org.eclipse.jst.jsf.facesconfig.ui.preference.ComboFieldEditor.java Source code

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Here is the source code for org.eclipse.jst.jsf.facesconfig.ui.preference.ComboFieldEditor.java

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/*******************************************************************************
 * Copyright (c) 2004, 2006 Sybase, Inc. 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:
 *     Sybase, Inc. - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.jsf.facesconfig.ui.preference;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.preference.FieldEditor;
import org.eclipse.swt.SWT;
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;
import org.eclipse.swt.widgets.Control;

/**
 * 
 * A field editor for a combo box that allows the drop-down selection of one of
 * a list of items.
 * 
 */

/*package*/ class ComboFieldEditor extends FieldEditor {

    /**
     * 
     * The <code>Combo</code> widget.
     * 
     */

    private Combo fCombo;

    /**
     * 
     * The value (not the name) of the currently selected item in the Combo
     * widget.
     * 
     */

    private String fValue;

    /**
     * 
     * The names (labels) and underlying values to populate the combo widget.
     * These should be
     * 
     * arranged as: { {name1, value1}, {name2, value2}, ...}
     * 
     */

    private String[][] fEntryNamesAndValues;

    /**
     * @param name
     * @param labelText
     * @param entryNamesAndValues
     * @param parent
     */
    public ComboFieldEditor(String name, String labelText, String[][] entryNamesAndValues, Composite parent) {

        init(name, labelText);

        Assert.isTrue(checkArray(entryNamesAndValues));

        fEntryNamesAndValues = entryNamesAndValues;

        createControl(parent);

    }

    /**
     * 
     * Checks whether given <code>String[][]</code> is of "type"
     * 
     * <code>String[][2]</code>.
     * 
     * 
     * 
     * @return <code>true</code> if it is ok, and <code>false</code>
     *         otherwise
     * 
     */

    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;

    }

    /**
     * 
     * @see FieldEditor#adjustForNumColumns(int)
     * 
     */

    protected void adjustForNumColumns(int numColumns) {

        if (numColumns > 1) {

            Control control = getLabelControl();

            int left = numColumns;

            if (control != null) {

                ((GridData) control.getLayoutData()).horizontalSpan = 1;

                left = left - 1;

            }

            ((GridData) fCombo.getLayoutData()).horizontalSpan = left;

        } else {

            Control control = getLabelControl();

            if (control != null) {

                ((GridData) control.getLayoutData()).horizontalSpan = 1;

            }

            ((GridData) fCombo.getLayoutData()).horizontalSpan = 1;

        }

    }

    /**
     * 
     * @see FieldEditor#doFillIntoGrid(Composite, int)
     * 
     */

    protected void doFillIntoGrid(Composite parent, int numColumns) {

        int comboC = 1;

        if (numColumns > 1) {

            comboC = numColumns - 1;

        }

        Control control = getLabelControl(parent);

        GridData gd = new GridData();

        gd.horizontalSpan = 1;

        control.setLayoutData(gd);

        control = getComboBoxControl(parent);

        gd = new GridData();

        gd.horizontalSpan = comboC;

        gd.horizontalAlignment = GridData.FILL;

        control.setLayoutData(gd);

    }

    /**
     * 
     * @see FieldEditor#doLoad()
     * 
     */

    protected void doLoad() {

        updateComboForValue(getPreferenceStore().getString(getPreferenceName()));

    }

    /**
     * 
     * @see FieldEditor#doLoadDefault()
     * 
     */

    protected void doLoadDefault() {

        updateComboForValue(getPreferenceStore().getDefaultString(getPreferenceName()));

    }

    /**
     * 
     * @see FieldEditor#doStore()
     * 
     */

    protected void doStore() {

        if (fValue == null) {

            getPreferenceStore().setToDefault(getPreferenceName());

            return;

        }

        getPreferenceStore().setValue(getPreferenceName(), fValue);

    }

    /**
     * 
     * @see FieldEditor#getNumberOfControls()
     * 
     */

    public int getNumberOfControls() {

        return 1;

    }

    /**
     * 
     * Lazily create and return the Combo control.
     * @param parent 
     * @return the combo box
     * 
     */

    public Combo getComboBoxControl(Composite parent) {

        if (fCombo == null) {

            fCombo = new Combo(parent, SWT.READ_ONLY);

            for (int i = 0; i < fEntryNamesAndValues.length; i++) {

                fCombo.add(fEntryNamesAndValues[i][0], i);

            }

            fCombo.addSelectionListener(new SelectionAdapter() {

                public void widgetSelected(SelectionEvent evt) {

                    String oldValue = fValue;

                    String name = fCombo.getText();

                    fValue = getValueForName(name);

                    setPresentsDefaultValue(false);

                    fireValueChanged(VALUE, oldValue, fValue);

                }

            });

        }

        return fCombo;

    }

    /**
     * 
     * Given the name (label) of an entry, return the corresponding value.
     * @param name 
     * @return the value corresponding to name or the first value if
     * not found
     * 
     */

    protected String getValueForName(String name) {

        for (int i = 0; i < fEntryNamesAndValues.length; i++) {

            String[] entry = fEntryNamesAndValues[i];

            if (name.equals(entry[0])) {

                return entry[1];

            }

        }

        return fEntryNamesAndValues[0][0];

    }

    /**
     * 
     * Set the name in the combo widget to match the specified value.
     * @param value 
     * 
     */

    protected void updateComboForValue(String value) {

        fValue = value;

        for (int i = 0; i < fEntryNamesAndValues.length; i++) {

            if (value.equals(fEntryNamesAndValues[i][1])) {

                fCombo.setText(fEntryNamesAndValues[i][0]);

                return;

            }

        }

        if (fEntryNamesAndValues.length > 0) {

            fValue = fEntryNamesAndValues[0][1];

        }

    }

}