/*******************************************************************************
* Copyright (c) 2000, 2006 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:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jface.preference;
import org.eclipse.core.runtime.Assert;
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.
*
* @since 3.3
*/
public 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;
/**
* Create the combo box field editor.
*
* @param name the name of the preference this field editor works on
* @param labelText the label text of the field editor
* @param entryNamesAndValues the names (labels) and underlying values to populate the combo widget. These should be
* arranged as: { {name1, value1}, {name2, value2}, ...}
* @param parent the parent composite
*/
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;
}
/* (non-Javadoc)
* @see org.eclipse.jface.preference.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;
}
}
/* (non-Javadoc)
* @see org.eclipse.jface.preference.FieldEditor#doFillIntoGrid(org.eclipse.swt.widgets.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);
control.setFont(parent.getFont());
}
/* (non-Javadoc)
* @see org.eclipse.jface.preference.FieldEditor#doLoad()
*/
protected void doLoad() {
updateComboForValue(getPreferenceStore().getString(getPreferenceName()));
}
/* (non-Javadoc)
* @see org.eclipse.jface.preference.FieldEditor#doLoadDefault()
*/
protected void doLoadDefault() {
updateComboForValue(getPreferenceStore().getDefaultString(getPreferenceName()));
}
/* (non-Javadoc)
* @see org.eclipse.jface.preference.FieldEditor#doStore()
*/
protected void doStore() {
if (fValue == null) {
getPreferenceStore().setToDefault(getPreferenceName());
return;
}
getPreferenceStore().setValue(getPreferenceName(), fValue);
}
/* (non-Javadoc)
* @see org.eclipse.jface.preference.FieldEditor#getNumberOfControls()
*/
public int getNumberOfControls() {
return 2;
}
/*
* Lazily create and return the Combo control.
*/
private Combo getComboBoxControl(Composite parent) {
if (fCombo == null) {
fCombo = new Combo(parent, SWT.READ_ONLY);
fCombo.setFont(parent.getFont());
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.
*/
private 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.
*/
private 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];
fCombo.setText(fEntryNamesAndValues[0][0]);
}
}
}