RetroArch/pkg/android/phoenix/src/com/retroarch/browser/retroactivity/RetroActivityCamera.java

package com.retroarch.browser.retroactivity;

import java.io.IOException;

import com.retroarch.browser.preferences.util.UserPreferences;

import android.annotation.SuppressLint;
import android.content.SharedPreferences;
import android.graphics.SurfaceTexture;
import android.graphics.SurfaceTexture.OnFrameAvailableListener;
import android.hardware.Camera;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;

//For Android 3.0 and up

/**
 * Class which provides {@link Camera} functionality
 * to {@link RetroActivityFuture}.
 */
@SuppressLint("NewApi")
public class RetroActivityCamera extends RetroActivityCommon
{
  private Camera mCamera = null;
  private long lastTimestamp = 0;
  private SurfaceTexture texture;
  private boolean updateSurface = true;
  private boolean camera_service_running = false;

  /**
   * Executed when the {@link Camera}
   * is staring to capture.
   */
  public void onCameraStart()
  {
    if (camera_service_running)
      return;

    if (mCamera != null)
      mCamera.startPreview();
    camera_service_running = true;
  }

  /**
   * Executed when the {@link Camera} is done capturing.
   * <p>
   * Note that this does not release the currently held 
   * {@link Camera} instance and must be freed by calling
   * {@link #onCameraFree}
   */
  public void onCameraStop()
  {
    if (!camera_service_running)
      return;

    if (mCamera != null)
      mCamera.stopPreview();
    camera_service_running = false;
  }

  /**
   * Releases the currently held {@link Camera} instance.
   */
  public void onCameraFree()
  {
    onCameraStop();
    
    if (mCamera != null)
      mCamera.release();
  }

  /**
   * Initializes the camera for use.
   */
  public void onCameraInit()
  {
    if (mCamera != null)
      return;
    
    mCamera = Camera.open();
  }

  /**
   * Polls the camera for updates to the {@link SurfaceTexture}.
   * 
   * @return true if polling was successful, false otherwise.
   */
  public boolean onCameraPoll()
  {
    if (!camera_service_running)
      return false;
    
    if (texture == null)
    {
      Log.i("RetroActivity", "No texture");
      return true;
    }
    else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH)
    {
      if (updateSurface)
      {
        texture.updateTexImage();
      }
      
      long newTimestamp = texture.getTimestamp();
      
      if (newTimestamp != lastTimestamp)
      {
        lastTimestamp = newTimestamp;
        return true;
      }
      
      return false;
    }

    return true;
  }

  /**
   * Initializes the {@link SurfaceTexture} used by the
   * {@link Camera} with a given OpenGL texure ID.
   * 
   * @param gl_texid texture ID to initialize the 
   *        {@link SurfaceTexture} with.
   */
  public void onCameraTextureInit(int gl_texid)
  {
    texture = new SurfaceTexture(gl_texid);
    texture.setOnFrameAvailableListener(onCameraFrameAvailableListener);
  }

  /**
   * Sets the {@link Camera} texture with the texture represented
   * by the given OpenGL texture ID.
   * 
   * @param gl_texid     The texture ID representing the texture to set the camera to.
   * @throws IOException If setting the texture fails.
   */
  public void onCameraSetTexture(int gl_texid) throws IOException
  {
    if (texture == null)
      onCameraTextureInit(gl_texid);

    if (mCamera != null)
      mCamera.setPreviewTexture(texture);
  }

  private final OnFrameAvailableListener onCameraFrameAvailableListener = new OnFrameAvailableListener()
  {
    @Override
    public void onFrameAvailable(SurfaceTexture surfaceTexture)
    {
      updateSurface = true;
    }
  };

  @Override
  public void onCreate(Bundle savedInstanceState)
  {
    // Save the current setting for updates
    SharedPreferences prefs = UserPreferences.getPreferences(this);
    SharedPreferences.Editor edit = prefs.edit();
    edit.putBoolean("CAMERA_UPDATES_ON", false);
    edit.apply();

    camera_service_running = false;

    super.onCreate(savedInstanceState);
  }

  @Override
  public void onPause()
  {
    // Save the current setting for updates
    SharedPreferences prefs = UserPreferences.getPreferences(this);
    SharedPreferences.Editor edit = prefs.edit();
    edit.putBoolean("CAMERA_UPDATES_ON", camera_service_running);
    edit.apply();
    
    onCameraStop();
    super.onPause();
  }

  @Override
  public void onResume()
  {
    SharedPreferences prefs = UserPreferences.getPreferences(this);
    SharedPreferences.Editor edit = prefs.edit();

    /*
     * Get any previous setting for camera updates
     * Gets "false" if an error occurs
     */
    if (prefs.contains("CAMERA_UPDATES_ON"))
    {
      camera_service_running = prefs.getBoolean("CAMERA_UPDATES_ON", false);
      if (camera_service_running)
      {
        onCameraStart();
      }
    }
    else // Otherwise, turn off camera updates
    {
      edit.putBoolean("CAMERA_UPDATES_ON", false);
      edit.apply();
      camera_service_running = false;
    }

    super.onResume();
  }

  @Override
  public void onDestroy()
  {
    onCameraFree();
    super.onDestroy();
  }

  @Override
  public void onStop()
  {
    onCameraStop();
    super.onStop();
  }
}