Bug 508821 - [Content assist] More flexible API inI20210117-1940I20210117-1800

IContentAssistProcessor to decide whether to auto-activate or not

Change-Id: If228659acb69999a6caa73cd88dce7e5ff9ab0fa
Signed-off-by: Christoph Läubrich <laeubi@laeubi-soft.de>

6 files changed, 227 insertions, 215 deletions

diff --git a/org.eclipse.jface.text/src/org/eclipse/jface/internal/text/link/contentassist/ContentAssistant2.java b/org.eclipse.jface.text/src/org/eclipse/jface/internal/text/link/contentassist/ContentAssistant2.java
index 452455d9b22..7a6042143dc 100644
--- a/org.eclipse.jface.text/src/org/eclipse/jface/internal/text/link/contentassist/ContentAssistant2.java
+++ b/org.eclipse.jface.text/src/org/eclipse/jface/internal/text/link/contentassist/ContentAssistant2.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2018 IBM Corporation and others.
+ * Copyright (c) 2000, 2021 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -10,6 +10,7 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Christoph Läubrich - Bug 508821 - [Content assist] More flexible API in IContentAssistProcessor to decide whether to auto-activate or not
  *******************************************************************************/
 package org.eclipse.jface.internal.text.link.contentassist;
 
@@ -63,6 +64,7 @@ import org.eclipse.jface.text.contentassist.CompletionProposal;
 import org.eclipse.jface.text.contentassist.ICompletionProposal;
 import org.eclipse.jface.text.contentassist.ICompletionProposalExtension6;
 import org.eclipse.jface.text.contentassist.IContentAssistProcessor;
+import org.eclipse.jface.text.contentassist.IContentAssistProcessorExtension;
 import org.eclipse.jface.text.contentassist.IContentAssistant;
 import org.eclipse.jface.text.contentassist.IContentAssistantExtension;
 import org.eclipse.jface.text.contentassist.IContextInformation;
@@ -261,17 +263,6 @@ public class ContentAssistant2 implements IContentAssistant, IContentAssistantEx
 				threadToStop.interrupt();
 		}
 
-		private boolean contains(char[] characters, char character) {
-			if (characters != null) {
-				for (char c : characters) {
-					if (character == c) {
-						return true;
-					}
-				}
-			}
-			return false;
-		}
-
 		@Override
 		public void verifyKey(VerifyEvent e) {
 			// Only act on typed characters and ignore modifier-only events
@@ -281,15 +272,23 @@ public class ContentAssistant2 implements IContentAssistant, IContentAssistantEx
 			if (e.character != 0 && (e.stateMask == SWT.ALT))
 				return;
 
+
+
 			int showStyle;
 			int pos= fViewer.getSelectedRange().x;
-			char[] activation= getCompletionProposalAutoActivationCharacters(fViewer, pos);
+			IContentAssistProcessorExtension p= getProcessor(fViewer, pos);
+			if (p == null) {
+				stop();
+				return;
+			}
+
+
+
 
-			if (contains(activation, e.character) && !fProposalPopup.isActive())
+			if (p.isCompletionProposalAutoActivation(e.character, fViewer, pos) && !fProposalPopup.isActive())
 				showStyle= SHOW_PROPOSALS;
 			else {
-				activation= getContextInformationAutoActivationCharacters(fViewer, pos);
-				if (contains(activation, e.character) && !fContextInfoPopup.isActive())
+				if (p.isContextInformationAutoActivation(e.character, fViewer, pos) && !fContextInfoPopup.isActive())
 					showStyle= SHOW_CONTEXT_INFO;
 				else {
 					if (fThread != null && fThread.isAlive())
@@ -1322,10 +1321,10 @@ public class ContentAssistant2 implements IContentAssistant, IContentAssistantEx
 	 * @param offset a offset within the document
 	 * @return a content-assist processor or <code>null</code> if none exists
 	 */
-	private IContentAssistProcessor getProcessor(ITextViewer viewer, int offset) {
+	private IContentAssistProcessorExtension getProcessor(ITextViewer viewer, int offset) {
 		try {
 			String type= TextUtilities.getContentType(viewer.getDocument(), getDocumentPartitioning(), offset, true);
-			return getContentAssistProcessor(type);
+			return IContentAssistProcessorExtension.adapt(getContentAssistProcessor(type));
 		} catch (BadLocationException x) {
 		}
 		return null;
@@ -1413,38 +1412,6 @@ public class ContentAssistant2 implements IContentAssistant, IContentAssistantEx
 		return null;
 	}
 
