GrindrPlus Fix taps scroll

* Fix scroll mechanism upon clicking tap notifications

* From #48

app/src/main/java/com/grindrplus/hooks/ReverseRadarTabs.kt

@@ -11,9 +11,12 @@ import com.grindrplus.utils.HookStage
 import com.grindrplus.utils.hook
 import com.grindrplus.utils.hookConstructor
 import de.robv.android.xposed.XposedHelpers
+import de.robv.android.xposed.XposedHelpers.*
+import java.lang.Thread.sleep
 import java.util.ArrayList
 import java.util.Arrays
 import java.util.Collections
+import kotlin.concurrent.thread
 
 class ReverseRadarTabs : Hook(
     "Reverse radar tabs",
@@ -45,7 +48,7 @@ class ReverseRadarTabs : Hook(
                 //viewPagerClass.getMethod("setCurrentItem", Int::class.java).invoke(viewPager, 1)
             }*/
 
-        val radarTabs = XposedHelpers.callStaticMethod(findClass(radarTabs), "values") as Array<*>
+        val radarTabs = callStaticMethod(findClass(radarTabs), "values") as Array<*>
 
         findClass("$radarFragment\$a")
             .hookConstructor(HookStage.BEFORE) { param ->
@@ -57,14 +60,36 @@ class ReverseRadarTabs : Hook(
             }
 
 
-        //Unfortunately, some methods in RadarFragment use the ordinal of the RadarTab enum to determine the position in the TabLayout
+        //Unfortunately, some methods in RadarFragment use the ordinal of the RadarTab enum to determine the position in the TabLayout,
+        //which no longer reflects the actual position in the ViewPager
         findClass("com.google.android.material.tabs.TabLayout")
             .hook("getTabAt", HookStage.BEFORE) { param ->
                 if (!Thread.currentThread().stackTrace.any {
                         it.className.contains(radarFragment)
                     }) return@hook
                 param.setArg(0, radarTabs.size - 1 - param.arg<Int>(0))
             }
+
+        //This LiveData observer consumes the integer values from a flow and makes the ViewPager scroll to that position
+        //This is used to make the ViewPager scroll to the taps page upon clicking such notification.
+        //However, this is based on the ordinal values again, so we have to reverse the values, too.
+        findClass("K9.H0")
+            .hook("onChanged", HookStage.BEFORE) { param ->
+                //Check whether this observer is responsible for handling the ViewPager position
+                if (getIntField(param.thisObject(), "b") != 1) return@hook
+                val position = param.arg<Number>(0).toInt()
+                param.setArg(0, Integer.valueOf(radarTabs.size - 1 - position))
+            }
+
+        //The modified LiveData observer will no longer scroll to the first position when receiving a value 0.
+        //In order to still show the new first tab (TapsFragment) by default, we need to set the initial value to the last index,
+        //so that the LiveData observer reverts it back to 0.
+        findClass("ma.t0")
+            .hookConstructor(HookStage.AFTER) { param ->
+                val stateFlow = getObjectField(param.thisObject(), "I0")
+                //Set initial position to the last page, so that the onChanged hook of the LiveData observer reverts it to the new first page
+                callMethod(stateFlow, "setValue", Integer.valueOf(radarTabs.size - 1))
+            }
     }
 
 }