Move support check from display to browser

kasmweb/core/display.js

@@ -8,14 +8,7 @@
 
 import * as Log from './util/logging.js';
 import Base64 from "./base64.js";
-
+import { supportsImageMetadata } from './util/browser.js';
-let SUPPORTS_IMAGEDATA_CONSTRUCTOR = false;
-try {
-    new ImageData(new Uint8ClampedArray(4), 1, 1);
-    SUPPORTS_IMAGEDATA_CONSTRUCTOR = true;
-} catch (ex) {
-    // ignore failure
-}
 
 export default class Display {
     constructor(target) {
@@ -581,7 +574,7 @@ export default class Display {
     _rgbxImageData(x, y, width, height, arr, offset) {
         // NB(directxman12): arr must be an Type Array view
         let img;
-        if (SUPPORTS_IMAGEDATA_CONSTRUCTOR) {
+        if (supportsImageMetadata) {
             img = new ImageData(new Uint8ClampedArray(arr.buffer, arr.byteOffset, width * height * 4), width, height);
         } else {
             img = this._drawCtx.createImageData(width, height);

kasmweb/core/util/browser.js

@@ -49,6 +49,15 @@ export function supportsCursorURIs() {
     return _cursor_uris_supported;
 }
 
+let _supportsImageMetadata = false;
+try {
+    new ImageData(new Uint8ClampedArray(4), 1, 1);
+    _supportsImageMetadata = true;
+} catch (ex) {
+    // ignore failure
+}
+export const supportsImageMetadata = _supportsImageMetadata;
+
 export function isMac() {
     return navigator && !!(/mac/i).exec(navigator.platform);
 }