Performance improvements and other fixes in code completion (#3146)

* Avoid overloading the DOM tree of the ContentAssistWidget

Signed-off-by: Kaloyan Raev <kaloyan.r@zend.com>

* Ensure the code assist widget is closed when applying proposal

Signed-off-by: Kaloyan Raev <kaloyan.r@zend.com>

* Respect isIncomplete flag in the completion result

If the isIncomplete flag is false, i.e. the completion result is
complete, then additional typing for the same word should not trigger a
new completion request. The latest completion result should be reused.

Signed-off-by: Kaloyan Raev <kaloyan.r@zend.com>

* Fix flickering between keystrokes during code completion

Signed-off-by: Kaloyan Raev <kaloyan.r@zend.com>

* Fine tune the rules for making new completion request

Signed-off-by: Kaloyan Raev <kaloyan.r@zend.com>

* Set the correct offset when applying code completion

* Force a completion request message on Ctrl+Space

Signed-off-by: Kaloyan Raev <kaloyan.r@zend.com>

* Fixed retrieval of CompletionItem document via Resolve request

Signed-off-by: Kaloyan Raev <kaloyan.r@zend.com>

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/codeassist/CodeAssistProcessor.java

@@ -25,17 +25,22 @@
 public interface CodeAssistProcessor {
 
     /**
-     * Returns a list of completion proposals based on the
-     * specified location within the document that corresponds
-     * to the current cursor position within the text view.
+     * Returns a list of completion proposals based on the specified location
+     * within the document that corresponds to the current cursor position
+     * within the text view.
      *
      * @param editor
-     *         the editor whose document is used to compute the proposals
+     *            the editor whose document is used to compute the proposals
      * @param offset
-     *         an offset within the document for which completions should be computed
-     * @return an array of completion proposals or <code>null</code> if no proposals are possible
+     *            an offset within the document for which completions should be
+     *            computed
+     * @param triggered
+     *            if triggered by the content assist key binding
+     * 
+     * @return an array of completion proposals or <code>null</code> if no
+     *         proposals are possible
      */
-    void computeCompletionProposals(TextEditor editor, int offset, CodeAssistCallback callback);
+    void computeCompletionProposals(TextEditor editor, int offset, boolean triggered, CodeAssistCallback callback);
 
     /**
      * Returns the reason why this content assist processor

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/codeassist/CodeAssistant.java

@@ -50,8 +50,9 @@ public interface CodeAssistant {
      * appropriate content assist processor to invoke.
      * 
      * @param offset a document offset
+     * @param triggered if triggered by the content assist key binding
      * @param callback the callback to use once completions are ready
      */
-    void computeCompletionProposals(int offset, CodeAssistCallback callback);
+    void computeCompletionProposals(int offset, boolean triggered, CodeAssistCallback callback);
 
 }

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/codeassist/CodeAssistantImpl.java

@@ -52,12 +52,12 @@ public CodeAssistantImpl(@Assisted final DocumentPartitioner partitioner,
     }
 
     @Override
-    public void computeCompletionProposals(final int offset, final CodeAssistCallback callback) {
+    public void computeCompletionProposals(final int offset, final boolean triggered, final CodeAssistCallback callback) {
         this.lastErrorMessage = "processing";
 
         final CodeAssistProcessor processor = getProcessor(offset);
         if (processor != null) {
-            processor.computeCompletionProposals(textEditor, offset, callback);
+            processor.computeCompletionProposals(textEditor, offset, triggered, callback);
             this.lastErrorMessage = processor.getErrorMessage();
             if (this.lastErrorMessage != null) {
                 notificationManager.notify("", lastErrorMessage, FAIL, EMERGE_MODE);
@@ -66,7 +66,7 @@ public void computeCompletionProposals(final int offset, final CodeAssistCallbac
         } else {
             final CodeAssistProcessor fallbackProcessor = getFallbackProcessor();
             if (fallbackProcessor != null) {
-                fallbackProcessor.computeCompletionProposals(textEditor, offset, callback);
+                fallbackProcessor.computeCompletionProposals(textEditor, offset, triggered, callback);
                 this.lastErrorMessage = fallbackProcessor.getErrorMessage();
                 if (this.lastErrorMessage != null) {
                     this.textEditor.showMessage(this.lastErrorMessage);

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/codeassist/CompletionProposal.java

@@ -10,6 +10,7 @@
  *******************************************************************************/
 package org.eclipse.che.ide.api.editor.codeassist;
 
+import com.google.gwt.user.client.rpc.AsyncCallback;
 import com.google.gwt.user.client.ui.Widget;
 
 import org.eclipse.che.ide.api.icon.Icon;
@@ -28,10 +29,10 @@ public interface CompletionProposal {
     /**
      * Returns optional additional information about the proposal. The additional information will be presented to assist the user
      * in deciding if the selected proposal is the desired choice.
-     *
-     * @return the additional information or <code>null</code>
+     * 
+     * @param callback a callback to return a widget with additional information
      */
-    Widget getAdditionalProposalInfo();
+    void getAdditionalProposalInfo(AsyncCallback<Widget> callback);
 
     /**
      * Returns the string to be displayed in the list of completion proposals.

