org.mihalis.opal/src/main/java/org/mihalis/opal/textAssist/TextAssist.java

/*******************************************************************************
 * Copyright (c) 2011 Laurent CARON.
 * 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 (Snippet 320)
 *     Laurent CARON (laurent.caron@gmail.com) - Make a widget from the snippet
 *******************************************************************************/
package org.mihalis.opal.textAssist;

import java.util.List;

import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.events.VerifyListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableItem;
import org.eclipse.swt.widgets.Text;
import org.eclipse.swt.widgets.Widget;

/**
 * Instances of this class are selectable user interface objects that allow the
 * user to enter and modify text. The difference with the Text widget is that
 * when the user types something, some propositions are displayed.
 *
 * @see org.eclipse.swt.widgets.Text
 */
public class TextAssist extends Composite {

	/** The Constant SETTEXT_KEY. */
	private static final String SETTEXT_KEY = "org.mihalis.opal.textAssist.TextAssist.settext";
	
	/** The text. */
	private final Text text;
	
	/** The popup. */
	private final Shell popup;
	
	/** The table. */
	private final Table table;
	
	/** The content provider. */
	private TextAssistContentProvider contentProvider;
	
	/** The number of lines. */
	private int numberOfLines;

	/**
	 * 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
	 * @param contentProvider the content provider
	 * @see SWT#SINGLE
	 * @see SWT#MULTI
	 * @see SWT#READ_ONLY
	 * @see SWT#WRAP
	 * @see SWT#LEFT
	 * @see SWT#RIGHT
	 * @see SWT#CENTER
	 * @see SWT#PASSWORD
	 * @see SWT#SEARCH
	 * @see SWT#ICON_SEARCH
	 * @see SWT#ICON_CANCEL
	 * @see Widget#checkSubclass
	 * @see Widget#getStyle
	 * @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>
	 */
	public TextAssist(final Composite parent, final int style, final TextAssistContentProvider contentProvider) {
		super(parent, SWT.NONE);
		this.contentProvider = contentProvider;
		this.contentProvider.setTextAssist(this);

		setLayout(new FillLayout());
		numberOfLines = 10;
		text = new Text(this, style);
		popup = new Shell(getDisplay(), SWT.ON_TOP);
		popup.setLayout(new FillLayout());
		table = new Table(popup, SWT.SINGLE);

		addTextListener();
		addTableLittle();

		final int[] events = new int[] { SWT.Move, SWT.FocusOut };
		for (final int event : events) {
			getShell().addListener(event, new Listener() {
				@Override
				public void handleEvent(final Event event) {
					popup.setVisible(false);
				}
			});
		}

	}

	/**
	 * Adds the text listener.
	 */
	private void addTextListener() {
		text.addListener(SWT.KeyDown, createKeyDownListener());
		text.addListener(SWT.Modify, createModifyListener());
		text.addListener(SWT.FocusOut, createFocusOutListener());
	}

	/**
	 * Adds the table little.
	 */
	private void addTableLittle() {
		table.addListener(SWT.DefaultSelection, new Listener() {
			@Override
			public void handleEvent(final Event event) {
				text.setText(table.getSelection()[0].getText());
				popup.setVisible(false);
			}
		});
		table.addListener(SWT.KeyDown, new Listener() {
			@Override
			public void handleEvent(final Event event) {
				if (event.keyCode == SWT.ESC) {
					popup.setVisible(false);
				}
			}
		});

		table.addListener(SWT.FocusOut, createFocusOutListener());
	}

	/**
	 * Creates the key down listener.
	 *
	 * @return a listener for the keydown event
	 */
	private Listener createKeyDownListener() {
		return new Listener() {
			@Override
			public void handleEvent(final Event event) {
				switch (event.keyCode) {
				case SWT.ARROW_DOWN:
					int index = (table.getSelectionIndex() + 1) % table.getItemCount();
					table.setSelection(index);
					event.doit = false;
					break;
				case SWT.ARROW_UP:
					index = table.getSelectionIndex() - 1;
					if (index < 0) {
						index = table.getItemCount() - 1;
					}
					table.setSelection(index);
					event.doit = false;
					break;
				case SWT.CR:
				case SWT.KEYPAD_CR:
					if (popup.isVisible() && table.getSelectionIndex() != -1) {
						text.setText(table.getSelection()[0].getText());
						popup.setVisible(false);
					}
					break;
				case SWT.ESC:
					popup.setVisible(false);
					break;
				}
			}
		};
	}

