common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/widgets/EnumComboViewer.java - dali/webtools.dali - Git at Google

 /*******************************************************************************
  * Copyright (c) 2008, 2012 Oracle. 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:
  *     Oracle - initial API and implementation
  ******************************************************************************/
 package org.eclipse.jpt.common.ui.internal.widgets;

 import java.util.Arrays;
 import java.util.Comparator;
 import org.eclipse.jface.viewers.ComboViewer;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.ISelectionChangedListener;
 import org.eclipse.jface.viewers.LabelProvider;
 import org.eclipse.jface.viewers.SelectionChangedEvent;
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.jpt.common.ui.WidgetFactory;
 import org.eclipse.jpt.common.ui.internal.JptCommonUiMessages;
 import org.eclipse.jpt.common.utility.model.Model;
 import org.eclipse.jpt.common.utility.model.value.PropertyValueModel;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.swt.widgets.Composite;
 import com.ibm.icu.text.Collator;

 /**
  * This pane simply shows a combo where its data is populating through
  * {@link #choices()} and a default value can also be added.
  * <p>
  * Here the layout of this pane:
  * <pre>
  * -----------------------------------------------------------------------------
  * | ------------------------------------------------------------------------- |
  * | | I                                                                   |v| |
  * | ------------------------------------------------------------------------- |
  * -----------------------------------------------------------------------------</pre>
  *
  * @version 2.0
  * @since 1.0
  */
 @SuppressWarnings("nls")
 abstract class EnumComboViewer<T extends Model, V> extends Pane<T>
 {
 	/**
 	 * The main widget of this pane.
 	 */
 	private ComboViewer comboViewer;

 	/**
 	 * A constant used to represent the <code>null</code> value.
 	 */
 	public static final String NULL_VALUE = "null";

 	/**
 	 * Creates a new <code>EnumComboViewer</code>.
 	 *
 	 * @param parentPane The parent container of this one
 	 * @param parent The parent container
 	 * @param widgetFactory The factory used to create various widgets
 	 */
 	EnumComboViewer(Pane<? extends T> parentPane,
 	                        Composite parent) {

 		super(parentPane, parent);
 	}

 	/**
 	 * Creates a new <code>EnumComboViewer</code>.
 	 *
 	 * @param parentPane The parent container of this one
 	 * @param parent The parent container
 	 * @param widgetFactory The factory used to create various widgets
 	 */
 	EnumComboViewer(Pane<?> parentPane,
 	                        PropertyValueModel<? extends T> subjectHolder,
 	                        Composite parent) {

 		super(parentPane, subjectHolder, parent);
 	}

 	/**
 	 * Creates a new <code>EnumComboViewer</code>.
 	 *
 	 * @param subjectHolder The holder of this pane's subject
 	 * @param parent The parent container
 	 * @param widgetFactory The factory used to create various widgets
 	 */
 	EnumComboViewer(PropertyValueModel<? extends T> subjectHolder,
 	                        Composite parent,
 	                        WidgetFactory widgetFactory) {

 		super(subjectHolder, parent, widgetFactory);
 	}

 	/**
 	 * Creates the list of choices and add an extra element that represents the
 	 * default value.
 	 *
 	 * @return The combo's choices including the default value
 	 */
 	private Object[] buildChoices() {
 		V[] choices = getChoices();
 		if (sortChoices()) {
 			Arrays.sort(choices, buildComparator());
 		}

 		Object[] extendedChoices = new Object[choices.length + 1];
 		System.arraycopy(choices, 0, extendedChoices, 1, choices.length);
 		extendedChoices[0] = NULL_VALUE;

 		return extendedChoices;
 	}

 	/**
 	 * Return true to sort the choices in alphabetical order
 	 * @return
 	 */
 	protected boolean sortChoices() {
 		return true;
 	}

 	/**
 	 * Creates the <code>ComboViewer</code> with the right combo widgets.
 	 *
 	 * @param container The container of the combo
 	 * @return A new <code>ComboViewer</code> containing the right combo widget
 	 */
 	protected ComboViewer addComboViewer(Composite container) {
 		return addComboViewer(container, buildLabelProvider());
 	}

 	private Comparator<Object> buildComparator() {
 		return new Comparator<Object>() {
 			final LabelProvider labelProvider = buildLabelProvider();

 			public int compare(Object value1, Object value2) {
 				String displayString1 = this.labelProvider.getText(value1);
 				String displayString2 = this.labelProvider.getText(value2);
 				return Collator.getInstance().compare(displayString1, displayString2);
 			}
 		};
 	}