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/codeassist/DefaultChainedCodeAssistProcessor.java

@@ -36,13 +36,13 @@ protected void setProcessors(final Set<? extends CodeAssistProcessor> codeAssist
     }
 
     @Override
-    public void computeCompletionProposals(final TextEditor textEditor, final int offset, final CodeAssistCallback callback) {
+    public void computeCompletionProposals(final TextEditor textEditor, final int offset, final boolean triggered, final CodeAssistCallback callback) {
         if (!this.codeAssistProcessors.isEmpty()) {
             final List<CompletionProposal> proposalList = new ArrayList<>();
             final List<CodeAssistProcessor> expected = new ArrayList<>();
             for (final CodeAssistProcessor processor : this.codeAssistProcessors) {
                 expected.add(processor);
-                processor.computeCompletionProposals(textEditor, offset, new CodeAssistCallback() {
+                processor.computeCompletionProposals(textEditor, offset, triggered, new CodeAssistCallback() {
                     @Override
                     public void proposalComputed(final List<CompletionProposal> processorProposals) {
                         expected.remove(processor);

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/texteditor/TextEditorInit.java

@@ -191,7 +191,7 @@ private void configureCodeAssist(final DocumentHandle documentHandle) {
             final KeyBindingAction action = new KeyBindingAction() {
                 @Override
                 public boolean action() {
-                    showCompletion(codeAssistant);
+                    showCompletion(codeAssistant, true);
                     return true;
                 }
             };
@@ -202,7 +202,7 @@ public boolean action() {
             documentHandle.getDocEventBus().addHandler(CompletionRequestEvent.TYPE, new CompletionRequestHandler() {
                 @Override
                 public void onCompletionRequest(final CompletionRequestEvent event) {
-                    showCompletion(codeAssistant);
+                    showCompletion(codeAssistant, false);
                 }
             });
         } else {
@@ -234,8 +234,9 @@ public void onCompletionRequest(final CompletionRequestEvent event) {
      * Show the available completions.
      *
      * @param codeAssistant the code assistant
+     * @param triggered if triggered by the content assist key binding
      */
-    private void showCompletion(final CodeAssistant codeAssistant) {
+    private void showCompletion(final CodeAssistant codeAssistant, final boolean triggered) {
         final int cursor = textEditor.getCursorOffset();
         if (cursor < 0) {
             return;
@@ -248,7 +249,7 @@ public void computeCompletions(final CompletionReadyCallback callback) {
                     // cursor must be computed here again so it's original value is not baked in
                     // the SMI instance closure - important for completion update when typing
                     final int cursor = textEditor.getCursorOffset();
-                    codeAssistant.computeCompletionProposals(cursor, new CodeAssistCallback() {
+                    codeAssistant.computeCompletionProposals(cursor, triggered, new CodeAssistCallback() {
                         @Override
                         public void proposalComputed(final List<CompletionProposal> proposals) {
                             callback.onCompletionReady(proposals);

plugins/plugin-java/che-plugin-java-ext-lang-client/src/main/java/org/eclipse/che/ide/ext/java/client/editor/ActionCompletionProposal.java

@@ -10,11 +10,12 @@
  *******************************************************************************/
 package org.eclipse.che.ide.ext.java.client.editor;
 
+import com.google.gwt.user.client.rpc.AsyncCallback;
 import com.google.gwt.user.client.ui.Widget;
 
+import org.eclipse.che.ide.api.editor.codeassist.CompletionProposal;
 import org.eclipse.che.ide.api.icon.Icon;
 import org.eclipse.che.ide.ext.java.client.action.ProposalAction;
-import org.eclipse.che.ide.api.editor.codeassist.CompletionProposal;
 import org.eclipse.che.ide.util.loging.Log;
 
 /**
@@ -35,8 +36,8 @@ public ActionCompletionProposal(String display, String actionId, ProposalAction
     }
 
     @Override
-    public Widget getAdditionalProposalInfo() {
-        return null;
+    public void getAdditionalProposalInfo(AsyncCallback<Widget> callback) {
+        callback.onSuccess(null);
     }
 
     @Override

plugins/plugin-java/che-plugin-java-ext-lang-client/src/main/java/org/eclipse/che/ide/ext/java/client/editor/JavaCodeAssistProcessor.java

