feat: emulate vscode's "editor.action.triggerSuggest" command

Signed-off-by: Fred Bricon <fbricon@gmail.com>

src/main/java/com/redhat/devtools/lsp4ij/commands/editor/TriggerSuggestAction.java

@@ -0,0 +1,61 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Red Hat, Inc.
+ * Distributed under license by Red Hat, Inc. All rights reserved.
+ * This program is made available under the terms of the
+ * Eclipse Public License v2.0 which accompanies this distribution,
+ * and is available at https://www.eclipse.org/legal/epl-v20.html
+ *
+ * Contributors:
+ * Red Hat, Inc. - initial API and implementation
+ ******************************************************************************/
+package com.redhat.devtools.lsp4ij.commands.editor;
+
+import com.intellij.openapi.actionSystem.*;
+import com.intellij.openapi.actionSystem.ex.ActionUtil;
+import com.intellij.openapi.actionSystem.impl.SimpleDataContext;
+import com.intellij.openapi.fileEditor.FileEditor;
+import com.intellij.openapi.fileEditor.FileEditorManager;
+import com.intellij.openapi.fileEditor.TextEditor;
+import com.intellij.openapi.project.Project;
+import com.redhat.devtools.lsp4ij.commands.LSPCommand;
+import com.redhat.devtools.lsp4ij.commands.LSPCommandAction;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Emulates Visual Studio Code's "editor.action.triggerSuggest" command, to trigger code completion after selecting a completion item.
+ */
+public class TriggerSuggestAction extends LSPCommandAction {
+
+    private static final String CODE_COMPLETION_ACTION = "CodeCompletion";
+
+    @Override
+    protected void commandPerformed(@NotNull LSPCommand command, @NotNull AnActionEvent e) {
+        Project project = e.getProject();
+        if (project == null) {
+            return;
+        }
+        @Nullable TextEditor activeEditor = findActiveEditor(project);
+        if (activeEditor == null) {
+            return;
+        }
+        AnAction codeCompletionAction = ActionManager.getInstance().getAction(CODE_COMPLETION_ACTION);
+        if (codeCompletionAction != null ) {
+            DataContext dataContext = createDataContext(activeEditor, project);
+            ActionUtil.invokeAction(codeCompletionAction, dataContext, ActionPlaces.UNKNOWN, null, null);
+        }
+    }
+
+    private static DataContext createDataContext(TextEditor activeEditor, Project project) {
+        SimpleDataContext.Builder contextBuilder = SimpleDataContext.builder();
+        contextBuilder.add(CommonDataKeys.PROJECT, project)
+                      .add(CommonDataKeys.EDITOR, activeEditor.getEditor());
+        return contextBuilder.build();
+    }
+
+    public static @Nullable TextEditor findActiveEditor(Project project) {
+        FileEditorManager fileEditorManager = FileEditorManager.getInstance(project);
+        FileEditor editor = fileEditorManager.getSelectedEditor();
+        return editor instanceof TextEditor? (TextEditor) editor: null;
+    }
+}

src/main/java/com/redhat/devtools/lsp4ij/operations/completion/LSPCompletionProposal.java

@@ -107,6 +107,11 @@ public void handleInsert(@NotNull InsertionContext context) {
             EditorModificationUtil.moveCaretRelatively(editor, -template.getTemplateText().length());
             TemplateManager.getInstance(context.getProject()).startTemplate(context.getEditor(), template);
         }
+        // Execute custom command of the completion item if needed
+        Command command = item.getCommand();
+        if (command != null) {
+            executeCustomCommand(command, LSPIJUtils.toUri(context.getDocument()));
+        }
     }
 
     /**
@@ -267,11 +272,7 @@ protected void apply(Document document, char trigger, int stateMask, int offset)
                 LSPIJUtils.applyEdits(editor, document, Collections.singletonList(textEdit));
             }
 
-            // Execute custom command of the completion item if needed
-            Command command = item.getCommand();
-            if (command != null) {
-                executeCustomCommand(command, LSPIJUtils.toUri(document));
-            }
+
         } catch (RuntimeException ex) {
             LOGGER.warn(ex.getLocalizedMessage(), ex);
         }

src/main/resources/META-INF/plugin.xml

@@ -173,6 +173,13 @@
                 id="lsp.console.explorer.copy.command"
                 class="com.redhat.devtools.lsp4ij.console.explorer.actions.CopyStartServerCommandAction"
                 icon="AllIcons.Actions.Copy"/>
+
+
+        <!-- Common LSP Client actions   -->
+        <!-- Reuse VS Code action ids while waiting for standardization of LSP commands https://github.com/microsoft/language-server-protocol/issues/788 -->
+        <action id="editor.action.triggerSuggest"
+                class="com.redhat.devtools.lsp4ij.commands.editor.TriggerSuggestAction"
+        />
     </actions>
 
     <!-- LSP application listeners -->