feat: Android Auto Media Browsing Support

app/src/main/AndroidManifest.xml

@@ -69,11 +69,11 @@
         <meta-data
             android:name="com.google.android.gms.car.application.theme"
             android:resource="@style/Theme.Gramophone"/>
-<!-- TODO uncomment to enable Android Auto when library browsing is implemented
+
         <meta-data
             android:name="com.google.android.gms.car.application"
             android:resource="@xml/automotive_app_desc"/>
--->
+
         <activity
             android:name=".logic.ui.BugHandlerActivity"
             android:exported="false"
@@ -162,6 +162,13 @@
                 android:resource="@xml/file_paths" />
         </provider>
 
+        <provider
+            android:name=".logic.GramophoneAlbumArtProvider"
+            android:authorities="org.akanework.gramophone.albumart"
+            android:exported="true"
+            android:grantUriPermissions="true" />
+
+
         <receiver android:name=".ui.LyricWidgetProvider"
             android:exported="false">
             <intent-filter>
@@ -226,6 +233,7 @@
         <meta-data android:name="android.allow_multiple_resumed_activities" android:value="true" />
     </application>
 
+
     <queries>
         <intent>
             <action android:name="android.media.action.DISPLAY_AUDIO_EFFECT_CONTROL_PANEL" />

app/src/main/java/org/akanework/gramophone/logic/GramophoneAlbumArtProvider.kt

@@ -0,0 +1,166 @@
+package org.akanework.gramophone.logic
+
+import android.content.ContentProvider
+import android.content.ContentUris
+import android.content.ContentValues
+import android.content.Context
+import android.database.Cursor
+import android.graphics.Bitmap
+import android.media.ThumbnailUtils
+import android.net.Uri
+import android.os.Build
+import android.os.ParcelFileDescriptor
+import android.provider.MediaStore
+import android.util.Log
+import android.util.Size
+import uk.akane.libphonograph.Constants
+import uk.akane.libphonograph.utils.MiscUtils
+import java.io.File
+import java.io.IOException
+
+class GramophoneAlbumArtProvider : ContentProvider() {
+    private val TAG = "GramophoneProvider"
+
+    override fun onCreate() = true
+
+    override fun openFile(uri: Uri, mode: String): ParcelFileDescriptor? {
+        val context = context ?: return null
+        val segments = uri.pathSegments
+
+        if (segments.size < 3) return null
+
+        val type = segments[0] // song or album
+        val id = segments[1]
+        val encodedPath = segments[2]
+        val realPath = Uri.decode(encodedPath)
+
+        val cacheFile = File(context.cacheDir, uri.toString().hashCode().toString())
+
+        if (!cacheFile.exists()) {
+            when (type) {
+                "song" -> {
+                    generateSongCover(context, realPath, id, cacheFile)
+                }
+                "album" -> {
+                    generateAlbumCover(context, realPath, id, cacheFile)
+                }
+            }
+        }
+
+        if (!cacheFile.exists()) return null
+
+        return ParcelFileDescriptor.open(
+            cacheFile,
+            ParcelFileDescriptor.MODE_READ_ONLY
+        )
+    }
+
+    private fun generateSongCover(
+        context: Context,
+        path: String,
+        id: String,
+        outFile: File
+    ) {
+        val file = File(path)
+
+        val bmp = try {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+                ThumbnailUtils.createAudioThumbnail(
+                    file,
+                    Size(512, 512),
+                    null
+                )
+            } else null
+        } catch (e: IOException) {
+            Log.d(TAG, "failed to generate song cover",e)
+            null
+        }
+
+        if (bmp != null) {
+            saveBitmap(outFile, bmp)
+            return
+        }
+
+        // fallback MediaStore album art
+        val uri = ContentUris.withAppendedId(
+            MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
+            id.toLong()
+        ).buildUpon().appendPath("albumart").build()
+
+        try {
+            context.contentResolver.openInputStream(uri)?.use { input ->
+                outFile.outputStream().use { output ->
+                    input.copyTo(output)
+                }
+            }
+        } catch (e: Exception) {
+            Log.d(TAG, "failed to generate song cover",e)
+        }
+    }
+
+    private fun generateAlbumCover(
+        context: Context,
+        path: String,
+        id: String,
+        outFile: File
+    ) {
+        val cover = MiscUtils.findBestCover(File(path))
+
+        if (cover != null) {
+            cover.inputStream().use { input ->
+                outFile.outputStream().use { output ->
+                    input.copyTo(output)
+                }
+            }
+            return
+        }
+
+        val uri = ContentUris.withAppendedId(
+            Constants.baseAlbumCoverUri,
+            id.toLong()
+        )
+
+        try {
+            context.contentResolver.openInputStream(uri)?.use { input ->
+                outFile.outputStream().use { output ->
+                    input.copyTo(output)
+                }
+            }
+        } catch (e: Exception) {
+            Log.d(TAG, "failed to generate album cover",e)
+        }
+    }
+
+    private fun saveBitmap(file: File, bmp: Bitmap) {
+        file.outputStream().use {
+            bmp.compress(Bitmap.CompressFormat.JPEG, 85, it)
+        }
+    }
+    override fun query(
+        uri: Uri,
+        projection: Array<out String>?,
+        selection: String?,
+        selectionArgs: Array<out String>?,
+        sortOrder: String?
+    ): Cursor? = null
+
+    override fun getType(uri: Uri): String? = "image/jpeg"
+
+    override fun insert(
+        uri: Uri,
+        values: ContentValues?
+    ): Uri? = null
+
+    override fun delete(
+        uri: Uri,
+        selection: String?,
+        selectionArgs: Array<out String>?
+    ): Int = 0
+
+    override fun update(
+        uri: Uri,
+        values: ContentValues?,
+        selection: String?,
+        selectionArgs: Array<out String>?
+    ): Int = 0
+}