Add swipe to refresh

app/build.gradle

@@ -48,6 +48,7 @@ dependencies {
     implementation "androidx.work:work-runtime-ktx:2.2.0"
     implementation "androidx.room:room-runtime:2.2.0-rc01"
     implementation 'androidx.preference:preference:1.1.0'
+    implementation 'androidx.swiperefreshlayout:swiperefreshlayout:1.0.0'
     kapt "androidx.room:room-compiler:2.2.0-rc01"
     implementation "androidx.room:room-ktx:2.2.0-rc01"
     testImplementation 'junit:junit:4.12'

app/src/main/java/net/underdesk/circolapp/MainActivity.kt

@@ -48,6 +48,7 @@ class MainActivity : AppCompatActivity(), CircularLetterAdapter.AdapterCallback
     }
 
     var searchCallback: SearchCallback? = null
+    var refreshCallback: RefreshCallback? = null
     override var circularToDownload: Circular? = null
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -103,6 +104,10 @@ class MainActivity : AppCompatActivity(), CircularLetterAdapter.AdapterCallback
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
         // Handle item selection
         return when (item.itemId) {
+            R.id.menu_main_refresh -> {
+                refreshCallback?.refresh()
+                true
+            }
             R.id.menu_main_settings -> {
                 startActivity(Intent(this, SettingsActivity::class.java))
                 true
@@ -176,4 +181,8 @@ class MainActivity : AppCompatActivity(), CircularLetterAdapter.AdapterCallback
     interface SearchCallback {
         fun search(query: String)
     }
+
+    interface RefreshCallback {
+        fun refresh()
+    }
 }

app/src/main/java/net/underdesk/circolapp/fragments/CircularLetterFragment.kt

@@ -28,13 +28,15 @@ import androidx.lifecycle.Observer
 import androidx.lifecycle.ViewModelProviders
 import androidx.recyclerview.widget.LinearLayoutManager
 import com.google.android.material.snackbar.Snackbar
+import kotlinx.android.synthetic.main.fragment_circular_letters.*
 import kotlinx.android.synthetic.main.fragment_circular_letters.view.*
 import net.underdesk.circolapp.MainActivity
 import net.underdesk.circolapp.R
 import net.underdesk.circolapp.adapters.CircularLetterAdapter
 import net.underdesk.circolapp.viewmodels.CircularLetterViewModel
 
-class CircularLetterFragment : Fragment(), MainActivity.SearchCallback {
+class CircularLetterFragment : Fragment(), MainActivity.SearchCallback,
+    MainActivity.RefreshCallback {
 
     private lateinit var circularLetterViewModel: CircularLetterViewModel
 
@@ -67,12 +69,27 @@ class CircularLetterFragment : Fragment(), MainActivity.SearchCallback {
                 circularLetterViewModel.showMessage.postValue(false)
             }
         })
+        circularLetterViewModel.circularsUpdated.observe(this, Observer {
+            if (it) {
+                root.circulars_refresh.isRefreshing = false
+
+                circularLetterViewModel.showMessage.postValue(false)
+            }
+        })
+
+        root.circulars_refresh.setOnRefreshListener { circularLetterViewModel.updateCirculars() }
 
         (activity as MainActivity).searchCallback = this
+        (activity as MainActivity).refreshCallback = this
         return root
     }
 
     override fun search(query: String) {
         circularLetterViewModel.query.postValue(query)
     }
+
+    override fun refresh() {
+        circulars_refresh.isRefreshing = true
+        circularLetterViewModel.updateCirculars()
+    }
 }

app/src/main/java/net/underdesk/circolapp/fragments/FavouritesFragment.kt

@@ -44,6 +44,7 @@ class FavouritesFragment : Fragment(), MainActivity.SearchCallback {
         val root = inflater.inflate(R.layout.fragment_circular_letters, container, false)
 
         root.circulars_list.layoutManager = LinearLayoutManager(context)
+        root.circulars_refresh.isEnabled = false
 
         favouritesViewModel =
             ViewModelProviders.of(this).get(FavouritesViewModel::class.java)
@@ -56,6 +57,7 @@ class FavouritesFragment : Fragment(), MainActivity.SearchCallback {
         })
 
