From 9ac0e75f9abc77000f4e5f6de7d318206c0b58b0 Mon Sep 17 00:00:00 2001
From: Juanjo Diaz <juanjo.diazmo@gmail.com>
Date: Mon, 28 Nov 2022 19:17:24 +0100
Subject: [PATCH] fix: sync local clipboard to remote on canvas focus

---
 core/clipboard.js       | 26 ++++++--------------------
 tests/test.clipboard.js | 14 ++++++--------
 2 files changed, 12 insertions(+), 28 deletions(-)

diff --git a/core/clipboard.js b/core/clipboard.js
index d2e0de3c0..79822e1dc 100644
--- a/core/clipboard.js
+++ b/core/clipboard.js
@@ -10,8 +10,7 @@ export default class Clipboard {
 
         this._eventHandlers = {
             'copy': this._handleCopy.bind(this),
-            'paste': this._handlePaste.bind(this),
-            'pasteOnWindows': this._handlePasteOnWindow.bind(this)
+            'focus': this._handleFocus.bind(this)
         };
 
         // ===== EVENT HANDLERS =====
@@ -40,7 +39,7 @@ export default class Clipboard {
         }
     }
 
-    async _handlePaste(e) {
+    async _handleFocus() {
         try {
             if (navigator.permissions && navigator.permissions.query) {
                 const permission = await navigator.permissions.query({ name: "clipboard-read", allowWithoutGesture: false });
@@ -50,26 +49,15 @@ export default class Clipboard {
             // Some browsers might error due to lack of support, e.g. Firefox.
         }
 
-        let data;
         if (navigator.clipboard.readText) {
             try {
-                data = await navigator.clipboard.readText();
+                const data = await navigator.clipboard.readText();
+                this.onpaste(data);
             } catch (e) {
                 /* Do nothing */
                 return;
             }
-        } else if (e.clipboardData) {
-            data = e.clipboardData.getData('text/plain');
         }
-        this.onpaste(data);
-    }
-
-    // For some reason, the paste event doesn't trigger on the canvas element.
-    // As a workaround, we capture it on the window and check if the active
-    // element is the canvas.
-    async _handlePasteOnWindow(e) {
-        if (document.activeElement !== this._target) return;
-        this._eventHandlers.paste(e);
     }
 
     // ===== PUBLIC METHODS =====
@@ -77,15 +65,13 @@ export default class Clipboard {
     grab() {
         if (!Clipboard.isSupported) return;
         this._target.addEventListener('copy', this._eventHandlers.copy);
-        // this._target.addEventListener('paste', this._eventHandlers.paste);
-        window.addEventListener('paste', this._eventHandlers.pasteOnWindows);
+        this._target.addEventListener('focus', this._eventHandlers.focus);
     }
 
     ungrab() {
         if (!Clipboard.isSupported) return;
         this._target.removeEventListener('copy', this._eventHandlers.copy);
-        // this._target.removeEventListener('paste', this._eventHandlers.paste);
-        window.removeEventListener('paste', this._eventHandlers.pasteOnWindows);
+        this._target.removeEventListener('focus', this._eventHandlers.focus);
     }
 }
 
diff --git a/tests/test.clipboard.js b/tests/test.clipboard.js
index 7b400e605..5861b290e 100644
--- a/tests/test.clipboard.js
+++ b/tests/test.clipboard.js
@@ -46,16 +46,14 @@ describe('Automatic Clipboard Sync', function () {
     it('should copy local pasted data to the server clipboard', async function () {
         const text = 'Another random string for testing';
         const clipboard = new Clipboard();
-        clipboard.onpaste = pasterText => expect(pasterText).to.equal(text);
+
+        clipboard.onpaste = pastedText => expect(pastedText).to.equal(text);
         if (Clipboard.isSupported) {
-            const clipboardData = new DataTransfer();
-            clipboardData.setData("text/plain", text);
-            const clipboardEvent = new ClipboardEvent('paste', { clipboardData });
-            // Force initialization since the constructor is broken in Firefox
-            if (!clipboardEvent.clipboardData.items.length) {
-                clipboardEvent.clipboardData.items.add(text, "text/plain");
+            if (navigator.clipboard.readText) {
+                navigator.clipboard.readText.restore();
+                sinon.stub(navigator.clipboard, "readText").returns(text);
             }
-            await clipboard._handlePaste(clipboardEvent);
+            await clipboard._handleFocus();
             if (navigator.clipboard.readText) {
                 expect(navigator.clipboard.readText).to.have.been.called;
             }