Android PdfViewer

If you are using ProGuard in your Android project, you must add the following rule to your ProGuard configuration file to prevent the library from being stripped during obfuscation.

-keep class com.shockwave.**

Add the following dependency to your build.gradle file to use the library. You can choose between the latest beta version or a more stable version.

Beta version (3.2.0-beta.1): implementation 'com.github.barteksc:android-pdf-viewer:3.2.0-beta.1'

Stable version (2.8.2): implementation 'com.github.barteksc:android-pdf-viewer:2.8.2'

The library is available in the jcenter repository.

To ensure your app works correctly on 16 KB page size environments, use the following methods:

Android Emulator

1. Download an Android 15 system image that specifically supports 16 KB page sizes.
2. Create a virtual device using that image.

Physical Devices

Supported devices (running Android 15 QPR1+ or Android 15 QPR2 Beta 2+):

• Pixel 8 / 8 Pro
• Pixel 8a
• Pixel 9 / 9 Pro / 9 Pro XL

Note: You must enable "Boot with 16KB page size" in the device's Developer Options to test this mode.

If your APK fails the 16 KB alignment checks, you can use the provided realign_apk.bat script to fix it. It is recommended to work on a copy of your APK to avoid file lock issues.

1. Copy your APK: cp sample/build/outputs/apk/debug/sample-debug.apk sample-debug-copy.apk
2. Run the realignment script: .\realign_apk.bat "sample-debug-copy.apk"
3. Verify the fix: zipalign -c -p -v 4 sample-debug-copy.apk

Add the PDFView component to your XML layout file to provide the container for rendering PDF documents.

<com.github.barteksc.pdfviewer.PDFView
        android:id="@+id/pdfView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

To make the PDF scroll through single pages with a fling behavior similar to a ViewPager, use the following combination of settings:

pdfView.fromAsset("sample.pdf")
    .swipeHorizontal(true)
    .pageSnap(true)
    .autoSpacing(true)
    .pageFling(true)
    .load();

Use the PDFView API to load documents from various sources such as URIs, Files, Byte Arrays, InputStreams, Assets, or custom DocumentSource implementations. You can chain configuration methods to customize the viewer behavior (e.g., page selection, gestures, listeners, and fit policies) before calling .load().

pdfView.fromAsset("sample.pdf")
    .pages(0, 2, 1, 3, 3, 3) // all pages are displayed by default
    .enableSwipe(true) // allows to block changing pages using swipe
    .swipeHorizontal(false)
    .enableDoubletap(true)
    .defaultPage(0)
    .onLoad(onLoadCompleteListener)
    .onError(onErrorListener)
    .pageFitPolicy(FitPolicy.WIDTH)
    .load();

The library supports double-tap zooming with three levels: min (default 1), mid (default 1.75), and max (default 3). You can customize these levels using the following methods:

void setMinZoom(float zoom);
void setMidZoom(float zoom);
void setMaxZoom(float zoom);

The ScrollHandle replaces the old ScrollBar. To use it, register an implementation of the ScrollHandle interface using Configurator#scrollHandle().

You can use the provided DefaultScrollHandle. By default, it is placed on the right (vertical) or bottom (horizontal). To place it on the left or top, use the constructor with a second boolean argument: new DefaultScrollHandle(this, true).

You can verify if your APK is correctly aligned for 16 KB page sizes using manual commands or the provided scripts in the repository.

Manual Verification

1. Check alignment with zipalign:

   zipalign -c -p -v 4 your-app.apk

2. Check device page size via ADB: Run the following command on a 16 KB device/emulator. It should return 16384:

   adb shell getconf PAGE_SIZE

Using Repository Scripts

• Linux/macOS: ./check_16kb_alignment.sh <path_to_apk>
• Windows PowerShell: .\check_16kb_alignment.ps1 -ApkFile "<path_to_apk>"
• Windows Batch: .\realign_apk.bat "<path_to_apk>"
• Python (Cross-platform): python fix_16kb_alignment.py "<path_to_apk>"

zipalign -c -p -v 4 your-app.apk

adb shell getconf PAGE_SIZE
# Should return 16384

The library supports three modes for fitting pages to the screen via Configurator#pageFitPolicy(FitPolicy). Every page is scaled relative to other pages based on the selected policy:

• FitPolicy.WIDTH: The width of the widest page is equal to the screen width (Default).
• FitPolicy.HEIGHT: The height of the highest page is equal to the screen height.
• FitPolicy.BOTH: Every page is scaled to be fully visible on screen based on both widest and highest pages.