Java tutorial
/******************************************************************************* * Copyright (c) 2000, 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 *******************************************************************************/ package org.eclipse.ui.texteditor; import java.util.ResourceBundle; import org.eclipse.swt.SWT; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Shell; import org.eclipse.core.resources.IResource; import org.eclipse.jface.dialogs.Dialog; import org.eclipse.jface.dialogs.DialogPage; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.dialogs.MessageDialog; import org.eclipse.jface.preference.IPreferenceStore; import org.eclipse.jface.preference.PreferenceStore; import org.eclipse.ui.ide.dialogs.AbstractEncodingFieldEditor; import org.eclipse.ui.ide.dialogs.EncodingFieldEditor; import org.eclipse.ui.ide.dialogs.ResourceEncodingFieldEditor; import org.eclipse.ui.editors.text.IEncodingSupport; /** * Action for changing the encoding of the editor's * input element. * <p> * The following keys, prepended by the given option prefix, * are used for retrieving resources from the given bundle: * <ul> * <li><code>"dialog.title"</code> - the input dialog's title</li> * </ul> * This class may be instantiated but is not intended to be subclassed. * </p> * * @since 3.1 * @noextend This class is not intended to be subclassed by clients. */ public class ChangeEncodingAction extends TextEditorAction { private static final int APPLY_ID = IDialogConstants.OK_ID + IDialogConstants.CANCEL_ID + 1; private String fDialogTitle; private static final String ENCODING_PREF_KEY = "encoding"; //$NON-NLS-1$ /** * Creates a new action for the given text editor. * * @param editor the text editor * @see TextEditorAction#TextEditorAction(ResourceBundle, String, ITextEditor) * @since 3.5 */ public ChangeEncodingAction(ITextEditor editor) { this(TextEditorMessages.getBundleForConstructedKeys(), "Editor.ChangeEncodingAction.", editor); //$NON-NLS-1$ } /** * Creates a new action for the given text editor. The action configures its visual * representation from the given resource bundle. * * @param bundle the resource bundle * @param prefix a prefix to be prepended to the various resource keys (described in * <code>ResourceAction</code> constructor), or <code>null</code> if none * @param editor the text editor * @see TextEditorAction#TextEditorAction(ResourceBundle, String, ITextEditor) */ public ChangeEncodingAction(ResourceBundle bundle, String prefix, ITextEditor editor) { super(bundle, prefix, editor); String key = "dialog.title"; //$NON-NLS-1$; if (prefix != null && prefix.length() > 0) key = prefix + key; fDialogTitle = getString(bundle, key, null); } /* * @see org.eclipse.jface.action.Action#run() */ public void run() { final IResource resource = getResource(); final Shell parentShell = getTextEditor().getSite().getShell(); final IEncodingSupport encodingSupport = getEncodingSupport(); if (resource == null && encodingSupport == null) { MessageDialog.openInformation(parentShell, fDialogTitle, TextEditorMessages.ChangeEncodingAction_message_noEncodingSupport); return; } Dialog dialog = new Dialog(parentShell) { private AbstractEncodingFieldEditor fEncodingEditor; private IPreferenceStore store = null; /* * @see org.eclipse.jface.window.Window#configureShell(org.eclipse.swt.widgets.Shell) */ protected void configureShell(Shell newShell) { super.configureShell(newShell); newShell.setText(fDialogTitle); } /* * @see org.eclipse.jface.dialogs.Dialog#createDialogArea(org.eclipse.swt.widgets.Composite) */ protected Control createDialogArea(Composite parent) { Composite composite = (Composite) super.createDialogArea(parent); composite = new Composite(composite, SWT.NONE); GridLayout layout = new GridLayout(); layout.marginHeight = convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_MARGIN); layout.marginWidth = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_MARGIN); layout.verticalSpacing = convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_SPACING); layout.horizontalSpacing = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_SPACING); composite.setLayout(layout); GridData data = new GridData(GridData.FILL_BOTH); composite.setLayoutData(data); composite.setFont(parent.getFont()); DialogPage page = new MessageDialogPage(composite) { public void setErrorMessage(String newMessage) { super.setErrorMessage(newMessage); setButtonEnabledState(IDialogConstants.OK_ID, newMessage == null); setButtonEnabledState(APPLY_ID, newMessage == null); } private void setButtonEnabledState(int id, boolean state) { Button button = getButton(id); if (button != null) button.setEnabled(state); } }; if (resource != null) { fEncodingEditor = new ResourceEncodingFieldEditor("", composite, resource, null); //$NON-NLS-1$ fEncodingEditor.setPage(page); fEncodingEditor.load(); } else { fEncodingEditor = new EncodingFieldEditor(ENCODING_PREF_KEY, "", null, composite); //$NON-NLS-1$ store = new PreferenceStore(); String defaultEncoding = encodingSupport.getDefaultEncoding(); store.setDefault(ENCODING_PREF_KEY, defaultEncoding); String encoding = encodingSupport.getEncoding(); if (encoding != null) store.setValue(ENCODING_PREF_KEY, encoding); fEncodingEditor.setPreferenceStore(store); fEncodingEditor.setPage(page); fEncodingEditor.load(); if (encoding == null || encoding.equals(defaultEncoding) || encoding.length() == 0) fEncodingEditor.loadDefault(); } return composite; } /* * @see org.eclipse.jface.dialogs.Dialog#createButtonsForButtonBar(org.eclipse.swt.widgets.Composite) */ protected void createButtonsForButtonBar(Composite parent) { createButton(parent, APPLY_ID, TextEditorMessages.ChangeEncodingAction_button_apply_label, false); super.createButtonsForButtonBar(parent); } /* * @see org.eclipse.jface.dialogs.Dialog#buttonPressed(int) */ protected void buttonPressed(int buttonId) { if (buttonId == APPLY_ID) apply(); else super.buttonPressed(buttonId); } /* * @see org.eclipse.jface.dialogs.Dialog#okPressed() */ protected void okPressed() { apply(); super.okPressed(); } private void apply() { fEncodingEditor.store(); if (resource == null) { String encoding = fEncodingEditor.getPreferenceStore() .getString(fEncodingEditor.getPreferenceName()); encodingSupport.setEncoding(encoding); } } }; dialog.open(); } /* * @see org.eclipse.ui.texteditor.IUpdate#update() */ public void update() { setEnabled((getResource() != null || getEncodingSupport() != null) && !getTextEditor().isDirty()); } /** * Gets the resource which is being edited in the editor. * * @return the resource being edited or <code>null</code>s */ private IResource getResource() { if (getTextEditor() != null && getTextEditor().getEditorInput() != null) return (IResource) getTextEditor().getEditorInput().getAdapter(IResource.class); return null; } /** * Gets the editor's encoding support. * * @return the resource being edited or <code>null</code>s */ private IEncodingSupport getEncodingSupport() { if (getTextEditor() != null) return (IEncodingSupport) getTextEditor().getAdapter(IEncodingSupport.class); return null; } }