Add support for .class files

Signed-off-by: Jessica He <jhe@redhat.com>

Author: JessicaJHee

package.json

@@ -57,6 +57,18 @@
   ],
   "main": "./dist/extension",
   "contributes": {
+    "customEditors": [
+      {
+        "viewType": "decompiled.javaClass",
+        "displayName": "Decompiled Java Class File",
+        "selector": [
+          {
+            "scheme": "file",
+            "filenamePattern": "*.class"
+          }
+        ]
+      }
+    ],
     "javaBuildFilePatterns": [
       "^pom\\.xml$",
       ".*\\.gradle(\\.kts)?$"

src/commands.ts

@@ -79,9 +79,9 @@ export namespace Commands {
      */
     export const EXECUTE_WORKSPACE_COMMAND = 'java.execute.workspaceCommand';
 
-	/**
-	 * Execute Workspace build (compilation)
-	 */
+    /**
+     * Execute Workspace build (compilation)
+     */
     export const COMPILE_WORKSPACE = 'java.workspace.compile';
 
     /**
@@ -119,18 +119,18 @@ export namespace Commands {
      */
     export const OPEN_FORMATTER = 'java.open.formatter.settings';
 
-	/**
-	 * Open a file given the URI
-	 */
-	export const OPEN_FILE = 'java.open.file';
+    /**
+     * Open a file given the URI
+     */
+    export const OPEN_FILE = 'java.open.file';
 
     /**
      * Clean the Java language server workspace
      */
     export const CLEAN_WORKSPACE = 'java.clean.workspace';
     /**
      * Update the source attachment for the selected class file
-	 * client-side & server-side commands
+     * client-side & server-side commands
      */
     export const UPDATE_SOURCE_ATTACHMENT_CMD = 'java.project.updateSourceAttachment.command';
     export const UPDATE_SOURCE_ATTACHMENT = 'java.project.updateSourceAttachment';
@@ -140,25 +140,25 @@ export namespace Commands {
     export const RESOLVE_SOURCE_ATTACHMENT = 'java.project.resolveSourceAttachment';
     /**
      * Mark the folder as the source root of the closest project.
-	 * client-side & server-side commands
+     * client-side & server-side commands
      */
     export const ADD_TO_SOURCEPATH_CMD = 'java.project.addToSourcePath.command';
     export const ADD_TO_SOURCEPATH = 'java.project.addToSourcePath';
     /**
      * Unmark the folder as the source root of the project.
-	 * client-side & server-side commands
+     * client-side & server-side commands
      */
     export const REMOVE_FROM_SOURCEPATH_CMD = 'java.project.removeFromSourcePath.command';
     export const REMOVE_FROM_SOURCEPATH = 'java.project.removeFromSourcePath';
     /**
      * List all recognized source roots in the workspace.
-	 * client-side & server-side commands
+     * client-side & server-side commands
      */
     export const LIST_SOURCEPATHS_CMD = 'java.project.listSourcePaths.command';
     export const LIST_SOURCEPATHS = 'java.project.listSourcePaths';
     /**
      * Import new projects
-	 * client-side & server-side commands
+     * client-side & server-side commands
      */
     export const IMPORT_PROJECTS_CMD = 'java.project.import.command';
     export const IMPORT_PROJECTS = 'java.project.import';
@@ -170,7 +170,7 @@ export namespace Commands {
      * Generate hashCode() and equals().
      */
     export const HASHCODE_EQUALS_PROMPT = 'java.action.hashCodeEqualsPrompt';
-	/**
+    /**
      * Open settings.json
      */
     export const OPEN_JSON_SETTINGS = 'workbench.action.openSettingsJson';
@@ -182,10 +182,10 @@ export namespace Commands {
      * Organize imports silently.
      */
     export const ORGANIZE_IMPORTS_SILENTLY = "java.edit.organizeImports";
-	/**
-	 * Handle a paste event.
-	 */
-	export const HANDLE_PASTE_EVENT = "java.edit.handlePasteEvent";
+    /**
+     * Handle a paste event.
+     */
+    export const HANDLE_PASTE_EVENT = "java.edit.handlePasteEvent";
     /**
      * Custom paste action (triggers auto-import)
      */
@@ -320,4 +320,10 @@ export namespace Commands {
      * Clean everything in the shared index directory.
      */
     export const CLEAN_SHARED_INDEXES = "java.clean.sharedIndexes";
+
+    /**
+    * Get the uri of the decompiled class file.
+    */
+    export const GET_DECOMPILED_SOURCE = "java.decompile";
+
 }

