Could I use the close button(X) to stop scanner and close camera rather than smaller it ?

[suki-neithnet]

I'm developing on cordova, the camera always shows full sreen, but the qrbox border and shaded region not show, and I can't resize the camera view too.
Then if I click the close button(X) on the top left, it will smaller the camera view and the qrbox border and shaded region shows up, why?
But the camera video paused and the scanner is still running in background, I don't want.

Please look the screenshots below:

Codes here, just follow the basic use:

Html5Qrcode.getCameras().then(devices => {
  if (devices && devices.length) {
    var cameraId = devices[1].id;
    const html5QrCode = new Html5Qrcode(/* element id */ "reader");
    html5QrCode.start(
      cameraId, 
      {
        fps: 10,    // Optional, frame per seconds for qr code scanning
        qrbox: { width: 250, height: 250 }  // Optional, if you want bounded box UI
      },
      (decodedText, decodedResult) => {
        // do something when code is read
      },
      (errorMessage) => {
        // parse error, ignore it.
      })
    .catch((err) => {
      // Start failed, handle it.
    });
  }
}).catch(err => {

});

What I want to do are:

1. custom the camera view.
2. show the qr box border no matter camera view is in full screen or custom size
3. when click the close button, could I execute stop scanner and close it rather than smaller the camera view?

Could someone help me with these? it problems me for several days, thank you!