. This
* is the start offset of the composition within the document and in not
* changed by the input method editor itself during the in-line edit session
* but may need to be changed by clients of the IME. For example, if during
* an in-line edit operation, a text editor inserts characters above the
* IME, then the IME must be informed that the composition offset has
* changed.
*
* @param offset
* the offset of the composition
*
* @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 setCompositionOffset(int offset) {
checkWidget();
if (offset < 0)
return;
if (startOffset != -1) {
startOffset = offset;
}
}
}