LivePickerActivity.java

package com.fastebro.androidrgbtool.livepicker;

import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.graphics.PorterDuff;
import android.hardware.Camera;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageButton;

import com.fastebro.androidrgbtool.R;
import com.fastebro.androidrgbtool.rgb.MainActivity;
import com.fastebro.androidrgbtool.utils.CameraUtils;
import com.fastebro.androidrgbtool.widgets.CircleView;

import butterknife.BindView;
import butterknife.ButterKnife;
import timber.log.Timber;

public class LivePickerActivity extends AppCompatActivity implements LivePickerTextureView.OnColorPointedListener,
		View.OnClickListener {
	private static final String TAG = LivePickerActivity.class.getName();

	@BindView(R.id.live_picker_preview_container)
	FrameLayout livePreviewContainer;
	@BindView(R.id.live_picker_pointer_stroke)
	View pointerRing;
    @BindView(R.id.live_picker_btn_back)
    ImageButton btnBack;
    @BindView(R.id.live_picker_last_color)
    CircleView lastColor;
    @BindView(R.id.live_picker_btn_save_color)
    ImageButton btnSaveColor;
    @BindView(R.id.live_picker_btn_flash)
    ImageButton btnFlashToggle;

	private Camera camera;
	private CameraAsyncTask cameraAsyncTask;

	private LivePickerTextureView livePickerTextureView;
	private boolean isPortrait;
	private int pointedColor;

	private boolean isFlashOn;

	private static Camera getFacingBackCameraInstance() {
		Camera camera = null;
		try {
			camera = Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK);
		} catch (Exception e) {
			Timber.d("Error getting camera instance: %s", e.getMessage());
		}
		return camera;
	}

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_live_picker);

		ButterKnife.bind(this);

        initViews();
	}

	@Override
	protected void onResume() {
		super.onResume();

        isPortrait = getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT;

		cameraAsyncTask = new CameraAsyncTask();
		cameraAsyncTask.execute();
	}

	@Override
	protected void onPause() {
		super.onPause();

		if (cameraAsyncTask != null) {
			cameraAsyncTask.cancel(true);
		}

		releaseCameraPreview();
		releaseCamera();
	}

	@Override
	protected void onStop() {
		super.onStop();

		toggleFlash();
	}

	private void initViews() {
        btnBack.setOnClickListener(view -> {
			Intent intent = new Intent(this, MainActivity.class);
			startActivity(intent);
            finish();
        });

        btnSaveColor.setOnClickListener(view -> {
            // TODO
        });

        if (isFlashSupported()) {
            btnFlashToggle.setVisibility(View.VISIBLE);
            btnFlashToggle.setOnClickListener(view -> {
				toggleFlash();
            });
        }
    }

	private void releaseCameraPreview() {
		if (livePickerTextureView != null) {
			livePreviewContainer.removeView(livePickerTextureView);
		}
	}

	private void releaseCamera() {
		if (camera != null) {
			camera.stopPreview();
			camera.setPreviewCallback(null);
			camera.release();
			camera = null;
		}
	}

	@Override
	public void onColorPointed(int newColor) {
		pointedColor = newColor;
		pointerRing.getBackground().setColorFilter(pointedColor, PorterDuff.Mode.SRC_ATOP);
	}

	@Override
	public void onClick(View v) {
		// TODO
	}

	private class CameraAsyncTask extends AsyncTask<Void, Void, Camera> {

		FrameLayout.LayoutParams previewParams;

		@Override
		protected Camera doInBackground(Void... params) {
			return getFacingBackCameraInstance();
		}

		@Override
		protected void onPostExecute(Camera camera) {
			if (!isCancelled()) {
				LivePickerActivity.this.camera = camera;
				if (LivePickerActivity.this.camera == null) {
					LivePickerActivity.this.finish();
				} else {
					Camera.Parameters cameraParameters = camera.getParameters();
					Camera.Size bestSize = CameraUtils.getBestPreviewSize(
							cameraParameters.getSupportedPreviewSizes()
							, livePreviewContainer.getWidth()
							, livePreviewContainer.getHeight()
							, isPortrait);
					// Set optimal camera preview
					cameraParameters.setPreviewSize(bestSize.width, bestSize.height);
					// Set focus mode
					if (cameraParameters.getSupportedFocusModes().contains(
							Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO)) {
						cameraParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
					}

					camera.setParameters(cameraParameters);

					// Set camera orientation to match with current device orientation
					CameraUtils.setCameraDisplayOrientation(LivePickerActivity.this, camera);

					// Get proportional dimension for the layout used to display preview according to the preview size
					// used
					int[] adaptedDimension = CameraUtils.getProportionalDimension(
							bestSize
							, livePreviewContainer.getWidth()
							, livePreviewContainer.getHeight()
							, isPortrait);

					// Set up params for the layout used to display the preview
					previewParams = new FrameLayout.LayoutParams(adaptedDimension[0], adaptedDimension[1]);
					previewParams.gravity = Gravity.CENTER;

					// Set up camera preview
					livePickerTextureView = new LivePickerTextureView(LivePickerActivity.this, LivePickerActivity
							.this.camera);
					livePickerTextureView.setOnColorPointedListener(LivePickerActivity.this);
					livePickerTextureView.setOnClickListener(LivePickerActivity.this);

					livePreviewContainer.addView(livePickerTextureView, 0, previewParams);
				}
			}
		}

		@Override
		protected void onCancelled(Camera camera) {
			if (camera != null) {
				camera.release();
			}
		}
	}

	private boolean isFlashSupported() {
		return getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
	}

	private void toggleFlash() {
		if (camera != null) {
			final Camera.Parameters parameters = camera.getParameters();
			final String flashParameter = isFlashOn ? Camera.Parameters.FLASH_MODE_OFF : Camera.Parameters
					.FLASH_MODE_TORCH;
			parameters.setFlashMode(flashParameter);
			camera.stopPreview();
			camera.setParameters(parameters);
			camera.startPreview();
			isFlashOn = !isFlashOn;

			if (btnFlashToggle != null) {
				if (isFlashOn) {
					btnFlashToggle.setImageDrawable(getDrawable(R.drawable.ic_flash_off_white));
				} else {
					btnFlashToggle.setImageDrawable(getDrawable(R.drawable.ic_flash_on_white));
				}
			}
		}
	}
}