	/**
	 * Creates the modify listener.
	 *
	 * @return a listener for the modify event
	 */
	private Listener createModifyListener() {
		return new Listener() {
			@Override
			public void handleEvent(final Event event) {
				if (text.getData(SETTEXT_KEY) != null && Boolean.TRUE.equals(text.getData(SETTEXT_KEY))) {
					text.setData(SETTEXT_KEY, null);
					return;
				}
				text.setData(SETTEXT_KEY, null);

				final String string = text.getText();
				if (string.length() == 0) {
					popup.setVisible(false);
					return;
				}

				List<String> values = contentProvider.getContent(string);
				if (values == null || values.isEmpty()) {
					popup.setVisible(false);
					return;
				}

				if (values.size() > numberOfLines) {
					values = values.subList(0, numberOfLines);
				}

				table.removeAll();
				final int numberOfRows = Math.min(values.size(), numberOfLines);
				for (int i = 0; i < numberOfRows; i++) {
					final TableItem tableItem = new TableItem(table, SWT.NONE);
					tableItem.setText(values.get(i));
				}

				final Point point = text.toDisplay(text.getLocation().x, text.getSize().y + text.getBorderWidth() - 3);
				int x = point.x;
				int y = point.y;

				final Rectangle displayRect = getMonitor().getClientArea();
				final Rectangle parentRect = getDisplay().map(getParent(), null, getBounds());
				popup.pack();
				final int width = popup.getBounds().width;
				final int height = popup.getBounds().height;

				if (y + height > displayRect.y + displayRect.height) {
					y = parentRect.y - height;
				}
				if (x + width > displayRect.x + displayRect.width) {
					x = displayRect.x + displayRect.width - width;
				}

				popup.setLocation(x, y);
				popup.setVisible(true);

			}
		};
	}

	/**
	 * Creates the focus out listener.
	 *
	 * @return a listener for the FocusOut event
	 */
	private Listener createFocusOutListener() {
		return new Listener() {
			@Override
			public void handleEvent(final Event event) {
				/*
				 * Async is needed to wait until focus reaches its new Control
				 */
				TextAssist.this.getDisplay().asyncExec(new Runnable() {
					@Override
					public void run() {
						if (TextAssist.this.isDisposed() || TextAssist.this.getDisplay().isDisposed()) {
							return;
						}
						final Control control = TextAssist.this.getDisplay().getFocusControl();
						if (control == null || control != text && control != table) {
							popup.setVisible(false);
						}
					}
				});
			}
		};
	}

	/**
	 * Gets the background.
	 *
	 * @return the background
	 * @see org.eclipse.swt.widgets.Control#getBackground()
	 */
	@Override
	public Color getBackground() {
		checkWidget();
		return text.getBackground();
	}

	/**
	 * Gets the content provider.
	 *
	 * @return the contentProvider
	 */
	public TextAssistContentProvider getContentProvider() {
		checkWidget();
		return contentProvider;
	}

	/**
	 * Gets the foreground.
	 *
	 * @return the foreground
	 * @see org.eclipse.swt.widgets.Control#getForeground()
	 */
	@Override
	public Color getForeground() {
		checkWidget();
		return super.getForeground();
	}

	/**
	 * Sets the background.
	 *
	 * @param color the new background
	 * @see org.eclipse.swt.widgets.Text#setBackground(org.eclipse.swt.graphics.Color)
	 */
	@Override
	public void setBackground(final Color color) {
		checkWidget();
		text.setBackground(color);
	}

