Java tutorial
/******************************************************************************* * Copyright (c) 2005, 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 descent.internal.ui.text.java; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.Iterator; import java.util.List; import org.eclipse.core.runtime.Assert; import org.eclipse.core.runtime.IProgressMonitor; import org.eclipse.core.runtime.NullProgressMonitor; import org.eclipse.core.runtime.Platform; import org.eclipse.core.runtime.SubProgressMonitor; 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.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.swt.widgets.Shell; import org.eclipse.jface.action.LegacyActionTools; import org.eclipse.jface.bindings.TriggerSequence; import org.eclipse.jface.bindings.keys.KeySequence; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.dialogs.MessageDialog; import org.eclipse.jface.preference.IPreferenceStore; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.text.IDocument; import org.eclipse.jface.text.ITextViewer; import org.eclipse.jface.text.contentassist.ContentAssistEvent; import org.eclipse.jface.text.contentassist.ContentAssistant; import org.eclipse.jface.text.contentassist.ICompletionListener; import org.eclipse.jface.text.contentassist.ICompletionProposal; import org.eclipse.jface.text.contentassist.IContentAssistProcessor; import org.eclipse.jface.text.contentassist.IContentAssistantExtension2; import org.eclipse.jface.text.contentassist.IContentAssistantExtension3; import org.eclipse.jface.text.contentassist.IContextInformation; import org.eclipse.jface.text.contentassist.IContextInformationValidator; import org.eclipse.ui.PlatformUI; import org.eclipse.ui.dialogs.PreferencesUtil; import org.eclipse.ui.keys.IBindingService; import org.eclipse.ui.texteditor.ITextEditorActionDefinitionIds; import descent.internal.corext.util.Messages; import descent.ui.PreferenceConstants; import descent.ui.text.IJavaPartitions; import descent.ui.text.java.ContentAssistInvocationContext; import descent.internal.ui.JavaPlugin; import descent.internal.ui.JavaUIMessages; import descent.internal.ui.dialogs.OptionalMessageDialog; /** * A content assist processor that aggregates the proposals of the * {@link descent.ui.text.java.IJavaCompletionProposalComputer}s contributed via the * <code>descent.ui.javaCompletionProposalComputer</code> extension point. * <p> * Subclasses may extend: * <ul> * <li><code>createContext</code> to provide the context object passed to the computers</li> * <li><code>createProgressMonitor</code> to change the way progress is reported</li> * <li><code>filterAndSort</code> to add sorting and filtering</li> * <li><code>getContextInformationValidator</code> to add context validation (needed if any * contexts are provided)</li> * <li><code>getErrorMessage</code> to change error reporting</li> * </ul> * </p> * * @since 3.2 */ public class ContentAssistProcessor implements IContentAssistProcessor { private static final boolean DEBUG = "true" //$NON-NLS-1$ .equalsIgnoreCase(Platform.getDebugOption("descent.ui/debug/ResultCollector")); //$NON-NLS-1$ /** * Dialog settings key for the "all categories are disabled" warning dialog. See * {@link OptionalMessageDialog}. * * @since 3.3 */ private static final String PREF_WARN_ABOUT_EMPTY_ASSIST_CATEGORY = "EmptyDefaultAssistCategory"; //$NON-NLS-1$ private static final Comparator ORDER_COMPARATOR = new Comparator() { public int compare(Object o1, Object o2) { CompletionProposalCategory d1 = (CompletionProposalCategory) o1; CompletionProposalCategory d2 = (CompletionProposalCategory) o2; return d1.getSortOrder() - d2.getSortOrder(); } }; private final List fCategories; private final String fPartition; private final ContentAssistant fAssistant; private char[] fCompletionAutoActivationCharacters; /* cycling stuff */ private int fRepetition = -1; private List/*<List<CompletionProposalCategory>>*/ fCategoryIteration = null; private String fIterationGesture = null; private int fNumberOfComputedResults = 0; private String fErrorMessage; public ContentAssistProcessor(ContentAssistant assistant, String partition) { Assert.isNotNull(partition); Assert.isNotNull(assistant); fPartition = partition; fCategories = CompletionProposalComputerRegistry.getDefault().getProposalCategories(); fAssistant = assistant; fAssistant.addCompletionListener(new ICompletionListener() { /* * @see org.eclipse.jface.text.contentassist.ICompletionListener#assistSessionStarted(org.eclipse.jface.text.contentassist.ContentAssistEvent) */ public void assistSessionStarted(ContentAssistEvent event) { if (event.processor != ContentAssistProcessor.this) return; fIterationGesture = getIterationGesture(); KeySequence binding = getIterationBinding(); // this may show the warning dialog if all categories are disabled fCategoryIteration = getCategoryIteration(); for (Iterator it = fCategories.iterator(); it.hasNext();) { CompletionProposalCategory cat = (CompletionProposalCategory) it.next(); cat.sessionStarted(); } fRepetition = 0; if (event.assistant instanceof IContentAssistantExtension2) { IContentAssistantExtension2 extension = (IContentAssistantExtension2) event.assistant; if (fCategoryIteration.size() == 1) { extension.setRepeatedInvocationMode(false); extension.setShowEmptyList(false); } else { extension.setRepeatedInvocationMode(true); extension.setStatusLineVisible(true); extension.setStatusMessage(createIterationMessage()); extension.setShowEmptyList(true); if (extension instanceof IContentAssistantExtension3) { IContentAssistantExtension3 ext3 = (IContentAssistantExtension3) extension; ((ContentAssistant) ext3).setRepeatedInvocationTrigger(binding); } } } } /* * @see org.eclipse.jface.text.contentassist.ICompletionListener#assistSessionEnded(org.eclipse.jface.text.contentassist.ContentAssistEvent) */ public void assistSessionEnded(ContentAssistEvent event) { if (event.processor != ContentAssistProcessor.this) return; for (Iterator it = fCategories.iterator(); it.hasNext();) { CompletionProposalCategory cat = (CompletionProposalCategory) it.next(); cat.sessionEnded(); } fCategoryIteration = null; fRepetition = -1; fIterationGesture = null; if (event.assistant instanceof IContentAssistantExtension2) { IContentAssistantExtension2 extension = (IContentAssistantExtension2) event.assistant; extension.setShowEmptyList(false); extension.setRepeatedInvocationMode(false); extension.setStatusLineVisible(false); if (extension instanceof IContentAssistantExtension3) { IContentAssistantExtension3 ext3 = (IContentAssistantExtension3) extension; ((ContentAssistant) ext3).setRepeatedInvocationTrigger(KeySequence.getInstance()); } } } /* * @see org.eclipse.jface.text.contentassist.ICompletionListener#selectionChanged(org.eclipse.jface.text.contentassist.ICompletionProposal, boolean) */ public void selectionChanged(ICompletionProposal proposal, boolean smartToggle) { } }); } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#computeCompletionProposals(org.eclipse.jface.text.ITextViewer, int) */ public final ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) { long start = DEBUG ? System.currentTimeMillis() : 0; clearState(); IProgressMonitor monitor = createProgressMonitor(); monitor.beginTask(JavaTextMessages.ContentAssistProcessor_computing_proposals, fCategories.size() + 1); ContentAssistInvocationContext context = createContext(viewer, offset); long setup = DEBUG ? System.currentTimeMillis() : 0; monitor.subTask(JavaTextMessages.ContentAssistProcessor_collecting_proposals); List proposals = collectProposals(viewer, offset, monitor, context); long collect = DEBUG ? System.currentTimeMillis() : 0; monitor.subTask(JavaTextMessages.ContentAssistProcessor_sorting_proposals); List filtered = filterAndSortProposals(proposals, monitor, context); fNumberOfComputedResults = filtered.size(); long filter = DEBUG ? System.currentTimeMillis() : 0; ICompletionProposal[] result = (ICompletionProposal[]) filtered .toArray(new