src/extension.ts

@@ -26,6 +26,7 @@ import { runtimeStatusBarProvider } from './runtimeStatusBarProvider';
 import { serverStatusBarProvider } from './serverStatusBarProvider';
 import { ACTIVE_BUILD_TOOL_STATE, cleanWorkspaceFileName, getJavaServerMode, handleTextBlockClosing, onConfigurationChange, ServerMode } from './settings';
 import { snippetCompletionProvider } from './snippetCompletionProvider';
+import { JavaClassEditorProvider } from './javaClassEditor';
 import { StandardLanguageClient } from './standardLanguageClient';
 import { SyntaxLanguageClient } from './syntaxLanguageClient';
 import { convertToGlob, deleteDirectory, ensureExists, getBuildFilePatterns, getExclusionBlob, getInclusionPatternsFromNegatedExclusion, getJavaConfig, getJavaConfiguration, hasBuildToolConflicts } from './utils';
@@ -191,7 +192,7 @@ export function activate(context: ExtensionContext): Promise<ExtensionAPI> {
 							range: client.code2ProtocolConverter.asRange(range),
 							context: await client.code2ProtocolConverter.asCodeActionContext(context)
 						};
-						const showAt  = getJavaConfiguration().get<string>("quickfix.showAt");
+						const showAt = getJavaConfiguration().get<string>("quickfix.showAt");
 						if (showAt === 'line' && range.start.line === range.end.line && range.start.character === range.end.character) {
 							const textLine = document.lineAt(params.range.start.line);
 							if (textLine !== null) {
@@ -362,6 +363,9 @@ export function activate(context: ExtensionContext): Promise<ExtensionAPI> {
 			context.subscriptions.push(serverStatusBarProvider);
 			context.subscriptions.push(runtimeStatusBarProvider);
 
+			const classEditorProviderRegistration = window.registerCustomEditorProvider(JavaClassEditorProvider.viewType, new JavaClassEditorProvider(context));
+			context.subscriptions.push(classEditorProviderRegistration);
+
 			registerClientProviders(context, { contentProviderEvent: jdtEventEmitter.event });
 
 			apiManager.getApiInstance().onDidServerModeChange((event: ServerMode) => {
@@ -448,7 +452,7 @@ async function workspaceContainsBuildFiles(): Promise<boolean> {
 	const inclusionPatterns: string[] = getBuildFilePatterns();
 	const inclusionPatternsFromNegatedExclusion: string[] = getInclusionPatternsFromNegatedExclusion();
 	if (inclusionPatterns.length > 0 && inclusionPatternsFromNegatedExclusion.length > 0 &&
-			(await workspace.findFiles(convertToGlob(inclusionPatterns, inclusionPatternsFromNegatedExclusion), null, 1 /* maxResults */)).length > 0) {
+		(await workspace.findFiles(convertToGlob(inclusionPatterns, inclusionPatternsFromNegatedExclusion), null, 1 /* maxResults */)).length > 0) {
 		return true;
 	}
 
@@ -485,7 +489,7 @@ async function ensureNoBuildToolConflicts(context: ExtensionContext, clientOptio
 			clientOptions.initializationOptions.settings.java.import.maven.enabled = false;
 			context.workspaceState.update(ACTIVE_BUILD_TOOL_STATE, "gradle");
 		} else {
-			throw new Error (`Unknown build tool: ${activeBuildTool}`); // unreachable
+			throw new Error(`Unknown build tool: ${activeBuildTool}`); // unreachable
 		}
 	}
 