	/**
	 * Sets the content provider.
	 *
	 * @param contentProvider the contentProvider to set
	 */
	public void setContentProvider(final TextAssistContentProvider contentProvider) {
		checkWidget();
		this.contentProvider = contentProvider;
	}

	/**
	 * Gets the number of lines.
	 *
	 * @return the numberOfLines
	 */
	public int getNumberOfLines() {
		checkWidget();
		return numberOfLines;
	}

	/**
	 * Sets the number of lines.
	 *
	 * @param numberOfLines the numberOfLines to set
	 */
	public void setNumberOfLines(final int numberOfLines) {
		checkWidget();
		this.numberOfLines = numberOfLines;
	}

	/**
	 * Adds the listener.
	 *
	 * @param eventType the event type
	 * @param listener the listener
	 * @see org.eclipse.swt.widgets.Text#addListener(int,org.eclipse.swt.widgets.Listener)
	 */
	@Override
	public void addListener(final int eventType, final Listener listener) {
		checkWidget();
		text.addListener(eventType, listener);
	}

	/**
	 * Adds the modify listener.
	 *
	 * @param listener the listener
	 * @see org.eclipse.swt.widgets.Text#addModifyListener(org.eclipse.swt.events.ModifyListener)
	 */
	public void addModifyListener(final ModifyListener listener) {
		checkWidget();
		text.addModifyListener(listener);
	}

	/**
	 * Adds the selection listener.
	 *
	 * @param listener the listener
	 * @see org.eclipse.swt.widgets.Text#addSelectionListener(org.eclipse.swt.events.SelectionListener)
	 */
	public void addSelectionListener(final SelectionListener listener) {
		checkWidget();
		text.addSelectionListener(listener);
	}

	/**
	 * Adds the verify listener.
	 *
	 * @param listener the listener
	 * @see org.eclipse.swt.widgets.Text#addVerifyListener(org.eclipse.swt.events.VerifyListener)
	 */
	public void addVerifyListener(final VerifyListener listener) {
		checkWidget();
		text.addVerifyListener(listener);
	}

	/**
	 * Append.
	 *
	 * @param string the string
	 * @see org.eclipse.swt.widgets.Text#append(java.lang.String)
	 */
	public void append(final String string) {
		checkWidget();
		text.append(string);
	}

	/**
	 * Clear selection.
	 *
	 * @see org.eclipse.swt.widgets.Text#clearSelection()
	 */
	public void clearSelection() {
		checkWidget();
		text.clearSelection();
	}

	/**
	 * Compute size.
	 *
	 * @param wHint the w hint
	 * @param hHint the h hint
	 * @param changed the changed
	 * @return the point
	 * @see org.eclipse.swt.widgets.Text#computeSize(int, int, boolean)
	 */
	@Override
	public Point computeSize(final int wHint, final int hHint, final boolean changed) {
		checkWidget();
		return text.computeSize(wHint, hHint, changed);
	}

	/**
	 * Compute trim.
	 *
	 * @param x the x
	 * @param y the y
	 * @param width the width
	 * @param height the height
	 * @return the rectangle
	 * @see org.eclipse.swt.widgets.Text#computeTrim(int, int, int, int)
	 */
	@Override
	public Rectangle computeTrim(final int x, final int y, final int width, final int height) {
		checkWidget();
		return super.computeTrim(x, y, width, height);
	}

	/**
	 * Copy.
	 *
	 * @see org.eclipse.swt.widgets.Text#copy()
	 */
	public void copy() {
		checkWidget();
		text.copy();
	}

	/**
	 * Cut.
	 *
	 * @see org.eclipse.swt.widgets.Text#cut()
	 */
	public void cut() {
		checkWidget();
		text.cut();
	}

	/**
	 * Gets the caret line number.
	 *
	 * @return the caret line number
	 * @see org.eclipse.swt.widgets.Text#getCaretLineNumber()
	 */
	public int getCaretLineNumber() {
		checkWidget();
		return text.getCaretLineNumber();
	}

