Add spans for chapter start and verse superscript

Needs serious refactoring, but quickly approaching a minimally viable product. This is awesome.

app/src/main/kotlin/org/bspeice/minimalbible/activity/viewer/BookAdapter.kt

@@ -12,6 +12,11 @@ import org.crosswire.jsword.versification.BibleBook
 import org.bspeice.minimalbible.activity.viewer.BookAdapter.ChapterInfo
 import rx.subjects.PublishSubject
 import org.bspeice.minimalbible.service.lookup.VerseLookup
+import android.text.SpannableStringBuilder
+import android.text.style.StyleSpan
+import android.graphics.Typeface
+import android.text.style.SuperscriptSpan
+import android.text.style.RelativeSizeSpan
 
 /**
  * Adapter used for displaying a book
@@ -25,8 +30,16 @@ class BookAdapter(val b: Book, val lookup: VerseLookup)
     val bookList = versification.getBooks()
     val chapterCount = bookList.map { versification.getLastChapter(it) - 1 }.sum()
 
+    /**
+     * Store information needed to decode the text of a chapter
+     * Book, chapter, and bibleBook should be pretty self-explanatory
+     * The vStart, vEnd, and vOffset are needed to map between verses relative to their chapter,
+     * and the actual verse ordinal needed for parsing the text.
+     * So Genesis 1:1 would be chapter 1, bibleBook Genesis, vStart 1, vOffset 2
+     * since it actually starts at ordinal 3
+     */
     data class ChapterInfo(val book: Book, val chapter: Int, val bibleBook: BibleBook,
-                           val vStart: Int, val vEnd: Int)
+                           val vStart: Int, val vEnd: Int, val vOffset: Int)
 
     /**
      * A list of all ChapterInfo objects needed for displaying a book
@@ -37,17 +50,22 @@ class BookAdapter(val b: Book, val lookup: VerseLookup)
      *  } yield ChapterInfo(...)
      *
      *  Also note that getLastVerse() returns the number of verses in a chapter,
-     *  so we build the actual last verse by adding getFirstVerse and getLastVerse
+     *  not the actual last verse's ordinal
      */
     // TODO: Lazy compute values needed for this list
     val chapterList: List<ChapterInfo> = bookList.flatMap {
         val currentBook = it
         (1..versification.getLastChapter(currentBook)).map {
-            val firstVerse = versification.getFirstVerse(currentBook, it)
+            val firstVerseOrdinal = versification.getFirstVerse(currentBook, it)
+            val verseOrdinalOffset = firstVerseOrdinal - 1
             val verseCount = versification.getLastVerse(currentBook, it)
-            ChapterInfo(b, it, currentBook, firstVerse, firstVerse + verseCount)
+            val firstVerseRelative = 1
+            val lastVerseRelative = firstVerseRelative + verseCount
+
+            ChapterInfo(b, it, currentBook,
+                    firstVerseRelative, lastVerseRelative, verseOrdinalOffset)
         }
-    };
+    }
 
     /**
      * I'm not sure what the position argument actually represents,
@@ -94,13 +112,82 @@ class BookAdapter(val b: Book, val lookup: VerseLookup)
 class PassageView(val v: TextView, val b: Book, val lookup: VerseLookup)
 : RecyclerView.ViewHolder(v) {
 
-    fun getVerseText(verseRange: Progression<Int>) =
-            verseRange.map { lookup.getText(b.getVersification().decodeOrdinal(it)) }
+    // Span to be applied to an individual verse - doesn't know about the sizes
+    // of other verses so that's why start and end are relative
+    /**
+     * A holder object that knows how apply itself to a SpannableStringBuilder
+     * Since we don't know ahead of time where this verse will end up relative to the
+     * entire TextView (since there is one chapter per TextView) we use a start and end
+     * relative to the verse text itself. That is, rStart of 0 indicates verse text start,
+     * and rEnd of (text.length - 1) indicates the end of verse text
+     * @param span The span object we should apply
+     * @param rStart When the span should begin, relative to the verse
+     * @param rEnd When the span should end, relative to the verse
+     */
+    data class SpanHolder(val span: Any?, val rStart: Int, val rEnd: Int) {
+        // TODO: Is there a more case-class like way of doing this?
+        class object {
+            val EMPTY = SpanHolder(null, 0, 0)
+        }
+        /**
+         * Apply this span object to the specified builder
+         * Tries to be as close to immutable as possible. The offset is used to calculate
+         * the absolute position of when this span should start and end, since
+         * rStart and rEnd are relative to the verse text, and know nothing about the
+         * rest of the text in the TextView
+         */
+        fun apply(builder: SpannableStringBuilder, offset: Int): SpannableStringBuilder {
+            if (span != null)
+                builder.setSpan(span, rStart + offset, rEnd + offset, 0)
+            return builder
+        }
+    }
 
-    fun reduceText(verses: List<String>) = verses.join(" ")
+    // TODO: getRawVerse shouldn't know how to decode ints
+    fun getRawVerse(verse: Int): String =
+            lookup.getText(b.getVersification().decodeOrdinal(verse))
+
+    // TODO: This code is nasty, not sure how to refactor, but it needs doing
+    fun getProcessedVerse(verseOrdinal: Int, info: ChapterInfo): Pair<String, List<SpanHolder>> {
+        val rawText = getRawVerse(verseOrdinal)
+        // To be honest, I have no idea why I need to subtract one. But I do.
+        val relativeVerse = verseOrdinal - info.vOffset - 1
+        val processedText = when (relativeVerse) {
+            0 -> ""
+            1 -> "${info.chapter} $rawText"
+            else -> "$relativeVerse$rawText"
+        }
+        val spans: List<SpanHolder> = listOf(
+                when (relativeVerse) {
+                    0 -> SpanHolder.EMPTY
+                    1 -> SpanHolder(StyleSpan(Typeface.BOLD), 0, info.chapter.toString().length)
+                    else -> SpanHolder(SuperscriptSpan(), 0, relativeVerse.toString().length)
+                }
+        )
+        val secondSpan =
+                if (relativeVerse > 1)
+                // TODO: No magic numbers!
+                    spans plus SpanHolder(RelativeSizeSpan(0.6f), 0, relativeVerse.toString().length)
+                else
+                    spans
+
+        return Pair(processedText, secondSpan)
+    }
+
+    fun getAllVerses(verses: Progression<Int>, info: ChapterInfo) =
+            verses.map { getProcessedVerse(it + info.vOffset, info) }
+                    // For each verse, get the text
+                    .fold(SpannableStringBuilder(), { initialBuilder, versePair ->
+                        val offset = initialBuilder.length()
+                        val builderWithText = initialBuilder append versePair.first
+
+                        // And apply all spans
+                        versePair.second.fold(builderWithText, { postBuilder, span ->
+                            span.apply(postBuilder, offset)
+                        })
+                    })
 
-    // Uses functional style, but those parentheses man... you'd think I was writing LISP
     fun bind(info: ChapterInfo) {
-        v.setText(reduceText(getVerseText(info.vStart..info.vEnd)))
+        v setText getAllVerses(info.vStart..info.vEnd, info)
     }
 }