ICompletionProposal[filtered.size()]); monitor.done(); if (DEBUG) { System.err.println("Code Assist Stats (" + result.length + " proposals)"); //$NON-NLS-1$ //$NON-NLS-2$ System.err.println("Code Assist (setup):\t" + (setup - start)); //$NON-NLS-1$ System.err.println("Code Assist (collect):\t" + (collect - setup)); //$NON-NLS-1$ System.err.println("Code Assist (sort):\t" + (filter - collect)); //$NON-NLS-1$ } return result; } private void clearState() { fErrorMessage = null; fNumberOfComputedResults = 0; } private List collectProposals(ITextViewer viewer, int offset, IProgressMonitor monitor, ContentAssistInvocationContext context) { List proposals = new ArrayList(); List providers = getCategories(); for (Iterator it = providers.iterator(); it.hasNext();) { CompletionProposalCategory cat = (CompletionProposalCategory) it.next(); List computed = cat.computeCompletionProposals(context, fPartition, new SubProgressMonitor(monitor, 1)); proposals.addAll(computed); if (fErrorMessage == null) fErrorMessage = cat.getErrorMessage(); } return proposals; } /** * Filters and sorts the proposals. The passed list may be modified * and returned, or a new list may be created and returned. * * @param proposals the list of collected proposals (element type: * {@link ICompletionProposal}) * @param monitor a progress monitor * @param context TODO * @return the list of filtered and sorted proposals, ready for * display (element type: {@link ICompletionProposal}) */ protected List filterAndSortProposals(List proposals, IProgressMonitor monitor, ContentAssistInvocationContext context) { return proposals; } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#computeContextInformation(org.eclipse.jface.text.ITextViewer, int) */ public IContextInformation[] computeContextInformation(ITextViewer viewer, int offset) { clearState(); IProgressMonitor monitor = createProgressMonitor(); monitor.beginTask(JavaTextMessages.ContentAssistProcessor_computing_contexts, fCategories.size() + 1); monitor.subTask(JavaTextMessages.ContentAssistProcessor_collecting_contexts); List proposals = collectContextInformation(viewer, offset, monitor); monitor.subTask(JavaTextMessages.ContentAssistProcessor_sorting_contexts); List filtered = filterAndSortContextInformation(proposals, monitor); fNumberOfComputedResults = filtered.size(); IContextInformation[] result = (IContextInformation[]) filtered .toArray(new IContextInformation[filtered.size()]); monitor.done(); return result; } private List collectContextInformation(ITextViewer viewer, int offset, IProgressMonitor monitor) { List proposals = new ArrayList(); ContentAssistInvocationContext context = createContext(viewer, offset); List providers = getCategories(); for (Iterator it = providers.iterator(); it.hasNext();) { CompletionProposalCategory cat = (CompletionProposalCategory) it.next(); List computed = cat.computeContextInformation(context, fPartition, new SubProgressMonitor(monitor, 1)); proposals.addAll(computed); if (fErrorMessage == null) fErrorMessage = cat.getErrorMessage(); } return proposals; } /** * Filters and sorts the context information objects. The passed * list may be modified and returned, or a new list may be created * and returned. * * @param contexts the list of collected proposals (element type: * {@link IContextInformation}) * @param monitor a progress monitor * @return the list of filtered and sorted proposals, ready for * display (element type: {@link IContextInformation}) */ protected List filterAndSortContextInformation(List contexts, IProgressMonitor monitor) { return contexts; } /** * Sets this processor's set of characters triggering the activation of the * completion proposal computation. * * @param activationSet the activation set */ public final void setCompletionProposalAutoActivationCharacters(char[] activationSet) { fCompletionAutoActivationCharacters = activationSet; } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getCompletionProposalAutoActivationCharacters() */ public final char[] getCompletionProposalAutoActivationCharacters() { return fCompletionAutoActivationCharacters; } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getContextInformationAutoActivationCharacters() */ public char[] getContextInformationAutoActivationCharacters() { return null; } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getErrorMessage() */ public String getErrorMessage() { if (fNumberOfComputedResults > 0) return null; if (fErrorMessage != null) return fErrorMessage; return JavaUIMessages.JavaEditor_codeassist_noCompletions; } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getContextInformationValidator() */ public IContextInformationValidator getContextInformationValidator() { return null; } /** * Creates a progress monitor. * <p> * The default implementation creates a * <code>NullProgressMonitor</code>. * </p> * * @return a progress monitor */ protected IProgressMonitor createProgressMonitor() { return new NullProgressMonitor(); } /** * Creates the context that is passed to the completion proposal * computers. * * @param viewer the viewer that content assist is invoked on * @param offset the content assist offset * @return the context to be passed to the computers */ protected ContentAssistInvocationContext createContext(ITextViewer viewer, int offset) { return new ContentAssistInvocationContext(viewer, offset); } private List getCategories() { if (fCategoryIteration == null) return fCategories; int iteration = fRepetition % fCategoryIteration.size(); fAssistant.setStatusMessage(createIterationMessage()); fAssistant.setEmptyMessage(createEmptyMessage()); fRepetition++; // fAssistant.setShowMessage(fRepetition % 2 != 0); // return (List) fCategoryIteration.get(iteration); } private List getCategoryIteration() { List sequence = new ArrayList(); sequence.add(getDefaultCategories()); for (Iterator it = getSeparateCategories().iterator(); it.hasNext();) { CompletionProposalCategory cat = (CompletionProposalCategory) it.next(); sequence.add(Collections.singletonList(cat)); } return sequence; } private List getDefaultCategories() { // default mix - enable all included computers List included = getDefaultCategoriesUnchecked(); if ((IJavaPartitions.JAVA_DOC.equals(fPartition) || IDocument.DEFAULT_CONTENT_TYPE.equals(fPartition)) && included.isEmpty() && !fCategories.isEmpty()) if (informUserAboutEmptyDefaultCategory()) // preferences were restored - recompute the default categories included = getDefaultCategoriesUnchecked(); return included; } private List getDefaultCategoriesUnchecked() { List included = new ArrayList(); for (Iterator it = fCategories.iterator(); it.hasNext();) { CompletionProposalCategory category = (CompletionProposalCategory) it.next(); if (category.isIncluded() && category.hasComputers(fPartition)) included.add(category); } return included; } /** * Informs the user about the fact that there are no enabled categories in the default content * assist set and shows a link to the preferences. * * @since 3.3 */ private boolean informUserAboutEmptyDefaultCategory() { if (OptionalMessageDialog.isDialogEnabled(PREF_WARN_ABOUT_EMPTY_ASSIST_CATEGORY)) { final Shell shell = JavaPlugin.getActiveWorkbenchShell(); String title = JavaTextMessages.ContentAssistProcessor_all_disabled_title; String message = JavaTextMessages.ContentAssistProcessor_all_disabled_message; // see PreferencePage#createControl for the 'defaults' label final String restoreButtonLabel = JFaceResources.getString("defaults"); //$NON-NLS-1$ final String linkMessage = Messages.format( JavaTextMessages.ContentAssistProcessor_all_disabled_preference_link, LegacyActionTools.removeMnemonics(restoreButtonLabel)); final int restoreId = IDialogConstants.CLIENT_ID + 10; final OptionalMessageDialog dialog = new OptionalMessageDialog(PREF_WARN_ABOUT_EMPTY_ASSIST_CATEGORY, shell, title, null /* default image */, message, MessageDialog.WARNING, new String[] { restoreButtonLabel, IDialogConstants.CLOSE_LABEL }, 1) { /* * @see