Copy to clipboard not working on all platforms

[nx10]

Copy to clipboard is confirmed not working in:

• Safari 14.0.2 (macOS Big Sur 11.1)
• VSCode webview (1.52.1)

Safari throws "NotAllowedError: The request is not allowed by the user agent or the platform in the current context, possibly because the user denied permission."

Maybe calling the clipboard API wrapped in the image load callback is not allowed?

It not working in the VSCode webview might be caused by IFrame security settings. (Needs further investigation)

The associated code is

httpgd/inst/www/httpgd.ts

Lines 486 to 502 in abe90b9

	public copyPlotPNG() {
	if (!navigator.clipboard) return;
	const canvas = document.createElement('canvas');
	document.body.appendChild(canvas);
	canvas.width = this.plotParams.width / this.scale;
	canvas.height = this.plotParams.height / this.scale;
	const ctx = canvas.getContext('2d');
	if (!ctx) return;
	const img = new Image();
	img.crossOrigin = 'anonymous';
	img.onload = () => {
	ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
	canvas.toBlob(blob => { if (blob) navigator.clipboard.write?.([new ClipboardItem({ 'image/png': blob })]) });
	};
	img.src = this.svgURL();
	document.body.removeChild(canvas);
	}

Thank you @psobolewskiPhD for the bug report.

[psobolewskiPhD]

Here's the error in JS Console on Big Sur Safari 14.0.2

Unhandled Promise Rejection: NotAllowedError: The request is not allowed by the user agent or the platform in the current context, possibly because the user denied permission.
It flags:

N (anonymous function)
N rejectPromise
N write
f (anonymous function)

Specially line 416 of httpgd.js:
(_b = (_a = navigator.clipboard).write) === null || _b === void 0 ? void 0 : _b.call(_a, [new ClipboardItem({ 'image/png': blob })]); });
Specifically this:
_b.call(_a, [new ClipboardItem({ 'image/png': blob })])

[psobolewskiPhD]

In VSCode I tried to use the Webview Dev tools, but it just shows an iframe with httpgd http link in another iframe

The VSCode WebView issue could be related to:
microsoft/vscode#65452 (comment)
but the other keybindings (save, clear) work...

[jeffreyxparker]

Not working VSCode, Sublime, or Chrome