PDF from Image

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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.app.Activity
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import android.content.Context
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import android.content.Intent
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import android.graphics.BitmapFactory
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import android.graphics.RectF
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import android.net.Uri
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import android.os.Bundle
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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.configuration.activity.PdfActivityConfiguration
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import com.pspdfkit.document.processor.NewPage
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import com.pspdfkit.document.processor.PageImage
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import com.pspdfkit.document.processor.PdfProcessor
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import com.pspdfkit.document.processor.PdfProcessorTask
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import com.pspdfkit.ui.PdfActivity
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import com.pspdfkit.utils.Size
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import com.pspdfkit.utils.getSupportParcelableExtra
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class PdfFromImageExample(context: Context) : SdkExample(context, R.string.pdfFromImageExampleTitle, R.string.pdfFromImageExampleDescription) {
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    override fun launchExample(context: Context, configuration: PdfActivityConfiguration.Builder) {
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        val intent = Intent(context, PdfFromImageActivity::class.java)
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        intent.putExtra(PdfFromImageActivity.EXTRA_CONFIGURATION, configuration.build())
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        context.startActivity(intent)
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    }
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}
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class PdfFromImageActivity : Activity() {
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    private lateinit var configuration: PdfActivityConfiguration
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    private var waitingForResult = false
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    override fun onCreate(savedInstanceState: Bundle?) {
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        super.onCreate(savedInstanceState)
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        // Extract the configuration for displaying the viewer activity.
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        configuration = intent.getSupportParcelableExtra(EXTRA_CONFIGURATION, PdfActivityConfiguration::class.java)
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            ?: throw ExceptionInInitializerError(
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                PdfFromImageActivity::class.java.simpleName +
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                    " was started without a PdfActivityConfiguration."
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            )
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        // Prevent the example from requesting multiple documents at the same time.
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        if (!waitingForResult) {
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            waitingForResult = true
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            startActivityForResult(getImagePickerIntent(), REQUEST_IMAGE)
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        }
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    }
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    private fun getImagePickerIntent(): Intent? {
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        // Creates an intent that will open a file picker with the filter set to only open images.
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        val intent = Intent()
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        intent.type = "image/*"
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        intent.action = Intent.ACTION_GET_CONTENT
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        return if (intent.resolveActivity(packageManager) == null) null else Intent.createChooser(intent, "")
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    }
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    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
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        // Once the image was picked we are done with this activity, close it.
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        finish()
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        if (requestCode == REQUEST_IMAGE && resultCode == RESULT_OK && data?.data != null) {
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            // Grab the path to the selected image.
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            val imageUri = data.data ?: return
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            // Create a PdfProcessorTask to create the new PDF.
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            val task = createPdfFromImageTask(imageUri)
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            // Obtain a path to put the resulting file.
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            // For simplicity we always put it in our application directory.
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            val outputPath = filesDir.resolve("image.pdf")
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            // Process the document.
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            PdfProcessor.processDocument(task, outputPath)
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            // And finally show it.
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            PdfActivity.showDocument(this, Uri.fromFile(outputPath), configuration)
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        }
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    }
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    /**
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     * This creates a [PdfProcessorTask] which will create a single page document using the supplied image as the page background.
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     */
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    private fun createPdfFromImageTask(imageUri: Uri): PdfProcessorTask {
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        // First obtain the size of the image.
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        val options = BitmapFactory.Options().apply {
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            // By setting this we won't actually load the image but only figure out the size.
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            inJustDecodeBounds = true
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        }
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        BitmapFactory.decodeStream(contentResolver.openInputStream(imageUri), null, options)
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        val imageHeight: Int = options.outHeight
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        val imageWidth: Int = options.outWidth
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        // We take A4 as a baseline, and alter the page's aspect ratio based on the given bitmap.
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        val pageSize: Size = if (imageWidth <= imageHeight) {
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            Size(NewPage.PAGE_SIZE_A4.width, imageHeight * (NewPage.PAGE_SIZE_A4.width / imageWidth))
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        } else {
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            Size(NewPage.PAGE_SIZE_A4.height, imageHeight * NewPage.PAGE_SIZE_A4.height / imageWidth)
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        }
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        // Now that we know the desired size we can create a PdfProcessorTask which will create a document containing a single page.
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        return PdfProcessorTask.newPage(
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            NewPage.emptyPage(pageSize)
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                // We initialize our new page using the passed in image URI and calculated page size.
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                .withPageItem(PageImage(this, imageUri, RectF(0f, pageSize.height, pageSize.width, 0f)))
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                .build()
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        )
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    }
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    companion object {
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        internal const val EXTRA_CONFIGURATION = "Nutrient.PdfFromImageActivity.configuration"
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        private const val REQUEST_IMAGE = 1
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    }
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}