Java tutorial
/******************************************************************************* * Copyright (c) 2003 Berthold Daum. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Common Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/cpl-v10.html * * Contributors: * Berthold Daum * see https://eclipse.org/articles/Article-Mutatis-mutandis/overlay-pages.html *******************************************************************************/ package eu.scasefp7.eclipse.core.ui.preferences; import java.util.ArrayList; import java.util.List; import org.eclipse.core.resources.IProject; import org.eclipse.core.resources.ProjectScope; import org.eclipse.core.runtime.IAdaptable; import org.eclipse.core.runtime.preferences.IScopeContext; import org.eclipse.core.runtime.preferences.InstanceScope; import org.eclipse.jface.preference.FieldEditor; import org.eclipse.jface.preference.FieldEditorPreferencePage; import org.eclipse.jface.preference.IPreferenceNode; import org.eclipse.jface.preference.IPreferencePage; import org.eclipse.jface.preference.IPreferenceStore; import org.eclipse.jface.preference.PreferenceDialog; import org.eclipse.jface.preference.PreferenceManager; import org.eclipse.jface.preference.PreferenceNode; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.BusyIndicator; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; 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.Link; import org.eclipse.ui.IWorkbenchPropertyPage; import org.eclipse.ui.preferences.ScopedPreferenceStore; import eu.scasefp7.eclipse.core.ui.Activator; /** * Based on Berthold Daum's approach, but using project-scoped preference store * * @author Berthold Daum */ public abstract class FieldEditorOverlayPage extends FieldEditorPreferencePage implements IWorkbenchPropertyPage { // Stores all created field editors private List<FieldEditor> editors = new ArrayList<FieldEditor>(); // Stores owning element of properties private IAdaptable element; // Additional buttons for property pages private Button useProjectSettingsButton; // Link to configure workspace settings private Link configureLink; // Overlay preference store for property pages private IPreferenceStore overlayStore; // The image descriptor of this pages title image private ImageDescriptor image; // Cache for page id private String pageId; /** * Constructor * * @param style - layout style * @wbp.parser.constructor */ public FieldEditorOverlayPage(int style) { super(style); } /** * Constructor * * @param title - title string * @param style - layout style */ public FieldEditorOverlayPage(String title, int style) { super(title, style); } /** * Constructor * * @param title - title string * @param image - title image * @param style - layout style */ public FieldEditorOverlayPage(String title, ImageDescriptor image, int style) { super(title, image, style); this.image = image; } /** * Returns the id of the current preference page as defined in plugin.xml * Subclasses must implement. * * @return - the qualifier */ protected abstract String getPageId(); /** * Receives the object that owns the properties shown in this property page. * * @see org.eclipse.ui.IWorkbenchPropertyPage#setElement(org.eclipse.core.runtime.IAdaptable) */ public void setElement(IAdaptable element) { this.element = element; } /** * Delivers the object that owns the properties shown in this property page. * * @see org.eclipse.ui.IWorkbenchPropertyPage#getElement() */ public IAdaptable getElement() { return element; } /** * Delivers the project that owns the properties shown in this property page. * @return project */ public IProject getProject() { IAdaptable element = getElement(); IProject adapter = (IProject) element.getAdapter(IProject.class); return adapter; } /** * Returns true if this instance represents a property page * * @return - true for property pages, false for preference pages */ public boolean isPropertyPage() { return getElement() != null; } /** * We override the addField method. This allows us to store each field * editor added by subclasses in a list for later processing. * * @see org.eclipse.jface.preference.FieldEditorPreferencePage#addField(org.eclipse.jface.preference.FieldEditor) */ protected void addField(FieldEditor editor) { editors.add(editor); super.addField(editor); } /** * We override the createControl method. In case of property pages we create * a new PropertyStore as local preference store. After all control have * been create, we enable/disable these controls. * * @see org.eclipse.jface.preference.PreferencePage#createControl() */ @SuppressWarnings("javadoc") public void createControl(Composite parent) { // Special treatment for property pages if (isPropertyPage()) { // Cache the page id pageId = getPageId(); // Create an overlay preference store and fill it with properties IProject project = getProject(); if (project != null) { ProjectScope ps = new ProjectScope(getProject()); ScopedPreferenceStore scoped = new ScopedPreferenceStore(ps, Activator.PLUGIN_ID); scoped.setSearchContexts(new IScopeContext[] { ps, InstanceScope.INSTANCE }); overlayStore = scoped; // Set overlay store as current preference store } } super.createControl(parent); // Update state of all subclass controls if (isPropertyPage()) { updateFieldEditors(); } } /** * We override the createContents