/******************************************************************************* * Copyright (c) 2000, 2004 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Common Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/cpl-v10.html *  * Contributors: *     IBM Corporation - initial API and implementation *******************************************************************************/package org.eclipse.swt.custom;import org.eclipse.swt.*;import org.eclipse.swt.events.*;import org.eclipse.swt.graphics.*;import org.eclipse.swt.widgets.*;/*** A PopupList is a list of selectable items that appears in its own shell positioned above* its parent shell.  It it used for selecting items when editing a Table cell (similar to the* list that appears when you open a Combo box).** The list will be positioned so that does not run off the screen and the largest number of items* are visible.  It may appear above the current cursor location or below it depending how close you * are to the edge of the screen.*/public class PopupList {	Shell  shell;	List   list;	int    minimumWidth;/** * Creates a PopupList above the specified shell.* * @param parent a Shell control which will be the parent of the new instance (cannot be null)*/public PopupList(Shell parent) {	this (parent, 0);}/** * Creates a PopupList above the specified shell.* * @param parent a widget which will be the parent of the new instance (cannot be null)* @param style the style of widget to construct* * @since 3.0 */public PopupList(Shell parent, int style) {	shell = new Shell(parent, checkStyle(style));		list = new List(shell, SWT.SINGLE | SWT.V_SCROLL);		// close dialog if user selects outside of the shell	shell.addListener(SWT.Deactivate, new Listener() {		public void handleEvent(Event e){				shell.setVisible (false);		}	});		// resize shell when list resizes	shell.addControlListener(new ControlListener() {		public void controlMoved(ControlEvent e){}		public void controlResized(ControlEvent e){			Rectangle shellSize = shell.getClientArea();			list.setSize(shellSize.width, shellSize.height);		}	});		// return list selection on Mouse Up or Carriage Return	list.addMouseListener(new MouseListener() {		public void mouseDoubleClick(MouseEvent e){}		public void mouseDown(MouseEvent e){}		public void mouseUp(MouseEvent e){			shell.setVisible (false);		}	});	list.addKeyListener(new KeyListener() {		public void keyReleased(KeyEvent e){}		public void keyPressed(KeyEvent e){			if (e.character == '\r'){				shell.setVisible (false);			}		}	});	}private static int checkStyle (int style) {	int mask = SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT;	return style & mask;}/*** Gets the widget font.* <p>* @return the widget font** @exception SWTError <ul>*		<li>ERROR_THREAD_INVALID_ACCESS when called from the wrong thread</li>*		<li>ERROR_WIDGET_DISPOSED when the widget has been disposed</li>*	</ul>*/public Font getFont () {	return list.getFont();}/*** Gets the items.* <p>* This operation will fail if the items cannot* be queried from the OS.** @return the items in the widget** @exception SWTError <ul>*		<li>ERROR_THREAD_INVALID_ACCESS when called from the wrong thread</li>*		<li>ERROR_WIDGET_DISPOSED when the widget has been disposed</li>* 		<li>ERROR_CANNOT_GET_ITEM when the operation fails</li>*	</ul>*/public String[] getItems () {	return list.getItems();}/*** Gets the minimum width of the list.** @return the minimum width of the list*/public int getMinimumWidth () {	return minimumWidth;}/*** Launches the Popup List, waits for an item to be selected and then closes PopupList.** @param rect the initial size and location of the PopupList; the dialog will be*        positioned so that it does not run off the screen and the largest number of items are visible** @return the text of the selected item or null if no item is selected*/public String open (Rectangle rect) {	Point listSize = list.computeSize (rect.width, SWT.DEFAULT);	Rectangle screenSize = shell.getDisplay().getBounds();	// Position the dialog so that it does not run off the screen and the largest number of items are visible	int spaceBelow = screenSize.height - (rect.y + rect.height) - 30;	int spaceAbove = rect.y - 30;	int y = 0;	if (spaceAbove > spaceBelow && listSize.y > spaceBelow) {		// place popup list above table cell		if (listSize.y > spaceAbove){			listSize.y = spaceAbove;		} else {			listSize.y += 2;		}		y = rect.y - listSize.y;			} else {		// place popup list below table cell		if (listSize.y > spaceBelow){			listSize.y = spaceBelow;		} else {			listSize.y += 2;		}		y = rect.y + rect.height;	}		// Make dialog as wide as the cell	listSize.x = rect.width;	// dialog width should not be les than minimumwidth	if (listSize.x < minimumWidth)		listSize.x = minimumWidth;		// Align right side of dialog with right side of cell	int x = rect.x + rect.width - listSize.x;		shell.setBounds(x, y, listSize.x, listSize.y);		shell.open();	list.setFocus();	Display display = shell.getDisplay();	while (!shell.isDisposed () && shell.isVisible ()) {		if (!display.readAndDispatch()) display.sleep();	}		String result = null;	if (!shell.isDisposed ()) {		String [] strings = list.getSelection ();		shell.dispose();		if (strings.length != 0) result = strings [0];	}	return result;}/*** Selects an item with text that starts with specified String.* <p>* If the item is not currently selected, it is selected.  * If the item at an index is selected, it remains selected.  * If the string is not matched, it is ignored.** @param string the text of the item** @exception SWTError <ul>*		<li>ERROR_THREAD_INVALID_ACCESS when called from the wrong thread</li>*		<li>ERROR_WIDGET_DISPOSED when the widget has been disposed</li>*	</ul>*/public void select(String string) {	String[] items = list.getItems();	// find the first entry in the list that starts with the	// specified string	if (string != null){		for (int i = 0; i < items.length; i++) {			if (items[i].startsWith(string)){				int index = list.indexOf(items[i]);				list.select(index);				break;			}		}	}}/*** Sets the widget font.* <p>* When new font is null, the font reverts* to the default system font for the widget.** @param font the new font (or null)* * @exception SWTError <ul>*		<li>ERROR_THREAD_INVALID_ACCESS when called from the wrong thread</li>*		<li>ERROR_WIDGET_DISPOSED when the widget has been disposed</li>*	</ul>*/public void setFont (Font font) {	list.setFont(font);}/*** Sets all items.* <p>* The previous selection is cleared.* The previous items are deleted.* The new items are added.* The top index is set to 0.** @param strings the array of items** This operation will fail when an item is null* or could not be added in the OS.** @exception SWTError <ul>*		<li>ERROR_THREAD_INVALID_ACCESS when called from the wrong thread</li>*		<li>ERROR_WIDGET_DISPOSED when the widget has been disposed</li>*		<li>ERROR_NULL_ARGUMENT when items is null</li>*		<li>ERROR_ITEM_NOT_ADDED when the operation fails</li>*	</ul>*/public void setItems (String[] strings) {	list.setItems(strings);}/*** Sets the minimum width of the list.** @param width the minimum width of the list*/public void setMinimumWidth (int width) {	if (width < 0)		SWT.error(SWT.ERROR_INVALID_ARGUMENT);			minimumWidth = width;}}