-	/**
-	 * Returns the characters which when typed by the user should automatically
-	 * initiate proposing completions. The position is used to determine the
-	 * appropriate content assist processor to invoke.
-	 *
-	 * @param textViewer the text viewer
-	 * @param offset a document offset
-	 * @return the auto activation characters
-	 *
-	 * @see IContentAssistProcessor#getCompletionProposalAutoActivationCharacters
-	 */
-	private char[] getCompletionProposalAutoActivationCharacters(ITextViewer textViewer, int offset) {
-		IContentAssistProcessor p= getProcessor(textViewer, offset);
-		return p != null ? p.getCompletionProposalAutoActivationCharacters() : null;
-	}
-
-	/**
-	 * Returns the characters which when typed by the user should automatically
-	 * initiate the presentation of context information. The position is used
-	 * to determine the appropriate content assist processor to invoke.
-	 *
-	 * @param textViewer the text viewer
-	 * @param offset a document offset
-	 * @return the auto activation characters
-	 *
-	 * @see IContentAssistProcessor#getContextInformationAutoActivationCharacters
-	 */
-	private char[] getContextInformationAutoActivationCharacters(ITextViewer textViewer, int offset) {
-		IContentAssistProcessor p= getProcessor(textViewer, offset);
-		return p != null ? p.getContextInformationAutoActivationCharacters() : null;
-	}
-
 	@Override
 	public boolean requestWidgetToken(IWidgetTokenOwner owner) {
 		hidePossibleCompletions();
diff --git a/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/CompletionProposalPopup.java b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/CompletionProposalPopup.java
index 128c97ae5d6..dcadb6e23f6 100644
--- a/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/CompletionProposalPopup.java
+++ b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/CompletionProposalPopup.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2018 IBM Corporation and others.
+ * Copyright (c) 2000, 2021 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -15,6 +15,7 @@
  *     Terry Parker, tparker@google.com - Protect against poorly behaved completion proposers - http://bugs.eclipse.org/429925
  *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 493649
  *     Mickael Istria (Red Hat Inc.) - [251156] Allow multiple contentAssitProviders internally & inheritance
+ *     Christoph Läubrich - Bug 508821 - [Content assist] More flexible API in IContentAssistProcessor to decide whether to auto-activate or not
  *******************************************************************************/
 package org.eclipse.jface.text.contentassist;
 
@@ -99,6 +100,7 @@ import org.eclipse.jface.text.IRewriteTarget;
 import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.ITextViewerExtension;
 import org.eclipse.jface.text.TextUtilities;
+import org.eclipse.jface.text.contentassist.ContentAssistant.TriggerType;
 
 
 /**
@@ -376,7 +378,7 @@ class CompletionProposalPopup implements IContentAssistListener {
 				if (fContentAssistant.isAutoActivation() && offset > 0 && event != null) {
 					try {
 						char charBeforeOffset= event.getDocument().getChar(offset - 1);
-						if (fContentAssistant.isAutoActivationTriggerChar(charBeforeOffset)) {
+						if (fContentAssistant.getAutoActivationTriggerType(charBeforeOffset) != TriggerType.NONE) {
 							fContentAssistant.fireSessionBeginEvent(true);
 							showProposals(true);
 						}
diff --git a/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistSubjectControlAdapter.java b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistSubjectControlAdapter.java
index e1f6e72de5a..bbec6b22266 100644
--- a/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistSubjectControlAdapter.java
+++ b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistSubjectControlAdapter.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2017 IBM Corporation and others.
+ * Copyright (c) 2000, 2021 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -12,11 +12,14 @@
  *     IBM Corporation - initial API and implementation
  *     Mickael Istria (Red Hat Inc.) - [251156] Allow multiple contentAssitProviders internally & inheritance
  *     Stephan Wahlbrink <sw@wahlbrink.eu> - Bug 512251 - Fix IllegalArgumentException in ContextInformationPopup
+ *     Christoph Läubrich - Bug 508821 - [Content assist] More flexible API in IContentAssistProcessor to decide whether to auto-activate or not
  *******************************************************************************/
 package org.eclipse.jface.text.contentassist;
 
 import static org.eclipse.jface.util.Util.isValid;
 