 	/**
 	 * Creates the display string for the given element. If the element is the
 	 * virtual <code>null</code> value then its display string will be "Default"
 	 * appended by the actual default value, if it exists.
 	 *
 	 * @param value The value to convert into a human readable string
 	 * @return The string representation of the given element
 	 */
 	@SuppressWarnings("unchecked")
 	private String buildDisplayString(Object value) {
 		if (value == NULL_VALUE) {
 			V defaultValue = (getSubject() != null) ? getDefaultValue() : null;

 			if (defaultValue != null) {
 				String displayString = displayString(defaultValue);
 				return NLS.bind(JptCommonUiMessages.EnumComboViewer_defaultWithDefault, displayString);
 			}
 			return nullDisplayString();
 		}

 		return displayString((V) value);
 	}

 	final LabelProvider buildLabelProvider() {
 		return new LabelProvider() {
 			@Override
 			public String getText(Object element) {
 				return buildDisplayString(element);
 			}
 		};
 	}

 	private ISelection buildSelection() {
 		Object value = (getSubject() != null) ? getValue() : null;

 		if (value == null) {
 			value = NULL_VALUE;
 		}

 		return new StructuredSelection(value);
 	}

 	private ISelectionChangedListener buildSelectionChangedListener() {
 		return new ISelectionChangedListener() {
 			public void selectionChanged(SelectionChangedEvent e) {
 				if (!isPopulating()) {
 					StructuredSelection selection = (StructuredSelection) e.getSelection();
 					valueChanged(selection.getFirstElement());
 				}
 			}
 		};
 	}

 	/**
 	 * Returns the possible choices to show in the viewer.
 	 *
 	 * @return The items to show in the combos
 	 */
 	protected abstract V[] getChoices();

 	/**
 	 * Returns the default value, this method is not called if the subject is
 	 * <code>null</code>.
 	 *
 	 * @return The value that is declared as being the default when it is not
 	 * defined or <code>null</code> if there is no default value
 	 */
 	protected abstract V getDefaultValue();

 	/**
 	 * Returns the displayable string for the given value.
 	 *
 	 * @param value The value to translate into a human readable string
 	 * @return The localized text representing the given value
 	 */
 	protected abstract String displayString(V value);

 	/**
 	 * Returns the displayable string for a null value.
 	 */
 	protected String nullDisplayString() {
 		return null; //I would rather display nothing than "Default()"
 	}

 	/*
 	 * (non-Javadoc)
 	 */
 	@Override
 	protected void doPopulate() {
 		super.doPopulate();
 		this.populateCombo();
 	}

 	/**
 	 * Returns
 	 *
 	 * @return
 	 */
 	final ComboViewer getComboViewer() {
 		return this.comboViewer;
 	}

 	/**
 	 * Retrieves the subject's value. The subject is never <code>null</code>.
 	 *
 	 * @return The subject' value, which can be <code>null</code>
 	 */
 	protected abstract V getValue();

 	/*
 	 * (non-Javadoc)
 	 */
 	@Override
 	protected final void initializeLayout(Composite container) {

 		this.comboViewer = this.addComboViewer(container);
 		this.comboViewer.addSelectionChangedListener(buildSelectionChangedListener());
 	}

 	/**
 	 * Populates the combo by re-adding all the items.
 	 */
 	private void populateCombo() {

 		removeAll();
 		this.comboViewer.add(buildChoices());
 		updateSelection();
 	}

 	/*
 	 * (non-Javadoc)
 	 */
 	@Override
 	protected void propertyChanged(String propertyName) {
 		super.propertyChanged(propertyName);
 		this.populateCombo();
 	}

 	/**
 	 * Removes all the items from the combo.
 	 */
 	abstract void removeAll();

 	/**
 	 * Requests the given new value be set on the subject.
 	 *
 	 * @param value The new value to be set
 	 */
 	protected abstract void setValue(V value);

 	/**
 	 * Updates the cursor, which is required to show the entire selected item
 	 * within the combo's area.
 	 */
 	abstract void updateCursor();

 	/**
 	 * Updates the combo's selected item.
 	 */
 	private void updateSelection() {
 		this.comboViewer.setSelection(buildSelection());
 		updateCursor();
 	}

