Move preference extension functions to utils

app/src/main/java/eu/kanade/tachiyomi/util/preference/PreferenceExtensions.kt

@@ -2,6 +2,8 @@ package eu.kanade.tachiyomi.util.preference
 
 import android.widget.CompoundButton
 import com.tfcporciuncula.flow.Preference
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.onEach
 
 /**
  * Binds a checkbox or switch view with a boolean preference.
@@ -10,3 +12,22 @@ fun CompoundButton.bindToPreference(pref: Preference<Boolean>) {
     isChecked = pref.get()
     setOnCheckedChangeListener { _, isChecked -> pref.set(isChecked) }
 }
+
+fun <T> Preference<T>.asImmediateFlow(block: (T) -> Unit): Flow<T> {
+    block(get())
+    return asFlow()
+        .onEach { block(it) }
+}
+
+operator fun <T> Preference<Set<T>>.plusAssign(item: T) {
+    set(get() + item)
+}
+
+operator fun <T> Preference<Set<T>>.minusAssign(item: T) {
+    set(get() - item)
+}
+
+fun Preference<Boolean>.toggle(): Boolean {
+    set(!get())
+    return get()
+}