+import java.util.Set;
+
 import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.custom.VerifyKeyListener;
 import org.eclipse.swt.events.KeyListener;
@@ -241,38 +244,21 @@ class ContentAssistSubjectControlAdapter implements IContentAssistSubjectControl
 			return fContentAssistSubjectControl.supportsVerifyKeyListener();
 		return true;
 	}
+
 	/**
-	 * Returns the characters which when typed by the user should automatically
-	 * initiate proposing completions. The position is used to determine the
-	 * appropriate content assist processor to invoke.
+	 * Returns the processors for the given offset
 	 *
 	 * @param contentAssistant the content assistant
 	 * @param offset a document offset
-	 * @return the auto activation characters
+	 * @return the processors set
 	 * @see IContentAssistProcessor#getCompletionProposalAutoActivationCharacters()
 	 */
-	public char[] getCompletionProposalAutoActivationCharacters(ContentAssistant contentAssistant, int offset) {
+	Set<IContentAssistProcessor> getContentAssistProcessors(ContentAssistant contentAssistant, int offset) {
 		if (fContentAssistSubjectControl != null)
-			return contentAssistant.getCompletionProposalAutoActivationCharacters(fContentAssistSubjectControl, offset);
-		return contentAssistant.getCompletionProposalAutoActivationCharacters(fViewer, offset);
+			return contentAssistant.getProcessors(fContentAssistSubjectControl, offset);
+		return contentAssistant.getProcessors(fViewer, offset);
 	}
 
-	/**
-	 * Returns the characters which when typed by the user should automatically
-	 * initiate the presentation of context information. The position is used
-	 * to determine the appropriate content assist processor to invoke.
-	 *
-	 * @param contentAssistant the content assistant
-	 * @param offset a document offset
-	 * @return the auto activation characters
-	 *
-	 * @see IContentAssistProcessor#getContextInformationAutoActivationCharacters()
-	 */
-	char[] getContextInformationAutoActivationCharacters(ContentAssistant contentAssistant, int offset) {
-		if (fContentAssistSubjectControl != null)
-			return contentAssistant.getContextInformationAutoActivationCharacters(fContentAssistSubjectControl, offset);
-		return contentAssistant.getContextInformationAutoActivationCharacters(fViewer, offset);
-	}
 
 	/**
 	 * Creates and returns a completion proposal popup for the given content assistant.
@@ -347,7 +333,7 @@ class ContentAssistSubjectControlAdapter implements IContentAssistSubjectControl
 	public void installValidator(ContextFrame frame) {
 		if (fContentAssistSubjectControl != null) {
 			if (frame.fValidator instanceof ISubjectControlContextInformationValidator)
-				((ISubjectControlContextInformationValidator)frame.fValidator).install(frame.fInformation, fContentAssistSubjectControl, frame.fOffset);
+				((ISubjectControlContextInformationValidator) frame.fValidator).install(frame.fInformation, fContentAssistSubjectControl, frame.fOffset);
 		} else
 			frame.fValidator.install(frame.fInformation, fViewer, frame.fOffset);
 	}
@@ -360,7 +346,7 @@ class ContentAssistSubjectControlAdapter implements IContentAssistSubjectControl
 	public void installContextInformationPresenter(ContextFrame frame) {
 		if (fContentAssistSubjectControl != null) {
 			if (frame.fPresenter instanceof ISubjectControlContextInformationPresenter)
-				((ISubjectControlContextInformationPresenter)frame.fValidator).install(frame.fInformation, fContentAssistSubjectControl, frame.fBeginOffset);
+				((ISubjectControlContextInformationPresenter) frame.fValidator).install(frame.fInformation, fContentAssistSubjectControl, frame.fBeginOffset);
 		} else
 			frame.fPresenter.install(frame.fInformation, fViewer, frame.fBeginOffset);
 	}
@@ -396,4 +382,5 @@ class ContentAssistSubjectControlAdapter implements IContentAssistSubjectControl
 		else
 			fViewer.getTextWidget().removeSelectionListener(selectionListener);
 	}
+
 }
diff --git a/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistant.java b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistant.java
index e88c8f03422..2f92d9c4906 100644
--- a/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistant.java
+++ b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistant.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2018 IBM Corporation and others.
+ * Copyright (c) 2000, 2021 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -15,6 +15,7 @@
  *     Marcel Bruch, bruch@cs.tu-darmstadt.de - [content assist] Allow to re-sort proposals - https://bugs.eclipse.org/bugs/show_bug.cgi?id=350991
  *     John Glassmyer, jogl@google.com - catch Content Assist exceptions to protect navigation keys - http://bugs.eclipse.org/434901
  *     Mickael Istria (Red Hat Inc.) - [251156] Allow multiple contentAssitProviders internally & inheritance
+ *     Christoph Läubrich - Bug 508821 - [Content assist] More flexible API in IContentAssistProcessor to decide whether to auto-activate or not
  *******************************************************************************/
 package org.eclipse.jface.text.contentassist;
 
