/*******************************************************************************
* Copyright (c) 2004, 2009 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
* Daniel Megert daniel_megert@ch.ibm.com Bug 169696
*******************************************************************************/
package org.eclipse.ui.ide.dialogs;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.util.List;
import org.eclipse.jface.preference.FieldEditor;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Group;
import org.eclipse.ui.WorkbenchEncoding;
import org.eclipse.ui.ide.IDEEncoding;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;
/**
* The abstract superclass of field editors used to set an encoding. Any user
* entered encodings will be added to the list of encodings available via
* {@link org.eclipse.ui.ide.IDEEncoding}.
* <p>
* Subclasses may extend, but must call <code>createEncodingGroup</code>
* during <code>doFillIntoGrid</code>.
* </p>
*
* @see org.eclipse.ui.ide.IDEEncoding
* @since 3.1
*/
public abstract class AbstractEncodingFieldEditor extends FieldEditor {
private Composite container;
private Button defaultEncodingButton;
private String defaultEnc;
private Button otherEncodingButton;
private Combo encodingCombo;
private boolean isValid = true;
private String oldSelectedEncoding;
private String groupTitle = IDEWorkbenchMessages.WorkbenchPreference_encoding;
/**
* Creates a new encoding field editor with no settings set.
*/
protected AbstractEncodingFieldEditor() {
super();
}
/**
* Creates a new encoding field editor with the given preference name, label
* and parent.
*
* @param name
* the name of the preference this field editor works on
* @param labelText
* the label text of the field editor
* @param parent
* the parent of the field editor's control
*/
protected AbstractEncodingFieldEditor(String name, String labelText,
Composite parent) {
super(name, labelText, parent);
}
/**
* Creates a new encoding field editor with the given preference name, label
* and parent.
*
* @param name
* the name of the preference this field editor works on
* @param labelText
* the label text of the field editor
* @param groupTitle
* the title for the field editor's control. If groupTitle is
* <code>null</code> the control will be unlabelled
* (by default a {@link Composite} instead of a {@link Group}.
* @param parent
* the parent of the field editor's control
* @see AbstractEncodingFieldEditor#setGroupTitle(String)
* @since 3.3
*/
protected AbstractEncodingFieldEditor(String name, String labelText,
String groupTitle, Composite parent) {
init(name, labelText);
this.groupTitle = groupTitle;
createControl(parent);
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.preference.FieldEditor#adjustForNumColumns(int)
*/
protected void adjustForNumColumns(int numColumns) {
((GridData) getContainer().getLayoutData()).horizontalSpan = numColumns;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.preference.FieldEditor#doFillIntoGrid(org.eclipse.swt.widgets.Composite,
* int)
*/
protected void doFillIntoGrid(Composite parent, int numColumns) {
container = createEncodingGroup(parent, numColumns);
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.preference.FieldEditor#doLoad()
*/
protected void doLoad() {
if (encodingCombo != null) {
List encodings = IDEEncoding.getIDEEncodings();
String resourcePreference = getStoredValue();
populateEncodingsCombo(encodings, resourcePreference);
updateEncodingState(resourcePreference == null);
}
}
/**
* Returns the value that is currently stored for the encoding.
*
* @return the currently stored encoding
*/
protected abstract String getStoredValue();
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.preference.FieldEditor#doLoadDefault()
*/
protected void doLoadDefault() {
updateEncodingState(true);
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.preference.FieldEditor#getNumberOfControls()
*/
public int getNumberOfControls() {
return 1;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.preference.FieldEditor#isValid()
*/
public boolean isValid() {
return isValid;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.preference.FieldEditor#refreshValidState()
*/
protected void refreshValidState() {
updateValidState();
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.preference.FieldEditor#setPreferenceStore(org.eclipse.jface.preference.IPreferenceStore)
*/
public void setPreferenceStore(IPreferenceStore store) {
super.setPreferenceStore(store);
defaultEnc = store.getDefaultString(getPreferenceName());
updateDefaultEncoding();
}
private void updateDefaultEncoding() {
defaultEncodingButton.setText(defaultButtonText());
}
private Composite getContainer() {
return container;
}
/**
* Creates a composite with all the encoding controls.
* <p>
* Subclasses may extend.