	/**
	 * Gets the caret location.
	 *
	 * @return the caret location
	 * @see org.eclipse.swt.widgets.Text#getCaretLocation()
	 */
	public Point getCaretLocation() {
		checkWidget();
		return text.getCaretLocation();
	}

	/**
	 * Gets the caret position.
	 *
	 * @return the caret position
	 * @see org.eclipse.swt.widgets.Text#getCaretPosition()
	 */
	public int getCaretPosition() {
		checkWidget();
		return text.getCaretPosition();
	}

	/**
	 * Gets the char count.
	 *
	 * @return the char count
	 * @see org.eclipse.swt.widgets.Text#getCharCount()
	 */
	public int getCharCount() {
		checkWidget();
		return text.getCharCount();
	}

	/**
	 * Gets the double click enabled.
	 *
	 * @return the double click enabled
	 * @see org.eclipse.swt.widgets.Text#getDoubleClickEnabled()
	 */
	public boolean getDoubleClickEnabled() {
		checkWidget();
		return text.getDoubleClickEnabled();
	}

	/**
	 * Gets the echo char.
	 *
	 * @return the echo char
	 * @see org.eclipse.swt.widgets.Text#getEchoChar()
	 */
	public char getEchoChar() {
		checkWidget();
		return text.getEchoChar();
	}

	/**
	 * Gets the editable.
	 *
	 * @return the editable
	 * @see org.eclipse.swt.widgets.Text#getEditable()
	 */
	public boolean getEditable() {
		checkWidget();
		return text.getEditable();
	}

	/**
	 * Gets the enabled.
	 *
	 * @return the enabled
	 * @see org.eclipse.swt.widgets.Control#getEnabled()
	 */
	@Override
	public boolean getEnabled() {
		checkWidget();
		return super.getEnabled();
	}

	/**
	 * Gets the line count.
	 *
	 * @return the line count
	 * @see org.eclipse.swt.widgets.Text#getLineCount()
	 */
	public int getLineCount() {
		checkWidget();
		return text.getLineCount();
	}

	/**
	 * Gets the line delimiter.
	 *
	 * @return the line delimiter
	 * @see org.eclipse.swt.widgets.Text#getLineDelimiter()
	 */
	public String getLineDelimiter() {
		checkWidget();
		return text.getLineDelimiter();
	}

	/**
	 * Gets the line height.
	 *
	 * @return the line height
	 * @see org.eclipse.swt.widgets.Text#getLineHeight()
	 */
	public int getLineHeight() {
		checkWidget();
		return text.getLineHeight();
	}

	/**
	 * Gets the message.
	 *
	 * @return the message
	 * @see org.eclipse.swt.widgets.Text#getMessage()
	 */
	public String getMessage() {
		checkWidget();
		return text.getMessage();
	}

	/**
	 * Gets the orientation.
	 *
	 * @return the orientation
	 * @see org.eclipse.swt.widgets.Text#getOrientation()
	 */
	public int getOrientation() {
		checkWidget();
		return text.getOrientation();
	}

	/**
	 * Gets the selection.
	 *
	 * @return the selection
	 * @see org.eclipse.swt.widgets.Text#getSelection()
	 */
	public Point getSelection() {
		checkWidget();
		return text.getSelection();
	}

	/**
	 * Gets the selection count.
	 *
	 * @return the selection count
	 * @see org.eclipse.swt.widgets.Text#getSelectionCount()
	 */
	public int getSelectionCount() {
		checkWidget();
		return text.getSelectionCount();
	}

	/**
	 * Gets the selection text.
	 *
	 * @return the selection text
	 * @see org.eclipse.swt.widgets.Text#getSelectionText()
	 */
	public String getSelectionText() {
		checkWidget();
		return text.getSelectionText();
	}

