org.eclipse.actf.ai.voice.preferences.util.ComboFieldEditor.java Source code

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Here is the source code for org.eclipse.actf.ai.voice.preferences.util.ComboFieldEditor.java

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/*******************************************************************************
 * Copyright (c) 2007 IBM Corporation and Others
 * 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:
 *    Takashi ITOH - initial API and implementation
 *******************************************************************************/
package org.eclipse.actf.ai.voice.preferences.util;

import org.eclipse.jface.preference.FieldEditor;
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.layout.GridData;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;

/**
 * ComboFieldEditor has a combobox.
 */
public class ComboFieldEditor extends FieldEditor {

    Combo comboField;
    private String[][] labelsAndValues;
    protected String value;

    protected ComboFieldEditor(String name, String labelText, String[][] labelsAndValues, Composite parent) {
        init(name, labelText);
        initLabelsAndValues(labelsAndValues);
        createControl(parent);
        setEnabled(comboField.getItemCount() > 0, parent);
    }

    protected void initLabelsAndValues(String[][] labelsAndValues) {
        assert checkArray(labelsAndValues) == true;
        this.labelsAndValues = labelsAndValues;
    }

    protected void adjustForNumColumns(int numColumns) {
        GridData gd = (GridData) comboField.getLayoutData();
        gd.horizontalSpan = numColumns - 1;
        gd.grabExcessHorizontalSpace = gd.horizontalSpan == 1;
    }

    protected void doFillIntoGrid(Composite parent, int numColumns) {
        getLabelControl(parent);

        comboField = getComboControl(parent);
        GridData gd = new GridData(GridData.FILL_HORIZONTAL);
        gd.horizontalSpan = numColumns - 1;
        comboField.setLayoutData(gd);
    }

    protected void doLoad() {
        updateValue(getPreferenceStore().getString(getPreferenceName()));
    }

    protected void doLoadDefault() {
        updateValue(getPreferenceStore().getDefaultString(getPreferenceName()));
    }

    protected void doStore() {
        if (null != value) {
            getPreferenceStore().setValue(getPreferenceName(), value);
        } else {
            getPreferenceStore().setToDefault(getPreferenceName());
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.eclipse.jface.preference.FieldEditor#getNumberOfControls()
     */
    public int getNumberOfControls() {
        return 2;
    }

    private boolean checkArray(String[][] table) {
        if (table == null)
            return false;
        for (int i = 0; i < table.length; i++) {
            String[] array = table[i];
            if (array == null || array.length != 2)
                return false;
        }
        return true;
    }

    private void updateValue(String selectedValue) {
        if (null != selectedValue) {
            for (int i = 0; i < labelsAndValues.length; i++) {
                if (labelsAndValues[i][1].equals(selectedValue)) {
                    comboField.select(i);
                    this.value = selectedValue;
                    return;
                }
            }
        }
        if (labelsAndValues.length > 0) {
            comboField.select(0);
            this.value = labelsAndValues[0][1];
        }
        return;
    }

    /**
     * @return The combobox object.
     */
    public Combo getComboControl() {
        return comboField;
    }

    protected Combo getComboControl(Composite parent) {
        if (null == comboField) {
            comboField = new Combo(parent, SWT.DROP_DOWN | SWT.SIMPLE | SWT.BORDER | SWT.READ_ONLY);
            comboField.setFont(parent.getFont());
            if (null != labelsAndValues) {
                for (int i = 0; i < labelsAndValues.length; i++) {
                    comboField.add(labelsAndValues[i][0]);
                }
            }
            comboField.addSelectionListener(new SelectionAdapter() {
                public void widgetSelected(SelectionEvent event) {
                    int index = comboField.getSelectionIndex();
                    if (index >= 0) {
                        String oldValue = value;
                        value = labelsAndValues[index][1];
                        setPresentsDefaultValue(false);
                        fireValueChanged(VALUE, oldValue, value);
                    }
                }
            });
            comboField.addDisposeListener(new DisposeListener() {
                public void widgetDisposed(DisposeEvent event) {
                    comboField = null;
                }
            });
        } else {
            checkParent(comboField, parent);
        }
        return comboField;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.eclipse.jface.preference.FieldEditor#setEnabled(boolean,
     *      org.eclipse.swt.widgets.Composite)
     */
    public void setEnabled(boolean enabled, Composite parent) {
        super.setEnabled(enabled, parent);
        getComboControl(parent).setEnabled(enabled);
    }
}