Android Open Source - Flashlight Main Activity

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License

The source code is released under:

MIT License

Java Source Code

package com.omihaz.flashlight;
/*from   w  ww.  j  av a 2 s. c o m*/
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.graphics.Color;
import android.hardware.Camera;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.TextView;

import java.io.IOException;

public class MainActivity extends Activity implements SurfaceHolder.Callback {
    private static final String TAG = "Flashlight";

    private BroadcastReceiver mReceiver;
    private TextView mStatusView;
    private GestureDetector mGestureDetector;
    private Camera mCamera;

    private boolean mEnabled;

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

        mGestureDetector = new GestureDetector(this, new DoubleClickGestureListener());
        mGestureDetector.setIsLongpressEnabled(false);

        mReceiver = new KeyGuardReceiver(this);
        registerReceiver(mReceiver, new IntentFilter(Intent.ACTION_USER_PRESENT));

        createSurface();
        createStatusView();
    }

    @SuppressWarnings("deprecation")
    private void createSurface() {
        SurfaceView surfaceView = (SurfaceView) findViewById(R.id.surface);

        SurfaceHolder holder = surfaceView.getHolder();
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1) {
            holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        }
        holder.addCallback(this);
    }

    private void createStatusView() {
        mStatusView = (TextView) findViewById(R.id.status);

        mStatusView.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                if (mGestureDetector != null) {
                    mGestureDetector.onTouchEvent(event);
                }

                return true;
            }
        });

        mStatusView.post(new Runnable() {
            @Override
            public void run() {
                mCamera = Camera.open();
            }
        });

        updateViewState();
    }

    @Override
    protected void onDestroy() {
        if (mReceiver != null) {
            unregisterReceiver(mReceiver);
            mReceiver = null;
        }

        if (mCamera != null) {
            mCamera.release();
            mCamera = null;
        }

        super.onDestroy();
    }

    @Override
    protected void onStop() {
        super.onStop();
        updateLightState(false);
    }

    private void resumeLight() {
        if (mCamera != null) {
            updateLightState(false);
            updateLightState();
        }
    }

    private void updateLightState() {
        updateLightState(mEnabled);
    }

    private void updateLightState(boolean enabled) {
        if (mCamera == null) {
            Log.w(TAG, "Cannot change light state, because camera not found!");
            return;
        }

        Camera.Parameters params = mCamera.getParameters();
        params.setFlashMode(
                enabled ? Camera.Parameters.FLASH_MODE_TORCH : Camera.Parameters.FLASH_MODE_OFF
        );
        mCamera.setParameters(params);

        updateViewState();
    }

    private void updateViewState() {
        mStatusView.setBackgroundColor(getBackgroundStatusColor());
        mStatusView.setTextColor(getTextStatusColor());
        mStatusView.setText(mEnabled ? R.string.turn_off : R.string.turn_on);
        mStatusView.setKeepScreenOn(mEnabled);
    }

    private int getBackgroundStatusColor() {
        return mEnabled ? Color.WHITE : Color.BLACK;
    }

    private int getTextStatusColor() {
        return mEnabled ? Color.BLACK : Color.WHITE;
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        if (mCamera != null) {
            try {
                mCamera.setPreviewDisplay(holder);
                mCamera.startPreview();
                resumeLight();
            } catch (IOException e) {
                Log.e(TAG, "Cannot set preview mode to camera", e);
            }
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        if (mCamera != null) {
            mCamera.stopPreview();
        }
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    }

    private final class DoubleClickGestureListener extends GestureDetector.SimpleOnGestureListener {
        @Override
        public boolean onSingleTapConfirmed(MotionEvent e) {
            return updateState(true);
        }

        @Override
        public boolean onDoubleTap(MotionEvent e) {
            return updateState(!mEnabled);
        }

        private boolean updateState(boolean enable) {
            if (mEnabled != enable) {
                mEnabled = enable;
                updateLightState();
                return true;
            }

            return false;
        }
    }

    private static class KeyGuardReceiver extends BroadcastReceiver {
        private final MainActivity mActivity;
        private KeyGuardReceiver(MainActivity activity) {
            mActivity = activity;
        }

        @Override
        public void onReceive(Context context, Intent intent) {
            if (mActivity == null || context == null || intent == null) {
                return;
            }

            if (Intent.ACTION_USER_PRESENT.equals(intent.getAction())) {
                mActivity.resumeLight();
            }
        }
    }

}

Java Source Code List

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