	/**
	 * Gets the tabs.
	 *
	 * @return the tabs
	 * @see org.eclipse.swt.widgets.Text#getTabs()
	 */
	public int getTabs() {
		checkWidget();
		return text.getTabs();
	}

	/**
	 * Gets the text.
	 *
	 * @return the text
	 * @see org.eclipse.swt.widgets.Text#getText()
	 */
	public String getText() {
		checkWidget();
		return text.getText();
	}

	/**
	 * Gets the text.
	 *
	 * @param start the start
	 * @param end the end
	 * @return the text
	 * @see org.eclipse.swt.widgets.Text#getText(int, int)
	 */
	public String getText(final int start, final int end) {
		checkWidget();
		return text.getText(start, end);
	}

	/**
	 * Gets the text limit.
	 *
	 * @return the text limit
	 * @see org.eclipse.swt.widgets.Text#getTextLimit()
	 */
	public int getTextLimit() {
		checkWidget();
		return text.getTextLimit();
	}

	/**
	 * Gets the top index.
	 *
	 * @return the top index
	 * @see org.eclipse.swt.widgets.Text#getTopIndex()
	 */
	public int getTopIndex() {
		checkWidget();
		return text.getTopIndex();
	}

	/**
	 * Gets the top pixel.
	 *
	 * @return the top pixel
	 * @see org.eclipse.swt.widgets.Text#getTopPixel()
	 */
	public int getTopPixel() {
		checkWidget();
		return text.getTopPixel();
	}

	/**
	 * Insert.
	 *
	 * @param string the string
	 * @see org.eclipse.swt.widgets.Text#insert(java.lang.String)
	 */
	public void insert(final String string) {
		checkWidget();
		text.insert(string);
	}

	/**
	 * Paste.
	 *
	 * @see org.eclipse.swt.widgets.Text#paste()
	 */
	public void paste() {
		checkWidget();
		text.paste();
	}

	/**
	 * Removes the modify listener.
	 *
	 * @param listener the listener
	 * @see org.eclipse.swt.widgets.Text#removeModifyListener(org.eclipse.swt.events.ModifyListener)
	 */
	public void removeModifyListener(final ModifyListener listener) {
		checkWidget();
		text.removeModifyListener(listener);
	}

	/**
	 * Removes the selection listener.
	 *
	 * @param listener the listener
	 * @see org.eclipse.swt.widgets.Text#removeSelectionListener(org.eclipse.swt.events.SelectionListener)
	 */
	public void removeSelectionListener(final SelectionListener listener) {
		checkWidget();
		text.removeSelectionListener(listener);
	}

	/**
	 * Removes the verify listener.
	 *
	 * @param listener the listener
	 * @see org.eclipse.swt.widgets.Text#removeVerifyListener(org.eclipse.swt.events.VerifyListener)
	 */
	public void removeVerifyListener(final VerifyListener listener) {
		checkWidget();
		text.removeVerifyListener(listener);
	}

	/**
	 * Select all.
	 *
	 * @see org.eclipse.swt.widgets.Text#selectAll()
	 */
	public void selectAll() {
		checkWidget();
		text.selectAll();
	}

	/**
	 * Sets the double click enabled.
	 *
	 * @param doubleClick the new double click enabled
	 * @see org.eclipse.swt.widgets.Text#setDoubleClickEnabled(boolean)
	 */
	public void setDoubleClickEnabled(final boolean doubleClick) {
		checkWidget();
		text.setDoubleClickEnabled(doubleClick);
	}

	/**
	 * Sets the echo char.
	 *
	 * @param echo the new echo char
	 * @see org.eclipse.swt.widgets.Text#setEchoChar(char)
	 */
	public void setEchoChar(final char echo) {
		checkWidget();
		text.setEchoChar(echo);
	}

	/**
	 * Sets the editable.
	 *
	 * @param editable the new editable
	 * @see org.eclipse.swt.widgets.Text#setEditable(boolean)
	 */
	public void setEditable(final boolean editable) {
		checkWidget();
		text.setEditable(editable);
	}