method. In case of property pages we * insert two radio buttons at the top of the page. * * @see org.eclipse.jface.preference.PreferencePage#createContents(org.eclipse.swt.widgets.Composite) */ protected Control createContents(Composite parent) { if (isPropertyPage()) { createSelectionGroup(parent); } return super.createContents(parent); } /** * Creates and initializes a selection group with two choice buttons and one * push button. * * @param parent - the parent composite */ private void createSelectionGroup(Composite parent) { Composite comp = new Composite(parent, SWT.NONE); GridLayout layout = new GridLayout(2, false); layout.marginHeight = 0; layout.marginWidth = 0; comp.setLayout(layout); comp.setLayoutData(new GridData(GridData.FILL_HORIZONTAL)); useProjectSettingsButton = createSettingsButton(comp, "Use pr&oject-specific settings"); configureLink = createLink(comp, "&Configure Workspace Settings..."); // Set workspace/project radio buttons try { Boolean useProject = getPreferenceStore().getBoolean(PreferenceConstants.P_USE_PROJECT_PREFS); if (useProject) { useProjectSettingsButton.setSelection(true); configureLink.setEnabled(false); } else { useProjectSettingsButton.setSelection(false); } } catch (Exception e) { useProjectSettingsButton.setSelection(false); } } /** * Convenience method creating a check button * * @param parent - the parent composite * @param label - the button label * @return - the new button */ private Button createSettingsButton(Composite parent, String label) { final Button button = new Button(parent, SWT.CHECK); button.setText(label); button.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { configureLink.setEnabled(button.isEnabled()); updateFieldEditors(); } }); return button; } /** * Convenience method creating a link * * @param parent - the parent composite * @param label - the link label * @return - the new link */ private Link createLink(Composite composite, String label) { Link link = new Link(composite, SWT.NONE); link.setLayoutData(new GridData(SWT.RIGHT, SWT.CENTER, true, false, 1, 1)); link.setFont(composite.getFont()); link.setText("<A>" + label + "</A>"); //$NON-NLS-1$//$NON-NLS-2$ link.addSelectionListener(new SelectionListener() { public void widgetSelected(SelectionEvent e) { configureWorkspaceSettings(); } public void widgetDefaultSelected(SelectionEvent e) { configureWorkspaceSettings(); } }); return link; } /** * Returns in case of property pages the overlay store, in case of * preference pages the standard preference store * * @see org.eclipse.jface.preference.PreferencePage#getPreferenceStore() */ public IPreferenceStore getPreferenceStore() { if (isPropertyPage()) return overlayStore; return super.getPreferenceStore(); } /* * Enables or disables the field editors and buttons of this page */ private void updateFieldEditors() { // We iterate through all field editors boolean enabled = useProjectSettingsButton.getSelection(); updateFieldEditors(enabled); } /** * Enables or disables the field editors and buttons of this page Subclasses * may override. * * @param enabled - true if enabled */ protected void updateFieldEditors(boolean enabled) { Composite parent = getFieldEditorParent(); for (FieldEditor editor : editors) { editor.setEnabled(enabled, parent); } } /** * We override the performOk method. In case of property pages we copy the * values in the overlay store into the property values of the selected * project. We also save the state of the radio buttons. * * @see org.eclipse.jface.preference.IPreferencePage#performOk() */ public boolean performOk() { boolean result = super.performOk(); if (result && isPropertyPage()) { // Save state of radio buttons in project properties getPreferenceStore().setValue(PreferenceConstants.P_USE_PROJECT_PREFS, useProjectSettingsButton.getSelection()); } return result; } /** * We override the performDefaults method. In case of property pages we * switch back to the workspace settings and disable the field editors. * * @see org.eclipse.jface.preference.PreferencePage#performDefaults() */ protected void performDefaults() { if (isPropertyPage()) { useProjectSettingsButton.setSelection(false); configureLink.setEnabled(true); updateFieldEditors(); } super.performDefaults(); } /** * Creates a new preferences page and opens it */ protected void configureWorkspaceSettings() { try { // create a new instance of the current class IPreferencePage page = (IPreferencePage) this.getClass().newInstance(); page.setTitle(getTitle()); page.setImageDescriptor(image); // and show it showPreferencePage(pageId, page); } catch (InstantiationException | IllegalAccessException e) { Activator.log("Unable to show preference page.", e); } } /** * Show a single preference pages * * @param id - the preference page identification * @param page - the preference page */ protected void showPreferencePage(String id, IPreferencePage page) { final IPreferenceNode targetNode = new PreferenceNode(id, page); PreferenceManager manager = new PreferenceManager(); manager.addToRoot(targetNode); final PreferenceDialog dialog = new PreferenceDialog(getControl().getShell(), manager); BusyIndicator.showWhile(getControl().getDisplay(), new Runnable() { public void run() { dialog.create(); dialog.setMessage(targetNode.getLabelText()); dialog.open(); } }); } }