src/main/kotlin/net/pterodactylus/sone/template/ShortenFilter.kt

   1 package net.pterodactylus.sone.template
   2
   3 import net.pterodactylus.sone.text.LinkPart
   4 import net.pterodactylus.sone.text.Part
   5 import net.pterodactylus.sone.text.PlainTextPart
   6 import net.pterodactylus.util.template.Filter
   7 import net.pterodactylus.util.template.TemplateContext
   8 import java.util.*
   9
  10 /**
  11  * [Filter] that shortens a number of [Part]s in order to restrict the maximum visible text length.
  12  */
  13 class ShortenFilter : Filter {
  14
  15         override fun format(templateContext: TemplateContext?, data: Any?, parameters: Map<String, Any?>?): Any? {
  16                 @Suppress("UNCHECKED_CAST")
  17                 val parts = data as? Iterable<Part> ?: return null
  18                 val length = parameters?.parseInt("length") ?: -1
  19                 val cutOffLength = parameters?.parseInt("cut-off-length") ?: length
  20                 if (length > -1) {
  21                         var allPartsLength = 0
  22                         val shortenedParts = ArrayList<Part>()
  23                         for (part in parts) {
  24                                 if (part is PlainTextPart) {
  25                                         val longText = part.text
  26                                         if (allPartsLength < cutOffLength) {
  27                                                 if (allPartsLength + longText.length > cutOffLength) {
  28                                                         shortenedParts.add(PlainTextPart(longText.substring(0, cutOffLength - allPartsLength) + "…"))
  29                                                 } else {
  30                                                         shortenedParts.add(part)
  31                                                 }
  32                                         }
  33                                         allPartsLength += longText.length
  34                                 } else if (part is LinkPart) {
  35                                         if (allPartsLength < cutOffLength) {
  36                                                 shortenedParts.add(part)
  37                                         }
  38                                         allPartsLength += part.text.length
  39                                 } else {
  40                                         if (allPartsLength < cutOffLength) {
  41                                                 shortenedParts.add(part)
  42                                         }
  43                                 }
  44                         }
  45                         if (allPartsLength > length) {
  46                                 return shortenedParts
  47                         }
  48                 }
  49                 return parts
  50         }
  51
  52         private fun Map<String, Any?>.parseInt(key: String) = this[key]?.toString()?.toInt()
  53
  54 }