 	/**
 	 * The selection changes, notify the subclass to set the value.
 	 *
 	 * @param value The new selected item
 	 */
 	@SuppressWarnings("unchecked")
 	private void valueChanged(Object value) {

 		// Convert the default "null" value to a real null
 		if (value == NULL_VALUE) {
 			value = null;
 		}

 		setPopulating(true);

 		try {
 			setValue((V) value);
 		}
 		finally {
 			setPopulating(false);
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2008, 2012 Oracle. 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:
	* Oracle - initial API and implementation
	******************************************************************************/
	package org.eclipse.jpt.common.ui.internal.widgets;

	import java.util.Arrays;
	import java.util.Comparator;
	import org.eclipse.jface.viewers.ComboViewer;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.jface.viewers.ISelectionChangedListener;
	import org.eclipse.jface.viewers.LabelProvider;
	import org.eclipse.jface.viewers.SelectionChangedEvent;
	import org.eclipse.jface.viewers.StructuredSelection;
	import org.eclipse.jpt.common.ui.WidgetFactory;
	import org.eclipse.jpt.common.ui.internal.JptCommonUiMessages;
	import org.eclipse.jpt.common.utility.model.Model;
	import org.eclipse.jpt.common.utility.model.value.PropertyValueModel;
	import org.eclipse.osgi.util.NLS;
	import org.eclipse.swt.widgets.Composite;
	import com.ibm.icu.text.Collator;

	/**
	* This pane simply shows a combo where its data is populating through
	* {@link #choices()} and a default value can also be added.
	* <p>
	* Here the layout of this pane:
	* <pre>
	* -----------------------------------------------------------------------------
	* \| ------------------------------------------------------------------------- \|
	* \| \| I \|v\| \|
	* \| ------------------------------------------------------------------------- \|
	* -----------------------------------------------------------------------------</pre>
	*
	* @version 2.0
	* @since 1.0
	*/
	@SuppressWarnings("nls")
	abstract class EnumComboViewer<T extends Model, V> extends Pane<T>
	{
	/**
	* The main widget of this pane.
	*/
	private ComboViewer comboViewer;

	/**
	* A constant used to represent the <code>null</code> value.
	*/
	public static final String NULL_VALUE = "null";

	/**
	* Creates a new <code>EnumComboViewer</code>.
	*
	* @param parentPane The parent container of this one
	* @param parent The parent container
	* @param widgetFactory The factory used to create various widgets
	*/
	EnumComboViewer(Pane<? extends T> parentPane,
	Composite parent) {

	super(parentPane, parent);
	}

	/**
	* Creates a new <code>EnumComboViewer</code>.
	*
	* @param parentPane The parent container of this one
	* @param parent The parent container
	* @param widgetFactory The factory used to create various widgets
	*/
	EnumComboViewer(Pane<?> parentPane,
	PropertyValueModel<? extends T> subjectHolder,
	Composite parent) {

	super(parentPane, subjectHolder, parent);
	}

	/**
	* Creates a new <code>EnumComboViewer</code>.
	*
	* @param subjectHolder The holder of this pane's subject
	* @param parent The parent container
	* @param widgetFactory The factory used to create various widgets
	*/
	EnumComboViewer(PropertyValueModel<? extends T> subjectHolder,
	Composite parent,
	WidgetFactory widgetFactory) {

	super(subjectHolder, parent, widgetFactory);
	}

	/**
	* Creates the list of choices and add an extra element that represents the
	* default value.
	*
	* @return The combo's choices including the default value
	*/
	private Object[] buildChoices() {
	V[] choices = getChoices();
	if (sortChoices()) {
	Arrays.sort(choices, buildComparator());
	}

	Object[] extendedChoices = new Object[choices.length + 1];
	System.arraycopy(choices, 0, extendedChoices, 1, choices.length);
	extendedChoices[0] = NULL_VALUE;

	return extendedChoices;
	}

	/**
	* Return true to sort the choices in alphabetical order
	* @return
	*/
	protected boolean sortChoices() {
	return true;
	}

	/**
	* Creates the <code>ComboViewer</code> with the right combo widgets.
	*
	* @param container The container of the combo
	* @return A new <code>ComboViewer</code> containing the right combo widget
	*/
	protected ComboViewer addComboViewer(Composite container) {
	return addComboViewer(container, buildLabelProvider());
	}

	private Comparator<Object> buildComparator() {
	return new Comparator<Object>() {
	final LabelProvider labelProvider = buildLabelProvider();

	public int compare(Object value1, Object value2) {
	String displayString1 = this.labelProvider.getText(value1);
	String displayString2 = this.labelProvider.getText(value2);
	return Collator.getInstance().compare(displayString1, displayString2);
	}
	};
	}

