Add help shortcut for source migration (closes #3951)

(cherry picked from commit 56c19e57a9c062341c848975a150ca21d151006e)

# Conflicts:
#	app/src/main/java/eu/kanade/tachiyomi/ui/browse/migration/sources/MigrationSourcesController.kt

app/src/main/java/eu/kanade/tachiyomi/ui/browse/migration/sources/MigrationSourcesController.kt

@@ -1,6 +1,9 @@
 package eu.kanade.tachiyomi.ui.browse.migration.sources
 
 import android.view.LayoutInflater
+import android.view.Menu
+import android.view.MenuInflater
+import android.view.MenuItem
 import android.view.View
 import android.view.ViewGroup
 import androidx.recyclerview.widget.LinearLayoutManager
@@ -16,6 +19,7 @@ import eu.kanade.tachiyomi.ui.browse.migration.advanced.design.PreMigrationContr
 import eu.kanade.tachiyomi.ui.browse.migration.manga.MigrationMangaController
 import eu.kanade.tachiyomi.util.lang.await
 import eu.kanade.tachiyomi.util.lang.launchUI
+import eu.kanade.tachiyomi.util.system.openInBrowser
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import rx.schedulers.Schedulers
@@ -31,6 +35,10 @@ class MigrationSourcesController :
 
     private var adapter: SourceAdapter? = null
 
+    init {
+        setHasOptionsMenu(true)
+    }
+
     override fun createPresenter(): MigrationSourcesPresenter {
         return MigrationSourcesPresenter()
     }
@@ -54,6 +62,17 @@ class MigrationSourcesController :
         super.onDestroyView(view)
     }
 
+    override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
+        inflater.inflate(R.menu.source_migration, menu)
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        when (item.itemId) {
+            R.id.action_source_migration_help -> activity?.openInBrowser(HELP_URL)
+        }
+        return super.onOptionsItemSelected(item)
+    }
+
     fun setSources(sourcesWithManga: List<SourceItem>) {
         adapter?.updateDataSet(sourcesWithManga)
     }
@@ -95,4 +114,8 @@ class MigrationSourcesController :
         }
     }
     // SY <--
+
+    companion object {
+        const val HELP_URL = "https://tachiyomi.org/help/guides/source-migration/"
+    }
 }

app/src/main/res/menu/source_migration.xml

@@ -0,0 +1,11 @@
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <item
+        android:id="@+id/action_source_migration_help"
+        android:icon="@drawable/ic_help_24dp"
+        android:title="@string/migration_help_guide"
+        app:iconTint="?attr/colorOnPrimary"
+        app:showAsAction="ifRoom" />
+
+</menu>

app/src/main/res/values/strings.xml

@@ -622,6 +622,7 @@
     <string name="recent_manga_time">Ch. %1$s - %2$s</string>
 
     <!-- Source migration screen -->
+    <string name="migration_help_guide">Source migration guide</string>
     <string name="migration_info">Tap to select the source to migrate from</string>
     <string name="migration_dialog_what_to_include">Select data to include</string>
     <string name="migration_selection_prompt">Select a source to migrate from</string>