setCapture deprecated

[PexMor]

JS setCapture()

The setCapture is deprecated in Firefox at least.

Firefox in console gives hint:

Element.setCapture() is deprecated. Use Element.setPointerCapture() instead.
For more help https://developer.mozilla.org/docs/Web/API/Element/setPointerCapture events.js:66:15
Document.releaseCapture() is deprecated. Use Element.releasePointerCapture() instead.
For more help https://developer.mozilla.org/docs/Web/API/Element/releasePointerCapture

To Reproduce

Open noVNC client in Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:94.0) Gecko/20100101 Firefox/94.0 browser.

Expected behavior

The replacement functions are called and Firefox does not complain.

Client (please complete the following information):

• OS: MacOS BigSur
• Browser: Firefox
• Browser version: 94

Server (please complete the following information):

• noVNC version: 1.3.0
• VNC server: QEMU
• WebSocket proxy: websockify

[samhed]

👍
Microsoft Edge on Windows 10 also complains in a similar way.

[marc-legendre]

I'm pretty sure this is also the source of behavior differences between browsers, since the function exists mainly in Firefox, and is emulated for other browsers.

For example, in Chrome, clicking inside the canvas results in mouseleave events being fired on the RFB container when a mouse button is released. This issue does not happen with Firefox. (I have not tested other browsers.)

This difference can be demonstrated in the app with a simple change like

diff --git i/app/ui.js w/app/ui.js
index 39d28a3..fee531c 100644
--- i/app/ui.js
+++ w/app/ui.js
@@ -114,6 +114,8 @@ const UI = {
         UI.initFullscreen();
 
         // Setup event handlers
+        document.getElementById("noVNC_container")
+            .addEventListener('mouseleave', console.log);
         UI.addControlbarHandlers();
         UI.addTouchSpecificHandlers();
         UI.addExtraKeysHandlers();