Bookmark Highlighting

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/*
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 *   Copyright © 2020-2026 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.annotation.SuppressLint
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import android.content.Context
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import android.graphics.Canvas
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import android.graphics.ColorFilter
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import android.graphics.PixelFormat
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import android.graphics.Rect
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import android.graphics.drawable.Drawable
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import android.net.Uri
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import android.os.Bundle
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import android.view.Gravity
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import android.view.ViewGroup
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import android.widget.FrameLayout
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import android.widget.Toast
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import androidx.core.content.ContextCompat
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import androidx.core.view.ViewCompat
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import androidx.core.view.WindowInsetsCompat
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import com.google.android.material.floatingactionbutton.FloatingActionButton
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import com.pspdfkit.bookmarks.Bookmark
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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.tasks.ExtractAssetTask
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import com.pspdfkit.configuration.activity.PdfActivityConfiguration
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import com.pspdfkit.configuration.activity.ThumbnailBarMode
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import com.pspdfkit.document.PdfDocument
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import com.pspdfkit.ui.PdfActivity
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import com.pspdfkit.ui.PdfActivityIntentBuilder
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import com.pspdfkit.ui.drawable.PdfDrawable
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import com.pspdfkit.ui.drawable.PdfDrawableProvider
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import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers
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import io.reactivex.rxjava3.disposables.Disposable
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import kotlin.math.roundToInt
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private val initialThumbnailBarMode = ThumbnailBarMode.THUMBNAIL_BAR_MODE_SCROLLABLE
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/**
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 * Example showing how to use the drawable API to put a drawn highlight on all pages that contain a bookmark.
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 */
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class BookmarkHighlightingExample(context: Context) :
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    SdkExample(context, R.string.bookmarkHighlightingExampleTitle, R.string.bookmarkHighlightingExampleDescription) {
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    override fun launchExample(context: Context, configuration: PdfActivityConfiguration.Builder) {
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        // This uses larger thumbnails making our bookmark indicator more easily visible.
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        configuration
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            .setThumbnailBarMode(initialThumbnailBarMode)
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            .title("Bookmark Indicator")
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        // Start the activity once the example document has been extracted from the app's assets.
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        ExtractAssetTask.extract(BOOKMARK_DOCUMENT, title, context) { documentFile ->
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            val intent =
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                PdfActivityIntentBuilder
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                    .fromUri(context, Uri.fromFile(documentFile))
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                    .configuration(configuration.build())
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                    .activityClass(BookmarkHighlightingActivity::class)
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                    .build()
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            // Start the BookmarkHighlightingActivity for the extracted document.
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            context.startActivity(intent)
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        }
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    }
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    companion object {
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        const val BOOKMARK_DOCUMENT = "bookmark_highlight_example.pdf"
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    }
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}
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class BookmarkHighlightingActivity : PdfActivity() {
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    private lateinit var toggleThumbnailBarModeFab: FloatingActionButton
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    /** List of bookmarks that current exist in the document. */
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    private val currentBookmarks = mutableListOf<Bookmark>()
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    private var currentThumbnailBarMode = initialThumbnailBarMode
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    private var currentToast: Toast? = null
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    /** Drawable provider that will put a bookmark icon on bookmarked pages. */
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    private val drawableProvider =
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        object : PdfDrawableProvider() {
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            override suspend fun getDrawablesForPage(context: Context, document: PdfDocument, pageIndex: Int): List<PdfDrawable> {
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                if (currentBookmarks.any { it.pageIndex == pageIndex }) {
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                    // If there's bookmark for the given page index, add our drawable.
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                    return listOf(BookmarkDrawable(this@BookmarkHighlightingActivity))
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                } else {
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                    // Otherwise we draw nothing.
