[`PdfViewerFragment`](https://developer.android.com/reference/kotlin/androidx/pdf/viewer/fragment/PdfViewerFragment) is a specialized `Fragment` that you
can use to display PDF documents within your Android application.
`PdfViewerFragment` simplifies PDF rendering, enabling you to concentrate on
other aspects of your app's functionality.

## Results

![A PDF document rendered within an Android application using PdfViewerFragment.](https://developer.android.com/static/media/images/grow/pdf_title_page.png) PDF document displayed in an app.

## Version compatibility

To use `PdfViewerFragment`, your application must target a minimum of Android S
(API level 31) and SDK extension level 13. If these compatibility requirements
are not satisfied, the library throws an
[`UnsupportedOperationException`](https://developer.android.com/reference/java/lang/UnsupportedOperationException).
| **Note:** Edit mode is not currently supported in `PdfViewerFragment`.

You can check the SDK extension version at runtime using the `SdkExtensions`
module. This enables you to conditionally load the fragment and PDF document
only if the device meets the necessary requirements.  

    if (SdkExtensions.getExtensionVersion(Build.VERSION_CODES.S) >= 13) {
        // Load the fragment and document.
    }

## Dependencies

To incorporate the PDF viewer into your application, declare the
[androidx.pdf](https://developer.android.com/jetpack/androidx/releases/pdf) dependency in your app's module `build.gradle`
file. The PDF library is accessible from the Google Maven repository.  

    dependencies {
        val pdfVersion = "1.0.0-alpha0X"
        implementation("androidx.pdf:pdf:pdf-viewer-fragment:$pdfVersion")
    }

## `PdfViewerFragment` features

`PdfViewerFragment` presents PDF documents in paginated format, making them easy
to navigate. For efficient loading, the fragment employs a two‑pass
rendering strategy that progressively loads page dimensions.

To optimize memory usage, `PdfViewerFragment` renders only the currently visible
pages and releases the bitmaps for pages that are off‑screen.
Additionally, `PdfViewerFragment` includes a floating action button (FAB) that
supports annotations by firing an implicit `android.intent.action.ANNOTATE`
intent containing the document URI.

## Implementation

Adding a PDF viewer to your Android application is a multistep process.

### Create the activity layout

Begin by defining the layout XML for the activity that hosts the PDF viewer. The
layout should include a `FrameLayout` to contain the `PdfViewerFragment` and
buttons for user interactions, such as searching within the document.  

    <androidx.constraintlayout.widget.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/pdf_container_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:orientation="vertical"
        tools:context=".MainActivity">

        <FrameLayout
            android:id="@+id/fragment_container_view"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_marginBottom="8dp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="parent"/>

        <com.google.android.material.button.MaterialButton
            android:id="@+id/search_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/search_string"
            app:strokeWidth="1dp"
            android:layout_marginStart="8dp"
            android:layout_marginBottom="8dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent" />

    </androidx.constraintlayout.widget.ConstraintLayout>

### Set up the activity

The activity that hosts `PdfViewerFragment` must extend
[`AppCompatActivity`](https://developer.android.com/reference/kotlin/androidx/appcompat/app/AppCompatActivity). In the `onCreate()` method of the
activity, set the content view to the layout you created, and initialize any
necessary UI elements.  

    class MainActivity : AppCompatActivity() {
        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            setContentView(R.layout.activity_main)

            val getContentButton: MaterialButton = findViewById(R.id.launch_button)
            val searchButton: MaterialButton = findViewById(R.id.search_button)
        }
    }

### Initialize `PdfViewerFragment`

Create an instance of `PdfViewerFragment` using a fragment manager obtained from
[`getSupportFragmentManager()`](https://developer.android.com/reference/kotlin/androidx/fragment/app/FragmentActivity#getSupportFragmentManager()). Check whether an
instance of the fragment already exists before creating a new one, especially
during configuration changes.

In the following example, the `initializePdfViewerFragment()` function handles
the creation and commitment of the fragment transaction. The function replaces
an existing fragment in a container with an instance of your
`PdfViewerFragment`.  

    class MainActivity : AppCompatActivity() {
        @RequiresExtension(extension = Build.VERSION_CODES.S, version = 13)
        private var pdfViewerFragment: PdfViewerFragment? = null

        override fun onCreate(savedInstanceState: Bundle?) {
            // ...

            if (pdfViewerFragment == null) {
                pdfViewerFragment =
                    supportFragmentManager
                        .findFragmentByTag(PDF_VIEWER_FRAGMENT_TAG) as PdfViewerFragment?
            }

        }

        // Used to instantiate and commit the fragment.
        @RequiresExtension(extension = Build.VERSION_CODES.S, version = 13)
        private fun initializePdfViewerFragment() {
            // This condition can be skipped if you want to create a new fragment every time.
            if (pdfViewerFragment == null) {
                val fragmentManager: FragmentManager = supportFragmentManager