@@ -22,7 +23,6 @@ import static org.eclipse.jface.util.Util.isValid;
 
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
@@ -30,7 +30,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
-import java.util.function.Function;
 
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.SWTError;
@@ -114,6 +113,10 @@ public class ContentAssistant implements IContentAssistant, IContentAssistantExt
 	 */
 	public static final String SELECT_PREVIOUS_PROPOSAL_COMMAND_ID= "org.eclipse.ui.edit.text.contentAssist.selectPreviousProposal"; //$NON-NLS-1$
 
+	enum TriggerType {
+		CONTEXT_INFORMATION,
+		COMPLETION_PROPOSAL, NONE;
+	}
 
 	/**
 	 * A generic closer class used to monitor various interface events in order to determine whether
@@ -303,17 +306,6 @@ public class ContentAssistant implements IContentAssistant, IContentAssistantExt
 				threadToStop.interrupt();
 		}
 
-		private boolean contains(char[] characters, char character) {
-			if (characters != null) {
-				for (char c : characters) {
-					if (character == c) {
-						return true;
-					}
-				}
-			}
-			return false;
-		}
-
 		@Override
 		public void keyPressed(KeyEvent e) {
 			// Only act on typed characters and ignore modifier-only events
@@ -323,24 +315,20 @@ public class ContentAssistant implements IContentAssistant, IContentAssistantExt
 			if (e.character != 0 && (e.stateMask == SWT.ALT))
 				return;
 
+			TriggerType triggerType= getAutoActivationTriggerType(e.character);
+
 			// Only act on characters that are trigger candidates. This
 			// avoids computing the model selection on every keystroke
-			if (!isAutoActivationTriggerChar(e.character)) {
+			if (triggerType == TriggerType.NONE) {
 				stop();
 				return;
 			}
 
 			int showStyle;
-			int pos= fContentAssistSubjectControlAdapter.getSelectedRange().x;
-			char[] activation;
-
-			activation= fContentAssistSubjectControlAdapter.getCompletionProposalAutoActivationCharacters(ContentAssistant.this, pos);
-
-			if (contains(activation, e.character) && !isProposalPopupActive())
+			if (triggerType == TriggerType.COMPLETION_PROPOSAL && !isProposalPopupActive())
 				showStyle= SHOW_PROPOSALS;
 			else {
-				activation= fContentAssistSubjectControlAdapter.getContextInformationAutoActivationCharacters(ContentAssistant.this, pos);
-				if (contains(activation, e.character) && !isContextInfoPopupActive())
+				if (triggerType == TriggerType.CONTEXT_INFORMATION && !isContextInfoPopupActive())
 					showStyle= SHOW_CONTEXT_INFO;
 				else {
 					stop();
@@ -1187,26 +1175,28 @@ public class ContentAssistant implements IContentAssistant, IContentAssistantExt
 	}
 