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                    return emptyList()
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                }
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            }
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        }
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    /** Used to stop the bookmark loading process when closing the activity. */
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    private var bookmarkLoadingDisposable: Disposable? = null
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    override fun onCreate(savedInstanceState: Bundle?) {
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        super.onCreate(savedInstanceState)
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        currentThumbnailBarMode =
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            savedInstanceState?.getString(KEY_THUMBNAIL_BAR_MODE)
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                ?.let(ThumbnailBarMode::valueOf)
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                ?: initialThumbnailBarMode
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        toggleThumbnailBarModeFab =
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            FloatingActionButton(this).apply {
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                setImageResource(R.drawable.ic_layout_customization)
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                val margin = (16 * resources.displayMetrics.density).roundToInt()
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                layoutParams =
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                    FrameLayout.LayoutParams(
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                        FrameLayout.LayoutParams.WRAP_CONTENT,
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                        FrameLayout.LayoutParams.WRAP_CONTENT,
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                    ).apply {
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                        gravity = Gravity.BOTTOM or Gravity.END
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                        setMargins(margin, margin, margin, margin)
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                    }
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                setOnClickListener {
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                    currentThumbnailBarMode = nextThumbnailBarMode(currentThumbnailBarMode)
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                    applyThumbnailBarMode()
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                    currentToast?.cancel()
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                    currentToast =
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                        Toast
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                            .makeText(
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                                this@BookmarkHighlightingActivity,
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                                getString(
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                                    R.string.thumbnail_bar_mode_changed,
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                                    getString(currentThumbnailBarMode.labelRes),
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                                ),
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                                Toast.LENGTH_SHORT,
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                            ).also { it.show() }
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                }
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            }
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        findViewById<FrameLayout>(android.R.id.content).addView(toggleThumbnailBarModeFab)
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        ViewCompat.setOnApplyWindowInsetsListener(toggleThumbnailBarModeFab) { view, insets ->
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            val navigationBarsInsets = insets.getInsets(WindowInsetsCompat.Type.navigationBars())
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            (view.layoutParams as? ViewGroup.MarginLayoutParams)?.let { params ->
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                params.bottomMargin = (16 * resources.displayMetrics.density).roundToInt() + navigationBarsInsets.bottom
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                view.layoutParams = params
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            }
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            insets
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        }
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        ViewCompat.requestApplyInsets(toggleThumbnailBarModeFab)
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        applyThumbnailBarMode()
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    }
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    override fun onDocumentLoaded(document: PdfDocument) {
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        super.onDocumentLoaded(document)
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        // When the document is initially loaded we prepare the first set of bookmarks to be displayed.
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        bookmarkLoadingDisposable =
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            document
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                .bookmarkProvider
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                .bookmarksAsync
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                .firstOrError()
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                .observeOn(AndroidSchedulers.mainThread())
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                .subscribe { bookmarks ->
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                    updateBookmarkDrawables(bookmarks)
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                }
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        // Afterwards we subscribe to be updated whenever the list of bookmarks change.
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        document.bookmarkProvider.addBookmarkListener {
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            // This is always called on the UI thread so no need for special concurrency handling.
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            updateBookmarkDrawables(it)
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        }
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        applyThumbnailBarMode()
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    }
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    private fun updateBookmarkDrawables(newBookmarks: List<Bookmark>) {
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        currentBookmarks.clear()
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        currentBookmarks.addAll(newBookmarks)
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        // We need to add and remove the provider so the drawables are correctly redrawn.
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        pspdfKitViews.thumbnailBarView?.apply {
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            removeDrawableProvider(drawableProvider)
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            addDrawableProvider(drawableProvider)
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        }
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        pspdfKitViews.thumbnailGridView?.apply {
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            removeDrawableProvider(drawableProvider)
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            addDrawableProvider(drawableProvider)
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        }
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    }
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    override fun onSaveInstanceState(outState: Bundle) {
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        super.onSaveInstanceState(outState)
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        outState.putString(KEY_THUMBNAIL_BAR_MODE, currentThumbnailBarMode.name)
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    }
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    override fun onDestroy() {
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        super.onDestroy()
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        // Make sure to dispose of this before closing the activity.
