AI Assistant Multiple Documents: ViewPager

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/*
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 *   Copyright © 2025-2026 PSPDFKit GmbH. All rights reserved.
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 *
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 *   The PSPDFKit Sample applications are licensed with a modified BSD license.
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 *   Please see License for details. This notice may not be removed from this file.
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 */
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package com.pspdfkit.catalog.examples.kotlin
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import android.content.Context
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import android.content.Intent
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import android.graphics.RectF
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import android.os.Bundle
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import androidx.appcompat.app.AppCompatActivity
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import androidx.appcompat.widget.Toolbar
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import androidx.fragment.app.Fragment
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import androidx.viewpager2.adapter.FragmentStateAdapter
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import androidx.viewpager2.widget.ViewPager2
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import com.google.android.material.tabs.TabLayoutMediator
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import com.pspdfkit.ai.showAiAssistant
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import com.pspdfkit.catalog.R
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import com.pspdfkit.catalog.SdkExample
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import com.pspdfkit.catalog.SdkExample.Companion.WELCOME_DOC
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import com.pspdfkit.catalog.examples.kotlin.AiAssistantComposeActivity.Companion.PREFERENCES_NAME
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import com.pspdfkit.catalog.examples.kotlin.AiAssistantComposeActivity.Companion.PREF_AI_IP_ADDRESS
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import com.pspdfkit.catalog.examples.kotlin.AiAssistantViewPagerActivity.Companion.EXTRA_CONFIGURATION
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import com.pspdfkit.catalog.utils.JwtGenerator
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import com.pspdfkit.configuration.PdfConfiguration
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import com.pspdfkit.configuration.activity.PdfActivityConfiguration
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import com.pspdfkit.document.providers.AssetDataProvider
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import com.pspdfkit.document.providers.getDataProviderFromDocumentSource
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import com.pspdfkit.ui.DocumentDescriptor
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import com.pspdfkit.ui.PdfFragment
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import com.pspdfkit.utils.getSupportParcelableExtra
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import io.nutrient.domain.ai.AiAssistant
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import io.nutrient.domain.ai.AiAssistantProvider
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/**
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 * Shows how to implement AI Assistant chat supporting multiple documents analysis and interaction inside a ViewPager.
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 */
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class AiAssistantViewPagerExample(context: Context) : SdkExample(context, R.string.aiAssistantViewPagerExampleTitle, R.string.aiAssistantViewPagerExampleDescription) {
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    override fun launchExample(context: Context, configuration: PdfActivityConfiguration.Builder) {
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        val intent = Intent(context, AiAssistantViewPagerActivity::class.java)
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        configuration.setAiAssistantEnabled(true)
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        intent.putExtra(
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            EXTRA_CONFIGURATION,
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            configuration.build().configuration
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        )
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        context.startActivity(intent)
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    }
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}
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class AiAssistantViewPagerActivity : AppCompatActivity(), AiAssistantProvider {
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    private lateinit var pager: ViewPager2
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    private lateinit var fragmentAdapter: ViewPagerPdfFragmentAdapter
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    private var selectedPage = 0
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    private val sessionId = AiAssistantViewPagerActivity::class.java.simpleName
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    var ipAddressValue = ""
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    override fun onCreate(savedInstanceState: Bundle?) {
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        super.onCreate(savedInstanceState)
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        setContentView(R.layout.activity_view_pager_ai_assistant)
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        findViewById<Toolbar>(R.id.main_toolbar).let {
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            it.setOnMenuItemClickListener { _ ->
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                showAiAssistant(this@AiAssistantViewPagerActivity)
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                false
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            }
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        }
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        val preferences = getSharedPreferences(PREFERENCES_NAME, MODE_PRIVATE)
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        ipAddressValue = preferences.getString(PREF_AI_IP_ADDRESS, "") ?: ""
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        fragmentAdapter = ViewPagerPdfFragmentAdapter(this@AiAssistantViewPagerActivity, documentDescriptors)
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        pager = findViewById<ViewPager2>(R.id.view_pager).apply {
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            this.adapter = fragmentAdapter
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            isUserInputEnabled = false
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            registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
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                override fun onPageSelected(position: Int) {
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                    super.onPageSelected(position)
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                    selectedPage = position // Save the selected page.
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                }
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                override fun onPageScrollStateChanged(state: Int) {
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                    super.onPageScrollStateChanged(state)
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                    // Refresh the fragment when the user stops scrolling.
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                    if (state == 0) supportFragmentManager.findFragmentByTag("f$selectedPage")?.let { if (it is PdfFragment) it.refreshPages() }
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                }
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            })
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        }
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        TabLayoutMediator(findViewById(R.id.tab_layout), pager) { tab, position -> tab.text = "Tab ${position + 1}" }.attach()
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    }
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    companion object {
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        val assetFiles = listOf(WELCOME_DOC, "Scientific-paper.pdf", "Teacher.pdf", "The-Cosmic-Context-for-Life.pdf")
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        internal const val EXTRA_CONFIGURATION = "Nutrient.AIAssistantViewPagerActivity.configuration"
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    }
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    var assistant: AiAssistant? = null
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    override fun getAiAssistant(): AiAssistant {
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        return assistant ?: initialiseAiAssistant().also {
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            assistant = it
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        }
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    }
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    val documentDescriptors = assetFiles.map {
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        DocumentDescriptor.fromDataProviders(listOf(AssetDataProvider(it)), listOf(), listOf())
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    }
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    fun initialiseAiAssistant(): AiAssistant {
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        return com.pspdfkit.ai.createAiAssistant(
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            context = this,
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            documentsDescriptors = documentDescriptors,
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            serverUrl = "http://$ipAddressValue:4000",
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            sessionId = sessionId,
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            jwtToken = { documentIds ->
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                JwtGenerator.generateJwtToken(
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                    this@AiAssistantViewPagerActivity,
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                    claims = mapOf(
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                        "document_ids" to documentIds,
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                        "session_ids" to listOf(sessionId),
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                        "request_limit" to mapOf(
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                            "requests" to 160,
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                            "time_period_s" to 1000 * 60 * 10
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                        )
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                    )
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                )
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            }
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        )
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    }
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    @OptIn(ExperimentalStdlibApi::class)
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    override fun navigateTo(
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        documentRect: List<RectF>,
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        pageIndex: Int,
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        documentIndex: Int
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    ) {
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        val fragment = fragmentAdapter.fragments[documentIndex]
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        pager.setCurrentItem(documentIndex, true)
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        fragment.highlight(this@AiAssistantViewPagerActivity, documentRect, pageIndex)
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    }
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}
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/** Minimal [FragmentStateAdapter] to provide [PdfFragment] for each page. */
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class ViewPagerPdfFragmentAdapter(val activity: AiAssistantViewPagerActivity, descriptors: List<DocumentDescriptor>) : FragmentStateAdapter(activity) {
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    val configuration = activity.intent.getSupportParcelableExtra(EXTRA_CONFIGURATION, PdfConfiguration::class.java) ?: throw IllegalStateException("Activity Intent was missing configuration extra!")
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    override fun getItemCount(): Int = 4
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    val fragments = descriptors.map {
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        val dataProvider = it.documentSource.getDataProviderFromDocumentSource()
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        PdfFragment.newInstance(dataProvider, null, configuration)
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    }
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    override fun createFragment(position: Int): Fragment {
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        return fragments[position]
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    }
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}