 	/**
+	 * @param c the character to check
 	 * @return whether the given char is an auto-activation trigger char
 	 * @since 3.15
 	 */
-	boolean isAutoActivationTriggerChar(char c) {
+	TriggerType getAutoActivationTriggerType(char c) {
 		if (fProcessors == null)
-			return false;
-
-		for (Set<IContentAssistProcessor> processorsForContentType : fProcessors.values()) {
-			for (IContentAssistProcessor processor : processorsForContentType) {
-				char[] triggers= processor.getCompletionProposalAutoActivationCharacters();
-				if (triggers != null && new String(triggers).indexOf(c) >= 0) {
-					return true;
-				}
-				triggers= processor.getContextInformationAutoActivationCharacters();
-				if (triggers != null && new String(triggers).indexOf(c) >= 0) {
-					return true;
-				}
+			return TriggerType.NONE;
+		int offset= fContentAssistSubjectControlAdapter.getSelectedRange().x;
+		Set<IContentAssistProcessor> processors= fContentAssistSubjectControlAdapter.getContentAssistProcessors(this, offset);
+		if (processors == null) {
+			return TriggerType.NONE;
+		}
+		for (IContentAssistProcessor processor : processors) {
+			IContentAssistProcessorExtension extension= IContentAssistProcessorExtension.adapt(processor);
+			if (extension.isCompletionProposalAutoActivation(c, fViewer, offset)) {
+				return TriggerType.COMPLETION_PROPOSAL;
+			}
+			if (extension.isContextInformationAutoActivation(c, fViewer, offset)) {
+				return TriggerType.CONTEXT_INFORMATION;
 			}
 		}
-		return false;
+		return TriggerType.NONE;
 	}
 
 	/**
@@ -1916,7 +1906,7 @@ public class ContentAssistant implements IContentAssistant, IContentAssistantExt
 	 * @return the content-assist processors or <code>null</code> if none exists
 	 * @since 3.13
 	 */
-	private Set<IContentAssistProcessor> getProcessors(ITextViewer viewer, int offset) {
+	Set<IContentAssistProcessor> getProcessors(ITextViewer viewer, int offset) {
 		try {
 
 			IDocument document= viewer.getDocument();
@@ -1938,7 +1928,7 @@ public class ContentAssistant implements IContentAssistant, IContentAssistantExt
 	 * @return the content-assist processors or <code>null</code> if none exists
 	 * @since 3.13
 	 */
-	private Set<IContentAssistProcessor> getProcessors(IContentAssistSubjectControl contentAssistSubjectControl, int offset) {
+	Set<IContentAssistProcessor> getProcessors(IContentAssistSubjectControl contentAssistSubjectControl, int offset) {
 		try {
 
 			IDocument document= contentAssistSubjectControl.getDocument();
@@ -2188,95 +2178,6 @@ public class ContentAssistant implements IContentAssistant, IContentAssistantExt
 		return null;
 	}
 