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        bookmarkLoadingDisposable?.dispose()
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    }
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    private fun applyThumbnailBarMode() {
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        pspdfKitViews.thumbnailBarView?.setThumbnailBarMode(currentThumbnailBarMode)
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        toggleThumbnailBarModeFab.contentDescription =
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            getString(R.string.toggle_thumbnail_bar_mode, getString(currentThumbnailBarMode.labelRes))
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    }
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    private fun nextThumbnailBarMode(currentMode: ThumbnailBarMode): ThumbnailBarMode {
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        val modes = enumValues<ThumbnailBarMode>()
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        return modes[(currentMode.ordinal + 1) % modes.size]
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    }
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    private val ThumbnailBarMode.labelRes: Int
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        get() =
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            when (this) {
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                ThumbnailBarMode.THUMBNAIL_BAR_MODE_FLOATING -> R.string.thumbnail_bar_mode_floating
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                ThumbnailBarMode.THUMBNAIL_BAR_MODE_PINNED -> R.string.thumbnail_bar_mode_pinned
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                ThumbnailBarMode.THUMBNAIL_BAR_MODE_SCROLLABLE -> R.string.thumbnail_bar_mode_scrollable
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                ThumbnailBarMode.THUMBNAIL_BAR_MODE_NONE -> R.string.thumbnail_bar_mode_none
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            }
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    private companion object {
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        private const val KEY_THUMBNAIL_BAR_MODE = "thumbnail_bar_mode"
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    }
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}
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/**
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 * An implementation of [PdfDrawable], which shows an indicator on bookmarked pages.
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 */
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private class BookmarkDrawable(private val context: Context) : PdfDrawable() {
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    // This has to be non null, otherwise this whole example will do nothing.
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    private val bookmarkDrawable: Drawable = ContextCompat.getDrawable(context, R.drawable.ic_bookmark_highlight)!!
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    /**
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     * This will draw our bookmarkDrawable on to the page.
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     */
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    @SuppressLint("CanvasSize")
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    override fun draw(canvas: Canvas) {
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        // First we convert our DP constants to their respective pixel sizes.
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        val baseSize = BASE_SIZE_DP * context.resources.displayMetrics.density
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        val bookmarkSize = BOOKMARK_SIZE_DP * context.resources.displayMetrics.density
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        val margin = MARGIN_DP * context.resources.displayMetrics.density
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        // We use the canvas size here since that will be the size of the entire page in the thumbnail bar / grid.
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        // Based on this size we calculate the real size our bookmark icon will be.
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        val ratio = canvas.width / baseSize
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        val effectiveBookmarkSize = bookmarkSize * ratio
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        val effectiveMargin = margin * ratio
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        // Then we place the bookmark in top right edge, with some margin to the right,
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        // and moving it up a bit so it sits flush with the page edge.
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        bookmarkDrawable.bounds =
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            Rect(
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                (canvas.width - effectiveBookmarkSize - effectiveMargin).toInt(),
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                -effectiveMargin.toInt(),
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                (canvas.width - effectiveMargin).toInt(),
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                effectiveBookmarkSize.toInt(),
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            )
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        // Finally we simply draw it onto the page.
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        bookmarkDrawable.draw(canvas)
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    }
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    override fun setAlpha(alpha: Int) {
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        // Not required.
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    }
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    @Deprecated("Deprecated in Java")
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    override fun getOpacity(): Int = PixelFormat.TRANSLUCENT
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    override fun setColorFilter(colorFilter: ColorFilter?) {
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        // Not required.
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    }
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    companion object {
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        /** The width in DP at which the bookmark icon will have it's size, used to scale depending on context. */
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        const val BASE_SIZE_DP = 100
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        /** The size of the bookmark icon assuming the size of the canvas is BASE_SIZE_DP. */
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        const val BOOKMARK_SIZE_DP = 24
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        /** The margin to apply to the bookmark icon. */
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        const val MARGIN_DP = 8
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    }
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}