Simplify the PublicationOpener by adding a DefaultPublicationParser

readium/shared/src/main/java/org/readium/r2/shared/OptIn.kt

@@ -49,19 +49,6 @@ public annotation class ExperimentalReadiumApi
 )
 public annotation class DelicateReadiumApi
 
-@RequiresOptIn(
-    level = RequiresOptIn.Level.WARNING,
-    message = "Support for PDF is still experimental. The API may be changed in the future without notice."
-)
-@Retention(AnnotationRetention.BINARY)
-@Target(
-    AnnotationTarget.CLASS,
-    AnnotationTarget.FUNCTION,
-    AnnotationTarget.TYPEALIAS,
-    AnnotationTarget.PROPERTY
-)
-public annotation class PdfSupport
-
 @RequiresOptIn(
     level = RequiresOptIn.Level.WARNING,
     message = "Support for SearchService is still experimental. The API may be changed in the future without notice."

readium/streamer/src/main/java/org/readium/r2/streamer/PublicationOpener.kt

@@ -6,55 +6,29 @@
 
 package org.readium.r2.streamer
 
-import android.content.Context
-import org.readium.r2.shared.PdfSupport
 import org.readium.r2.shared.publication.Publication
 import org.readium.r2.shared.publication.protection.ContentProtection
 import org.readium.r2.shared.publication.protection.FallbackContentProtection
 import org.readium.r2.shared.util.DebugError
 import org.readium.r2.shared.util.Error
 import org.readium.r2.shared.util.Try
 import org.readium.r2.shared.util.asset.Asset
-import org.readium.r2.shared.util.asset.AssetOpener
 import org.readium.r2.shared.util.data.ReadError
 import org.readium.r2.shared.util.getOrElse
-import org.readium.r2.shared.util.http.HttpClient
 import org.readium.r2.shared.util.logging.WarningLogger
-import org.readium.r2.shared.util.pdf.PdfDocumentFactory
 import org.readium.r2.streamer.parser.PublicationParser
-import org.readium.r2.streamer.parser.audio.AudioParser
-import org.readium.r2.streamer.parser.epub.EpubParser
-import org.readium.r2.streamer.parser.image.ImageParser
-import org.readium.r2.streamer.parser.pdf.PdfParser
-import org.readium.r2.streamer.parser.readium.ReadiumWebPubParser
 
 /**
- * Opens a Publication using a list of parsers.
+ * Opens a [Publication] from an [Asset].
  *
- * The [PublicationOpener] is configured to use Readium's default parsers, which you can bypass
- * using ignoreDefaultParsers. However, you can provide additional [parsers] which will take
- * precedence over the default ones. This can also be used to provide an alternative configuration
- * of a default parser.
- *
- * @param context Application context.
- * @param parsers Parsers used to open a publication, in addition to the default parsers.
- * @param ignoreDefaultParsers When true, only parsers provided in parsers will be used.
+ * @param parser Parses the content of a publication [Asset].
  * @param contentProtections Opens DRM-protected publications.
- * @param httpClient Service performing HTTP requests.
- * @param pdfFactory Parses a PDF document, optionally protected by password.
- * @param assetOpener Opens assets in case of indirection.
  * @param onCreatePublication Called on every parsed [Publication.Builder]. It can be used to modify
  *   the manifest, the root container or the list of service factories of a [Publication].
  */
-@OptIn(PdfSupport::class)
 public class PublicationOpener(
-    context: Context,
-    parsers: List<PublicationParser> = emptyList(),
-    ignoreDefaultParsers: Boolean = false,
+    private val parser: PublicationParser,
     contentProtections: List<ContentProtection>,
-    private val httpClient: HttpClient,
-    pdfFactory: PdfDocumentFactory<*>?,
-    assetOpener: AssetOpener,
     private val onCreatePublication: Publication.Builder.() -> Unit = {}
 ) {
     public sealed class OpenError(
@@ -74,18 +48,6 @@ public class PublicationOpener(
     private val contentProtections: List<ContentProtection> =
         contentProtections + FallbackContentProtection()
 
-    private val defaultParsers: List<PublicationParser> =
-        listOfNotNull(
-            EpubParser(),
-            pdfFactory?.let { PdfParser(context, it) },
-            ReadiumWebPubParser(context, httpClient, pdfFactory),
-            ImageParser(assetOpener.assetSniffer),
-            AudioParser(assetOpener.assetSniffer)
-        )
-
-    private val parsers: List<PublicationParser> = parsers +
-        if (!ignoreDefaultParsers) defaultParsers else emptyList()
-
     /**
      * Opens a [Publication] from the given asset.
      *
@@ -139,7 +101,7 @@ public class PublicationOpener(
             }
         }
 
-        val builder = parse(transformedAsset, warnings)
+        val builder = parser.parse(transformedAsset, warnings)
             .getOrElse { return Try.failure(wrapParserException(it)) }
 
         builder.apply {
@@ -152,22 +114,6 @@ public class PublicationOpener(
         return Try.success(publication)
     }
 
-    private suspend fun parse(
-        publicationAsset: Asset,
-        warnings: WarningLogger?
-    ): Try<Publication.Builder, PublicationParser.ParseError> {
-        for (parser in parsers) {
-            val result = parser.parse(publicationAsset, warnings)
-            if (
-                result is Try.Success ||
-                result is Try.Failure && result.value !is PublicationParser.ParseError.FormatNotSupported
-            ) {
-                return result
-            }
-        }
-        return Try.failure(PublicationParser.ParseError.FormatNotSupported())
-    }
-
     private fun wrapParserException(e: PublicationParser.ParseError): OpenError =
         when (e) {
             is PublicationParser.ParseError.FormatNotSupported ->

readium/streamer/src/main/java/org/readium/r2/streamer/parser/PublicationParser.kt

