Add way to show how to input a given character (fix #17)

package.json

@@ -17,6 +17,7 @@
   "activationEvents": [
     "onCommand:unicode-latex.insertMathSymbol",
     "onCommand:unicode-latex.replaceLatexNames",
+    "onCommand:unicode-latex.showLatexCode",
     "onLanguage:plaintext"
   ],
   "main": "./out/src/extension",
@@ -29,6 +30,10 @@
       {
         "command": "unicode-latex.replaceLatexNames",
         "title": "Unicode: Replace LaTeX"
+      },
+      {
+        "command": "unicode-latex.showLatexCode",
+        "title": "Unicode: Show LaTex Code"
       }
     ]
   },

src/extension.ts

@@ -8,6 +8,7 @@ let latexItems: vscode.QuickPickItem[] = [];
 let pickOptions: vscode.QuickPickOptions = {
     matchOnDescription: true,
 };
+var latexSymbols2: { [name:string]: string} = {};
 
 export function activate(context: vscode.ExtensionContext) {
 
@@ -17,6 +18,7 @@ export function activate(context: vscode.ExtensionContext) {
             description: name,
             label: latexSymbols[name],
         });
+        latexSymbols2[latexSymbols[name]] = name;
     }
 
     let insertion = vscode.commands.registerCommand('unicode-latex.insertMathSymbol', () => {
@@ -25,13 +27,17 @@ export function activate(context: vscode.ExtensionContext) {
     let replacement = vscode.commands.registerCommand('unicode-latex.replaceLatexNames', () => {
         replaceWithUnicode(vscode.window.activeTextEditor);
     });
+    let showLatex = vscode.commands.registerCommand('unicode-latex.showLatexCode', () => {
+        appendLatexOfUnicode(vscode.window.activeTextEditor);
+    });
 
     const selector: vscode.DocumentSelector = ['plaintext', 'markdown', 'coq'];
     const provider = new LatexCompletionItemProvider(latexSymbols);
     let completionSub = vscode.languages.registerCompletionItemProvider(selector, provider, '\\');
 
     context.subscriptions.push(insertion);
     context.subscriptions.push(replacement);
+    context.subscriptions.push(showLatex);
     context.subscriptions.push(completionSub);
 }
 
@@ -78,5 +84,24 @@ function replaceWithUnicode(editor: vscode.TextEditor) {
     });
 }
 
+function appendLatexOfUnicode(editor: vscode.TextEditor) {
+    if (!editor) { return; }
+
+    // If nothing is selected, do nothing
+    let selection = (() => {
+        if (editor.selection.start.isBefore(editor.selection.end)) {
+            return editor.selection;
+        } else {
+            return;
+        }
+    })();
+
+    let text = editor.document.getText(selection);
+    if (latexSymbols2.hasOwnProperty(text)){
+        editor.edit((editBuilder) => {
+            editBuilder.insert(editor.selection.end, latexSymbols2[text]);
+        });
+    }
+}
 // this method is called when your extension is deactivated
 export function deactivate() {}