              // Fragment initialization.
              pdfViewerFragment = PdfViewerFragmentExtended()
              val transaction: FragmentTransaction = fragmentManager.beginTransaction()

              // Replace an existing fragment in a container with an instance of a new fragment.
              transaction.replace(
                  R.id.fragment,4_container_view,
                  pdfViewerFragment!!,
                  PDF_VIEWER_FRAGMENT_TAG
              )
              transaction.commitAllowingStateLoss()
              fragmentManager.executePendingTransactions()
            }
        }

        companion object {
            private const val MIME_TYPE_PDF = "application/pdf"
            private const val PDF_VIEWER_FRAGMENT_TAG = "pdf_viewer_fragment_tag"
        }
    }

## Extend `PdfViewerFragment` functionality

`PdfViewerFragment` exposes public functions that you can override to extend its
capabilities. Create a new class that inherits from `PdfViewerFragment`. In your
subclass, override methods such as `onLoadDocumentSuccess()` and
`onLoadDocumentError()` to add custom logic, like logging metrics.  

    @RequiresExtension(extension = Build.VERSION_CODES.S, version = 13)
    class PdfViewerFragmentExtended : PdfViewerFragment() {
              private val someLogger : SomeLogger = // ... used to log metrics

              override fun onLoadDocumentSuccess() {
                    someLogger.log(/** log document success */)
              }

              override fun onLoadDocumentError(error: Throwable) {
                    someLogger.log(/** log document error */, error)
              }
    }

## Enable document search

While `PdfViewerFragment` does not include a built-in search menu, it supports a
search bar. You control the visibility of the search bar using the
`isTextSearchActive` API. To enable document search, you set the
`isTextSearchActive` property of your `PdfViewerFragment` instance.

Use [`WindowCompat.setDecorFitsSystemWindows()`](https://developer.android.com/reference/kotlin/androidx/core/view/WindowCompat#setDecorFitsSystemWindows(android.view.Window,boolean)) to ensure `WindowInsetsCompat` is
correctly passed to content views, which is necessary for the proper positioning
of the search view.  

    class MainActivity : AppCompatActivity() {
        @RequiresExtension(extension = Build.VERSION_CODES.S, version = 13)
        override fun onCreate(savedInstanceState: Bundle?) {
            // ...
            searchButton.setOnClickListener {
                pdfViewerFragment?.isTextSearchActive =
                    pdfViewerFragment?.isTextSearchActive == false
            }

            // Ensure WindowInsetsCompat are passed to content views without being
            // consumed by the decor view. These insets are used to calculate the
            // position of the search view.
            WindowCompat.setDecorFitsSystemWindows(window, false)
        }
    }

## Integrate with the file picker

To allow users to select PDF files from their device, integrate
`PdfViewerFragment` with the Android file picker. First, update your activity's
layout XML to include a button that launches the file picker.  

    <androidx.constraintlayout.widget.ConstraintLayout
        ...
        tools:context=".MainActivity">

        <FrameLayout
            ...
            app:layout_constraintBottom_toTopOf="@+id/launch_button"/>

        // Adding a button to open file picker.
        <com.google.android.material.button.MaterialButton
            android:id="@+id/launch_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/launch_string"
            app:strokeWidth="1dp"
            android:layout_marginEnd="8dp"
            android:layout_marginBottom="8dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toStartOf="@id/search_button"/>

        <com.google.android.material.button.MaterialButton
            ...
            app:layout_constraintStart_toEndOf="@id/launch_button" />

    </androidx.constraintlayout.widget.ConstraintLayout>

Next, in your activity, launch the file picker using
[`registerForActivityResult(GetContent())`](https://developer.android.com/reference/kotlin/androidx/activity/result/ActivityResultCaller#(androidx.activity.result.ActivityResultCaller).registerForActivityResult(androidx.activity.result.contract.ActivityResultContract,kotlin.Any,kotlin.Function1)). When
the user selects a file, the callback provides a URI. You then set the
`documentUri` property of your `PdfViewerFragment` instance with this URI to
load and display the selected PDF.  

    class MainActivity : AppCompatActivity() {
        // ...

        private var filePicker: ActivityResultLauncher<String> =
            registerForActivityResult(GetContent()) { uri: Uri? ->
                uri?.let {
                    initializePdfViewerFragment()
                    pdfViewerFragment?.documentUri = uri
                }
            }

        override fun onCreate(savedInstanceState: Bundle?) {
            // ...
            getContentButton.setOnClickListener { filePicker.launch(MIME_TYPE_PDF) }
        }

        private fun initializePdfViewerFragment() {
            // ...
        }

        companion object {
            private const val MIME_TYPE_PDF = "application/pdf"
            // ...
        }
    }

## Customize the UI

You can customize the user interface of `PdfViewerFragment` by overriding XML
attributes the library exposes. This enables you to tailor the appearance of
elements like the scrollbar and page indicator to match your app's design.

