org.mihalis.opal/src/main/java/org/mihalis/opal/preferenceWindow/PreferenceWindow.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:
 *     Laurent CARON (laurent.caron at gmail dot com) - Initial implementation and API
 *******************************************************************************/
package org.mihalis.opal.preferenceWindow;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.mihalis.opal.preferenceWindow.widgets.PWWidget;
import org.mihalis.opal.utils.ResourceManager;
import org.mihalis.opal.utils.SWTGraphicUtil;

/**
 * This class is a preference window.
 */
public class PreferenceWindow {
	
	/** The values. */
	private final Map<String, ValueAndAssociatedWidgets> values;
	
	/** The tabs. */
	private final List<PWTab> tabs;
	
	/** The parent shell. */
	private final Shell parentShell;
	
	/** The returned value. */
	private boolean returnedValue;
	
	/** The shell. */
	private Shell shell;
	
	/** The instance. */
	private static PreferenceWindow instance;
	
	/** The container. */
	private PWTabContainer container;
	
	/** The selected tab. */
	private int selectedTab;

	/**
	 * Constructor.
	 *
	 * @param parent parent shell (may be null)
	 * @param values a map that contains all values that will be displayed in
	 *            widgets
	 */
	private PreferenceWindow(final Shell parent, final Map<String, Object> values) {
		this.parentShell = parent;
		this.values = new HashMap<String, ValueAndAssociatedWidgets>(values.size());

		for (final Entry<String, Object> entry : values.entrySet()) {
			this.values.put(entry.getKey(), new ValueAndAssociatedWidgets(entry.getValue()));
		}

		this.tabs = new ArrayList<PWTab>();
	}

	/**
	 * Create a preference window (a singleton).
	 *
	 * @param parent parent shell (may be null)
	 * @param values a map that contains all values that will be displayed in
	 *            widgets
	 * @return the preference window
	 */
	public static PreferenceWindow create(final Shell parent, final Map<String, Object> values) {
		instance = new PreferenceWindow(parent, values);
		return instance;
	}

	/**
	 * Create a preference window (a singleton).
	 *
	 * @param values a map that contains all values that will be displayed in
	 *            widgets
	 * @return the preference window
	 */
	public static PreferenceWindow create(final Map<String, Object> values) {
		instance = new PreferenceWindow(null, values);
		return instance;
	}

	/**
	 * Gets the single instance of PreferenceWindow.
	 *
	 * @return an instance of the preference window
	 */
	public static PreferenceWindow getInstance() {
		if (instance == null) {
			throw new NullPointerException("The instance of PreferenceWindow has not yet been created or has been destroyed.");
		}
		return instance;
	}

	/**
	 * Add a tab to the preference window.
	 *
	 * @param image image associated to the tab
	 * @param text text associated to the image
	 * @return the
	 */
	public PWTab addTab(final Image image, final String text) {
		final PWTab tab = new PWTab(image, text);
		this.tabs.add(tab);
		return tab;
	}

	/**
	 * Add a widget that is linked to a given property.
	 *
	 * @param propertyKey the property
	 * @param widget the widget
	 */
	public void addWidgetLinkedTo(final String propertyKey, final PWWidget widget) {
		if (!this.values.containsKey(propertyKey)) {
			this.values.put(propertyKey, new ValueAndAssociatedWidgets(null));
		}
		this.values.get(propertyKey).addWidget(widget);
	}

	/**
	 * Add a row group that is linked to a given property.
	 *
	 * @param propertyKey the property
	 * @param rowGroup the widget
	 */
	public void addRowGroupLinkedTo(final String propertyKey, final PWRowGroup rowGroup) {
		if (!this.values.containsKey(propertyKey)) {
			this.values.put(propertyKey, new ValueAndAssociatedWidgets(null));
		}
		this.values.get(propertyKey).addRowGroup(rowGroup);
	}

	/**
	 * Open the preference window.
	 *
	 * @return <code>true</code> if the user pressed on the Ok button,
	 *         <code>false</code> if the user pressed on the Cancel button
	 */
	public boolean open() {
		if (this.parentShell == null) {
			this.shell = new Shell(SWT.SHELL_TRIM);
		} else {
			this.shell = new Shell(instance.parentShell, SWT.SHELL_TRIM);
		}

		this.shell.addListener(SWT.Dispose, new Listener() {

			@Override
			public void handleEvent(final Event event) {
				instance = null;	// NOSONAR
			}
		});

		buildShell();
		openShell();

		return this.returnedValue;
	}

	/**
	 * Builds the shell.
	 */
	private void buildShell() {
		this.shell.setText(ResourceManager.getLabel(ResourceManager.PREFERENCES));
		final GridLayout gridLayout = new GridLayout(2, false);
		gridLayout.marginWidth = gridLayout.marginHeight = 0;
		gridLayout.horizontalSpacing = gridLayout.verticalSpacing = 0;
		this.shell.setLayout(gridLayout);
		this.container = new PWTabContainer(this.shell, SWT.NONE, this.tabs);
		this.container.setLayoutData(new GridData(GridData.FILL, GridData.FILL, true, true, 2, 1));
		this.container.build();

		final Label sep = new Label(this.shell, SWT.SEPARATOR | SWT.HORIZONTAL);
		sep.setLayoutData(new GridData(GridData.FILL, GridData.FILL, true, true, 2, 1));

		buildButtons();

