Webtoon Split: Improve performance (#7947)

app/src/main/java/eu/kanade/tachiyomi/ui/reader/model/StencilPage.kt

@@ -1,15 +1,16 @@
 package eu.kanade.tachiyomi.ui.reader.model
 
-import eu.kanade.tachiyomi.util.system.ImageUtil
+import java.io.InputStream
 
 class StencilPage(
     parent: ReaderPage,
-    val splitData: ImageUtil.SplitData,
+    stencilStream: () -> InputStream,
 ) : ReaderPage(parent.index, parent.url, parent.imageUrl) {
 
     override var chapter: ReaderChapter = parent.chapter
 
     init {
-        stream = parent.stream
+        status = READY
+        stream = stencilStream
     }
 }

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/webtoon/WebtoonAdapter.kt

@@ -28,6 +28,7 @@ class WebtoonAdapter(val viewer: WebtoonViewer) : RecyclerView.Adapter<RecyclerV
     var currentChapter: ReaderChapter? = null
 
     fun onLongStripSplit(currentStrip: Any?, newStrips: List<StencilPage>) {
+        if (newStrips.isEmpty()) return
         if (currentStrip is StencilPage) return
 
         val placeAtIndex = items.indexOf(currentStrip) + 1

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/webtoon/WebtoonPageHolder.kt

@@ -19,7 +19,6 @@ import eu.kanade.tachiyomi.ui.reader.viewer.ReaderPageImageView
 import eu.kanade.tachiyomi.ui.reader.viewer.ReaderProgressIndicator
 import eu.kanade.tachiyomi.ui.webview.WebViewActivity
 import eu.kanade.tachiyomi.util.system.ImageUtil
-import eu.kanade.tachiyomi.util.system.ImageUtil.SplitData
 import eu.kanade.tachiyomi.util.system.dpToPx
 import rx.Observable
 import rx.Subscription
@@ -286,27 +285,31 @@ class WebtoonPageHolder(
 
         if (viewer.config.longStripSplit) {
             if (page is StencilPage) {
-                val splitData = (page as StencilPage).splitData
-                return ImageUtil.splitStrip(imageStream, splitData)
+                return imageStream
             }
-
             val isStripSplitNeeded = ImageUtil.isStripSplitNeeded(imageStream)
             if (isStripSplitNeeded) {
-                val splitData = onStripSplit(imageStream)
-                splitData?.let { return ImageUtil.splitStrip(imageStream, it) }
+                onStripSplit(imageStream)?.let { return it }
             }
         }
 
         return imageStream
     }
 
-    private fun onStripSplit(imageStream: BufferedInputStream): SplitData? {
+    private fun onStripSplit(imageStream: BufferedInputStream): InputStream? {
         val page = page ?: return null
-        val splitData = ImageUtil.getSplitDataForStream(imageStream).toMutableList()
-        val toReturn = splitData.removeFirstOrNull()
-        val newPages = splitData.map { StencilPage(page, it) }
+        val streamFn = page.stream ?: return null
+        val splitData = ImageUtil.getSplitDataForStream(imageStream)
+        if (splitData.size == 1) return imageStream
+        val newPages = splitData.map {
+            StencilPage(page) { ImageUtil.splitStrip(it, streamFn) }
+        }.toMutableList()
+        return newPages.removeFirst().stream?.invoke()
+            .also {
+                // Doing this first and then returning InputStream
+                // results in various issues with splitting
                 viewer.onLongStripSplit(page, newPages)
-        return toReturn
+            }
     }
 
     /**

app/src/main/java/eu/kanade/tachiyomi/util/system/ImageUtil.kt

@@ -268,8 +268,8 @@ object ImageUtil {
     /**
      * Split the imageStream according to the provided splitData
      */
-    fun splitStrip(imageStream: InputStream, splitData: SplitData): InputStream {
-        val bitmapRegionDecoder = getBitmapRegionDecoder(imageStream)
+    fun splitStrip(splitData: SplitData, streamFn: () -> InputStream): InputStream {
+        val bitmapRegionDecoder = getBitmapRegionDecoder(streamFn())
             ?: throw Exception("Failed to create new instance of BitmapRegionDecoder")
 
         logcat {