When I change the page orientation come at the beginning of page

Question

I am using barteksc-AndroidPdfViewer. I am using this code

package com.github.barteksc.sample;

import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.net.Uri;
import android.provider.OpenableColumns;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.Toast;

import com.github.barteksc.pdfviewer.PDFView;
import com.github.barteksc.pdfviewer.listener.OnLoadCompleteListener;
import com.github.barteksc.pdfviewer.listener.OnPageChangeListener;
import com.github.barteksc.pdfviewer.scroll.DefaultScrollHandle;
import com.shockwave.pdfium.PdfDocument;

import org.androidannotations.annotations.AfterViews;
import org.androidannotations.annotations.EActivity;
import org.androidannotations.annotations.NonConfigurationInstance;
import org.androidannotations.annotations.OnActivityResult;
import org.androidannotations.annotations.OptionsItem;
import org.androidannotations.annotations.OptionsMenu;
import org.androidannotations.annotations.ViewById;

import java.util.List;

@EActivity(R.layout.activity_main)
@OptionsMenu(R.menu.options)
public class PDFViewActivity extends AppCompatActivity implements OnPageChangeListener, OnLoadCompleteListener {

    private static final String TAG = PDFViewActivity.class.getSimpleName();

    private final static int REQUEST_CODE = 42;
    public static final int PERMISSION_CODE = 42042;

    public static final String SAMPLE_FILE = "sample.pdf";
    public static final String READ_EXTERNAL_STORAGE = "android.permission.READ_EXTERNAL_STORAGE";

    @ViewById
    PDFView pdfView;

    @NonConfigurationInstance
    Uri uri;

    @NonConfigurationInstance
    Integer pageNumber = 0;

    String pdfFileName;

    @OptionsItem(R.id.pickFile)
    void pickFile() {
        int permissionCheck = ContextCompat.checkSelfPermission(this,
                READ_EXTERNAL_STORAGE);

        if (permissionCheck != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(
                    this,
                    new String[]{READ_EXTERNAL_STORAGE},
                    PERMISSION_CODE
            );

            return;
        }

        launchPicker();
    }

    void launchPicker() {
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setType("application/pdf");
        try {
            startActivityForResult(intent, REQUEST_CODE);
        } catch (ActivityNotFoundException e) {
            //alert user that file manager not working
            Toast.makeText(this, R.string.toast_pick_file_error, Toast.LENGTH_SHORT).show();
        }
    }

    @AfterViews
    void afterViews() {
        if (uri != null) {
            displayFromUri(uri);
        } else {
            displayFromAsset(SAMPLE_FILE);
        }
        setTitle(pdfFileName);
    }

    private void displayFromAsset(String assetFileName) {
        pdfFileName = assetFileName;

        pdfView.fromAsset(SAMPLE_FILE)
                .defaultPage(pageNumber)
                .onPageChange(this)
                .enableAnnotationRendering(true)
                .onLoad(this)
                .scrollHandle(new DefaultScrollHandle(this))
                .load();
    }

    private void displayFromUri(Uri uri) {
        pdfFileName = getFileName(uri);

        pdfView.fromUri(uri)
                .defaultPage(pageNumber)
                .onPageChange(this)
                .enableAnnotationRendering(true)
                .onLoad(this)
                .scrollHandle(new DefaultScrollHandle(this))
                .load();
    }

    @OnActivityResult(REQUEST_CODE)
    public void onResult(int resultCode, Intent intent) {
        if (resultCode == RESULT_OK) {
            uri = intent.getData();
            displayFromUri(uri);
        }
    }

    @Override
    public void onPageChanged(int page, int pageCount) {
        pageNumber = page;
        setTitle(String.format("%s %s / %s", pdfFileName, page + 1, pageCount));
    }

    public String getFileName(Uri uri) {
        String result = null;
        if (uri.getScheme().equals("content")) {
            Cursor cursor = getContentResolver().query(uri, null, null, null, null);
            try {
                if (cursor != null && cursor.moveToFirst()) {
                    result = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
                }
            } finally {
                if (cursor != null) {
                    cursor.close();
                }
            }
        }
        if (result == null) {
            result = uri.getLastPathSegment();
        }
        return result;
    }

    @Override
    public void loadComplete(int nbPages) {
        PdfDocument.Meta meta = pdfView.getDocumentMeta();
        Log.e(TAG, "title = " + meta.getTitle());
        Log.e(TAG, "author = " + meta.getAuthor());
        Log.e(TAG, "subject = " + meta.getSubject());
        Log.e(TAG, "keywords = " + meta.getKeywords());
        Log.e(TAG, "creator = " + meta.getCreator());
        Log.e(TAG, "producer = " + meta.getProducer());
        Log.e(TAG, "creationDate = " + meta.getCreationDate());
        Log.e(TAG, "modDate = " + meta.getModDate());

        printBookmarksTree(pdfView.getTableOfContents(), "-");