-	/**
-	 * Returns the characters which when typed by the user should automatically initiate proposing
-	 * completions. The position is used to determine the appropriate content assist processor to
-	 * invoke.
-	 *
-	 * @param contentAssistSubjectControl the content assist subject control
-	 * @param offset a document offset
-	 * @return the auto activation characters
-	 * @see IContentAssistProcessor#getCompletionProposalAutoActivationCharacters()
-	 * @since 3.0
-	 */
-	char[] getCompletionProposalAutoActivationCharacters(IContentAssistSubjectControl contentAssistSubjectControl, int offset) {
-		return mergeResults(getProcessors(contentAssistSubjectControl, offset), IContentAssistProcessor::getCompletionProposalAutoActivationCharacters);
-	}
-
-	/**
-	 * Returns the characters which when typed by the user should automatically initiate proposing
-	 * completions. The position is used to determine the appropriate content assist processor to
-	 * invoke.
-	 *
-	 * @param viewer the text viewer
-	 * @param offset a document offset
-	 * @return the auto activation characters
-	 * @see IContentAssistProcessor#getCompletionProposalAutoActivationCharacters()
-	 */
-	char[] getCompletionProposalAutoActivationCharacters(ITextViewer viewer, int offset) {
-		return mergeResults(getProcessors(viewer, offset), IContentAssistProcessor::getCompletionProposalAutoActivationCharacters);
-	}
-
-	/**
-	 * Returns the characters which when typed by the user should automatically initiate the
-	 * presentation of context information. The position is used to determine the appropriate
-	 * content assist processor to invoke.
-	 *
-	 * @param viewer the text viewer
-	 * @param offset a document offset
-	 * @return the auto activation characters
-	 * @see IContentAssistProcessor#getContextInformationAutoActivationCharacters()
-	 * @since 3.0
-	 */
-	char[] getContextInformationAutoActivationCharacters(ITextViewer viewer, int offset) {
-		return mergeResults(getProcessors(viewer, offset), IContentAssistProcessor::getContextInformationAutoActivationCharacters);
-	}
-
-	/**
-	 * Returns the characters which when typed by the user should automatically initiate the
-	 * presentation of context information. The position is used to determine the appropriate
-	 * content assist processor to invoke.
-	 *
-	 * @param contentAssistSubjectControl the content assist subject control
-	 * @param offset a document offset
-	 * @return the auto activation characters
-	 * @see IContentAssistProcessor#getContextInformationAutoActivationCharacters()
-	 * @since 3.0
-	 */
-	char[] getContextInformationAutoActivationCharacters(IContentAssistSubjectControl contentAssistSubjectControl, int offset) {
-		return mergeResults(getProcessors(contentAssistSubjectControl, offset), IContentAssistProcessor::getContextInformationAutoActivationCharacters);
-	}
-
-	private char[] mergeResults(Collection<IContentAssistProcessor> processors, Function<IContentAssistProcessor, char[]> f) {
-		if (processors == null) {
-			return null;
-		}
-		char[][] arrays = processors.stream()
-			.map(f)
-			.filter(Objects::nonNull)
-			.filter(array -> array.length > 0)
-			.toArray(char[][]::new);
-		if (arrays.length == 0) {
-			return null;
-		} else if (arrays.length == 1) {
-			return arrays[0];
-		} else {
-			LinkedHashSet<Character> res = new LinkedHashSet<>();
-			for (char[] current : arrays) {
-				for (char c : current) {
-					res.add(Character.valueOf(c));
-				}
-			}
-			char[] array = new char[res.size()];
-			int index = 0;
-			for (Character c : res) {
-				array[index] = c.charValue();
-				index++;
-			}
-			return array;
-		}
-	}
-
 	@Override
 	public boolean requestWidgetToken(IWidgetTokenOwner owner) {
 		return false;
diff --git a/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/IContentAssistProcessor.java b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/IContentAssistProcessor.java
index 42ab49a8502..04d9e6b8c46 100644
--- a/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/IContentAssistProcessor.java
+++ b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/IContentAssistProcessor.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2005 IBM Corporation and others.
+ * Copyright (c) 2000, 2021 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -10,6 +10,7 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Christoph Läubrich - Bug 508821 - [Content assist] More flexible API in IContentAssistProcessor to decide whether to auto-activate or not
  *******************************************************************************/
 package org.eclipse.jface.text.contentassist;
 
@@ -17,16 +18,29 @@ import org.eclipse.jface.text.ITextViewer;
 
 
 /**
- * A content assist processor proposes completions and
- * computes context information for a particular content type.
- * A content assist processor is a {@link org.eclipse.jface.text.contentassist.IContentAssistant}
- * plug-in.
+ * A content assist processor proposes completions and computes context information for a particular
+ * content type. A content assist processor is a
+ * {@link org.eclipse.jface.text.contentassist.IContentAssistant} plug-in.
  * <p>
- * This interface must be implemented by clients. Implementers should be
- * registered with a content assistant in order to get involved in the
- * assisting process.
+ * This interface must be implemented by clients. Implementers should be registered with a content
+ * assistant in order to get involved in the assisting process.
  * </p>
-*/
+ * In order to provide backward compatibility for clients of <code>IContentAssistProcessor</code>,
+ * extension interfaces are used to provide a means of evolution. The following extension interfaces
+ * exist:
+ * </p>
+ * <ul>
+ * <li>{@link org.eclipse.jface.text.contentassist.IContentAssistProcessorExtension} since version
+ * 3.17 introducing the following functions:
+ * <ul>
+ * <li>isCompletionProposalAutoActivation(char, ITextViewer, int) providing context information when
+ * calculating auto activation</li>
+ * <li>isContextInformationAutoActivation(char, ITextViewer, int) providing context information when
+ * calculating auto activation</li>
+ * </ul>
+ * </li>
+ * </ul>
+ */
 public interface IContentAssistProcessor {
 
