When I Change The Page Orientation Come At The Beginning Of Page

I am using barteksc-AndroidPdfViewer. I am using this code package com.github.barteksc.sample; import android.content.ActivityNotFoundException; import android.content.Intent; im

Solution 1:

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

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

publicvoidonCreate(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

Solution 2:

@EActivity(R.layout.activity_pdf_app_bar_main)@OptionsMenu(R.menu.options)publicclassPDFActivityextendsAppCompatActivityimplementsOnPageChangeListener, OnLoadCompleteListener
{
    privatestaticfinalStringTAG= PDFActivity.class.getSimpleName();
    privatefinalstaticintREQUEST_CODE=42;
    publicstaticfinalintPERMISSION_CODE=42042;
    publicstaticfinalStringSAMPLE_FILE="myPDF.pdf";
    publicstaticfinalStringREAD_EXTERNAL_STORAGE="android.permission.READ_EXTERNAL_STORAGE";
    privateintmCurrentPage=0;
    privatefinalstaticStringKEY_CURRENT_PAGE="current_page";
    private ProgressDialog progressDialog;
    @ViewById
    PDFView pdfView;
    @NonConfigurationInstance
    Uri uri;
    @NonConfigurationInstance
    String pdfFileName;
    @OptionsItem(R.id.pickFile)voidpickFile()
    {
        intpermissionCheck= ContextCompat.checkSelfPermission(this, READ_EXTERNAL_STORAGE);
        if (permissionCheck != PackageManager.PERMISSION_GRANTED)
        {
            ActivityCompat.requestPermissions(this, newString[]{READ_EXTERNAL_STORAGE}, PERMISSION_CODE);
            return;
        }
        launchPicker();
    }
    voidlaunchPicker()
    {
        Intentintent=newIntent(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();
        }
    }
    @AfterViewsvoidafterViews()
    {
        pdfView.setBackgroundColor(Color.WHITE);
        if (uri != null)
        {
            displayFromUri(uri);
        }
        else
        {
            displayFromAsset(SAMPLE_FILE);
        }
        setTitle(pdfFileName);
        Toolbartoolbar= (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        if (getSupportActionBar() != null)
        {
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            getSupportActionBar().setDisplayShowHomeEnabled(true);
        }
    }

    privatevoiddisplayFromAsset(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(newOnPageScrollListener() {
                    @OverridepublicvoidonPageScrolled(int page, float positionOffset) {
                        Log.d(TAG, "onPageScrolled: page " + page + " positionOffset " + positionOffset);
                    }
                })
                .onRender(newOnRenderListener()
                {
                    @OverridepublicvoidonInitiallyRendered(int nbPages, float pageWidth, float pageHeight)
                    {
                        pdfView.fitToWidth(mCurrentPage);
                    }
                })
                .onLoad(newOnLoadCompleteListener() {
                    @OverridepublicvoidloadComplete(int nbPages) {
                        Log.d(TAG, "loadComplete: totalPages " + nbPages);
                    }
                })
                .onError(newOnErrorListener() {
                    @OverridepublicvoidonError(Throwable t) {
                        Log.d(TAG, " onError");
                    }
                })
                .scrollHandle(newDefaultScrollHandle(this))
                .spacing(2)
                .load();
    }
    privatevoiddisplayFromUri(Uri uri)
    {
        pdfFileName = getFileName(uri);
        pdfView.fromUri(uri)
                .defaultPage(mCurrentPage)
                .onPageChange(this)
                .enableAnnotationRendering(true)
                .onLoad(this)
                .scrollHandle(newDefaultScrollHandle(this))
                .load();
    }
    @OnActivityResult(REQUEST_CODE)publicvoidonResult(int resultCode, Intent intent)
    {
        if (resultCode == RESULT_OK)
        {
            uri = intent.getData();
            displayFromUri(uri);
        }
    }
    @OverridepublicvoidonPageChanged(int page, int pageCount)
    {
        mCurrentPage = page;
        setTitle(String.format("%s %s / %s", "Page Number", page + 1, pageCount));
    }
    public String getFileName(Uri uri)
    {
        Stringresult=null;
        if (uri.getScheme().equals("content"))
        {
            Cursorcursor= 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;
    }
    @OverridepublicvoidloadComplete(int nbPages)
    {
        if (mCurrentPage >= 0)
        {
            pdfView.jumpTo(mCurrentPage);
        }
        PdfDocument.Metameta= 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(), "-");
    }
    publicvoidprintBookmarksTree(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 + "-");
            }
        }
    }
    @OverridepublicvoidonRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNullint[] grantResults)
    {
        if (requestCode == PERMISSION_CODE)
        {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
            {
                launchPicker();
            }
        }
    }

    @OverridepublicbooleanonOptionsItemSelected(MenuItem item)
    {
        if (item.getItemId() == android.R.id.home)
        {
            finish();
        }
        returnsuper.onOptionsItemSelected(item);
    }

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

    @OverrideprotectedvoidonRestoreInstanceState(Bundle savedInstanceState)
    {
        super.onRestoreInstanceState(savedInstanceState);
        mCurrentPage = savedInstanceState.getInt(KEY_CURRENT_PAGE);
    }

    @OverridepublicvoidonSaveInstanceState(Bundle outState)
    {
        super.onSaveInstanceState(outState);
        outState.putInt(KEY_CURRENT_PAGE, mCurrentPage);
    }
}