jasima_gui.editor.EditorWidget.java Source code

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Here is the source code for jasima_gui.editor.EditorWidget.java

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/*******************************************************************************
 * Copyright (c) 2010-2015 Torsten Hildebrandt and jasima contributors
 *
 * This file is part of jasima, v1.2.
 *
 * jasima is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * jasima is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with jasima.  If not, see <http://www.gnu.org/licenses/>.
 *******************************************************************************/
package jasima_gui.editor;

import jasima_gui.Activator;

import java.util.ArrayList;

import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.dialogs.ErrorDialog;
import org.eclipse.jface.dialogs.IMessageProvider;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.ui.forms.widgets.ExpandableComposite;
import org.eclipse.ui.forms.widgets.FormToolkit;
import org.eclipse.ui.forms.widgets.ScrolledForm;

public abstract class EditorWidget extends Composite {

    public interface EditorListener {
        public void statusTextChanged(String statusText);
    }

    protected final ArrayList<EditorListener> editorListeners = new ArrayList<EditorWidget.EditorListener>();
    protected FormToolkit toolkit;
    protected IProperty property;
    protected TopLevelEditor topLevelEditor;
    protected String statusText = "";

    public EditorWidget(Composite parent) {
        super(parent, 0);
        toolkit = new FormToolkit(getDisplay());
        toolkit.adapt(this);
        setLayout(new FillLayout());
    }

    public final void initialize(IProperty property, TopLevelEditor topLevelEditor) {
        this.property = property;
        this.topLevelEditor = topLevelEditor;
    }

    /**
     * This method must be overridden and used to create the user interface of
     * the editor. It is called after initialize.
     */
    public abstract void createControls();

    public void addEditorListener(EditorListener listener) {
        editorListeners.add(listener);
        listener.statusTextChanged(statusText);
    }

    protected void setStatusText(String statusText) {
        assert statusText != null;
        assert isExpandable();
        this.statusText = statusText;
        for (EditorListener listener : editorListeners) {
            listener.statusTextChanged(statusText);
        }
    }

    /**
     * Retrieve the value previously set by {@link #setStatusText(String)}.
     */
    public final String getStatusText() {
        return statusText;
    }

    /**
     * An expandable editor will be shown inside an {@link ExpandableComposite}.
     * This should be used for big editors that can not fit into one line.
     * 
     * @return true if this widget must be shown inside an
     *         {@link ExpandableComposite}
     */
    public boolean isExpandable() {
        return false;
    }

    /**
     * Can be used by an expandable editor to return any control that will be
     * shown in the header.
     * 
     * @return any control or null
     */
    public Control getToolBar() {
        return null;
    }

    @Override
    public void dispose() {
        toolkit.dispose();
        super.dispose();
    }

    /**
     * Must be implemented to set the property's value to this widget's value.
     * 
     * The implementation should use IProperty.setValue.
     */
    public abstract void storeValue();

    /**
     * Must be implemented to set this widget's value to the property's value.
     * 
     * The implementation should use IProperty.getValue.
     */
    public abstract void loadValue();

    protected void reLayout() {
        ScrolledForm sf = getScrolledForm();
        sf.getBody().layout(true, true);
        sf.reflow(true);
    }

    /**
     * Looks for the innermost ScrolledForm parent.
     * 
     * @return the ScrolledForm this editor widget is contained in
     */
    protected ScrolledForm getScrolledForm() {
        Composite comp = getParent();
        while (!(comp instanceof ScrolledForm)) {
            comp = comp.getParent();
            assert comp != null : "EditorWidget must always appear in a ScrolledForm.";
        }
        return (ScrolledForm) comp;
    }

    /**
     * Shows a modal error dialog. This should only be used when the user's work
     * flow has to be interrupted.
     * 
     * @param format
     *            the format string
     * @param args
     *            arguments for the format string
     */
    protected void showErrorDialog(String format, Object... args) {
        ErrorDialog.openError(getShell(), null, null,
                new Status(IStatus.ERROR, Activator.PLUGIN_ID, String.format(format, args)));
    }

    /**
     * Shows an error without interrupting the user's work flow. This should be
     * used for errors that can be ignored temporarily, like invalid property
     * values.
     * 
     * @param message
     *            the error message that should be shown
     */
    protected void showError(String message) {
        if (message != null && (message = message.trim()).isEmpty())
            message = null;
        if (message == null && getScrolledForm().getMessageType() == IMessageProvider.NONE) {
            return;
        }
        getScrolledForm().setMessage(message, message == null ? IMessageProvider.NONE : IMessageProvider.ERROR);
    }

    /**
     * Hides any error that is shown.
     */
    protected void hideError() {
        showError(null);
    }

}