package org.eclipse.swt.internal.extension;

import org.eclipse.ercp.swt.mobile.ConstrainedText;

import org.eclipse.ercp.swt.mobile.Internal_MobilePackageSupport;

import org.eclipse.swt.SWTException;

import org.eclipse.swt.internal.qt.OS;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.swt.widgets.Event;

import org.eclipse.swt.widgets.Internal_PackageSupport;

import org.eclipse.swt.widgets.Listener;

/**

 * An extension class to ConstrainedText.

 * 

 * <p>

 * To listen to caret movement or selection change events, create listeners

 * of type <code>SWTExtension.CaretMoved</code> or 

 * <code>SWTExtension.ContentSelected</code>. 

 * </p><p>

 * Here is an example of using a <code>ConstrainedTextExtension</code> 

 * with the extended listeners:

 * <code><pre>

 * ConstrainedTextExtension text = new ConstrainedTextExtension(shell, SWT.LEFT, ConstrainedText.DECIMAL);

 * text.setText("123456789");

 *      

 * text.addListener(SWTExtension.CaretMoved, new Listener() {

 *     public void handleEvent(Event event) {

 *         System.out.println("Caret moved, new position "+event.x);

 *     }});

 *      

 * text.addListener(SWTExtension.ContentSelected, new Listener() {

 *     public void handleEvent(Event event) {

 *         System.out.println("Selection changed, pos "+event.x+", len "+event.count);

 *     }});

 * </pre></code></p>

 */

public class ConstrainedTextExtension extends ConstrainedText {

public ConstrainedTextExtension(Composite parent, int style, int constrainedStyle) {

    super(parent, style, constrainedStyle, true);

}

/**

 * Adds the listener to the collection of listeners who will

 * be notified when an event of the given type occurs. When the

 * event does occur in the widget, the listener is notified by

 * sending it the <code>handleEvent()</code> message. The event

 * type is one of the event constants defined in class <code>SWT</code>.

 * 

 * To listen to caret moved event, add a listener of type 

 * <code>SWTExtension.CaretMoved</code>. New position of the caret is placed

 * in <code>event.x</code>.

 *

 * To listen to content selection event, add a listener of type

 * <code>SWTExtension.ContentSelected</code>. Index of the first selected 

 * character is placed in <code>event.x</code>, number of selected characters 

 * is placed in <code>event.count</code>.

 *

 * @param eventType the type of event to listen for

 * @param listener the listener which should be notified when the event occurs

 *

 * @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 Listener

 * @see SWTExtension

 * @see Event

 * @see #removeListener(int, Listener)

 * @see #notifyListeners

 */

public void addListener(int eventType, Listener listener) {

    super.addListener(eventType, listener);

}

/**

 * Returns the number of lines.

 *

 * @return the number of lines in the widget

 *

 * @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 getLineCount() {

    checkWidget();

    return 1;

}

/**

 * Returns the height of a line.

 *

 * @return the height of a row of 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 int getLineHeight () {

    checkWidget();

    return OS.QWidget_QFontMetrics_lineSpacing(Internal_PackageSupport.handle(this));

}

/**

 * Gets the selected text, or an empty string if there is no current selection.

 *

 * @return the selected 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 getSelectionText () {

    return Internal_MobilePackageSupport.getSelectionText(this); 

}

/**

 * Returns the zero-relative index of the line which is currently

 * at the top of the receiver.

 * <p>

 * This index can change when lines are scrolled or new lines are added or removed.

 * </p>

 *

 * @return the index of the top line

 *

 * @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 getTopIndex () {

    checkWidget ();

    return 0;

}

/**

 * Returns the top pixel.

 * <p>

 * The top pixel is the pixel position of the line

 * that is currently at the top of the widget.  On

 * some platforms, a text widget can be scrolled by

 * pixels instead of lines so that a partial line

 * is displayed at the top of the widget.

 * </p><p>

 * The top pixel changes when the widget is scrolled.

 * The top pixel does not include the widget trimming.

 * </p>

 *

 * @return the pixel position of the top line

 *

 * @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 getTopPixel () {

    checkWidget ();

    return 0;

}

}