    }

    public void printBookmarksTree(List<PdfDocument.Bookmark> tree, String sep) {
        for (PdfDocument.Bookmark b : tree) {

            Log.e(TAG, String.format("%s %s, p %d", sep, b.getTitle(), b.getPageIdx()));

            if (b.hasChildren()) {
                printBookmarksTree(b.getChildren(), sep + "-");
            }
        }
    }

    /**
     * Listener for response to user permission request
     *
     * @param requestCode  Check that permission request code matches
     * @param permissions  Permissions that requested
     * @param grantResults Whether permissions granted
     */
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[],
                                           @NonNull int[] grantResults) {
        if (requestCode == PERMISSION_CODE) {
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                launchPicker();
            }
        }
    }

}

to change the orientation of the page. But if I have to assume if the portrait mode and page number 15 in change page orientation of the page when we started the landscape.

Please help me about this.

Check this answer. Maybe it could help you: https://stackoverflow.com/questions/5726657/how-to-detect-orientation-change-in-layout-in-android — Joe Hackerberg, May 29 '17 at 15:10
@Akis Still not, It can't implement I'm trying many times but fail to implement — Ahmer Afzal, Jun 13 '17 at 04:39

Sarantis Tofas · Answer 1 · 2017-05-29T17:14:20.017

When you change orientation Android will by default reload the activity and this is why you are losing the current page.

There are 2 solutions one is the best practice and the other might work depending on the case.

Solution 1:

Save the last known page on onSaveInstanceState and then get the page back on onCreate

protected void onSaveInstanceState(Bundle outState) {
  super.onSaveInstanceState(outState);
  outState.putInt("current_page", pageNumber);
}

public void onCreate(Bundle savedInstanceState) {
  if (savedInstanceState != null){
    pageNumber = savedInstanceState.getInt("current_page");
  }
}

Solution 2:

Set the android:configChanges="orientation|screenSize" atribbute in your Manifest file. This will retain the state of the screen exactly like it was before the orientation change.

Also please have a read on the activity lifecycle: https://developer.android.com/guide/components/activities/activity-lifecycle.html

`android:configChanges="orientation|screenSize"` works fine but it could not `pdfView.fitToWidth();` If possible please put this method on above code it'll easy implement for me. — Ahmer Afzal, May 30 '17 at 01:32
@AhmerAfzal you should go for solution 1 or add a onOrientationChange event and call pdfView.fitToWidth() when the orientation changes. — Sarantis Tofas, May 30 '17 at 09:09

score 0 · Accepted Answer · answered Jun 23 '17 at 12:50

@EActivity(R.layout.activity_pdf_app_bar_main)
@OptionsMenu(R.menu.options)
public class PDFActivity extends AppCompatActivity implements OnPageChangeListener, OnLoadCompleteListener
{
    private static final String TAG = PDFActivity.class.getSimpleName();
    private final static int REQUEST_CODE = 42;
    public static final int PERMISSION_CODE = 42042;
    public static final String SAMPLE_FILE = "myPDF.pdf";
    public static final String READ_EXTERNAL_STORAGE = "android.permission.READ_EXTERNAL_STORAGE";
    private int mCurrentPage = 0;
    private final static String KEY_CURRENT_PAGE = "current_page";
    private ProgressDialog progressDialog;
    @ViewById
    PDFView pdfView;
    @NonConfigurationInstance
    Uri uri;
    @NonConfigurationInstance
    String pdfFileName;
    @OptionsItem(R.id.pickFile)
    void pickFile()
    {
        int permissionCheck = ContextCompat.checkSelfPermission(this, READ_EXTERNAL_STORAGE);
        if (permissionCheck != PackageManager.PERMISSION_GRANTED)
        {
            ActivityCompat.requestPermissions(this, new String[]{READ_EXTERNAL_STORAGE}, PERMISSION_CODE);
            return;
        }
        launchPicker();
    }
    void launchPicker()
    {
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setType("application/pdf");
        try
        {
            startActivityForResult(intent, REQUEST_CODE);
        }
        catch (ActivityNotFoundException e)
        {
            Toast.makeText(this, R.string.toast_pick_file_error, Toast.LENGTH_SHORT).show();
        }
    }
    @AfterViews
    void afterViews()
    {
        pdfView.setBackgroundColor(Color.WHITE);
        if (uri != null)
        {
            displayFromUri(uri);
        }
        else
        {
            displayFromAsset(SAMPLE_FILE);
        }
        setTitle(pdfFileName);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        if (getSupportActionBar() != null)
        {
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            getSupportActionBar().setDisplayShowHomeEnabled(true);
        }
    }

