From 843a8dcd698b82cae29b193c8b3bbd7dbff4c80b Mon Sep 17 00:00:00 2001
From: Enrico Ros <enrico.ros@gmail.com>
Date: Sat, 3 Feb 2024 00:33:52 -0800
Subject: [PATCH] HTML5Video ops: use async/await

---
 .../composer/CameraCaptureModal.tsx           | 38 +++++++++++--------
 src/common/util/videoUtils.ts                 | 28 +++++++++-----
 2 files changed, 41 insertions(+), 25 deletions(-)

diff --git a/src/apps/chat/components/composer/CameraCaptureModal.tsx b/src/apps/chat/components/composer/CameraCaptureModal.tsx
index cb147f668..6c78a6ed4 100644
--- a/src/apps/chat/components/composer/CameraCaptureModal.tsx
+++ b/src/apps/chat/components/composer/CameraCaptureModal.tsx
@@ -7,7 +7,7 @@ import InfoIcon from '@mui/icons-material/Info';
 import KeyboardArrowDownIcon from '@mui/icons-material/KeyboardArrowDown';
 
 import { InlineError } from '~/common/components/InlineError';
-import { downloadVideoFrameAsPNG, renderVideoFrameToFile } from '~/common/util/videoUtils';
+import { downloadVideoFrameAsPNG, renderVideoFrameAsPNGFile } from '~/common/util/videoUtils';
 import { useCameraCapture } from '~/common/components/useCameraCapture';
 
 
@@ -16,11 +16,12 @@ export function CameraCaptureModal(props: {
   onAttachImage: (file: File) => void
   // onOCR: (ocrText: string) => void }
 }) {
-  // state
-  // const [ocrProgress/*, setOCRProgress*/] = React.useState<number | null>(null);
-  const [showInfo, setShowInfo] = React.useState(false);
 
-  // camera operations
+  // state
+  const [showInfo, setShowInfo] = React.useState(false);
+  // const [ocrProgress/*, setOCRProgress*/] = React.useState<number | null>(null);
+
+  // external state
   const {
     videoRef,
     cameras, cameraIdx, setCameraIdx,
@@ -29,10 +30,14 @@ export function CameraCaptureModal(props: {
   } = useCameraCapture();
 
 
-  const stopAndClose = () => {
+  // derived state
+  const { onCloseModal, onAttachImage } = props;
+
+
+  const stopAndClose = React.useCallback(() => {
     resetVideo();
-    props.onCloseModal();
-  };
+    onCloseModal();
+  }, [onCloseModal, resetVideo]);
 
   /*const handleVideoOCRClicked = async () => {
     if (!videoRef.current) return;
@@ -53,18 +58,21 @@ export function CameraCaptureModal(props: {
     props.onOCR(result.data.text);
   };*/
 
-  const handleVideoSnapClicked = () => {
+  const handleVideoSnapClicked = React.useCallback(async () => {
     if (!videoRef.current) return;
-    renderVideoFrameToFile(videoRef.current, 'camera', (file) => {
-      props.onAttachImage(file);
+    try {
+      const file = await renderVideoFrameAsPNGFile(videoRef.current, 'camera');
+      onAttachImage(file);
       stopAndClose();
-    });
-  };
+    } catch (error) {
+      console.error('Error capturing video frame:', error);
+    }
+  }, [onAttachImage, stopAndClose, videoRef]);
 
-  const handleVideoDownloadClicked = () => {
+  const handleVideoDownloadClicked = React.useCallback(() => {
     if (!videoRef.current) return;
     downloadVideoFrameAsPNG(videoRef.current, 'camera');
-  };
+  }, [videoRef]);
 
 
   return (
diff --git a/src/common/util/videoUtils.ts b/src/common/util/videoUtils.ts
index 48b0a3fc7..36e3f3571 100644
--- a/src/common/util/videoUtils.ts
+++ b/src/common/util/videoUtils.ts
@@ -5,7 +5,7 @@
  */
 
 export function downloadVideoFrameAsPNG(videoElement: HTMLVideoElement, prefixName: string) {
-  // video to canvas to png
+  // current video frame -> canvas -> dataURL PNG
   const renderedFrame = _renderVideoFrameToCanvas(videoElement);
   const imageDataURL = renderedFrame.toDataURL('image/png');
 
@@ -13,20 +13,20 @@ export function downloadVideoFrameAsPNG(videoElement: HTMLVideoElement, prefixNa
   const link = document.createElement('a');
   link.download = _prettyFileName(prefixName, renderedFrame);
   link.href = imageDataURL;
+  document.body.appendChild(link); // Ensure visibility in the DOM for Firefox
   link.click();
+  document.body.removeChild(link); // Clean up
 }
 
-export function renderVideoFrameToFile(videoElement: HTMLVideoElement, prefixName: string, callback: (file: File) => void) {
-  // video to canvas
+export async function renderVideoFrameAsPNGFile(videoElement: HTMLVideoElement, prefixName: string): Promise<File> {
+  // current video frame -> canvas -> Blob PNG
   const renderedFrame = _renderVideoFrameToCanvas(videoElement);
+  const blob = await _canvasToBlob(renderedFrame, 'image/png');
 
-  // canvas to blob to file to callback
-  renderedFrame.toBlob((blob) => {
-    if (blob) {
-      const file = new File([blob], _prettyFileName(prefixName, renderedFrame), { type: blob.type });
-      callback(file);
-    }
-  }, 'image/png');
+  // to File
+  if (!blob)
+    throw new Error('Failed to convert canvas to Blob');
+  return new File([blob], _prettyFileName(prefixName, renderedFrame), { type: blob.type });
 }
 
 function _prettyFileName(prefixName: string, renderedFrame: HTMLCanvasElement) {
@@ -45,3 +45,11 @@ function _renderVideoFrameToCanvas(videoElement: HTMLVideoElement): HTMLCanvasEl
   return canvas;
 }
 
+/**
+ * Creates a Blob object representing the image contained in the canvas
+ * @param canvas The canvas element to convert to a Blob.
+ * @param imageFormat Browsers are required to support image/png; many will support additional formats including image/jpeg and image/webp.
+ */
+async function _canvasToBlob(canvas: HTMLCanvasElement, imageFormat: string = 'image/png'): Promise<Blob | null> {
+  return new Promise((resolve) => canvas.toBlob(resolve, imageFormat));
+}
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