	/**
	 * Sets the enabled.
	 *
	 * @param value the new enabled
	 * @see org.eclipse.swt.widgets.Text#setEnabled(boolean)
	 */
	@Override
	public void setEnabled(final boolean value) {
		checkWidget();
		text.setEnabled(value);
	}

	/**
	 * Sets the font.
	 *
	 * @param font the new font
	 * @see org.eclipse.swt.widgets.Text#setFont(org.eclipse.swt.graphics.Font)
	 */
	@Override
	public void setFont(final Font font) {
		checkWidget();
		text.setFont(font);
		table.setFont(font);
	}

	/**
	 * Sets the foreground.
	 *
	 * @param color the new foreground
	 * @see org.eclipse.swt.widgets.Text#setForeground(org.eclipse.swt.graphics.Color)
	 */
	@Override
	public void setForeground(final Color color) {
		checkWidget();
		text.setForeground(color);
	}

	/**
	 * Sets the message.
	 *
	 * @param string the new message
	 * @see org.eclipse.swt.widgets.Text#setMessage(java.lang.String)
	 */
	public void setMessage(final String string) {
		checkWidget();
		text.setMessage(string);
	}

	/**
	 * Sets the orientation.
	 *
	 * @param orientation the new orientation
	 * @see org.eclipse.swt.widgets.Text#setOrientation(int)
	 */
	public void setOrientation(final int orientation) {
		checkWidget();
		text.setOrientation(orientation);
	}

	/**
	 * Sets the redraw.
	 *
	 * @param redraw the new redraw
	 * @see org.eclipse.swt.widgets.Text#setRedraw(boolean)
	 */
	@Override
	public void setRedraw(final boolean redraw) {
		checkWidget();
		text.setRedraw(redraw);
	}

	/**
	 * Sets the selection.
	 *
	 * @param start the start
	 * @param end the end
	 * @see org.eclipse.swt.widgets.Text#setSelection(int, int)
	 */
	public void setSelection(final int start, final int end) {
		checkWidget();
		text.setSelection(start, end);
	}

	/**
	 * Sets the selection.
	 *
	 * @param start the new selection
	 * @see org.eclipse.swt.widgets.Text#setSelection(int)
	 */
	public void setSelection(final int start) {
		checkWidget();
		text.setSelection(start);
	}

	/**
	 * Sets the selection.
	 *
	 * @param selection the new selection
	 * @see org.eclipse.swt.widgets.Text#setSelection(org.eclipse.swt.graphics.Point)
	 */
	public void setSelection(final Point selection) {
		checkWidget();
		text.setSelection(selection);
	}

	/**
	 * Sets the tabs.
	 *
	 * @param tabs the new tabs
	 * @see org.eclipse.swt.widgets.Text#setTabs(int)
	 */
	public void setTabs(final int tabs) {
		checkWidget();
		text.setTabs(tabs);
	}

	/**
	 * Sets the text.
	 *
	 * @param text the new text
	 * @see org.eclipse.swt.widgets.Text#setText(java.lang.String)
	 */
	public void setText(final String text) {
		checkWidget();
		this.text.setData(SETTEXT_KEY, Boolean.TRUE);
		this.text.setText(text);
	}

	/**
	 * Sets the text limit.
	 *
	 * @param textLimit the new text limit
	 * @see org.eclipse.swt.widgets.Text#setTextLimit(int)
	 */
	public void setTextLimit(final int textLimit) {
		checkWidget();
		text.setTextLimit(textLimit);
	}

	/**
	 * Sets the top index.
	 *
	 * @param topIndex the new top index
	 * @see org.eclipse.swt.widgets.Text#setTopIndex(int)
	 */
	public void setTopIndex(final int topIndex) {
		checkWidget();
		text.setTopIndex(topIndex);
	}

	/**
	 * Show selection.
	 *
	 * @see org.eclipse.swt.widgets.Text#showSelection()
	 */
	public void showSelection() {
		checkWidget();
		text.showSelection();
	}

}