	/**
	* Creates the display string for the given element. If the element is the
	* virtual <code>null</code> value then its display string will be "Default"
	* appended by the actual default value, if it exists.
	*
	* @param value The value to convert into a human readable string
	* @return The string representation of the given element
	*/
	@SuppressWarnings("unchecked")
	private String buildDisplayString(Object value) {
	if (value == NULL_VALUE) {
	V defaultValue = (getSubject() != null) ? getDefaultValue() : null;

	if (defaultValue != null) {
	String displayString = displayString(defaultValue);
	return NLS.bind(JptCommonUiMessages.EnumComboViewer_defaultWithDefault, displayString);
	}
	return nullDisplayString();
	}

	return displayString((V) value);
	}

	final LabelProvider buildLabelProvider() {
	return new LabelProvider() {
	@Override
	public String getText(Object element) {
	return buildDisplayString(element);
	}
	};
	}

	private ISelection buildSelection() {
	Object value = (getSubject() != null) ? getValue() : null;

	if (value == null) {
	value = NULL_VALUE;
	}

	return new StructuredSelection(value);
	}

	private ISelectionChangedListener buildSelectionChangedListener() {
	return new ISelectionChangedListener() {
	public void selectionChanged(SelectionChangedEvent e) {
	if (!isPopulating()) {
	StructuredSelection selection = (StructuredSelection) e.getSelection();
	valueChanged(selection.getFirstElement());
	}
	}
	};
	}

	/**
	* Returns the possible choices to show in the viewer.
	*
	* @return The items to show in the combos
	*/
	protected abstract V[] getChoices();

	/**
	* Returns the default value, this method is not called if the subject is
	* <code>null</code>.
	*
	* @return The value that is declared as being the default when it is not
	* defined or <code>null</code> if there is no default value
	*/
	protected abstract V getDefaultValue();

	/**
	* Returns the displayable string for the given value.
	*
	* @param value The value to translate into a human readable string
	* @return The localized text representing the given value
	*/
	protected abstract String displayString(V value);

	/**
	* Returns the displayable string for a null value.
	*/
	protected String nullDisplayString() {
	return null; //I would rather display nothing than "Default()"
	}

	/*
	* (non-Javadoc)
	*/
	@Override
	protected void doPopulate() {
	super.doPopulate();
	this.populateCombo();
	}

	/**
	* Returns
	*
	* @return
	*/
	final ComboViewer getComboViewer() {
	return this.comboViewer;
	}

	/**
	* Retrieves the subject's value. The subject is never <code>null</code>.
	*
	* @return The subject' value, which can be <code>null</code>
	*/
	protected abstract V getValue();

	/*
	* (non-Javadoc)
	*/
	@Override
	protected final void initializeLayout(Composite container) {

	this.comboViewer = this.addComboViewer(container);
	this.comboViewer.addSelectionChangedListener(buildSelectionChangedListener());
	}

	/**
	* Populates the combo by re-adding all the items.
	*/
	private void populateCombo() {

	removeAll();
	this.comboViewer.add(buildChoices());
	updateSelection();
	}

	/*
	* (non-Javadoc)
	*/
	@Override
	protected void propertyChanged(String propertyName) {
	super.propertyChanged(propertyName);
	this.populateCombo();
	}

	/**
	* Removes all the items from the combo.
	*/
	abstract void removeAll();

	/**
	* Requests the given new value be set on the subject.
	*
	* @param value The new value to be set
	*/
	protected abstract void setValue(V value);

	/**
	* Updates the cursor, which is required to show the entire selected item
	* within the combo's area.
	*/
	abstract void updateCursor();

	/**
	* Updates the combo's selected item.
	*/
	private void updateSelection() {
	this.comboViewer.setSelection(buildSelection());
	updateCursor();
	}

	/**
	* The selection changes, notify the subclass to set the value.
	*
	* @param value The new selected item
	*/
	@SuppressWarnings("unchecked")
	private void valueChanged(Object value) {

	// Convert the default "null" value to a real null
	if (value == NULL_VALUE) {
	value = null;
	}

	setPopulating(true);

	try {
	setValue((V) value);
	}
	finally {
	setPopulating(false);
	}
	}
	}