Android Open Source - simpleCamera Camera Preview

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License

The source code is released under:

MIT License

Java Source Code

package com.example.simplecamera;
/*  ww w . j  a  v  a 2  s .co  m*/
import java.io.IOException;

import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

/** A basic Camera preview class */
public class CameraPreview extends SurfaceView implements
    SurfaceHolder.Callback {
  private SurfaceHolder mHolder;
  private Camera mCamera;
  protected String TAG = "camera preview";
  protected int parentWidth, parentHeight;

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

    camera.setDisplayOrientation(90);
    camera.getParameters().setPreviewSize(parentWidth, parentHeight);
    
    // 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);
  }
  
  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
      super.onMeasure(widthMeasureSpec, heightMeasureSpec);

      parentWidth = MeasureSpec.getSize(widthMeasureSpec);
      parentHeight = MeasureSpec.getSize(heightMeasureSpec);
  }

  public void surfaceCreated(SurfaceHolder holder) {
    // The Surface has been created, now tell the camera where to draw the
    // preview.
    if (mCamera == null){
      /* Sometimes the surface will be created BEFORE onResume is called.
        This causes a crash, so we just return if mCamera is null, and surfaceCreated
        will be called again during onResume */
      Log.e(TAG, "camera is null");
      return;
    }
    
    
    try {
      mCamera.setPreviewDisplay(holder);
      mCamera.startPreview();
    } catch (IOException e) {
      Log.d(TAG, "Error setting camera preview: " + e.getMessage());
    }
    Log.i(TAG, "surface created");
  }

  public void surfaceDestroyed(SurfaceHolder holder) {
    // Surface will be destroyed when we return, so stop the preview.
    if (mCamera != null) {
      // Call stopPreview() to stop updating the preview surface.
      // mCamera.stopPreview();
      stopPreviewAndFreeCamera();
    }
    Log.i(TAG, "surface destroyed");
  }

  /**
   * When this function returns, mCamera will be null.
   */
  private void stopPreviewAndFreeCamera() {

    if (mCamera != null) {
      // Call stopPreview() to stop updating the preview surface.
      mCamera.stopPreview();
      Log.i(TAG, "preview stopped");

      // Important: Call release() to release the camera for use by other
      // applications. Applications should release the camera immediately
      // during onPause() and re-open() it during onResume()).
      mCamera.release();
      Log.i(TAG, "camera released");

      mCamera = null;
    }
  }
  
  public void surfaceChanged(SurfaceHolder holder, int format, int w, int 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 {
      mCamera.setPreviewDisplay(mHolder);
      mCamera.startPreview();

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

Java Source Code List

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