@@ -699,7 +703,7 @@ function openLogFile(logFile, openingFailureWarning: string, column: ViewColumn
 			if (!doc) {
 				return false;
 			}
-			return window.showTextDocument(doc, {viewColumn: column, preview: false})
+			return window.showTextDocument(doc, { viewColumn: column, preview: false })
 				.then(editor => !!editor);
 		}, () => false)
 		.then(didOpen => {
@@ -937,7 +941,7 @@ async function cleanJavaWorkspaceStorage() {
 				}
 			}
 		});
-    }
+	}
 }
 
 function registerOutOfMemoryDetection(storagePath: string) {

src/javaClassEditor.ts

@@ -0,0 +1,67 @@
+import path = require('path');
+import * as vscode from 'vscode';
+import { Uri, window, ExtensionContext} from "vscode";
+import { getNonce } from "./webviewUtils";
+
+class JavaClassDocument implements vscode.CustomDocument {
+	constructor(uri: Uri) { this.uri = uri; }
+	uri: Uri;
+	dispose(): void { }
+}
+
+export class JavaClassEditorProvider implements vscode.CustomReadonlyEditorProvider {
+
+	private context: ExtensionContext;
+
+	openCustomDocument(uri: Uri, openContext: vscode.CustomDocumentOpenContext, token: vscode.CancellationToken): JavaClassDocument {
+		return new JavaClassDocument(uri);
+	}
+
+	constructor (context: ExtensionContext) {
+		this.context = context;
+	}
+
+	public static readonly viewType = 'decompiled.javaClass';
+
+	async resolveCustomEditor(document: vscode.CustomDocument, webviewPanel: vscode.WebviewPanel, token: vscode.CancellationToken): Promise<void> {
+		const nonce: string = getNonce();
+		webviewPanel.webview.options = {
+			enableScripts: true,
+			localResourceRoots: [Uri.joinPath(Uri.parse(this.context.extensionPath), 'webview-resources')]
+		};
+		const classUri = Uri.parse((document.uri.toString()).replace(/^file/, "class"));
+		const styleUri = Uri.file(
+			path.join(this.context.extensionPath, 'webview-resources', 'button.css')
+		);
+		const style: string = `<link rel="stylesheet" type="text/css" href="${webviewPanel.webview.asWebviewUri(styleUri).toString()}">`;
+		webviewPanel.webview.html = `
+		<html lang="en">
+		<head>
+			<meta http-equiv="Content-Security-Policy" content="default-src 'none'; script-src 'nonce-${nonce}'; style-src ${webviewPanel.webview.cspSource};">
+			${style}
+		</head>
+		<body>
+			<div class="center">
+				<p>This file is not displayed in the text editor because it is a Java class file. Click here to decompile and open.</p>
+				<button id="btn"><center>Decompile Class File</center></button>
+			<div>
+			<script nonce="${nonce}">
+				const vscode = acquireVsCodeApi();
+				document.getElementById("btn").addEventListener("click", decompiled);
+				function decompiled() {
+					vscode.postMessage({ command: 'decompiled' });
+				}
+			</script>
+		</body>
+		</html>
+		`;
+		webviewPanel.webview.onDidReceiveMessage(message => {
+			switch (message.command) {
+				case 'decompiled':
+					webviewPanel.dispose();
+					window.showTextDocument(classUri, { preview: false });
+					return;
+			}
+		}, undefined, this.context.subscriptions);
+	}
+}

src/providerDispatcher.ts

@@ -28,10 +28,13 @@ export function registerClientProviders(context: ExtensionContext, options: Prov
 	const jdtProvider = createJDTContentProvider(options);
 	context.subscriptions.push(workspace.registerTextDocumentContentProvider('jdt', jdtProvider));
 
+	const classProvider = createClassContentProvider(options);
+	context.subscriptions.push(workspace.registerTextDocumentContentProvider('class', classProvider));
+
 	overwriteWorkspaceSymbolProvider(context);
 
 	return {
-		handles: [hoverProvider, symbolProvider, jdtProvider]
+		handles: [hoverProvider, symbolProvider, jdtProvider, classProvider]
 	};
 }
 
@@ -81,6 +84,27 @@ function createJDTContentProvider(options: ProviderOptions): TextDocumentContent
 	};
 }
 
