org.mihalis.opal/src/main/java/org/mihalis/opal/propertyTable/editor/PTChooserEditor.java

/*******************************************************************************
 * Copyright (c) 2012 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:
 *     Laurent CARON (laurent.caron at gmail dot com) - initial API and implementation 
 *******************************************************************************/
package org.mihalis.opal.propertyTable.editor;

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ControlEditor;
import org.eclipse.swt.custom.TableEditor;
import org.eclipse.swt.custom.TreeEditor;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Item;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableItem;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;
import org.mihalis.opal.propertyTable.PTProperty;
import org.mihalis.opal.propertyTable.PTWidget;
import org.mihalis.opal.utils.ResourceManager;
import org.mihalis.opal.utils.SWTGraphicUtil;

/**
 * This abstract class represents a chooser. A chooser is composed of :
 * <ul>
 * <li>a displayed value (text)
 * <li>a "X" button to erase the value (set to null)
 * <li>a "..." button to open an extra window to set up the value
 * </ul>
 * 
 */
public abstract class PTChooserEditor extends PTEditor {

	/** The widget. */
	private PTWidget widget;
	
	/** The item. */
	private Item item;
	
	/** The property. */
	private PTProperty property;

	/**
	 * Render.
	 *
	 * @param widget the widget
	 * @param item the item
	 * @param property the property
	 * @return the control editor
	 * @see org.mihalis.opal.propertyTable.editor.PTEditor#render(org.mihalis.opal.propertyTable.PTWidget,
	 *      org.eclipse.swt.widgets.Item,
	 *      org.mihalis.opal.propertyTable.PTProperty)
	 */
	@Override
	public ControlEditor render(final PTWidget widget, final Item item, final PTProperty property) {
		this.widget = widget;
		this.item = item;
		this.property = property;

		if (item instanceof TableItem) {
			((TableItem) item).setText(1, getTextFor(property));
		} else {
			((TreeItem) item).setText(1, getTextFor(property));
		}

		final Color bgColor = getBackgroundColor(property);
		if (bgColor != null) {
			if (item instanceof TableItem) {
				((TableItem) item).setBackground(1, bgColor);
			}
			if (item instanceof TreeItem) {
				((TreeItem) item).setBackground(1, bgColor);
			}
			SWTGraphicUtil.addDisposer(item, bgColor);
		}

		ControlEditor editor;
		if (widget.getWidget() instanceof Table) {
			editor = new TableEditor((Table) widget.getWidget());
		} else {
			editor = new TreeEditor((Tree) widget.getWidget());
		}

		final Composite buttonHolder = new Composite(widget.getWidget(), SWT.NONE);
		final FillLayout buttonHolderLayout = new FillLayout(SWT.HORIZONTAL);
		buttonHolderLayout.marginWidth = buttonHolderLayout.marginHeight = 0;
		buttonHolder.setLayout(buttonHolderLayout);

		createEraseButton(buttonHolder);
		createPlusButton(buttonHolder);

		buttonHolder.pack();
		editor.minimumWidth = buttonHolder.getSize().x;
		editor.horizontalAlignment = SWT.RIGHT;

		if (widget.getWidget() instanceof Table) {
			((TableEditor) editor).setEditor(buttonHolder, (TableItem) item, 1);
		} else {
			((TreeEditor) editor).setEditor(buttonHolder, (TreeItem) item, 1);
		}

		return editor;
	}

	/**
	 * Creates the "erase" button.
	 *
	 * @param buttonHolder parent composite
	 */
	private void createEraseButton(final Composite buttonHolder) {
		final Button eraseButton = new Button(buttonHolder, SWT.PUSH);
		eraseButton.setText(" X ");
		eraseButton.setToolTipText(ResourceManager.getLabel(ResourceManager.ERASE_PROPERTY));
		eraseButton.setEnabled(this.property.isEnabled());
		eraseButton.pack();

		eraseButton.addSelectionListener(new SelectionAdapter() {
			/**
			 * @see org.eclipse.swt.events.SelectionAdapter#widgetSelected(org.eclipse.swt.events.SelectionEvent)
			 */
			@Override
			public void widgetSelected(final SelectionEvent e) {
				PTChooserEditor.this.property.setValue(null);
				if (PTChooserEditor.this.item instanceof TableItem) {
					((TableItem) PTChooserEditor.this.item).setBackground(1, Display.getDefault().getSystemColor(SWT.COLOR_LIST_BACKGROUND));
					((TableItem) PTChooserEditor.this.item).setText(1, getTextFor(PTChooserEditor.this.property));
				}
				if (PTChooserEditor.this.item instanceof TreeItem) {
					((TreeItem) PTChooserEditor.this.item).setBackground(1, Display.getDefault().getSystemColor(SWT.COLOR_LIST_BACKGROUND));
					((TreeItem) PTChooserEditor.this.item).setText(1, getTextFor(PTChooserEditor.this.property));
				}
			}
		});

		eraseButton.addListener(SWT.FocusIn, new Listener() {

			@Override
			public void handleEvent(final Event event) {
				PTChooserEditor.this.widget.updateDescriptionPanel(PTChooserEditor.this.property);
			}
		});
	}

	/**
	 * Creates the "plus" button.
	 *
	 * @param buttonHolder aprent composite
	 */
	private void createPlusButton(final Composite buttonHolder) {
		final Button plusButton = new Button(buttonHolder, SWT.PUSH);
		plusButton.setText("...");
		plusButton.setToolTipText(ResourceManager.getLabel(ResourceManager.EDIT_PROPERTY));
		plusButton.setEnabled(this.property.isEnabled());

		plusButton.addSelectionListener(new SelectionAdapter() {
			/**
			 * @see org.eclipse.swt.events.SelectionAdapter#widgetSelected(org.eclipse.swt.events.SelectionEvent)
			 */
			@Override
			public void widgetSelected(final SelectionEvent e) {
				openWindow(PTChooserEditor.this.widget, PTChooserEditor.this.item, PTChooserEditor.this.property);
			}
		});

		plusButton.addListener(SWT.FocusIn, new Listener() {

			@Override
			public void handleEvent(final Event event) {
				PTChooserEditor.this.widget.updateDescriptionPanel(PTChooserEditor.this.property);
			}
		});

		plusButton.pack();
	}

	/**
	 * Open the window to edit the property.
	 *
	 * @param widget parent widget
	 * @param item item
	 * @param property edited property
	 */
	protected abstract void openWindow(PTWidget widget, Item item, PTProperty property);

	/**
	 * Gets the text for.
	 *
	 * @param property property
	 * @return the string representation of the value stored in the property
	 */
	protected abstract String getTextFor(PTProperty property);

	/**
	 * Get the background color of an item.
	 *
	 * @param property property
	 * @return a background color (for the PTColorEditor) or null (for other
	 *         editors).
	 */
	protected abstract Color getBackgroundColor(PTProperty property);

}