Getting Current Device Orientation for CameraX UI Rotation

[Ali safwat - علي صفوت‎]

When using CameraX, rotating my device recreates the activity, risking memory leaks. I want to disable this behavior and lock the screen's orientation. How can I then listen for the physical device rotation so I can animate UI elements like buttons to match the new orientation?

[Leo Huang]

Hi, 

You can listener to OrientationEventListener.

Sample code

```

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.OrientationEventListener
import android.view.Surface

class YourActivity : AppCompatActivity() {

    private lateinit var orientationEventListener: OrientationEventListener
    private var lastKnownRotation = 0 // To keep track of the last known rotation

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_your)

        orientationEventListener = object : OrientationEventListener(this) {
            override fun onOrientationChanged(orientation: Int) {
                if (orientation == ORIENTATION_UNKNOWN) {
                    return // Device is flat, do nothing
                }

                // Determine the rotation based on the orientation degrees
                val rotation = when (orientation) {
                    in 45..134 -> Surface.ROTATION_270 // Reverse Landscape
                    in 135..224 -> Surface.ROTATION_180 // Reverse Portrait
                    in 225..314 -> Surface.ROTATION_90  // Landscape
                    else -> Surface.ROTATION_0 // Portrait
                }

                // Animate only if the rotation has changed
                if (rotation != lastKnownRotation) {
                    lastKnownRotation = rotation
                    animateUiElements(rotation)
                }
            }
        }
    }

    override fun onResume() {
        super.onResume()
        if (orientationEventListener.canDetectOrientation()) {
            orientationEventListener.enable()
        }
    }

    override fun onPause() {
        super.onPause()
        orientationEventListener.disable()
    }
}

alisa...@gmail.com 在 2025年7月21日 星期一下午5:13:18 [UTC+8] 的信中寫道：

[Scott Nien]

FYI, If you run into memory leak issues where the activity instance is held within CameraX codes and you are using CameraX 1.5.0,  we will soon have a beta03 release that fixes the issue. 

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[Ali safwat - علي صفوت‎]

Thanks for all reply I am really appreciate it thank you 

I need to ask one more question 

What is optimal or the best practice here 

Rotate all activity or just listen on orientation event Listener and get rotation angle to rotate my ui with graphic layer 

[Charcoal Chen]

Hi,

Please also refer to ImageCapture/ImageAnalysis target rotation guidelines. You can check the scenarios matching your app's requirements to handle the rotation related settings.

To view this discussion visit https://groups.google.com/a/android.com/d/msgid/camerax-developers/f6f2a594-b8ee-4c65-af13-69ed5da59b34n%40android.com.

[Ali safwat - علي صفوت‎]

when i pick image in landcapse mode and save it in my gallery it appears
as portait 

when i use my device camera the image in landscape appear as accully landscape  

this form my device camera and saved in gallery 

this form camera x and also saved in gallery