bundles/common/org.eclipse.apogy.common.emf.ui/src/org/eclipse/apogy/common/emf/ui/preferences/NativeDecimalFormatComposite.java

/*******************************************************************************
 * Copyright (c) 2018 Agence spatiale canadienne / Canadian Space Agency
 * 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:
 *     Pierre Allard, 
 *     Regent L'Archeveque,
<<<<<<< HEAD
 *     Olivier L. Larouche
 * 
=======
 *     Olivier L. Larouche - initial API and implementation
>>>>>>> refs/heads/eclipse_pa
 * SPDX-License-Identifier: EPL-1.0
 *     
 *******************************************************************************/
package org.eclipse.apogy.common.emf.ui.preferences;

import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.List;

import org.eclipse.apogy.common.emf.ui.Activator;
import org.eclipse.core.databinding.DataBindingContext;
import org.eclipse.core.databinding.UpdateListStrategy;
import org.eclipse.core.databinding.UpdateValueStrategy;
import org.eclipse.core.databinding.conversion.Converter;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.jface.databinding.swt.WidgetProperties;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.plugin.AbstractUIPlugin;

public class NativeDecimalFormatComposite extends Composite {

	private DataBindingContext bindingContext;

	private final Text doubleText;
	private final Text floatText;
	private final Text byteText;
	private final Text shortText;
	private final Text intText;
	private final Text longText;

	private final List<Text> textList;

	public NativeDecimalFormatComposite(Composite parent, int style) {
		super(parent, style);
		setLayout(new GridLayout(2, false));
		addDisposeListener(new DisposeListener() {
			@Override
			public void widgetDisposed(DisposeEvent e) {
				if (NativeDecimalFormatComposite.this.bindingContext != null) {
					NativeDecimalFormatComposite.this.bindingContext.dispose();
				}
			}
		});

		this.textList = new ArrayList<Text>();

		/** Synthax information button */
		Button infoButton = new Button(this, SWT.None);
		infoButton.setLayoutData(new GridData(SWT.RIGHT, SWT.FILL, false, true, 2, 1));
		ImageDescriptor image = AbstractUIPlugin.imageDescriptorFromPlugin("org.eclipse.jface",
				"/icons/full/message_info.png");
		infoButton.setImage(image.createImage());
		infoButton.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				String message = "0\trepresents a digit\n" + "#\trepresents a digit, zero shows as absent\n"
						+ ".\trepresents a placeholder for decimal separator\n"
						+ ",\trepresents a placeholder for grouping separator\n\n" + "Examples with input 123123.123:\n"
						+ "\t- 000000000.000000 : " + new DecimalFormat("000000000.000000").format(123123.123)
						+ "\n\t- #########.###### : " + new DecimalFormat("#########.######").format(123123.123)
						+ "\n\t- ###,###.### : " + new DecimalFormat("###,###.###").format(123123.123);
				MessageDialog.openInformation(getShell(), "Synthax", message);
			}
		});

		/** Double */
		Label doubleLabel = new Label(this, SWT.None);
		doubleLabel.setText("Double float :");
		doubleLabel.setLayoutData(new GridData(SWT.RIGHT, SWT.CENTER, false, false, 1, 1));

		this.doubleText = new Text(this, SWT.BORDER);
		this.doubleText.setText(" ");
		this.doubleText.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false, 1, 1));
		this.textList.add(this.doubleText);

		/** Float */
		Label floatLabel = new Label(this, SWT.None);
		floatLabel.setText("Floating point :");
		floatLabel.setLayoutData(new GridData(SWT.RIGHT, SWT.CENTER, false, false, 1, 1));

		this.floatText = new Text(this, SWT.BORDER);
		this.floatText.setText(" ");
		this.floatText.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false, 1, 1));
		this.textList.add(this.floatText);

		/** Byte */
		Label byteLabel = new Label(this, SWT.None);
		byteLabel.setText("Byte :");
		byteLabel.setLayoutData(new GridData(SWT.RIGHT, SWT.CENTER, false, false, 1, 1));

		this.byteText = new Text(this, SWT.BORDER);
		this.byteText.setText(" ");
		this.byteText.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false, 1, 1));
		this.textList.add(this.byteText);

		/** Short */
		Label shortLabel = new Label(this, SWT.None);
		shortLabel.setText("Short integer :");
		shortLabel.setLayoutData(new GridData(SWT.RIGHT, SWT.CENTER, false, false, 1, 1));

		this.shortText = new Text(this, SWT.BORDER);
		this.shortText.setText(" ");
		this.shortText.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false, 1, 1));
		this.textList.add(this.shortText);

		/** Int */
		Label intLabel = new Label(this, SWT.None);
		intLabel.setText("Integer :");
		intLabel.setLayoutData(new GridData(SWT.RIGHT, SWT.CENTER, false, false, 1, 1));

		this.intText = new Text(this, SWT.BORDER);
		this.intText.setText(" ");
		this.intText.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false, 1, 1));
		this.textList.add(this.intText);

