at.ac.tuwien.caa.docscan.ui.StartActivity.java Source code

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Here is the source code for at.ac.tuwien.caa.docscan.ui.StartActivity.java

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/*********************************************************************************
 *  DocScan is a Android app for document scanning.
 *
 *  Author:         Fabian Hollaus, Florian Kleber, Markus Diem
 *  Organization:   TU Wien, Computer Vision Lab
 *  Date created:   21. July 2016
 *
 *  This file is part of DocScan.
 *
 *  DocScan is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  DocScan is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with DocScan.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************************/

package at.ac.tuwien.caa.docscan.ui;

import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.design.widget.Snackbar;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.view.View;

import at.ac.tuwien.caa.docscan.R;

/**
 * Activity called after the app is started. This activity is responsible for requesting the camera
 * permission. If the permission is given the CameraActivity is started via an intent.
 * Based on this example: <a href="https://github.com/googlesamples/android-RuntimePermissionsBasic">android-RuntimePermissionsBasic
 </a>
 */
public class StartActivity extends AppCompatActivity implements ActivityCompat.OnRequestPermissionsResultCallback {

    private static final int PERMISSION_CAMERA = 0;
    private View mLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_container_view);
        mLayout = findViewById(R.id.main_frame_layout);
        showCameraPreview();

    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        if (requestCode == PERMISSION_CAMERA) {
            // Request for camera permission.
            if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // Permission has been granted. Start camera preview Activity.
                Snackbar.make(mLayout, "Camera permission was granted. Starting preview.", Snackbar.LENGTH_SHORT)
                        .show();
                startCamera();
            } else {
                // Permission request was denied.
                Snackbar.make(mLayout, "Camera permission request was denied.", Snackbar.LENGTH_SHORT).show();
            }
        }
        // END_INCLUDE(onRequestPermissionsResult)
    }

    private void showCameraPreview() {
        // BEGIN_INCLUDE(startCamera)
        // Check if the Camera permission has been granted
        if (ActivityCompat.checkSelfPermission(this,
                Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) {
            // Permission is already available, start camera preview
            Snackbar.make(mLayout, "Camera permission is available. Starting preview.", Snackbar.LENGTH_SHORT)
                    .show();

            startCamera();

        } else {
            // Permission is missing and must be requested.
            requestCameraPermission();
        }
        // END_INCLUDE(startCamera)
    }

    private void requestCameraPermission() {

        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[] { Manifest.permission.CAMERA }, PERMISSION_CAMERA);
        } else
            startCamera();

    }

    private void startCamera() {

        Intent intent = new Intent(this, CameraActivity.class);
        intent.setFlags(
                Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        startActivity(intent);

        finish();

    }

}