Error inflating when extending a class


Question

I'm trying to create a custom view GhostSurfaceCameraView that extends SurfaceView. Here's my class definition file

GhostSurfaceCameraView.java:

public class GhostSurfaceCameraView extends SurfaceView implements SurfaceHolder.Callback {
    SurfaceHolder mHolder;
    Camera mCamera;

    GhostSurfaceCameraView(Context context) {
        super(context);

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, acquire the camera and tell it where to draw.
        mCamera = Camera.open();
        try {
            mCamera.setPreviewDisplay(holder);
        } catch (IOException exception) {
            mCamera.release();
            mCamera = null;
            // TODO: add more exception handling logic here
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // Surface will be destroyed when we return, so stop the preview.
        // Because the CameraDevice object is not a shared resource, it's very
        // important to release it when the activity is paused.
        mCamera.stopPreview();
        mCamera.release();
        mCamera = null;
    }   

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // Now that the size is known, set up the camera parameters and begin
        // the preview.
        Camera.Parameters parameters = mCamera.getParameters();
        parameters.setPreviewSize(w, h);
        parameters.set("orientation", "portrait");
        // parameters.setRotation(90); // API 5+
        mCamera.setParameters(parameters);
        mCamera.startPreview();
    }
}

And this is in my ghostviewscreen.xml:

<com.alpenglow.androcap.GhostSurfaceCameraView android:id="@+id/ghostview_cameraview"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"/>

Now in the activity I made:

protected void onCreate(Bundle savedInstanceState) {
    try {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.ghostviewscreen);
    }
}

When setContentView() gets called, an exception is thrown:

Binary XML file 09-17 22:47:01.958: ERROR/ERROR(337):
ERROR IN CODE:
android.view.InflateException: Binary
XML file line #14: Error inflating
class
com.alpenglow.androcap.GhostSurfaceCameraView

Can anyone tell me why I get this error? Thanks.

1
188
5/21/2016 12:34:53 PM

Accepted Answer

I think I figured out why this wasn't working. I was only providing a constructor for the case of one parameter 'context' when I should have provided a constructor for the two parameter 'Context, AttributeSet' case. I also needed to give the constructor(s) public access. Here's my fix:

public class GhostSurfaceCameraView extends SurfaceView implements SurfaceHolder.Callback {
        SurfaceHolder mHolder;
        Camera mCamera;

        public GhostSurfaceCameraView(Context context)
        {
            super(context);
            init();
        }
        public GhostSurfaceCameraView(Context context, AttributeSet attrs)
        {
            super(context, attrs);
            init();
        }
        public GhostSurfaceCameraView(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
            init();
        }
366
9/18/2010 12:14:13 AM

@Tim - Both the constructors are not required, only the ViewClassName(Context context, AttributeSet attrs ) constructor is necessary. I found this out the painful way, after hours and hours of wasted time.

I am very new to Android development, but I am making a wild guess here, that it maybe due to the fact that since we are adding the custom View class in the XML file, we are setting several attributes to it in the XML, which needs to be processed at the time of instantiation. Someone far more knowledgeable than me will be able to shed clearer light on this matter though.


Licensed under: CC-BY-SA with attribution
Not affiliated with: Stack Overflow
Icon