The customizable attributes include:

- `fastScrollVerticalThumbDrawable` --- Sets the drawable for the scrollbar thumb.
- `fastScrollPageIndicatorBackgroundDrawable` --- Sets the background drawable for the page indicator.
- `fastScrollPageIndicatorMarginEnd` --- Sets the right margin for the page indicator. Ensure margin values are positive.
- `fastScrollVerticalThumbMarginEnd` --- Sets the right margin for the vertical scrollbar thumb. Ensure margin values are positive.

To apply these customizations, define a custom style in your XML resources.  

    <resources>
        <style name="pdfContainerStyle">
            <item name="fastScrollVerticalThumbDrawable">@drawable/custom_thumb_drawable</item>
            <item name="fastScrollPageIndicatorBackgroundDrawable">@drawable/custom_page_indicator_background</item>
            <item name="fastScrollVerticalThumbMarginEnd">8dp</item>
        </style>
    </resources>

Then, provide the custom style resource to `PdfViewerFragment` using
`PdfStylingOptions` when you create an instance of the fragment with
`PdfViewerFragment.newInstance(stylingOptions)`.  

    private fun initializePdfViewerFragment() {
        // This condition can be skipped if you want to create a new fragment every time.
        if (pdfViewerFragment == null) {
          val fragmentManager: FragmentManager = supportFragmentManager

          // Create styling options.
          val stylingOptions = PdfStylingOptions(R.style.pdfContainerStyle)

          // Fragment initialization.
          pdfViewerFragment = PdfViewerFragment.newInstance(stylingOptions)

          // Execute fragment transaction.
        }
    }

If you've subclassed `PdfViewerFragment`, use the protected constructor to
provide the styling options. This ensures your custom styles are applied
correctly to your extended fragment.  

    class StyledPdfViewerFragment: PdfViewerFragment {

        constructor() : super()

        private constructor(pdfStylingOptions: PdfStylingOptions) : super(pdfStylingOptions)

        companion object {
            fun newInstance(): StyledPdfViewerFragment {
                val stylingOptions = PdfStylingOptions(R.style.pdfContainerStyle)
                return StyledPdfViewerFragment(stylingOptions)
            }
        }
    }

## Complete implementation

The following code provides a complete example of how to implement
`PdfViewerFragment` in your activity, including initialization, file picker
integration, search functionality, and UI customization.  

    class MainActivity : AppCompatActivity() {

        private var pdfViewerFragment: PdfViewerFragment? = null
        private var filePicker: ActivityResultLauncher<String> =
            registerForActivityResult(GetContent()) { uri: Uri? ->
                uri?.let {
                    initializePdfViewerFragment()
                    pdfViewerFragment?.documentUri = uri
                }
            }

        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            setContentView(R.layout.activity_main)

            if (pdfViewerFragment == null) {
                pdfViewerFragment =
                    supportFragmentManager
                       .findFragmentByTag(PDF_VIEWER_FRAGMENT_TAG) as PdfViewerFragment?
            }

            val getContentButton: MaterialButton = findViewById(R.id.launch_button)
            val searchButton: MaterialButton = findViewById(R.id.search_button)

            getContentButton.setOnClickListener { filePicker.launch(MIME_TYPE_PDF) }
            searchButton.setOnClickListener {
                pdfViewerFragment?.isTextSearchActive = pdfViewerFragment?.isTextSearchActive == false
            }
        }

        private fun initializePdfViewerFragment() {
            // This condition can be skipped if you want to create a new fragment every time.
            if (pdfViewerFragment == null) {
                val fragmentManager: FragmentManager = supportFragmentManager

              // Create styling options.
              // val stylingOptions = PdfStylingOptions(R.style.pdfContainerStyle)

              // Fragment initialization.
              // For customization:
              // pdfViewerFragment = PdfViewerFragment.newInstance(stylingOptions)
              pdfViewerFragment = PdfViewerFragmentExtended()
              val transaction: FragmentTransaction = fragmentManager.beginTransaction()

              // Replace an existing fragment in a container with an instance of a new fragment.
              transaction.replace(
                  R.id.fragment_container_view,
                  pdfViewerFragment!!,
                  PDF_VIEWER_FRAGMENT_TAG
              )
              transaction.commitAllowingStateLoss()
              fragmentManager.executePendingTransactions()
            }
        }

        companion object {
            private const val MIME_TYPE_PDF = "application/pdf"
            private const val PDF_VIEWER_FRAGMENT_TAG = "pdf_viewer_fragment_tag"
        }
    }

### Key points about the code

- Ensure your project meets the minimum API level and SDK extension requirements.
- The activity hosting `PdfViewerFragment` must extend `AppCompatActivity`.
- You can extend `PdfViewerFragment` to add custom behaviors.
- Customize the UI of `PdfViewerFragment` by overriding XML attributes.