@@ -155,7 +155,9 @@ public static Icon getIcon(final String image) {
     }
 
     @Override
-    public void computeCompletionProposals(final TextEditor textEditor, final int offset,
+    public void computeCompletionProposals(final TextEditor textEditor,
+                                           final int offset,
+                                           final boolean triggered,
                                            final CodeAssistCallback callback) {
         if (errorMessage != null) {
             return;

plugins/plugin-java/che-plugin-java-ext-lang-client/src/main/java/org/eclipse/che/ide/ext/java/client/editor/JavaCompletionProposal.java

@@ -79,14 +79,14 @@ public JavaCompletionProposal(final int id,
 
     /** {@inheritDoc} */
     @Override
-    public Widget getAdditionalProposalInfo() {
+    public void getAdditionalProposalInfo(AsyncCallback<Widget> callback) {
         Frame frame = new Frame();
         frame.setSize("100%", "100%");
         frame.getElement().getStyle().setBorderStyle(Style.BorderStyle.NONE);
         frame.getElement().setAttribute("sandbox", ""); // empty value, not null
         frame.getElement().getStyle().setProperty("resize", "both");
         frame.setUrl(client.getProposalDocUrl(id, sessionId));
-        return frame;
+        callback.onSuccess(frame);
     }
 
     /** {@inheritDoc} */

plugins/plugin-languageserver/che-plugin-languageserver-ide/pom.xml

@@ -120,6 +120,15 @@
             </testResource>
         </testResources>
         <plugins>
+            <plugin>
+                <groupId>com.mycila</groupId>
+                <artifactId>license-maven-plugin</artifactId>
+                <configuration>
+                    <excludes>
+                        <exclude>**/org/eclipse/che/plugin/languageserver/ide/editor/codeassist/LatestCompletionResult.java</exclude>
+                    </excludes>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>build-helper-maven-plugin</artifactId>

plugins/plugin-languageserver/che-plugin-languageserver-ide/src/main/java/org/eclipse/che/plugin/languageserver/ide/editor/codeassist/CompletionItemBasedCompletionProposal.java

@@ -14,66 +14,97 @@
 
 import com.google.gwt.dom.client.Style;
 import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
+import com.google.gwt.user.client.rpc.AsyncCallback;
 import com.google.gwt.user.client.ui.Label;
 import com.google.gwt.user.client.ui.Widget;
 
-import java.util.List;
-
 import org.eclipse.che.api.languageserver.shared.lsapi.CompletionItemDTO;
 import org.eclipse.che.api.languageserver.shared.lsapi.RangeDTO;
 import org.eclipse.che.api.languageserver.shared.lsapi.TextDocumentIdentifierDTO;
 import org.eclipse.che.api.promises.client.Operation;
 import org.eclipse.che.api.promises.client.OperationException;
+import org.eclipse.che.api.promises.client.Promise;
 import org.eclipse.che.api.promises.client.PromiseError;
 import org.eclipse.che.ide.api.editor.codeassist.Completion;
 import org.eclipse.che.ide.api.editor.codeassist.CompletionProposal;
 import org.eclipse.che.ide.api.editor.document.Document;
 import org.eclipse.che.ide.api.editor.text.LinearRange;
 import org.eclipse.che.ide.api.editor.text.TextPosition;
 import org.eclipse.che.ide.api.icon.Icon;
-import org.eclipse.che.ide.util.loging.Log;
 import org.eclipse.che.plugin.languageserver.ide.LanguageServerResources;
 import org.eclipse.che.plugin.languageserver.ide.filters.Match;
 import org.eclipse.che.plugin.languageserver.ide.service.TextDocumentServiceClient;
 
+import java.util.List;
+
 /**
  * @author Anatolii Bazko
+ * @author Kaloyan Raev
  */
 public class CompletionItemBasedCompletionProposal implements CompletionProposal {
 
-    private final CompletionItemDTO         completionItem;
+    private CompletionItemDTO               completionItem;
     private final TextDocumentServiceClient documentServiceClient;
     private final TextDocumentIdentifierDTO documentId;
     private final LanguageServerResources   resources;
     private final Icon                      icon;
     private final ServerCapabilities        serverCapabilities;
     private final List<Match>               highlights;
+    private final int                       offset;
+    private boolean resolved;
 
     CompletionItemBasedCompletionProposal(CompletionItemDTO completionItem,
                                           TextDocumentServiceClient documentServiceClient,
                                           TextDocumentIdentifierDTO documentId,
-                                          LanguageServerResources resources, Icon icon,
+                                          LanguageServerResources resources,
+                                          Icon icon,
                                           ServerCapabilities serverCapabilities,
-                                          List<Match> highlights) {
+                                          List<Match> highlights,
+                                          int offset) {
         this.completionItem = completionItem;
         this.documentServiceClient = documentServiceClient;
         this.documentId = documentId;
         this.resources = resources;
         this.icon = icon;
         this.serverCapabilities = serverCapabilities;
         this.highlights = highlights;
+        this.offset = offset;
+        this.resolved = false;
     }
 
