Handle middle click to paste selection

This appears to work in Chrome but not Firefox

src/SelectionManager.ts

@@ -2,10 +2,11 @@
  * @license MIT
  */
 
+import * as Mouse from './utils/Mouse';
+import * as Browser from './utils/Browser';
 import { CharMeasure } from './utils/CharMeasure';
 import { CircularList } from './utils/CircularList';
 import { EventEmitter } from './EventEmitter';
-import * as Mouse from './utils/Mouse';
 import { ITerminal } from './Interfaces';
 import { SelectionModel } from './SelectionModel';
 
@@ -299,16 +300,13 @@ export class SelectionManager extends EventEmitter {
       this._refreshAnimationFrame = window.requestAnimationFrame(() => this._refresh());
     }
 
-    // If the refresh comes from a mouse event then emit a newselection event
-    if (!fromMouseEvent) {
-      return;
-    }
-    // TODO: Only do this when the selection has actually changed
-    // TODO: Ensure we're not doing more work than absolutely necessary, particularly for large selections
-    // TODO: Only do this on Linux
-    const selectionText = this.selectionText;
-    if (selectionText.length) {
-      this.emit('newselection', this.selectionText);
+    // If the platform is Linux and the refresh call comes from a mouse event,
+    // we need to update the selection for middle click to paste selection.
+    if (Browser.isLinux && fromMouseEvent) {
+      const selectionText = this.selectionText;
+      if (selectionText.length) {
+        this.emit('newselection', this.selectionText);
+      }
     }
   }
 
@@ -560,7 +558,7 @@ export class SelectionManager extends EventEmitter {
     if (!previousSelectionEnd ||
         previousSelectionEnd[0] !== this._model.selectionEnd[0] ||
         previousSelectionEnd[1] !== this._model.selectionEnd[1]) {
-      this.refresh();
+      this.refresh(true);
     }
   }
 

src/handlers/Clipboard.ts

@@ -80,7 +80,7 @@ export function pasteHandler(ev: ClipboardEvent, term: ITerminal) {
  * @param term The terminal on which to apply the handled paste event
  * @param selectionManager The terminal's selection manager.
  */
-export function rightClickHandler(ev: MouseEvent, textarea: HTMLTextAreaElement, selectionManager: ISelectionManager) {
+export function moveTextAreaUnderMouseCursor(ev: MouseEvent, textarea: HTMLTextAreaElement, selectionManager: ISelectionManager) {
   // Bring textarea at the cursor position
   textarea.style.position = 'fixed';
   textarea.style.width = '20px';

src/utils/Browser.ts

@@ -20,3 +20,4 @@ export const isMac = contains(['Macintosh', 'MacIntel', 'MacPPC', 'Mac68K'], pla
 export const isIpad = platform === 'iPad';
 export const isIphone = platform === 'iPhone';
 export const isMSWindows = contains(['Windows', 'Win16', 'Win32', 'WinCE'], platform);
+export const isLinux = platform.indexOf('Linux') >= 0;

src/xterm.js

@@ -13,7 +13,7 @@
 import { CompositionHelper } from './CompositionHelper';
 import { EventEmitter } from './EventEmitter';
 import { Viewport } from './Viewport';
-import { rightClickHandler, pasteHandler, copyHandler } from './handlers/Clipboard';
+import { moveTextAreaUnderMouseCursor, pasteHandler, copyHandler } from './handlers/Clipboard';
 import { CircularList } from './utils/CircularList';
 import { C0 } from './EscapeSequences';
 import { InputHandler } from './InputHandler';
@@ -537,15 +537,29 @@ Terminal.prototype.initGlobal = function() {
   on(this.textarea, 'paste', pasteHandlerWrapper);
   on(this.element, 'paste', pasteHandlerWrapper);
 
+  // Handle right click context menus
   if (term.browser.isFirefox) {
     on(this.element, 'mousedown', event => {
       if (ev.button == 2) {
-        rightClickHandler(event, this.textarea, this.selectionManager);
+        moveTextAreaUnderMouseCursor(event, this.textarea, this.selectionManager);
       }
     });
   } else {
     on(this.element, 'contextmenu', event => {
-      rightClickHandler(event, this.textarea, this.selectionManager);
+      moveTextAreaUnderMouseCursor(event, this.textarea, this.selectionManager);
+    });
+  }
+
+  // Move the textarea under the cursor when middle clicking on Linux to ensure
+  // middle click to paste selection works. This only appears to work in Chrome
+  // at the time is writing.
+  if (term.browser.isLinux) {
+    // Use auxclick event over mousedown the latter doesn't seem to work. Note
+    // that the regular click event doesn't fire for the middle mouse button.
+    on(this.element, 'click', event => {
+      if (event.button === 1) {
+        moveTextAreaUnderMouseCursor(event, this.textarea, this.selectionManager);
+      }
     });
   }
 };