Get rid of unnecessary callbacks.

pennlabs · Feb 8, 2024 · b892c7f · b892c7f
1 parent ce424c8
commit b892c7f
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Showing 2 changed files with 30 additions and 33 deletions.
diff --git a/PennMobile/src/main/java/com/pennapps/labs/pennmobile/HomeFragment.kt b/PennMobile/src/main/java/com/pennapps/labs/pennmobile/HomeFragment.kt
@@ -31,6 +31,7 @@ import kotlinx.android.synthetic.main.include_main.*
 import kotlinx.android.synthetic.main.loading_panel.*
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import java.util.*
 
 class HomeFragment : Fragment() {
@@ -165,24 +166,21 @@ class HomeFragment : Fragment() {
             lifecycleScope.launch(Dispatchers.Default) {
                 // set adapter if it is null
                 if (binding.homeCellsRv.adapter == null) {
-                    homepageViewModel.populateHomePageCells(studentLife, bearerToken, deviceID) {
-                        mActivity.runOnUiThread {
-                            binding.homeCellsRv.adapter = HomeAdapter(homepageViewModel)
-                            binding.homeCellsRv.visibility = View.INVISIBLE
-                            binding.internetConnectionHome.visibility = View.GONE
-                            binding.homeRefreshLayout.isRefreshing = false
-                        }
+                    homepageViewModel.populateHomePageCells(studentLife, bearerToken, deviceID)
+                    withContext(Dispatchers.Main) {
+                        binding.homeCellsRv.adapter = HomeAdapter(homepageViewModel)
+                        binding.homeCellsRv.visibility = View.INVISIBLE
+                        binding.internetConnectionHome.visibility = View.GONE
+                        binding.homeRefreshLayout.isRefreshing = false
                     }
                 } else { // otherwise, call updateHomePageCells which only updates the cells that are changed
-                    homepageViewModel.updateHomePageCells(studentLife, bearerToken, deviceID, { pos ->
-                       mActivity.runOnUiThread {
-                           binding.homeCellsRv.adapter!!.notifyItemChanged(pos)
-                       }
-                    }, {
-                       mActivity.runOnUiThread {
-                           binding.homeRefreshLayout.isRefreshing = false
-                       }
-                    })
+                    val updatedIndices = homepageViewModel.updateHomePageCells(studentLife, bearerToken, deviceID)
+                    withContext(Dispatchers.Main) {
+                        updatedIndices.forEach { pos ->
+                            binding.homeCellsRv.adapter!!.notifyItemChanged(pos)
+                        }
+                        binding.homeRefreshLayout.isRefreshing = false
+                    }
                 }
             }
         }

diff --git a/PennMobile/src/main/java/com/pennapps/labs/pennmobile/classes/HomepageViewModel.kt b/PennMobile/src/main/java/com/pennapps/labs/pennmobile/classes/HomepageViewModel.kt
@@ -96,34 +96,34 @@ class HomepageViewModel : HomepageDataModel, ViewModel() {
     }
 
     /**
-     * Updates each homepage cell. If a cell changes, then update is called with the index of the
-     * cell that was changed (created with the intention to play nice with RecyclerView and is used
-     * in conjunction with NotifyItemChanged().
+     * Returns a list of updated cell positions.
      */
     @Synchronized
-    fun updateHomePageCells(studentLife: StudentLife, bearerToken: String, deviceID: String,
-                              update: (Int) -> Unit, callback: () -> Unit) {
+    fun updateHomePageCells(studentLife: StudentLife, bearerToken: String,
+                            deviceID: String) : List<Int> {
         val prevList = homepageCells.toList()
-        populateHomePageCells(studentLife, bearerToken, deviceID) {
-            for (i in 0 until NUM_CELLS) {
-                if (prevList[i] != homepageCells[i]) {
-                    update(i)
-                    Log.i("CellUpdates", "updated index ${i}")
-                } else {
-                    Log.i("CellUpdates", "saved an update at index ${i}")
-                }
+        populateHomePageCells(studentLife, bearerToken, deviceID)
+
+        val updatedIndices = mutableListOf<Int>()
+
+        for (i in 0 until NUM_CELLS) {
+            if (prevList[i] != homepageCells[i]) {
+                updatedIndices.add(i);
+                Log.i("CellUpdates", "updated index ${i}")
+            } else {
+                Log.i("CellUpdates", "saved an update at index ${i}")
             }
-            callback.invoke()
         }
+
+        return updatedIndices
     }
 
     /**
      * Makes the network requests that populates the Homepage Cells.
      * This function requires a correct (non-expired) bearerToken!!
      */
     @Synchronized
-    fun populateHomePageCells(studentLife: StudentLife, bearerToken: String, deviceID: String,
-                              callback: () -> Unit) {
+    fun populateHomePageCells(studentLife: StudentLife, bearerToken: String, deviceID: String) {
         val isLoggedIn = bearerToken != "Bearer "
 
         if (isLoggedIn) {
@@ -143,7 +143,6 @@ class HomepageViewModel : HomepageDataModel, ViewModel() {
             getNews(studentLife, latch)
             latch.await()
         }
-        callback.invoke()
     }
 
     /**