		/** Long */
		Label longLabel = new Label(this, SWT.None);
		longLabel.setText("Long integer :");
		longLabel.setLayoutData(new GridData(SWT.RIGHT, SWT.CENTER, false, false, 1, 1));

		this.longText = new Text(this, SWT.BORDER);
		this.longText.setText(" ");
		this.longText.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false, 1, 1));
		this.textList.add(this.longText);

		updateTexts();
		initDataBindings();
	}

	/**
	 * Updates all the texts.
	 */
	public void updateTexts() {
		this.doubleText.setText(
				Activator.getDefault().getPreferenceStore().getString(PreferencesConstants.NATIVE_FORMAT_DOUBLE_ID));
		this.floatText.setText(
				Activator.getDefault().getPreferenceStore().getString(PreferencesConstants.NATIVE_FORMAT_FLOAT_ID));
		this.byteText.setText(
				Activator.getDefault().getPreferenceStore().getString(PreferencesConstants.NATIVE_FORMAT_BYTE_ID));
		this.shortText.setText(
				Activator.getDefault().getPreferenceStore().getString(PreferencesConstants.NATIVE_FORMAT_SHORT_ID));
		this.intText.setText(
				Activator.getDefault().getPreferenceStore().getString(PreferencesConstants.NATIVE_FORMAT_INT_ID));
		this.longText.setText(
				Activator.getDefault().getPreferenceStore().getString(PreferencesConstants.NATIVE_FORMAT_LONG_ID));
	}

	private void initDataBindings() {

		if (this.bindingContext != null) {
			this.bindingContext.dispose();
		}

		this.bindingContext = new DataBindingContext();

		/** Update value strategies */
		UpdateValueStrategy policyNever = new UpdateValueStrategy(UpdateListStrategy.POLICY_NEVER);
		UpdateValueStrategy validFormatUpdateStrategy = new UpdateValueStrategy(UpdateListStrategy.POLICY_UPDATE)
				.setConverter(new Converter(String.class, Color.class) {
					@Override
					public Object convert(Object fromObject) {
						if (fromObject != null && isValid((String) fromObject)) {
							return getDisplay().getSystemColor(SWT.COLOR_TRANSPARENT);
						}
						return getDisplay().getSystemColor(SWT.COLOR_RED);
					}
				});

		/** Bind the text with the background for each text */
		for (Text text : this.textList) {
			IObservableValue<?> textText = WidgetProperties.text(SWT.Modify).observe(text);
			IObservableValue<?> backgroundText = WidgetProperties.background().observe(text);

			this.bindingContext.bindValue(backgroundText, textText, policyNever, validFormatUpdateStrategy);
		}
	}

	/**
	 * Used to save the content of the texts boxes in the preferences if their input
	 * is valid.
	 */
	public void savePreferences() {
		if (isValid(this.doubleText.getText())) {
			Activator.getDefault().getPreferenceStore().setValue(PreferencesConstants.NATIVE_FORMAT_DOUBLE_ID,
					this.doubleText.getText());
		}
		if (isValid(this.floatText.getText())) {
			Activator.getDefault().getPreferenceStore().setValue(PreferencesConstants.NATIVE_FORMAT_FLOAT_ID,
					this.floatText.getText());
		}
		if (isValid(this.byteText.getText())) {
			Activator.getDefault().getPreferenceStore().setValue(PreferencesConstants.NATIVE_FORMAT_BYTE_ID,
					this.byteText.getText());
		}
		if (isValid(this.shortText.getText())) {
			Activator.getDefault().getPreferenceStore().setValue(PreferencesConstants.NATIVE_FORMAT_SHORT_ID,
					this.shortText.getText());
		}
		if (isValid(this.intText.getText())) {
			Activator.getDefault().getPreferenceStore().setValue(PreferencesConstants.NATIVE_FORMAT_INT_ID,
					this.intText.getText());
		}
		if (isValid(this.longText.getText())) {
			Activator.getDefault().getPreferenceStore().setValue(PreferencesConstants.NATIVE_FORMAT_LONG_ID,
					this.longText.getText());
		}
	}

	/**
	 * Tries to create a {@link DecimalFormat} with the specified {@link String}.
	 * 
	 * @param str {@link String} to use as pattern for the created
	 *            {@link DecimalFormat}.
	 * @return true if a {@link DecimalFormat} can be created, false otherwise.
	 */
	private boolean isValid(String str) {
		if ("".equals(str)) {
			return false;
		}

		for (int i = 0; i < str.length(); i++) {
			char character = str.charAt(i);
			if (character != '0' && character != '.' && character != '#' && character != ',') {
				return false;
			}
		}

		try {
			new DecimalFormat(str);
			return true;
		} catch (Exception e) {
			return false;
		}
	}
}