* </p>
*
* @param parent
* the parent widget
* @param numColumns
* the number of columns in the parent
* @return the group control
*/
protected Composite createEncodingGroup(Composite parent, int numColumns) {
Composite topControl;
GridLayout layout = new GridLayout();
layout.numColumns = 2;
if (groupTitle == null){
topControl = new Composite(parent, SWT.NONE);
layout.marginWidth = 0;
layout.marginHeight = 0;
}
else {
Group top = new Group(parent, SWT.NONE);
top.setText(groupTitle);
topControl = top;
}
GridData data = new GridData(GridData.FILL_HORIZONTAL);
topControl.setLayoutData(data);
topControl.setLayout(layout);
SelectionAdapter buttonListener = new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
updateEncodingState(defaultEncodingButton.getSelection());
updateValidState();
}
};
defaultEncodingButton = new Button(topControl, SWT.RADIO);
defaultEnc = findDefaultEncoding();
defaultEncodingButton.setText(defaultButtonText());
data = new GridData();
data.horizontalSpan = 2;
defaultEncodingButton.setLayoutData(data);
defaultEncodingButton.addSelectionListener(buttonListener);
otherEncodingButton = new Button(topControl, SWT.RADIO);
otherEncodingButton
.setText(IDEWorkbenchMessages.WorkbenchPreference_otherEncoding);
otherEncodingButton.addSelectionListener(buttonListener);
encodingCombo = new Combo(topControl, SWT.NONE);
data = new GridData();
encodingCombo.setLayoutData(data);
encodingCombo.addSelectionListener(new SelectionAdapter() {
/*
* (non-Javadoc)
*
* @see org.eclipse.swt.events.SelectionListener#widgetSelected(org.eclipse.swt.events.SelectionEvent)
*/
public void widgetSelected(SelectionEvent e) {
updateValidState();
}
});
encodingCombo.addKeyListener(new KeyAdapter() {
/*
* (non-Javadoc)
*
* @see org.eclipse.swt.events.KeyListener#keyReleased(org.eclipse.swt.events.KeyEvent)
*/
public void keyReleased(KeyEvent e) {
updateValidState();
}
});
return topControl;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.preference.FieldEditor#setEnabled(boolean,
* org.eclipse.swt.widgets.Composite)
* @since 3.3
*/
public void setEnabled(boolean enabled, Composite parent) {
if (container != null)
container.setEnabled(enabled);
if (defaultEncodingButton != null)
defaultEncodingButton.setEnabled(enabled);
if (otherEncodingButton != null)
otherEncodingButton.setEnabled(enabled);
if (encodingCombo != null)
encodingCombo.setEnabled(enabled && otherEncodingButton.getSelection());
}
/**
* Returns the default encoding for the object being shown.
*
* @return the default encoding for the object being shown
*/
protected String findDefaultEncoding() {
return WorkbenchEncoding.getWorkbenchDefaultEncoding();
}
/**
* Returns the text for the default encoding button.
*
* @return the text for the default encoding button
*/
protected String defaultButtonText() {
return NLS.bind(
IDEWorkbenchMessages.WorkbenchPreference_defaultEncoding,
defaultEnc);
}
/**
* Populates the encodings combo. Sets the text based on the selected
* encoding. If there is no selected encoding, the text is set to the
* default encoding.
*
* @param encodings
* the list of encodings (list of String)
* @param selectedEncoding
* the selected encoding, or <code>null</code>
*/
private void populateEncodingsCombo(List encodings, String selectedEncoding) {
String[] encodingStrings = new String[encodings.size()];
encodings.toArray(encodingStrings);
encodingCombo.setItems(encodingStrings);
if (selectedEncoding == null) {
encodingCombo.setText(getDefaultEnc());
} else {
encodingCombo.setText(selectedEncoding);
}
}
private void updateEncodingState(boolean useDefault) {
defaultEncodingButton.setSelection(useDefault);
otherEncodingButton.setSelection(!useDefault);
if (useDefault) {
encodingCombo.setText(getDefaultEnc());
}
encodingCombo.setEnabled(!useDefault);
setPresentsDefaultValue(useDefault);
updateValidState();
}
private void updateValidState() {
boolean isValidNow = isEncodingValid();
if (isValidNow != isValid) {
isValid = isValidNow;
if (isValid) {
clearErrorMessage();
} else {
showErrorMessage(IDEWorkbenchMessages.WorkbenchPreference_unsupportedEncoding);
}
fireStateChanged(IS_VALID, !isValid, isValid);
}
String newValue = getSelectedEncoding();
if (isValid && !newValue.equals(oldSelectedEncoding)) {
fireValueChanged(VALUE, oldSelectedEncoding, newValue);
oldSelectedEncoding = newValue;
}
}
/**
* Returns the currently selected encoding.
*
* @return the currently selected encoding
*/
protected String getSelectedEncoding() {
if (defaultEncodingButton.getSelection()) {
return defaultEnc;
}
return encodingCombo.getText();
}
private boolean isEncodingValid() {
return defaultEncodingButton.getSelection()
|| isValidEncoding(encodingCombo.getText());
}
/**
* Returns whether or not the given encoding is valid.
*
* @param enc
* the encoding to validate
* @return <code>true</code> if the encoding is valid, <code>false</code>
* otherwise
*/
private boolean isValidEncoding(String enc) {
try {
return Charset.isSupported(enc);
} catch (IllegalCharsetNameException e) {
// This is a valid exception
return false;
}
}
/**
* Returns the default encoding.
*
* @return the default encoding
*/
protected String getDefaultEnc() {
return defaultEnc;
}
/**
* Returns whether or not the encoding setting changed.
*
* @param encodingSetting
* the setting from the page.
* @return boolean <code>true</code> if the resource encoding is the same
* as before.
*/
protected boolean hasSameEncoding(String encodingSetting) {
String current = getStoredValue();
if (encodingSetting == null) {
// Changed if default is selected and there is no setting
return current == null || current.length() == 0;
}
return encodingSetting.equals(current);
}
/**
* Return whether or not the default has been selected.
*
* @return <code>true</code> if the default button has been selected.
*/
boolean isDefaultSelected() {
return defaultEncodingButton.getSelection();
}
/**
* Set the title of the group to groupTitle. If this is not called a default
* title is used. If groupTitle is <code>null</code> the control will be
* unlabelled (by default a {@link Composite} instead of a {@link Group}.
*
* <strong>NOTE</strong> this value must be set before
* {@link #createControl(Composite)} is called or it will be ignored.
*
* @param groupTitle
* The groupTitle to set.
* @since 3.3
*/
public void setGroupTitle(String groupTitle) {
this.groupTitle = groupTitle;
}
}