     @Override
-    public Widget getAdditionalProposalInfo() {
-        if (completionItem.getDocumentation() != null && !completionItem.getDocumentation().isEmpty()) {
-            Label label = new Label(completionItem.getDocumentation());
-            label.setWordWrap(true);
-            label.getElement().getStyle().setFontSize(13, Style.Unit.PX);
-            label.setSize("100%", "100%");
-            return label;
+    public void getAdditionalProposalInfo(final AsyncCallback<Widget> callback) {
+        if (completionItem.getDocumentation() == null && canResolve()) {
+            resolve().then(new Operation<CompletionItemDTO>() {
+                @Override
+                public void apply(CompletionItemDTO item) throws OperationException {
+                    completionItem = item;
+                    resolved = true;
+                    callback.onSuccess(createAdditionalInfoWidget());
+                }
+            }).catchError(new Operation<PromiseError>() {
+                @Override
+                public void apply(PromiseError e) throws OperationException {
+                    callback.onFailure(e.getCause());
+                }
+            });
+        } else {
+            callback.onSuccess(createAdditionalInfoWidget());
+        }
+    }
+
+    private Widget createAdditionalInfoWidget() {
+        String documentation = completionItem.getDocumentation();
+        if (documentation == null || documentation.trim().isEmpty()) {
+            documentation = "No documentation found.";
         }
-        return null;
+
+        Label label = new Label(documentation);
+        label.setWordWrap(true);
+        label.getElement().getStyle().setFontSize(13, Style.Unit.PX);
+        label.getElement().getStyle().setMarginLeft(4, Style.Unit.PX);
+        label.setSize("100%", "100%");
+        return label;
     }
 
     @Override
@@ -129,50 +160,43 @@ public Icon getIcon() {
 
     @Override
     public void getCompletion(final CompletionCallback callback) {
+        callback.onCompletion(new CompletionImpl(completionItem, offset));
+    }
 
-        if (serverCapabilities.getCompletionProvider() != null &&
-            serverCapabilities.getCompletionProvider().getResolveProvider() != null &&
-            serverCapabilities.getCompletionProvider().getResolveProvider()) {
-            completionItem.setTextDocumentIdentifier(documentId);
-            documentServiceClient.resolveCompletionItem(completionItem).then(new Operation<CompletionItemDTO>() {
-                @Override
-                public void apply(CompletionItemDTO arg) throws OperationException {
-                    callback.onCompletion(new CompletionImpl(arg));
-                }
-            }).catchError(new Operation<PromiseError>() {
-                @Override
-                public void apply(PromiseError arg) throws OperationException {
-                    Log.error(getClass(), arg);
-                    //try to apply with default text
-                    callback.onCompletion(new CompletionImpl(completionItem));
-                }
-            });
-        } else {
-            callback.onCompletion(new CompletionImpl(completionItem));
-        }
+    private boolean canResolve() {
+        return !resolved &&
+               serverCapabilities.getCompletionProvider() != null &&
+               serverCapabilities.getCompletionProvider().getResolveProvider() != null &&
+               serverCapabilities.getCompletionProvider().getResolveProvider();
+    }
+
+    private Promise<CompletionItemDTO> resolve() {
+        completionItem.setTextDocumentIdentifier(documentId);
+        return documentServiceClient.resolveCompletionItem(completionItem);
     }
 
     private static class CompletionImpl implements Completion {
 
         private CompletionItemDTO completionItem;
+        private int               offset;
 
-        public CompletionImpl(CompletionItemDTO completionItem) {
+        public CompletionImpl(CompletionItemDTO completionItem, int offset) {
             this.completionItem = completionItem;
+            this.offset = offset;
         }
 
         @Override
         public void apply(Document document) {
-            //TODO in general resolve completion item may not provide getTextEdit, need to add checks
             if (completionItem.getTextEdit() != null) {
                 RangeDTO range = completionItem.getTextEdit().getRange();
                 int startOffset = document.getIndexFromPosition(
                         new TextPosition(range.getStart().getLine(), range.getStart().getCharacter()));
-                int endOffset = document
-                        .getIndexFromPosition(new TextPosition(range.getEnd().getLine(), range.getEnd().getCharacter()));
+                int endOffset = offset + document.getIndexFromPosition(
+                        new TextPosition(range.getEnd().getLine(), range.getEnd().getCharacter()));
                 document.replace(startOffset, endOffset - startOffset, completionItem.getTextEdit().getNewText());
             } else {
                 String insertText = completionItem.getInsertText() == null ? completionItem.getLabel() : completionItem.getInsertText();
-                document.replace(document.getCursorOffset(), 0, insertText);
+                document.replace(document.getCursorOffset() - offset, offset, insertText);
             }
         }