Always show missing chapter warning if there are missing chapters (#3755)

* Always show missing chapter warning if there are missing chapters

* Change function parameter names

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

@@ -0,0 +1,15 @@
+package eu.kanade.tachiyomi.ui.reader.viewer
+
+import eu.kanade.tachiyomi.data.database.models.Chapter
+import kotlin.math.floor
+
+object MissingChapters {
+
+    fun hasMissingChapters(higher: Chapter, lower: Chapter): Boolean {
+        return hasMissingChapters(higher.chapter_number, lower.chapter_number)
+    }
+
+    fun hasMissingChapters(higherChapterNumber: Float, lowerChapterNumber: Float): Boolean {
+        return floor(higherChapterNumber) - floor(lowerChapterNumber) - 1f > 0f
+    }
+}

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

@@ -92,7 +92,10 @@ class ReaderTransitionView @JvmOverloads constructor(context: Context, attrs: At
             is ChapterTransition.Next -> toChapterNumber - fromChapterNumber - 1f
         }
 
-        val hasMissingChapters = chapterDifference > 0f
+        val hasMissingChapters = when (transition) {
+            is ChapterTransition.Prev -> MissingChapters.hasMissingChapters(fromChapterNumber, toChapterNumber)
+            is ChapterTransition.Next -> MissingChapters.hasMissingChapters(toChapterNumber, fromChapterNumber)
+        }
 
         warning_text.text = resources.getQuantityString(R.plurals.missing_chapters_warning, chapterDifference.toInt(), chapterDifference.toInt())
         warning.isVisible = hasMissingChapters

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewerAdapter.kt

@@ -6,6 +6,7 @@ import eu.kanade.tachiyomi.ui.reader.model.ChapterTransition
 import eu.kanade.tachiyomi.ui.reader.model.ReaderChapter
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.ui.reader.model.ViewerChapters
+import eu.kanade.tachiyomi.ui.reader.viewer.MissingChapters
 import eu.kanade.tachiyomi.widget.ViewPagerAdapter
 import timber.log.Timber
 
@@ -33,6 +34,10 @@ class PagerViewerAdapter(private val viewer: PagerViewer) : ViewPagerAdapter() {
     fun setChapters(chapters: ViewerChapters, forceTransition: Boolean) {
         val newItems = mutableListOf<Any>()
 
+        // Forces chapter transition if there is missing chapters
+        val prevHasMissingChapters = if (chapters.prevChapter != null) MissingChapters.hasMissingChapters(chapters.currChapter.chapter, chapters.prevChapter.chapter) else false
+        val nextHasMissingChapters = if (chapters.nextChapter != null) MissingChapters.hasMissingChapters(chapters.nextChapter.chapter, chapters.currChapter.chapter) else false
+
         // Add previous chapter pages and transition.
         if (chapters.prevChapter != null) {
             // We only need to add the last few pages of the previous chapter, because it'll be
@@ -44,7 +49,7 @@ class PagerViewerAdapter(private val viewer: PagerViewer) : ViewPagerAdapter() {
         }
 
         // Skip transition page if the chapter is loaded & current page is not a transition page
-        if (forceTransition || chapters.prevChapter?.state !is ReaderChapter.State.Loaded) {
+        if (prevHasMissingChapters || forceTransition || chapters.prevChapter?.state !is ReaderChapter.State.Loaded) {
             newItems.add(ChapterTransition.Prev(chapters.currChapter, chapters.prevChapter))
         }
 
@@ -59,7 +64,7 @@ class PagerViewerAdapter(private val viewer: PagerViewer) : ViewPagerAdapter() {
         // Add next chapter transition and pages.
         nextTransition = ChapterTransition.Next(chapters.currChapter, chapters.nextChapter)
             .also {
-                if (forceTransition ||
+                if (nextHasMissingChapters || forceTransition ||
                     chapters.nextChapter?.state !is ReaderChapter.State.Loaded
                 ) {
                     newItems.add(it)

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

@@ -9,6 +9,7 @@ import eu.kanade.tachiyomi.ui.reader.model.ChapterTransition
 import eu.kanade.tachiyomi.ui.reader.model.ReaderChapter
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.ui.reader.model.ViewerChapters
+import eu.kanade.tachiyomi.ui.reader.viewer.MissingChapters
 
 /**
  * RecyclerView Adapter used by this [viewer] to where [ViewerChapters] updates are posted.
@@ -29,6 +30,10 @@ class WebtoonAdapter(val viewer: WebtoonViewer) : RecyclerView.Adapter<RecyclerV
     fun setChapters(chapters: ViewerChapters, forceTransition: Boolean) {
         val newItems = mutableListOf<Any>()
 
+        // Forces chapter transition if there is missing chapters
+        val prevHasMissingChapters = if (chapters.prevChapter != null) MissingChapters.hasMissingChapters(chapters.currChapter.chapter, chapters.prevChapter.chapter) else false
+        val nextHasMissingChapters = if (chapters.nextChapter != null) MissingChapters.hasMissingChapters(chapters.nextChapter.chapter, chapters.currChapter.chapter) else false
+
         // Add previous chapter pages and transition.
         if (chapters.prevChapter != null) {
             // We only need to add the last few pages of the previous chapter, because it'll be
@@ -40,7 +45,7 @@ class WebtoonAdapter(val viewer: WebtoonViewer) : RecyclerView.Adapter<RecyclerV
         }
 
         // Skip transition page if the chapter is loaded & current page is not a transition page
-        if (forceTransition || chapters.prevChapter?.state !is ReaderChapter.State.Loaded) {
+        if (prevHasMissingChapters || forceTransition || chapters.prevChapter?.state !is ReaderChapter.State.Loaded) {
             newItems.add(ChapterTransition.Prev(chapters.currChapter, chapters.prevChapter))
         }
 
@@ -53,7 +58,7 @@ class WebtoonAdapter(val viewer: WebtoonViewer) : RecyclerView.Adapter<RecyclerV
         currentChapter = chapters.currChapter
 
         // Add next chapter transition and pages.
-        if (forceTransition || chapters.nextChapter?.state !is ReaderChapter.State.Loaded) {
+        if (nextHasMissingChapters || forceTransition || chapters.nextChapter?.state !is ReaderChapter.State.Loaded) {
             newItems.add(ChapterTransition.Next(chapters.currChapter, chapters.nextChapter))
         }