1

I get an error when trying to make a custom SurfaceView view in my apps.

<com.example.test.CustomSurfaceView
    android:id="@+id/cameraPreview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

Here is the class:

package com.example.test;
import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import java.util.List;
public class CustomSurfaceView extends SurfaceView implements SurfaceHolder.Callback {

private static final String TAG = "CameraPreview";

private Context mContext;
private SurfaceHolder mHolder;
private Camera mCamera;
private List<Camera.Size> mSupportedPreviewSizes;
private Camera.Size mPreviewSize;

public CustomSurfaceView(Context context, Context mContext) {
    super(context);
    this.mContext = mContext;
}

public CustomSurfaceView(Context context, Camera camera) {
    super(context);
    mContext = context;
    mCamera = camera;

    // supported preview sizes
    mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
    for(Camera.Size str: mSupportedPreviewSizes)
        Log.e(TAG, str.width + "/" + str.height);

    // Install a SurfaceHolder.Callback so we get notified when the
    // underlying surface is created and destroyed.
    mHolder = getHolder();
    mHolder.addCallback(this);
    // deprecated setting, but required on Android versions prior to 3.0
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

public void surfaceCreated(SurfaceHolder holder) {
    // empty. surfaceChanged will take care of stuff
}

public void surfaceDestroyed(SurfaceHolder holder) {
    // empty. Take care of releasing the Camera preview in your activity.
}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
    Log.e(TAG, "surfaceChanged => w=" + w + ", h=" + h);
    // If your preview can change or rotate, take care of those events here.
    // Make sure to stop the preview before resizing or reformatting it.
    if (mHolder.getSurface() == null){
        // preview surface does not exist
        return;
    }

    // stop preview before making changes
    try {
        mCamera.stopPreview();
    } catch (Exception e){
        // ignore: tried to stop a non-existent preview
    }

    // set preview size and make any resize, rotate or reformatting changes here
    // start preview with new settings
    try {
        Camera.Parameters parameters = mCamera.getParameters();
        parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
        mCamera.setParameters(parameters);
        mCamera.setDisplayOrientation(90);
        mCamera.setPreviewDisplay(mHolder);
        mCamera.startPreview();

    } catch (Exception e){
        Log.d(TAG, "Error starting camera preview: " + e.getMessage());
    }
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
    final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);

    if (mSupportedPreviewSizes != null) {
        mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
    }

    if (mPreviewSize!=null) {
        float ratio;
        if(mPreviewSize.height >= mPreviewSize.width)
            ratio = (float) mPreviewSize.height / (float) mPreviewSize.width;
        else
            ratio = (float) mPreviewSize.width / (float) mPreviewSize.height;

        // One of these methods should be used, second method squishes preview slightly
        setMeasuredDimension(width, (int) (width * ratio));
        //        setMeasuredDimension((int) (width * ratio), height);
    }
}

private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w, int h) {
    final double ASPECT_TOLERANCE = 0.1;
    double targetRatio = (double) h / w;

    if (sizes == null)
        return null;

    Camera.Size optimalSize = null;
    double minDiff = Double.MAX_VALUE;

    int targetHeight = h;

    for (Camera.Size size : sizes) {
        double ratio = (double) size.height / size.width;
        if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE)
            continue;

        if (Math.abs(size.height - targetHeight) < minDiff) {
            optimalSize = size;
            minDiff = Math.abs(size.height - targetHeight);
        }
    }

    if (optimalSize == null) {
        minDiff = Double.MAX_VALUE;
        for (Camera.Size size : sizes) {
            if (Math.abs(size.height - targetHeight) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - targetHeight);
            }
        }
    }

    return optimalSize;
}
}

The error that I get:

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.test/com.example.test.HomeActivity}: android.view.InflateException: Binary XML file line #7: Binary XML file line #7: Error inflating class com.example.test.CustomSurfaceView

I actually have another custom viewpager view inside the same xml, but it works fine. any idea why I get this error? I actually have another custom viewpager view inside the same xml, but it works fine. any idea why I get this error?

1 Answer 1

7

If you put a view in your layout by using an XML tag for it, you must implement this constructor:

public View(Context context, AttributeSet attrs)
Sign up to request clarification or add additional context in comments.

Comments

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.