Support inlay hints for parameter names

Signed-off-by: sheche <sheche@microsoft.com>

Author: jdneo

package-lock.json

@@ -857,6 +857,22 @@
           "default": "line",
           "description": "Show quickfixes at the problem or line level.",
           "scope": "window"
+        },
+        "java.inlayHints.parameterNames.enabled": {
+          "type": "string",
+          "enum": [
+            "none",
+            "literals",
+            "all"
+          ],
+          "enumDescriptions": [
+            "Disable parameter name hints",
+            "Enable parameter name hints only for literal arguments",
+            "Enable parameter name hints for literal and non-literal arguments"
+          ],
+          "default": "literals",
+          "markdownDescription": "Enable/disable inlay hints for parameter names:\n```java\n\nInteger.valueOf(/* s: */ '123', /* radix: */ 10)\n \n```\n",
+          "scope": "window"
         }
       }
     },
@@ -1141,7 +1157,7 @@
     "@types/mocha": "^5.2.5",
     "@types/node": "^8.10.51",
     "@types/semver": "^7.3.8",
-    "@types/vscode": "^1.53.0",
+    "@types/vscode": "^1.65.0",
     "@types/winreg": "^1.2.30",
     "@types/winston": "^2.4.4",
     "gulp": "^4.0.2",

package.json

@@ -246,4 +246,6 @@ export namespace Commands {
     export const RUNTIME_VALIDATION_OPEN = 'java.runtimeValidation.open';
 
     export const RESOLVE_WORKSPACE_SYMBOL = 'java.project.resolveWorkspaceSymbol';
+
+    export const JAVA_EDIT_INLAY_HINTS = 'java.edit.inlayHints';
 }

src/commands.ts

@@ -4,7 +4,7 @@ import * as path from 'path';
 import * as os from 'os';
 import * as fs from 'fs';
 import * as fse from 'fs-extra';
-import { workspace, extensions, ExtensionContext, window, commands, ViewColumn, Uri, languages, IndentAction, InputBoxOptions, EventEmitter, OutputChannel, TextDocument, RelativePattern, ConfigurationTarget, WorkspaceConfiguration, env, UIKind, CodeActionContext, Diagnostic } from 'vscode';
+import { workspace, extensions, ExtensionContext, window, commands, ViewColumn, Uri, languages, IndentAction, InputBoxOptions, EventEmitter, OutputChannel, TextDocument, RelativePattern, ConfigurationTarget, WorkspaceConfiguration, env, UIKind, CodeActionContext, Diagnostic, CodeActionTriggerKind } from 'vscode';
 import { ExecuteCommandParams, ExecuteCommandRequest, LanguageClientOptions, RevealOutputChannelOn, ErrorHandler, Message, ErrorAction, CloseAction, DidChangeConfigurationNotification, CancellationToken, CodeActionRequest, CodeActionParams, Command } from 'vscode-languageclient';
 import { LanguageClient } from 'vscode-languageclient/node';
 import { collectJavaExtensions, isContributedPartUpdated } from './plugin';
@@ -134,6 +134,11 @@ export class OutputInfoCollector implements OutputChannel {
 		this.channel.appendLine(value);
 	}
 
+	replace(value: string): void {
+		this.clear();
+		this.append(value);
+	}
+
 	clear(): void {
 		this.channel.clear();
 	}
@@ -239,7 +244,8 @@ export function activate(context: ExtensionContext): Promise<ExtensionAPI> {
 						resolveAdditionalTextEditsSupport: true,
 						advancedIntroduceParameterRefactoringSupport: true,
 						actionableRuntimeNotificationSupport: true,
-						shouldLanguageServerExitOnShutdown: true
+						shouldLanguageServerExitOnShutdown: true,
+						inlayHintsSupport: true,
 					},
 					triggerFiles,
 				},
@@ -279,6 +285,7 @@ export function activate(context: ExtensionContext): Promise<ExtensionAPI> {
 								const codeActionContext: CodeActionContext = {
 									diagnostics: allDiagnostics,
 									only: context.only,
+									triggerKind: CodeActionTriggerKind.Invoke,
 								};
 								params.context = client.code2ProtocolConverter.asCodeActionContext(codeActionContext);
 							}

src/extension.ts

@@ -75,10 +75,10 @@ class JavaHoverProvider implements HoverProvider {
 
         const contributed = new MarkdownString(contributedCommands.map((command) => this.convertCommandToMarkdown(command)).join(' | '));
         contributed.isTrusted = true;
-        let contents: MarkedString[] = [ contributed ];
+        let contents: MarkdownString[] = [ contributed ];
         let range;
         if (serverHover && serverHover.contents) {
-            contents = contents.concat(serverHover.contents);
+            contents = contents.concat(serverHover.contents as MarkdownString[]);
             range = serverHover.range;
         }
         return new Hover(contents, range);

src/hoverAction.ts

@@ -0,0 +1,37 @@
+import { performance } from "perf_hooks";
+import { CancellationToken, commands, EventEmitter, ExtensionContext, InlayHint, InlayHintKind, InlayHintsProvider, Range, TextDocument, workspace } from "vscode";
+import { Commands } from "./commands";
+
+export class JavaInlayHintsProvider implements InlayHintsProvider {
+
+    private onDidChange = new EventEmitter<void>();
+    public onDidChangeInlayHints = this.onDidChange.event;
+
+    constructor(context: ExtensionContext) {
+        context.subscriptions.push(workspace.onDidChangeConfiguration(e => {
+            if (e.affectsConfiguration("java.inlayHints.parameterNames.enabled")) {
+                this.onDidChange.fire();
+            }
+        }));
+    }
+
+    public async provideInlayHints(document: TextDocument, range: Range, token: CancellationToken): Promise<InlayHint[]> {
+        const start = performance.now();
+        const hints = await commands.executeCommand<InlayHint[]>(Commands.EXECUTE_WORKSPACE_COMMAND,
+            Commands.JAVA_EDIT_INLAY_HINTS,
+            document.uri.toString(),
+            range.start.line,
+            range.start.character,
+            range.end.line,
+            range.end.character,
+            token
+        );
+        console.log(performance.now() - start);
+        for (const hint of hints) {
+            hint.paddingRight = true;
+            hint.kind = InlayHintKind.Parameter;
+        }
+
+        return hints;
+    }
+}

src/inlayHintsProvider.ts

@@ -33,6 +33,7 @@ import { TypeHierarchyDirection, TypeHierarchyItem } from "./typeHierarchy/proto
 import { buildFilePatterns } from './plugin';
 import { pomCodeActionMetadata, PomCodeActionProvider } from "./pom/pomCodeActionProvider";
 import { findRuntimes, IJavaRuntime } from "jdk-utils";
+import { JavaInlayHintsProvider } from "./inlayHintsProvider";
 
 const extensionName = 'Language Support for Java';
 const GRADLE_CHECKSUM = "gradle/checksum/prompt";
@@ -498,6 +499,14 @@ export class StandardLanguageClient {
 				scheme: "file",
 				pattern: "**/pom.xml"
 			}, new PomCodeActionProvider(context), pomCodeActionMetadata);
+
+			if (languages.registerInlayHintsProvider) {
+				context.subscriptions.push(languages.registerInlayHintsProvider([
+					{ scheme: "file", language: "java", pattern: "**/*.java" },
+					{ scheme: "jdt", language: "java", pattern: "**/*.class" },
+					{ scheme: "untitled", language: "java", pattern: "**/*.java" }
+				], new JavaInlayHintsProvider(context)));
+			}
 		});
 	}