descent.internal.ui.dialogs.OptionalMessageDialog#createCustomArea(org.eclipse.swt.widgets.Composite) */ protected Control createCustomArea(Composite composite) { // wrap link and checkbox in one composite without space Composite parent = new Composite(composite, SWT.NONE); GridLayout layout = new GridLayout(); layout.marginHeight = 0; layout.marginWidth = 0; layout.verticalSpacing = 0; parent.setLayout(layout); Composite linkComposite = new Composite(parent, SWT.NONE); layout = new GridLayout(); layout.marginHeight = convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_MARGIN); layout.marginWidth = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_MARGIN); layout.horizontalSpacing = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_SPACING); linkComposite.setLayout(layout); Link link = new Link(linkComposite, SWT.NONE); link.setText(linkMessage); link.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { close(); PreferencesUtil .createPreferenceDialogOn(shell, "descent.ui.preferences.CodeAssistPreferenceAdvanced", null, null) //$NON-NLS-1$ .open(); } }); GridData gridData = new GridData(SWT.FILL, SWT.BEGINNING, true, false); gridData.widthHint = this.getMinimumMessageWidth(); link.setLayoutData(gridData); // create checkbox and "don't show this message" prompt super.createCustomArea(parent); return parent; } /* * @see org.eclipse.jface.dialogs.MessageDialog#createButtonsForButtonBar(org.eclipse.swt.widgets.Composite) */ protected void createButtonsForButtonBar(Composite parent) { Button[] buttons = new Button[2]; buttons[0] = createButton(parent, restoreId, restoreButtonLabel, false); buttons[1] = createButton(parent, IDialogConstants.CLOSE_ID, IDialogConstants.CLOSE_LABEL, true); setButtons(buttons); } }; if (restoreId == dialog.open()) { IPreferenceStore store = JavaPlugin.getDefault().getPreferenceStore(); store.setToDefault(PreferenceConstants.CODEASSIST_CATEGORY_ORDER); store.setToDefault(PreferenceConstants.CODEASSIST_EXCLUDED_CATEGORIES); CompletionProposalComputerRegistry registry = CompletionProposalComputerRegistry.getDefault(); registry.reload(); return true; } } return false; } private List getSeparateCategories() { ArrayList sorted = new ArrayList(); for (Iterator it = fCategories.iterator(); it.hasNext();) { CompletionProposalCategory category = (CompletionProposalCategory) it.next(); if (category.isSeparateCommand() && category.hasComputers(fPartition)) sorted.add(category); } Collections.sort(sorted, ORDER_COMPARATOR); return sorted; } private String createEmptyMessage() { return Messages.format(JavaTextMessages.ContentAssistProcessor_empty_message, new String[] { getCategoryLabel(fRepetition) }); } private String createIterationMessage() { return Messages.format(JavaTextMessages.ContentAssistProcessor_toggle_affordance_update_message, new String[] { getCategoryLabel(fRepetition), fIterationGesture, getCategoryLabel(fRepetition + 1) }); } private String getCategoryLabel(int repetition) { int iteration = repetition % fCategoryIteration.size(); if (iteration == 0) return JavaTextMessages.ContentAssistProcessor_defaultProposalCategory; return toString((CompletionProposalCategory) ((List) fCategoryIteration.get(iteration)).get(0)); } private String toString(CompletionProposalCategory category) { return category.getDisplayName(); } private String getIterationGesture() { TriggerSequence binding = getIterationBinding(); return binding != null ? Messages.format(JavaTextMessages.ContentAssistProcessor_toggle_affordance_press_gesture, new Object[] { binding.format() }) : JavaTextMessages.ContentAssistProcessor_toggle_affordance_click_gesture; } private KeySequence getIterationBinding() { final IBindingService bindingSvc = (IBindingService) PlatformUI.getWorkbench() .getAdapter(IBindingService.class); TriggerSequence binding = bindingSvc .getBestActiveBindingFor(ITextEditorActionDefinitionIds.CONTENT_ASSIST_PROPOSALS); if (binding instanceof KeySequence) return (KeySequence) binding; return null; } }