Java tutorial
/******************************************************************************* * Copyright (c) 2005, 2010 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 * Anton Leherbauer (Wind River Systems) * Bryan Wilkinson (QNX) * Markus Schorn (Wind River Systems) * Kirk Beitz (Nokia) *******************************************************************************/ package org.eclipse.cdt.internal.ui.text.contentassist; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; 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.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.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.ui.PlatformUI; import org.eclipse.ui.dialogs.PreferencesUtil; import org.eclipse.ui.keys.IBindingService; import org.eclipse.ui.texteditor.ITextEditorActionDefinitionIds; import org.eclipse.cdt.ui.CUIPlugin; import org.eclipse.cdt.ui.PreferenceConstants; import org.eclipse.cdt.ui.text.contentassist.ContentAssistInvocationContext; import org.eclipse.cdt.internal.ui.dialogs.OptionalMessageDialog; import org.eclipse.cdt.internal.ui.util.Messages; /** * A content assist processor that aggregates the proposals of the * {@link org.eclipse.cdt.ui.text.contentassist.ICompletionProposalComputer}s contributed via the * <code>org.eclipse.cdt.ui.completionProposalComputer</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 4.0 */ public class ContentAssistProcessor implements IContentAssistProcessor { private static final boolean DEBUG = "true" //$NON-NLS-1$ .equalsIgnoreCase(Platform.getDebugOption("org.eclipse.cdt.ui/debug/ResultCollector")); //$NON-NLS-1$ /** * Dialog settings key for the "all categories are disabled" warning dialog. See * {@link OptionalMessageDialog}. */ private static final String PREF_WARN_ABOUT_EMPTY_ASSIST_CATEGORY = "EmptyDefaultAssistCategory"; //$NON-NLS-1$ private static final Comparator<CompletionProposalCategory> ORDER_COMPARATOR = new Comparator<CompletionProposalCategory>() { @Override public int compare(CompletionProposalCategory d1, CompletionProposalCategory d2) { return d1.getSortOrder() - d2.getSortOrder(); } }; private static final ICompletionProposal[] NO_PROPOSALS = {}; private final List<CompletionProposalCategory> 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; private boolean fIsAutoActivated; 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) */ @Override public void assistSessionStarted(ContentAssistEvent event) { if (event.processor != ContentAssistProcessor.this) return; fIsAutoActivated = event.isAutoActivated; fIterationGesture = getIterationGesture(); KeySequence binding = getIterationBinding(); // this may show the warning dialog if all categories are disabled fCategoryIteration = getCategoryIteration(); for (Object element : fCategories) { CompletionProposalCategory cat = (CompletionProposalCategory) element; 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) */ @Override public void assistSessionEnded(ContentAssistEvent event) { if (event.processor != ContentAssistProcessor.this) return; for (Object element : fCategories) { CompletionProposalCategory cat = (CompletionProposalCategory) element; 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(null); } } } /* * @see org.eclipse.jface.text.contentassist.ICompletionListener#selectionChanged(org.eclipse.jface.text.contentassist.ICompletionProposal, boolean) */ @Override public void selectionChanged(ICompletionProposal proposal, boolean smartToggle) { } }); } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#computeCompletionProposals(org.eclipse.jface.text.ITextViewer, int) */ @Override public final ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) { long start = DEBUG ? System.currentTimeMillis() : 0; if (isAutoActivated() && !verifyAutoActivation(viewer, offset)) { return NO_PROPOSALS; } clearState(); IProgressMonitor monitor = createProgressMonitor(); monitor.beginTask(ContentAssistMessages.ContentAssistProcessor_computing_proposals, fCategories.size() + 1); ContentAssistInvocationContext context = createContext(viewer, offset, true); if (context == null) return null; try { long setup = DEBUG ? System.currentTimeMillis() : 0; monitor.subTask(ContentAssistMessages.ContentAssistProcessor_collecting_proposals); List<ICompletionProposal> proposals = collectProposals(viewer, offset, monitor, context); long collect = DEBUG ? System.currentTimeMillis() : 0; monitor.subTask(ContentAssistMessages.ContentAssistProcessor_sorting_proposals); List<ICompletionProposal> filtered = filterAndSortProposals(proposals, monitor, context); fNumberOfComputedResults = filtered.size(); long filter = DEBUG ? System.currentTimeMillis() : 0; ICompletionProposal[] result = 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; } finally { context.dispose(); } } /** * Verify that auto activation is allowed. * <p> * The default implementation always returns <code>true</code>. * </p> * * @param viewer the text viewer * @param offset the offset where content assist was invoked on * @return <code>true</code> if auto activation is allowed */ protected boolean verifyAutoActivation(ITextViewer viewer, int offset) { return true; } private void clearState() { fErrorMessage = null; fNumberOfComputedResults = 0; } private List<ICompletionProposal> collectProposals(ITextViewer viewer, int offset, IProgressMonitor monitor, ContentAssistInvocationContext context) { List<ICompletionProposal> proposals = new ArrayList<ICompletionProposal>(); List<CompletionProposalCategory> providers = getCategories(); for (CompletionProposalCategory cat : providers) { List<ICompletionProposal> 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<ICompletionProposal> filterAndSortProposals(List<ICompletionProposal> proposals, IProgressMonitor monitor, ContentAssistInvocationContext context) { return proposals; } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#computeContextInformation(org.eclipse.jface.text.ITextViewer, int) */ @Override public IContextInformation[] computeContextInformation(ITextViewer viewer, int offset) { clearState(); IProgressMonitor monitor = createProgressMonitor(); monitor.beginTask(ContentAssistMessages.ContentAssistProcessor_computing_contexts, fCategories.size() + 1); monitor.subTask(ContentAssistMessages.ContentAssistProcessor_collecting_contexts); List<IContextInformation> proposals = collectContextInformation(viewer, offset, monitor); monitor.subTask(ContentAssistMessages.ContentAssistProcessor_sorting_contexts); List<IContextInformation> filtered = filterAndSortContextInformation(proposals, monitor); fNumberOfComputedResults = filtered.size(); IContextInformation[] result = filtered.toArray(new IContextInformation[filtered.size()]); monitor.done(); return result; } private List<IContextInformation> collectContextInformation(ITextViewer viewer, int offset, IProgressMonitor monitor) { List<IContextInformation> proposals = new ArrayList<IContextInformation>(); ContentAssistInvocationContext context = createContext(viewer, offset, false); try { List<CompletionProposalCategory> providers = getCategories(); for (CompletionProposalCategory cat : providers) { List<IContextInformation> computed = cat.computeContextInformation(context, fPartition, new SubProgressMonitor(monitor, 1)); proposals.addAll(computed); if (fErrorMessage == null) fErrorMessage = cat.getErrorMessage(); } return proposals; } finally { context.dispose(); } } /** * 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<IContextInformation> filterAndSortContextInformation(List<IContextInformation> contexts, IProgressMonitor monitor) { return contexts; } /** * Sets this processor's set of characters triggering the activation of the * completion proposal computation (including auto-correction auto-activation) * * @param activationSet the activation set */ public void setCompletionProposalAutoActivationCharacters(char[] activationSet) { fCompletionAutoActivationCharacters = activationSet; } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getCompletionProposalAutoActivationCharacters() */ @Override public char[] getCompletionProposalAutoActivationCharacters() { return fCompletionAutoActivationCharacters; } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getContextInformationAutoActivationCharacters() */ @Override public char[] getContextInformationAutoActivationCharacters() { return null; } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getErrorMessage() */ @Override public String getErrorMessage() { if (fNumberOfComputedResults > 0) return null; if (fErrorMessage != null) return fErrorMessage; return ContentAssistMessages.ContentAssistProcessor_no_completions; } /* * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getContextInformationValidator() */ @Override 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 * or <code>null</code> if no completion is possible */ protected ContentAssistInvocationContext createContext(ITextViewer viewer, int offset, boolean isCompletion) { return new ContentAssistInvocationContext(viewer, offset); } /** * Test whether the current session was auto-activated. * * @return <code>true</code> if the current session was auto-activated. */ protected boolean