Indicate obsolete extensions (#2494)

* Indicate obsolete extensions

* Make obsolete indicators red

* Move obsolete extensions up the list

* Add base button theme for holder

* Use red button color state instead of explicit text color

app/src/main/java/eu/kanade/tachiyomi/extension/ExtensionManager.kt

@@ -71,7 +71,7 @@ class ExtensionManager(
         private set(value) {
             field = value
             availableExtensionsRelay.call(value)
-            setUpdateFieldOfInstalledExtensions(value)
+            updatedInstalledExtensionsStatuses(value)
         }
 
     /**
@@ -158,18 +158,25 @@ class ExtensionManager(
      *
      * @param availableExtensions The list of extensions given by the [api].
      */
-    private fun setUpdateFieldOfInstalledExtensions(availableExtensions: List<Extension.Available>) {
+    private fun updatedInstalledExtensionsStatuses(availableExtensions: List<Extension.Available>) {
         val mutInstalledExtensions = installedExtensions.toMutableList()
         var changed = false
 
         for ((index, installedExt) in mutInstalledExtensions.withIndex()) {
             val pkgName = installedExt.pkgName
-            val availableExt = availableExtensions.find { it.pkgName == pkgName } ?: continue
+            val availableExt = availableExtensions.find { it.pkgName == pkgName }
 
-            val hasUpdate = availableExt.versionCode > installedExt.versionCode
-            if (installedExt.hasUpdate != hasUpdate) {
-                mutInstalledExtensions[index] = installedExt.copy(hasUpdate = hasUpdate)
-                changed = true
+            if (availableExt == null) {
+                if (!installedExt.isObsolete) {
+                    mutInstalledExtensions[index] = installedExt.copy(isObsolete = true)
+                    changed = true
+                }
+            } else {
+                val hasUpdate = availableExt.versionCode > installedExt.versionCode
+                if (installedExt.hasUpdate != hasUpdate) {
+                    mutInstalledExtensions[index] = installedExt.copy(hasUpdate = hasUpdate)
+                    changed = true
+                }
             }
         }
         if (changed) {

app/src/main/java/eu/kanade/tachiyomi/extension/model/Extension.kt

@@ -16,7 +16,8 @@ sealed class Extension {
                          override val versionCode: Int,
                          val sources: List<Source>,
                          override val lang: String,
-                         val hasUpdate: Boolean = false) : Extension()
+                         val hasUpdate: Boolean = false,
+                         val isObsolete: Boolean = false) : Extension()
 
     data class Available(override val name: String,
                          override val pkgName: String,