feat: readyToStartPreview property. Can be used to defer startPreview until permission is granted

Author: farfromrefug

src/ui-cameraview/index.android.ts

@@ -166,7 +166,7 @@ export class CameraView extends CameraViewBase {
     startPreview() {
         const nativeView = this.nativeViewProtected;
 
-        if (nativeView) {
+        if (this.readyToStartPreview && nativeView) {
             if (this.processor) {
                 this.nativeViewProtected.setAnalyserCallback(this.processor);
             }

src/ui-cameraview/index.common.ts

@@ -28,13 +28,20 @@ export enum ScaleType {
 }
 
 export abstract class CameraViewBase extends GridLayout {
+    readyToStartPreview: boolean;
     static FRAME_EVENT = 'frame';
     flashMode = 'off';
     abstract toggleCamera();
     abstract startPreview();
     abstract stopPreview();
     abstract focusAtPoint(x, y);
     abstract takePicture(options: TakePictureOptions): Promise<any>;
+
+    // [readyToStartPreviewProperty.setNative](value: boolean) {
+    //     if (value) {
+    //         this.startPreview();
+    //     }
+    // }
 }
 export const flashModeProperty = new Property<CameraViewBase, string | number>({
     name: 'flashMode',
@@ -55,6 +62,11 @@ export const saveToGalleryProperty = new Property<CameraViewBase, boolean>({
     defaultValue: false,
     valueConverter: booleanConverter
 });
+export const readyToStartPreviewProperty = new Property<CameraViewBase, boolean>({
+    name: 'readyToStartPreview',
+    defaultValue: true,
+    valueConverter: booleanConverter
+});
 export const pictureSizeProperty = new Property<CameraViewBase, string | { x: number; y: number }>({
     name: 'pictureSize'
 });

src/ui-cameraview/index.d.ts

@@ -18,6 +18,7 @@ export function deviceHasCamera(): boolean;
 
 export class CameraView extends GridLayout {
     autoFocus: boolean;
+    readyToStartPreview: boolean;
     processor;
     enablePinchZoom: boolean;
     saveToGallery: boolean;

src/ui-cameraview/index.ios.ts

@@ -212,11 +212,12 @@ export class CameraView extends CameraViewBase {
     }
     previewStarted = false;
     startPreview() {
-        if (this.previewStarted) {
+        const nativeView = this.nativeViewProtected;
+        if (!nativeView || this.previewStarted || !this.readyToStartPreview) {
             return;
         }
         this.previewStarted = true;
-        this.nativeViewProtected?.startPreviewAndReturnError();
+        nativeView.startPreviewAndReturnError();
     }
     stopPreview() {
         if (!this.previewStarted) {