isAutoActivated() { return fIsAutoActivated; } private List<CompletionProposalCategory> getCategories() { if (fCategoryIteration == null) return fCategories; int iteration = fRepetition % fCategoryIteration.size(); fAssistant.setStatusMessage(createIterationMessage()); fAssistant.setEmptyMessage(createEmptyMessage()); fRepetition++; // fAssistant.setShowMessage(fRepetition % 2 != 0); // return fCategoryIteration.get(iteration); } private List<List<CompletionProposalCategory>> getCategoryIteration() { List<List<CompletionProposalCategory>> sequence = new ArrayList<List<CompletionProposalCategory>>(); sequence.add(getDefaultCategories()); for (CompletionProposalCategory cat : getSeparateCategories()) { sequence.add(Collections.singletonList(cat)); } return sequence; } private List<CompletionProposalCategory> getDefaultCategories() { // default mix - enable all included computers List<CompletionProposalCategory> included = getDefaultCategoriesUnchecked(); if (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<CompletionProposalCategory> getDefaultCategoriesUnchecked() { List<CompletionProposalCategory> included = new ArrayList<CompletionProposalCategory>(); for (Object element : fCategories) { CompletionProposalCategory category = (CompletionProposalCategory) element; 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. */ private boolean informUserAboutEmptyDefaultCategory() { if (OptionalMessageDialog.isDialogEnabled(PREF_WARN_ABOUT_EMPTY_ASSIST_CATEGORY)) { final Shell shell = CUIPlugin.getActiveWorkbenchShell(); String title = ContentAssistMessages.ContentAssistProcessor_all_disabled_title; String message = ContentAssistMessages.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( ContentAssistMessages.ContentAssistProcessor_all_disabled_preference_link, LegacyActionTools.removeMnemonics(restoreButtonLabel)); final int restoreId = IDialogConstants.CLIENT_ID + 10; final int settingsId = IDialogConstants.CLIENT_ID + 11; 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 org.eclipse.cdt.internal.ui.dialogs.OptionalMessageDialog#createCustomArea(org.eclipse.swt.widgets.Composite) */ @Override 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() { @Override public void widgetSelected(SelectionEvent e) { setReturnCode(settingsId); close(); } }); 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) */ @Override 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); } }; int returnValue = dialog.open(); if (restoreId == returnValue || settingsId == returnValue) { if (restoreId == returnValue) { IPreferenceStore store = CUIPlugin.getDefault().getPreferenceStore(); store.setToDefault(PreferenceConstants.CODEASSIST_CATEGORY_ORDER); store.setToDefault(PreferenceConstants.CODEASSIST_EXCLUDED_CATEGORIES); } if (settingsId == returnValue) PreferencesUtil .createPreferenceDialogOn(shell, "org.eclipse.cdt.ui.preferences.CodeAssistPreferenceAdvanced", null, null) //$NON-NLS-1$ .open(); CompletionProposalComputerRegistry registry = CompletionProposalComputerRegistry.getDefault(); registry.reload(); return true; } } return false; } private List<CompletionProposalCategory> getSeparateCategories() { ArrayList<CompletionProposalCategory> sorted = new ArrayList<CompletionProposalCategory>(); for (Object element : fCategories) { CompletionProposalCategory category = (CompletionProposalCategory) element; if (category.isSeparateCommand() && category.hasComputers(fPartition)) sorted.add(category); } Collections.sort(sorted, ORDER_COMPARATOR); return sorted; } private String createEmptyMessage() { return Messages.format(ContentAssistMessages.ContentAssistProcessor_empty_message, getCategoryLabel(fRepetition)); } private String createIterationMessage() { return Messages.format(ContentAssistMessages.ContentAssistProcessor_toggle_affordance_update_message, getCategoryLabel(fRepetition), fIterationGesture, getCategoryLabel(fRepetition + 1)); } private String getCategoryLabel(int repetition) { int iteration = repetition % fCategoryIteration.size(); if (iteration == 0) return ContentAssistMessages.ContentAssistProcessor_defaultProposalCategory; return toString(fCategoryIteration.get(iteration).get(0)); } private String toString(CompletionProposalCategory category) { return category.getDisplayName(); } private String getIterationGesture() { TriggerSequence binding = getIterationBinding(); return binding != null ? Messages.format(ContentAssistMessages.ContentAssistProcessor_toggle_affordance_press_gesture, new Object[] { binding.format() }) : ContentAssistMessages.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; } }