/*******************************************************************************
 * Copyright (c) 2006 Sybase, Inc. 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:
 *     Sybase, Inc. - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.pagedesigner.properties.celleditors;

import java.text.MessageFormat;

import org.eclipse.jface.util.Assert;
import org.eclipse.jface.viewers.CellEditor;
import org.eclipse.jst.pagedesigner.common.widget.StyleCombo;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.FocusAdapter;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.TraverseEvent;
import org.eclipse.swt.events.TraverseListener;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

public class StyleComboCellEditor extends CellEditor {
	/**
	 * The list of items to present in the combo box.
	 */
	private String[] items;

	/**
	 * The zero-based index of the selected item.
	 */
	int selection;

	/**
	 * The custom combo box control.
	 */
	StyleCombo comboBox;

	/**
	 * Default ComboBoxCellEditor style
	 */
	private static final int defaultStyle = SWT.NONE;

	public StyleComboCellEditor() {
		setStyle(defaultStyle);
	}

	public StyleComboCellEditor(Composite parent, String[] items) {
		this(parent, items, defaultStyle);
	}

	public StyleComboCellEditor(Composite parent, String[] items, int style) {
		super(parent, style);
		setItems(items);
	}

	/**
	 * Returns the list of choices for the combo box
	 * 
	 * @return the list of choices for the combo box
	 */
	public String[] getItems() {
		return this.items;
	}

	/**
	 * Sets the list of choices for the combo box
	 * 
	 * @param items
	 *            the list of choices for the combo box
	 */
	public void setItems(String[] items) {
		Assert.isNotNull(items);
		this.items = items;
		populateComboBoxItems();
	}

	/*
	 * (non-Javadoc) Method declared on CellEditor.
	 */
	protected Control createControl(Composite parent) {

		comboBox = new StyleCombo(parent, getStyle());
		comboBox.setFont(parent.getFont());

		comboBox.addKeyListener(new KeyAdapter() {
			// hook key pressed - see PR 14201
			public void keyPressed(KeyEvent e) {
				keyReleaseOccured(e);
			}
		});

		comboBox.addSelectionListener(new SelectionAdapter() {
			public void widgetDefaultSelected(SelectionEvent event) {
				applyEditorValueAndDeactivate();
			}

			public void widgetSelected(SelectionEvent event) {
				selection = comboBox.getSelectionIndex();
			}
		});

		comboBox.addTraverseListener(new TraverseListener() {
			public void keyTraversed(TraverseEvent e) {
				if (e.detail == SWT.TRAVERSE_ESCAPE
						|| e.detail == SWT.TRAVERSE_RETURN) {
					e.doit = false;
				}
			}
		});

		comboBox.addFocusListener(new FocusAdapter() {
			public void focusLost(FocusEvent e) {
				StyleComboCellEditor.this.focusLost();
			}
		});
		return comboBox;
	}

	/**
	 * The <code>ComboBoxCellEditor</code> implementation of this
	 * <code>CellEditor</code> framework method returns the zero-based index
	 * of the current selection.
	 * 
	 * @return the zero-based index of the current selection wrapped as an
	 *         <code>Integer</code>
	 */
	protected Object doGetValue() {
		return new Integer(selection);
	}

	/*
	 * (non-Javadoc) Method declared on CellEditor.
	 */
	protected void doSetFocus() {
		comboBox.setFocus();
	}

	/**
	 * The <code>ComboBoxCellEditor</code> implementation of this
	 * <code>CellEditor</code> framework method sets the minimum width of the
	 * cell. The minimum width is 10 characters if <code>comboBox</code> is
	 * not <code>null</code> or <code>disposed</code> eles it is 60 pixels
	 * to make sure the arrow button and some text is visible. The list of
	 * CCombo will be wide enough to show its longest item.
	 */
	public LayoutData getLayoutData() {
		LayoutData layoutData = super.getLayoutData();
		if ((comboBox == null) || comboBox.isDisposed())
			layoutData.minimumWidth = 60;
		else {
			// make the comboBox 10 characters wide
			GC gc = new GC(comboBox);
			layoutData.minimumWidth = (gc.getFontMetrics()
					.getAverageCharWidth() * 10) + 10;
			gc.dispose();
		}
		return layoutData;
	}

	/**
	 * The <code>ComboBoxCellEditor</code> implementation of this
	 * <code>CellEditor</code> framework method accepts a zero-based index of
	 * a selection.
	 * 
	 * @param value
	 *            the zero-based index of the selection wrapped as an
	 *            <code>Integer</code>
	 */
	protected void doSetValue(Object value) {
		Assert.isTrue(comboBox != null && (value instanceof Integer));
		selection = ((Integer) value).intValue();
		comboBox.select(selection);
	}

	/**
	 * Updates the list of choices for the combo box for the current control.
	 */
	private void populateComboBoxItems() {
		if (comboBox != null && items != null) {
			comboBox.removeAll();
			for (int i = 0; i < items.length; i++)
				comboBox.add(items[i], i);

			setValueValid(true);
			selection = 0;
		}
	}

	/**
	 * Applies the currently selected value and deactiavates the cell editor
	 */
	void applyEditorValueAndDeactivate() {
		// must set the selection before getting value
		selection = comboBox.getSelectionIndex();
		Object newValue = doGetValue();
		markDirty();
		boolean isValid = isCorrect(newValue);
		setValueValid(isValid);
		if (!isValid) {
			// try to insert the current value into the error message.
			setErrorMessage(MessageFormat.format(getErrorMessage(),
					new Object[] { items[selection] }));
		}
		fireApplyEditorValue();
		deactivate();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.CellEditor#focusLost()
	 */
	protected void focusLost() {
		if (isActivated()) {
			applyEditorValueAndDeactivate();
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.CellEditor#keyReleaseOccured(org.eclipse.swt.events.KeyEvent)
	 */
	protected void keyReleaseOccured(KeyEvent keyEvent) {
		if (keyEvent.character == '\u001b') { // Escape character
			fireCancelEditor();
		} else if (keyEvent.character == '\t') { // tab key
			applyEditorValueAndDeactivate();
		}
	}
}