 	/**
diff --git a/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/IContentAssistProcessorExtension.java b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/IContentAssistProcessorExtension.java
new file mode 100644
index 00000000000..2be67dc2e65
--- /dev/null
+++ b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/IContentAssistProcessorExtension.java
@@ -0,0 +1,141 @@
+/*******************************************************************************
+ * Copyright (c) 2021 Christoph Läubrich and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Christoph Läubrich - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jface.text.contentassist;
+
+import org.eclipse.jface.text.ITextViewer;
+
+/**
+ * Extension interface of {@link IContentAssistProcessor} that allows to get additional information
+ * when queried for auto activation
+ *
+ * @since 3.17
+ */
+public interface IContentAssistProcessorExtension extends IContentAssistProcessor {
+
+	/**
+	 * @deprecated use {@link #isCompletionProposalAutoActivation(char, ITextViewer, int)} instead
+	 * @noreference use {@link #isCompletionProposalAutoActivation(char, ITextViewer, int)} instead
+	 * @nooverride This default method is not intended to be re-implemented or extended by
+	 *             clients.noimplement implement
+	 *             {@link #isCompletionProposalAutoActivation(char, ITextViewer, int)} instead
+	 */
+	@Deprecated
+	@Override
+	default char[] getCompletionProposalAutoActivationCharacters() {
+		throw new UnsupportedOperationException("use isCompletionProposalAutoActivation instead"); //$NON-NLS-1$
+	}
+
+
+	/**
+	 * @deprecated use {@link #isContextInformationAutoActivation(char, ITextViewer, int)} instead
+	 * @noreference use {@link #isContextInformationAutoActivation(char, ITextViewer, int)} instead
+	 * @nooverride This default method is not intended to be re-implemented or extended by
+	 *             clients.noimplement implement
+	 *             {@link #isContextInformationAutoActivation(char, ITextViewer, int)} instead
+	 */
+	@Deprecated
+	@Override
+	default char[] getContextInformationAutoActivationCharacters() {
+		throw new UnsupportedOperationException("use isContextInformationAutoActivation instead"); //$NON-NLS-1$
+	}
+
+	/**
+	 * Check if the given event should trigger an automatic completion proposal activation
+	 *
+	 * @param c the character to check
+	 * @param viewer the viewer
+	 * @param offset the current offset
+	 * @return <code>true</code> if auto activation is desired, <code>false</code> otherwise
+	 */
+	boolean isCompletionProposalAutoActivation(char c, ITextViewer viewer, int offset);
+	/**
+	 * Check if the given event should trigger an automatic context info activation
+	 *
+	 * @param c the character to check
+	 * @param viewer the viewer
+	 * @param offset the current offset
+	 * @return <code>true</code> if auto activation is desired, <code>false</code> otherwise
+	 */
+	boolean isContextInformationAutoActivation(char c, ITextViewer viewer, int offset);
+
+	static IContentAssistProcessorExtension adapt(IContentAssistProcessor processor) {
+		if (processor == null) {
+			return null;
+		}
+		if (processor instanceof IContentAssistProcessorExtension) {
+			return (IContentAssistProcessorExtension) processor;
+		}
+		return new IContentAssistProcessorExtension() {
+
+			@Override
+			public String getErrorMessage() {
+				return processor.getErrorMessage();
+			}
+
+			@Override
+			public IContextInformationValidator getContextInformationValidator() {
+				return processor.getContextInformationValidator();
+			}
+
+			@Override
+			public IContextInformation[] computeContextInformation(ITextViewer viewer, int offset) {
+				return processor.computeContextInformation(viewer, offset);
+			}
+
+			@Override
+			public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) {
+				return processor.computeCompletionProposals(viewer, offset);
+			}
+
+			@Deprecated
+			@Override
+			public char[] getCompletionProposalAutoActivationCharacters() {
+				return processor.getCompletionProposalAutoActivationCharacters();
+			}
+
+			@Deprecated
+			@Override
+			public char[] getContextInformationAutoActivationCharacters() {
+				return processor.getContextInformationAutoActivationCharacters();
+			}
+
+			@Override
+			public boolean isCompletionProposalAutoActivation(char c, ITextViewer viewer, int offset) {
+				char[] triggers= processor.getCompletionProposalAutoActivationCharacters();
+				if (triggers != null) {
+					for (char trigger : triggers) {
+						if (c == trigger) {
+							return true;
+						}
+					}
+				}
+				return false;
+			}
+
+			@Override
+			public boolean isContextInformationAutoActivation(char c, ITextViewer viewer, int offset) {
+				char[] triggers= processor.getContextInformationAutoActivationCharacters();
+				if (triggers != null) {
+					for (char trigger : triggers) {
+						if (c == trigger) {
+							return true;
+						}
+					}
+				}
+				return false;
+			}
+		};
+	}
+
+}