+function createClassContentProvider(options: ProviderOptions): TextDocumentContentProvider {
+	return <TextDocumentContentProvider>{
+		onDidChange: options.contentProviderEvent,
+		provideTextDocumentContent: async (uri: Uri, token: CancellationToken): Promise<string> => {
+			const languageClient: LanguageClient | undefined = await getActiveLanguageClient();
+
+			if (!languageClient) {
+				return '';
+			}
+			const originalUri = uri.toString().replace(/^class/, "file");
+			const decompiledContent: string = await commands.executeCommand(Commands.EXECUTE_WORKSPACE_COMMAND, Commands.GET_DECOMPILED_SOURCE, originalUri);
+			if (!decompiledContent) {
+				console.log(`Error while getting decompiled source : ${originalUri}`);
+				return "Error while getting decompiled source.";
+			} else {
+				return decompiledContent;
+			}
+		}
+	};
+}
+
 function createDocumentSymbolProvider(): DocumentSymbolProvider {
 	return <DocumentSymbolProvider>{
 		provideDocumentSymbols: async (document: TextDocument, token: CancellationToken): Promise<SymbolInformation[] | DocumentSymbol[]> => {
@@ -109,7 +133,7 @@ function createDocumentSymbolProvider(): DocumentSymbolProvider {
 
 const START_OF_DOCUMENT = new Range(new Position(0, 0), new Position(0, 0));
 
-function createWorkspaceSymbolProvider(existingWorkspaceSymbolProvider: WorkspaceSymbolProvider): WorkspaceSymbolProvider  {
+function createWorkspaceSymbolProvider(existingWorkspaceSymbolProvider: WorkspaceSymbolProvider): WorkspaceSymbolProvider {
 	return {
 		provideWorkspaceSymbols: async (query: string, token: CancellationToken) => {
 			// This is a workaround until vscode add support for qualified symbol search which is tracked by
@@ -159,9 +183,9 @@ function createWorkspaceSymbolProvider(existingWorkspaceSymbolProvider: Workspac
 }
 
 function overwriteWorkspaceSymbolProvider(context: ExtensionContext): void {
-	const disposable =  apiManager.getApiInstance().onDidServerModeChange( async (mode) => {
+	const disposable = apiManager.getApiInstance().onDidServerModeChange(async (mode) => {
 		if (mode === ServerMode.standard) {
-			const feature =  (await getActiveLanguageClient()).getFeature(WorkspaceSymbolRequest.method);
+			const feature = (await getActiveLanguageClient()).getFeature(WorkspaceSymbolRequest.method);
 			const providers = feature.getProviders();
 			if (providers && providers.length > 0) {
 				feature.dispose();
@@ -186,7 +210,7 @@ const REPLACE_JDT_LINKS_PATTERN: RegExp = /(\[(?:[^\]])+\]\()(jdt:\/\/(?:(?:(?:\
  * @returns the hover with all jdt:// links replaced with a command:// link that opens the jdt URI
  */
 function fixJdtSchemeHoverLinks(hover: Hover): Hover {
-	const newContents: (MarkedString|MarkdownString)[] = [];
+	const newContents: (MarkedString | MarkdownString)[] = [];
 	for (const content of hover.contents) {
 		if (content instanceof MarkdownString) {
 			const newContent: string = (<MarkdownString>content).value.replace(REPLACE_JDT_LINKS_PATTERN, (_substring, group1, group2) => {

webview-resources/button.css

@@ -0,0 +1,34 @@
+/* https://css-tricks.com/overriding-default-button-styles/ */
+
+button {
+    display: inline-block;
+    border: none;
+    padding: 12px 16px;
+    margin: 0;
+    text-decoration: none;
+    background: var(--vscode-button-background);
+    color: #ffffff;
+    font-family: sans-serif;
+    font-size: 14px;
+    cursor: pointer;
+    text-align: center;
+}
+
+button:hover,
+button:focus {
+    background: var(--vscode-button-hoverBackground);
+}
+button:focus {
+    outline: 1px solid var(--vscode-button-hoverBackground);
+    /* outline-offset: -4px; */
+}
+
+.center {
+	text-align: center;
+	margin: 0;
+	position: absolute;
+	top: 50%;
+	left: 50%;
+	-ms-transform: translate(-50%, -50%);
+	transform: translate(-50%, -50%);
+}