hover with detail levels

Author: sumneko

client/src/languageserver.ts

@@ -2,6 +2,7 @@ import * as path from 'path';
 import * as os from 'os';
 import * as fs from 'fs';
 import * as vscode from 'vscode';
+import * as LSP from 'vscode-languageserver-protocol';
 import {
     workspace as Workspace,
     ExtensionContext,
@@ -156,6 +157,9 @@ class LuaClient extends Disposable {
                 languageConfiguration: true,
                 storagePath: this.context.globalStorageUri.fsPath,
             },
+            middleware: {
+                provideHover: async () => undefined,
+            }
         };
 
         const config = Workspace.getConfiguration(
@@ -194,6 +198,7 @@ class LuaClient extends Disposable {
         this.onCommand();
         this.statusBar();
         this.languageConfiguration();
+        this.provideHover();
     }
 
     private async getCommand(config: vscode.WorkspaceConfiguration) {
@@ -359,6 +364,58 @@ class LuaClient extends Disposable {
             })
         )
     }
+
+    private provideHover() {
+        const client = this.client;
+        const levelMap = new WeakMap<vscode.VerboseHover, number>();
+        let provider = vscode.languages.registerHoverProvider('lua', {
+            provideHover: async (document, position, token, context?: vscode.HoverContext) => {
+                if (!client) {
+                    return null;
+                }
+                let level = 1;
+                if (context?.previousHover) {
+                    level = levelMap.get(context.previousHover) ?? 0;
+                    if (context.verbosityDelta !== undefined) {
+                        level += context.verbosityDelta;
+                    }
+                }
+                let params = {
+                    level: level,
+                    ...client.code2ProtocolConverter.asTextDocumentPositionParams(document, position),
+                }
+                return client?.sendRequest(
+                    LSP.HoverRequest.type,
+                    params,
+                    token,
+                ).then((result) => {
+                    if (token.isCancellationRequested) {
+                        return null;
+                    }
+                    if (result === null) {
+                        return null;
+                    }
+                    let verboseResult = result as LSP.Hover & { maxLevel?: number };
+                    let maxLevel = verboseResult.maxLevel ?? 0;
+                    let hover = client.protocol2CodeConverter.asHover(result);
+                    let verboseHover = new vscode.VerboseHover(
+                        hover.contents,
+                        hover.range,
+                        level < maxLevel,
+                        level > 0,
+                    );
+                    if (level > maxLevel) {
+                        level = maxLevel;
+                    }
+                    levelMap.set(verboseHover, level);
+                    return verboseHover;
+                }, (error) => {
+                    return client.handleFailedRequest(LSP.HoverRequest.type, token, error, null);
+                });
+            }
+        })
+        this.disposables.push(provider)
+    }
 }
 
 export function activate(context: ExtensionContext) {

client/src/vscode.proposed/editorHoverVerbosityLevel.d.ts

@@ -0,0 +1,76 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+declare module 'vscode' {
+
+	/**
+	 * A hover represents additional information for a symbol or word. Hovers are
+	 * rendered in a tooltip-like widget.
+	 */
+	export class VerboseHover extends Hover {
+
+		/**
+		 * Can increase the verbosity of the hover
+		 */
+		canIncreaseVerbosity?: boolean;
+
+		/**
+		 * Can decrease the verbosity of the hover
+		 */
+		canDecreaseVerbosity?: boolean;
+
+		/**
+		 * Creates a new hover object.
+		 *
+		 * @param contents The contents of the hover.
+		 * @param range The range to which the hover applies.
+		 */
+		constructor(contents: MarkdownString | MarkedString | Array<MarkdownString | MarkedString>, range?: Range, canIncreaseVerbosity?: boolean, canDecreaseVerbosity?: boolean);
+	}
+
+	export interface HoverContext {
+
+		/**
+		 * The delta by which to increase/decrease the hover verbosity level
+		 */
+		readonly verbosityDelta?: number;
+
+		/**
+		 * The previous hover sent for the same position
+		 */
+		readonly previousHover?: Hover;
+	}
+
+	export enum HoverVerbosityAction {
+		/**
+		 * Increase the hover verbosity
+		 */
+		Increase = 0,
+		/**
+		 * Decrease the hover verbosity
+		 */
+		Decrease = 1
+	}
+
+	/**
+	 * The hover provider class
+	 */
+	export interface HoverProvider {
+
+		/**
+		 * Provide a hover for the given position and document. Multiple hovers at the same
+		 * position will be merged by the editor. A hover can have a range which defaults
+		 * to the word range at the position when omitted.
+		 *
+		 * @param document The document in which the command was invoked.
+		 * @param position The position at which the command was invoked.
+		 * @param token A cancellation token.
+		 * @oaram context A hover context.
+		 * @returns A hover or a thenable that resolves to such. The lack of a result can be
+		 * signaled by returning `undefined` or `null`.
+		 */
+		provideHover(document: TextDocument, position: Position, token: CancellationToken, context?: HoverContext): ProviderResult<VerboseHover>;
+	}
+}