	}

	/**
	 * Builds the buttons.
	 */
	private void buildButtons() {
		final Button buttonOK = new Button(this.shell, SWT.PUSH);
		buttonOK.setText(ResourceManager.getLabel(ResourceManager.OK));
		final GridData gridDataOk = new GridData(GridData.END, GridData.END, true, false);
		gridDataOk.widthHint = 100;
		buttonOK.setLayoutData(gridDataOk);
		buttonOK.addSelectionListener(new SelectionAdapter() {

			/**
			 * @see org.eclipse.swt.events.SelectionAdapter#widgetSelected(org.eclipse.swt.events.SelectionEvent)
			 */
			@Override
			public void widgetSelected(final SelectionEvent e) {
				PreferenceWindow.this.returnedValue = true;
				PreferenceWindow.this.shell.dispose();
			}

		});
		this.shell.setDefaultButton(buttonOK);

		final Button buttonCancel = new Button(this.shell, SWT.PUSH);
		buttonCancel.setText(ResourceManager.getLabel(ResourceManager.CANCEL));
		final GridData gridDataCancel = new GridData(GridData.BEGINNING, GridData.END, false, false);
		gridDataCancel.widthHint = 100;
		buttonCancel.setLayoutData(gridDataCancel);
		buttonCancel.addSelectionListener(new SelectionAdapter() {

			/**
			 * @see org.eclipse.swt.events.SelectionAdapter#widgetSelected(org.eclipse.swt.events.SelectionEvent)
			 */
			@Override
			public void widgetSelected(final SelectionEvent e) {
				PreferenceWindow.this.returnedValue = false;
				PreferenceWindow.this.shell.dispose();
			}

		});
	}

	/**
	 * Open the shell.
	 */
	private void openShell() {
		this.shell.pack();
		this.shell.open();
		SWTGraphicUtil.centerShell(this.shell);

		while (!this.shell.isDisposed()) {
			if (!this.shell.getDisplay().readAndDispatch()) {
				this.shell.getDisplay().sleep();
			}
		}

	}

	/**
	 * Fire all enablers.
	 */
	public void fireEnablers() {
//		for (final String key : this.values.keySet()) {
//			this.values.get(key).fireValueChanged();
		// SONAR finds it more efficient to use the iterator on the entrySet of the map, to avoid the Map.key() lookup!:
		for (final ValueAndAssociatedWidgets mapValue : this.values.values()) {
			mapValue.fireValueChanged();
		}
	}

	/**
	 * Gets the selected tab.
	 *
	 * @return the selected tab
	 */
	public int getSelectedTab() {
		return this.selectedTab;
	}

	/**
	 * Gets the value for.
	 *
	 * @param key the key
	 * @return the value associated to the <i>key</i>
	 */
	public Object getValueFor(final String key) {
		if (this.values.containsKey(key)) {
			return this.values.get(key).getValue();
		}
		return null;
	}

	/**
	 * Gets the values.
	 *
	 * @return the list of all values
	 */
	public Map<String, Object> getValues() {
		final Map<String, Object> returnedValues = new HashMap<String, Object>();
//		for (final String key : this.values.keySet()) {
//			returnedValues.put(key, this.values.get(key).getValue());
		// SONAR finds it more efficient to use the iterator on the entrySet of the map, to avoid the Map.key() lookup!:
		for (final Map.Entry<String, ValueAndAssociatedWidgets> entry : this.values.entrySet()) {
			returnedValues.put(entry.getKey(), entry.getValue());
		}
		return returnedValues;
	}

	/**
	 * Store a value associated to the key.
	 *
	 * @param key the key
	 * @param value the value
	 */
	public void setValue(final String key, final Object value) {
		if (this.values.containsKey(key)) {
			this.values.get(key).setValue(value);
		} else {
			this.values.put(key, new ValueAndAssociatedWidgets(value));
		}

	}

	/**
	 * Set the selected tab.
	 *
	 * @param selectedTab the new selected tab
	 */
	public void setSelectedTab(final int selectedTab) {
		this.selectedTab = selectedTab;
		if (this.container != null) {
			this.container.redraw();
			this.container.update();
		}
	}

}