@@ -6,13 +6,22 @@
 
 package org.readium.r2.streamer.parser
 
+import android.content.Context
 import org.readium.r2.shared.publication.Publication
 import org.readium.r2.shared.util.Try
 import org.readium.r2.shared.util.asset.Asset
+import org.readium.r2.shared.util.asset.AssetOpener
+import org.readium.r2.shared.util.http.HttpClient
 import org.readium.r2.shared.util.logging.WarningLogger
+import org.readium.r2.shared.util.pdf.PdfDocumentFactory
+import org.readium.r2.streamer.parser.audio.AudioParser
+import org.readium.r2.streamer.parser.epub.EpubParser
+import org.readium.r2.streamer.parser.image.ImageParser
+import org.readium.r2.streamer.parser.pdf.PdfParser
+import org.readium.r2.streamer.parser.readium.ReadiumWebPubParser
 
 /**
- *  Parses a Publication from an asset.
+ * Parses a [Publication] from an [Asset].
  */
 public interface PublicationParser {
 
@@ -41,3 +50,56 @@ public interface PublicationParser {
             ParseError("An error occurred while trying to read asset.", cause)
     }
 }
+
+/**
+ * Default implementation of [PublicationParser] handling all the publication formats supported by
+ * Readium.
+ *
+ * @param additionalParsers Parsers used to open a publication, in addition to the default parsers. They take precedence over the default ones.
+ * @param httpClient Service performing HTTP requests.
+ * @param pdfFactory Parses a PDF document, optionally protected by password.
+ * @param assetOpener Opens assets in case of indirection.
+ */
+public class DefaultPublicationParser(
+    context: Context,
+    additionalParsers: List<PublicationParser> = emptyList(),
+    private val httpClient: HttpClient,
+    pdfFactory: PdfDocumentFactory<*>?,
+    assetOpener: AssetOpener
+) : PublicationParser by CompositePublicationParser(
+    additionalParsers + listOfNotNull(
+        EpubParser(),
+        pdfFactory?.let { PdfParser(context, it) },
+        ReadiumWebPubParser(context, httpClient, pdfFactory),
+        ImageParser(assetOpener.assetSniffer),
+        AudioParser(assetOpener.assetSniffer)
+    )
+)
+
+/**
+ * A composite [PublicationParser] which tries several parsers until it finds one which supports
+ * the asset.
+ */
+public class CompositePublicationParser(
+    private val parsers: List<PublicationParser>
+) : PublicationParser {
+
+    public constructor(vararg parsers: PublicationParser) :
+        this(parsers.toList())
+
+    override suspend fun parse(
+        asset: Asset,
+        warnings: WarningLogger?
+    ): Try<Publication.Builder, PublicationParser.ParseError> {
+        for (parser in parsers) {
+            val result = parser.parse(asset, warnings)
+            if (
+                result is Try.Success ||
+                result is Try.Failure && result.value !is PublicationParser.ParseError.FormatNotSupported
+            ) {
+                return result
+            }
+        }
+        return Try.failure(PublicationParser.ParseError.FormatNotSupported())
+    }
+}

readium/streamer/src/main/java/org/readium/r2/streamer/parser/pdf/PdfParser.kt

@@ -8,7 +8,6 @@ package org.readium.r2.streamer.parser.pdf
 
 import android.content.Context
 import org.readium.r2.shared.ExperimentalReadiumApi
-import org.readium.r2.shared.PdfSupport
 import org.readium.r2.shared.publication.*
 import org.readium.r2.shared.publication.services.InMemoryCacheService
 import org.readium.r2.shared.publication.services.InMemoryCoverService
@@ -27,7 +26,6 @@ import org.readium.r2.streamer.parser.PublicationParser
 /**
  * Parses a PDF file into a Readium [Publication].
  */
-@PdfSupport
 @OptIn(ExperimentalReadiumApi::class)
 public class PdfParser(
     context: Context,

test-app/src/main/java/org/readium/r2/testapp/Readium.kt

@@ -25,6 +25,7 @@ import org.readium.r2.shared.util.http.HttpResourceFactory
 import org.readium.r2.shared.util.resource.CompositeResourceFactory
 import org.readium.r2.shared.util.zip.ZipArchiveOpener
 import org.readium.r2.streamer.PublicationOpener
+import org.readium.r2.streamer.parser.DefaultPublicationParser
 
 /**
  * Holds the shared Readium objects and services used by the app.
@@ -70,15 +71,17 @@ class Readium(context: Context) {
     )
 
     /**
-     * The PublicationFactory is used to parse and open publications.
+     * The PublicationFactory is used to open publications.
      */
     val publicationOpener = PublicationOpener(
-        context,
-        contentProtections = contentProtections,
-        assetOpener = assetOpener,
-        httpClient = httpClient,
-        // Only required if you want to support PDF files using the PDFium adapter.
-        pdfFactory = PdfiumDocumentFactory(context)
+        parser = DefaultPublicationParser(
+            context,
+            assetOpener = assetOpener,
+            httpClient = httpClient,
+            // Only required if you want to support PDF files using the PDFium adapter.
+            pdfFactory = PdfiumDocumentFactory(context)
+        ),
+        contentProtections = contentProtections
     )
 
     fun onLcpDialogAuthenticationParentAttached(view: View) {