         (activity as MainActivity).searchCallback = this
+        (activity as MainActivity).refreshCallback = null
         return root
     }
 

app/src/main/java/net/underdesk/circolapp/fragments/RemindersFragment.kt

@@ -44,6 +44,7 @@ class RemindersFragment : Fragment(), MainActivity.SearchCallback {
         val root = inflater.inflate(R.layout.fragment_circular_letters, container, false)
 
         root.circulars_list.layoutManager = LinearLayoutManager(context)
+        root.circulars_refresh.isEnabled = false
 
         remindersViewModel =
             ViewModelProviders.of(this).get(RemindersViewModel::class.java)
@@ -56,6 +57,7 @@ class RemindersFragment : Fragment(), MainActivity.SearchCallback {
         })
 
         (activity as MainActivity).searchCallback = this
+        (activity as MainActivity).refreshCallback = null
         return root
     }
 

app/src/main/java/net/underdesk/circolapp/viewmodels/CircularLetterViewModel.kt

@@ -30,11 +30,7 @@ import java.io.IOException
 
 class CircularLetterViewModel(application: Application) : AndroidViewModel(application) {
     init {
-        object : Thread() {
+        updateCirculars()
-            override fun run() {
-                updateCirculars()
-            }
-        }.start()
     }
 
     val query = MutableLiveData<String>("")
@@ -47,18 +43,31 @@ class CircularLetterViewModel(application: Application) : AndroidViewModel(appli
     }
 
     val showMessage = MutableLiveData<Boolean>().apply { value = false }
+    val circularsUpdated = MutableLiveData<Boolean>().apply { value = false }
+    private var isNotUpdating = true
 
-    private fun updateCirculars() {
+    fun updateCirculars() {
-        val fetcher = DataFetcher()
+        if (isNotUpdating) {
+            object : Thread() {
+                override fun run() {
+                    isNotUpdating = false
+                    val fetcher = DataFetcher()
 
-        try {
+                    try {
-            val newCirculars = fetcher.getCircularsFromServer()
+                        val newCirculars = fetcher.getCircularsFromServer()
-            if (newCirculars.size != circulars.value?.size ?: true) {
+                        if (newCirculars.size != circulars.value?.size ?: true) {
-                AppDatabase.getInstance(getApplication()).circularDao().deleteAll()
+                            AppDatabase.getInstance(getApplication()).circularDao().deleteAll()
-                AppDatabase.getInstance(getApplication()).circularDao().insertAll(newCirculars)
+                            AppDatabase.getInstance(getApplication()).circularDao()
-            }
+                                .insertAll(newCirculars)
-        } catch (exception: IOException) {
+                        }
-            showMessage.postValue(true)
+                        circularsUpdated.postValue(true)
+                    } catch (exception: IOException) {
+                        showMessage.postValue(true)
+                    } finally {
+                        isNotUpdating = true
+                    }
+                }
+            }.start()
         }
     }
 }

app/src/main/res/layout/fragment_circular_letters.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.swiperefreshlayout.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/circulars_refresh"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
@@ -7,4 +8,4 @@
         android:id="@+id/circulars_list"
         android:layout_width="match_parent"
         android:layout_height="match_parent" />
-</androidx.constraintlayout.widget.ConstraintLayout>
+</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>

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

@@ -8,6 +8,10 @@
         android:title="@string/menu_search"
         app:actionViewClass="androidx.appcompat.widget.SearchView"
         app:showAsAction="ifRoom" />
+    <item
+        android:id="@+id/menu_main_refresh"
+        android:title="@string/menu_refresh"
+        app:showAsAction="never" />
     <item
         android:id="@+id/menu_main_settings"
         android:title="@string/title_settings" />

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

@@ -8,6 +8,7 @@
 
     <string name="menu_about">About</string>
     <string name="menu_search">Search</string>
+    <string name="menu_refresh">Refresh</string>
 
     <string name="preferences_general_header">General</string>
     <string name="preference_notifications_header">Notifications</string>