searchfilters: ViewModel for SearchFragment* and SearchFilter*DialogFragment

The ViewModel that hosts the search filters logic. It facilitates
the communication with the SearchFragment* and the
SearchFilter*DialogFragment based search filter UI's

Author: evermind-zz

app/src/main/java/org/schabi/newpipe/fragments/list/search/SearchViewModel.kt

@@ -0,0 +1,99 @@
+package org.schabi.newpipe.fragments.list.search
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewmodel.initializer
+import androidx.lifecycle.viewmodel.viewModelFactory
+import org.schabi.newpipe.extractor.NewPipe
+import org.schabi.newpipe.extractor.search.filter.FilterItem
+import org.schabi.newpipe.fragments.list.search.filter.InjectFilterItem
+import org.schabi.newpipe.fragments.list.search.filter.SearchFilterLogic
+import org.schabi.newpipe.fragments.list.search.filter.SearchFilterLogic.Factory.Variant
+
+/**
+ * This class hosts the search filters logic. It facilitates
+ * the communication with the SearchFragment* and the *DialogFragment
+ * based search filter UI's
+ */
+class SearchViewModel(
+    val serviceId: Int,
+    logicVariant: Variant,
+    userSelectedContentFilterList: List<Int>,
+    userSelectedSortFilterList: List<Int>
+) : ViewModel() {
+
+    private val selectedContentFilterMutableLiveData: MutableLiveData<MutableList<FilterItem>> =
+        MutableLiveData()
+    private var selectedSortFilterLiveData: MutableLiveData<MutableList<FilterItem>> =
+        MutableLiveData()
+    private var userSelectedSortFilterListMutableLiveData: MutableLiveData<ArrayList<Int>> =
+        MutableLiveData()
+    private var userSelectedContentFilterListMutableLiveData: MutableLiveData<ArrayList<Int>> =
+        MutableLiveData()
+    private var doSearchMutableLiveData: MutableLiveData<Boolean> = MutableLiveData()
+
+    val selectedContentFilterItemListLiveData: LiveData<MutableList<FilterItem>>
+        get() = selectedContentFilterMutableLiveData
+    val selectedSortFilterItemListLiveData: LiveData<MutableList<FilterItem>>
+        get() = selectedSortFilterLiveData
+    val userSelectedContentFilterListLiveData: LiveData<ArrayList<Int>>
+        get() = userSelectedContentFilterListMutableLiveData
+    val userSelectedSortFilterListLiveData: LiveData<ArrayList<Int>>
+        get() = userSelectedSortFilterListMutableLiveData
+    val doSearchLiveData: LiveData<Boolean>
+        get() = doSearchMutableLiveData
+
+    var searchFilterLogic: SearchFilterLogic
+
+    init {
+        // inject before creating SearchFilterLogic
+        InjectFilterItem.DividerBetweenYoutubeAndYoutubeMusic.run()
+
+        searchFilterLogic = SearchFilterLogic.Factory.create(
+            logicVariant,
+            NewPipe.getService(serviceId).searchQHFactory, null
+        )
+        searchFilterLogic.restorePreviouslySelectedFilters(
+            userSelectedContentFilterList,
+            userSelectedSortFilterList
+        )
+
+        searchFilterLogic.setCallback { userSelectedContentFilter: List<FilterItem?>,
+            userSelectedSortFilter: List<FilterItem?> ->
+            selectedContentFilterMutableLiveData.value =
+                userSelectedContentFilter as MutableList<FilterItem>
+            selectedSortFilterLiveData.value =
+                userSelectedSortFilter as MutableList<FilterItem>
+            userSelectedContentFilterListMutableLiveData.value =
+                searchFilterLogic.selectedContentFilters
+            userSelectedSortFilterListMutableLiveData.value =
+                searchFilterLogic.selectedSortFilters
+
+            doSearchMutableLiveData.value = true
+        }
+    }
+
+    fun weConsumedDoSearchLiveData() {
+        doSearchMutableLiveData.value = false
+    }
+
+    companion object {
+
+        fun getFactory(
+            serviceId: Int,
+            logicVariant: Variant,
+            userSelectedContentFilterList: ArrayList<Int>,
+            userSelectedSortFilterList: ArrayList<Int>
+        ) = viewModelFactory {
+            initializer {
+                SearchViewModel(
+                    serviceId,
+                    logicVariant,
+                    userSelectedContentFilterList,
+                    userSelectedSortFilterList
+                )
+            }
+        }
+    }
+}