    private void displayFromAsset(String assetFileName)
    {
        pdfFileName = assetFileName;
        pdfView.fromAsset(SAMPLE_FILE)
                .defaultPage(mCurrentPage)
                .enableSwipe(true)
                .swipeHorizontal(false)
                .enableDoubletap(true)
                .password(null)
                .enableAntialiasing(true)
                .onPageChange(this)
                .enableAnnotationRendering(true)
                .onPageScroll(new OnPageScrollListener() {
                    @Override
                    public void onPageScrolled(int page, float positionOffset) {
                        Log.d(TAG, "onPageScrolled: page " + page + " positionOffset " + positionOffset);
                    }
                })
                .onRender(new OnRenderListener()
                {
                    @Override
                    public void onInitiallyRendered(int nbPages, float pageWidth, float pageHeight)
                    {
                        pdfView.fitToWidth(mCurrentPage);
                    }
                })
                .onLoad(new OnLoadCompleteListener() {
                    @Override
                    public void loadComplete(int nbPages) {
                        Log.d(TAG, "loadComplete: totalPages " + nbPages);
                    }
                })
                .onError(new OnErrorListener() {
                    @Override
                    public void onError(Throwable t) {
                        Log.d(TAG, " onError");
                    }
                })
                .scrollHandle(new DefaultScrollHandle(this))
                .spacing(2)
                .load();
    }
    private void displayFromUri(Uri uri)
    {
        pdfFileName = getFileName(uri);
        pdfView.fromUri(uri)
                .defaultPage(mCurrentPage)
                .onPageChange(this)
                .enableAnnotationRendering(true)
                .onLoad(this)
                .scrollHandle(new DefaultScrollHandle(this))
                .load();
    }
    @OnActivityResult(REQUEST_CODE)
    public void onResult(int resultCode, Intent intent)
    {
        if (resultCode == RESULT_OK)
        {
            uri = intent.getData();
            displayFromUri(uri);
        }
    }
    @Override
    public void onPageChanged(int page, int pageCount)
    {
        mCurrentPage = page;
        setTitle(String.format("%s %s / %s", "Page Number", page + 1, pageCount));
    }
    public String getFileName(Uri uri)
    {
        String result = null;
        if (uri.getScheme().equals("content"))
        {
            Cursor cursor = getContentResolver().query(uri, null, null, null, null);
            try
            {
                if (cursor != null && cursor.moveToFirst())
                {
                    result = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
                }
            }
            finally
            {
                if (cursor != null)
                {
                    cursor.close();
                }
            }
        }
        if (result == null)
        {
            result = uri.getLastPathSegment();
        }
        return result;
    }
    @Override
    public void loadComplete(int nbPages)
    {
        if (mCurrentPage >= 0)
        {
            pdfView.jumpTo(mCurrentPage);
        }
        PdfDocument.Meta meta = pdfView.getDocumentMeta();
        Log.e(TAG, "title = " + meta.getTitle());
        Log.e(TAG, "author = " + meta.getAuthor());
        Log.e(TAG, "subject = " + meta.getSubject());
        Log.e(TAG, "keywords = " + meta.getKeywords());
        Log.e(TAG, "creator = " + meta.getCreator());
        Log.e(TAG, "producer = " + meta.getProducer());
        Log.e(TAG, "creationDate = " + meta.getCreationDate());
        Log.e(TAG, "modDate = " + meta.getModDate());
        Log.d(TAG, "totalPages " + nbPages);
        printBookmarksTree(pdfView.getTableOfContents(), "-");
    }
    public void printBookmarksTree(List<PdfDocument.Bookmark> tree, String sep)
    {
        for (PdfDocument.Bookmark b : tree)
        {
            Log.e(TAG, String.format("%s %s, p %d", sep, b.getTitle(), b.getPageIdx()));
            if (b.hasChildren())
            {
                printBookmarksTree(b.getChildren(), sep + "-");
            }
        }
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults)
    {
        if (requestCode == PERMISSION_CODE)
        {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
            {
                launchPicker();
            }
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item)
    {
        if (item.getItemId() == android.R.id.home)
        {
            finish();
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        if (savedInstanceState != null)
        {
            mCurrentPage = savedInstanceState.getInt(KEY_CURRENT_PAGE);
        }
        else
        {
            mCurrentPage = -1;
        }
    }

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState)
    {
        super.onRestoreInstanceState(savedInstanceState);
        mCurrentPage = savedInstanceState.getInt(KEY_CURRENT_PAGE);
    }

    @Override
    public void onSaveInstanceState(Bundle outState)
    {
        super.onSaveInstanceState(outState);
        outState.putInt(KEY_CURRENT_PAGE, mCurrentPage);
    }
}

When I change the page orientation come at the beginning of page

2 Answers2

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