PDFCreateActivity.java

package hu.autsoft.androidapidemos;

import android.Manifest;
import android.content.pm.PackageManager;
import android.graphics.Point;
import android.graphics.Rect;
import android.graphics.pdf.PdfDocument;
import android.os.Environment;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;

public class PDFCreateActivity extends AppCompatActivity {

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

        ButterKnife.bind(this);

        requestNeededPermission();
    }

    public void requestNeededPermission() {
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)
                != PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                    Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                Toast.makeText(PDFCreateActivity.this,
                        "I need it for pdf creating", Toast.LENGTH_SHORT).show();
            }

            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                    101);
        } else {
            Toast.makeText(PDFCreateActivity.this,
                    "WRITE_EXTERNAL_STORAGE perm granted", Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           String permissions[], int[] grantResults) {
        switch (requestCode) {
            case 101: {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    Toast.makeText(PDFCreateActivity.this,
                            "WRITE_EXTERNAL_STORAGE perm granted", Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(PDFCreateActivity.this,
                            "WRITE_EXTERNAL_STORAGE perm NOT granted", Toast.LENGTH_SHORT).show();
                }
                return;
            }
        }
    }

    @OnClick(R.id.btnCreatePdf)
    public void createPdfClicked(View v) {
        new Thread() {
            public void run() {
                // Get the directory for the app's private pictures directory.
                final File file = new File(
                        Environment.getExternalStorageDirectory(), "demo.pdf");

                if (file.exists ()) {
                    file.delete ();
                }

                FileOutputStream out = null;
                try {
                    out = new FileOutputStream(file);

                    PdfDocument document = new PdfDocument();
                    Point windowSize = new Point();
                    getWindowManager().getDefaultDisplay().getSize(windowSize);
                    PdfDocument.PageInfo pageInfo =
                            new PdfDocument.PageInfo.Builder(
                            windowSize.x, windowSize.y, 1).create();
                    PdfDocument.Page page = document.startPage(pageInfo);
                    View content = getWindow().getDecorView();
                    content.draw(page.getCanvas());
                    document.finishPage(page);
                    document.writeTo(out);
                    document.close();
                    out.flush();

                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            Toast.makeText(PDFCreateActivity.this, "File created: "+file.getAbsolutePath(), Toast.LENGTH_LONG).show();
                        }
                    });
                } catch (Exception e) {
                    Log.d("TAG_PDF", "File was not created: "+e.getMessage());
                } finally {
                    try {
                        out.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }.start();
    }
}