eu.numberfour.n4js.ui.editor.StyledTextDescriptor.java Source code

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Here is the source code for eu.numberfour.n4js.ui.editor.StyledTextDescriptor.java

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/**
 * Copyright (c) 2016 NumberFour AG.
 * 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:
 *   NumberFour AG - Initial API and implementation
 */
package eu.numberfour.n4js.ui.editor;

import static org.eclipse.jface.preference.PreferenceConverter.getColor;
import static org.eclipse.jface.preference.PreferenceConverter.getDefaultColor;
import static org.eclipse.swt.SWT.COLOR_LIST_BACKGROUND;
import static org.eclipse.swt.SWT.READ_ONLY;
import static org.eclipse.swt.widgets.Display.getDefault;
import static org.eclipse.ui.texteditor.AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND;
import static org.eclipse.ui.texteditor.AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT;

import java.util.concurrent.atomic.AtomicReference;

import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.ui.editors.text.EditorsUI;

/**
 * Representation of a descriptor for a {@link StyledText styled text}.
 */
public interface StyledTextDescriptor {

    /**
     * Returns with the string represented by the current text descriptor.
     *
     * @return the text.
     */
    String getText();

    /**
     * Returns with the {@link StyleRange style range} instances for the text descriptor if any. If no style ranges are
     * defined for the text, then this method returns with {@code null}.
     *
     * @return the style ranges for the text.
     */
    StyleRange[] getRanges();

    /**
     * Returns with the font for the text descriptor.
     * <p>
     * Clients must NOT dispose the the returning font.
     *
     * @return the font for the descriptor.
     */
    Font getFont();

    /**
     * Creates and returns with a new {@link StyledText styled text} instance hooked up to the given parent composite.
     *
     * @param parent
     *            the parent of the styled text control.
     * @param style
     *            style bits for the new text control.
     * @return a new styled text control initialized from the descriptor.
     */
    default StyledText toStyledText(final Composite parent, final int style) {

        final StyledText text = new StyledText(parent, READ_ONLY | style);
        text.setText(getText());
        text.setStyleRanges(getRanges());
        text.setFont(getFont());
        text.setEditable(false);
        text.setEnabled(false);

        final AtomicReference<Color> colorRef = new AtomicReference<>();
        final IPreferenceStore prefStore = EditorsUI.getPreferenceStore();
        if (null == prefStore || prefStore.getBoolean(PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT)) {

            colorRef.set(getDefault().getSystemColor(COLOR_LIST_BACKGROUND));

        } else {

            RGB rgb = null;
            if (prefStore.contains(PREFERENCE_COLOR_BACKGROUND)) {
                if (prefStore.isDefault(PREFERENCE_COLOR_BACKGROUND)) {
                    rgb = getDefaultColor(prefStore, PREFERENCE_COLOR_BACKGROUND);
                } else {
                    rgb = getColor(prefStore, PREFERENCE_COLOR_BACKGROUND);
                }
                if (rgb != null) {
                    colorRef.set(new Color(text.getDisplay(), rgb));
                }
            }

        }

        if (null != colorRef.get()) {
            text.setBackground(colorRef.get());
            text.addDisposeListener(e -> {
                if (!colorRef.get().isDisposed()) {
                    colorRef.get().dispose();
                }
            });
        }

        text.pack();
        return text;
    }

}