add error handling

Author: solygambas

10-mars-photos/.idea/deploymentTargetDropDown.xml

@@ -1,12 +1,14 @@
 package com.example.android.marsphotos
 
+import android.view.View
 import android.widget.ImageView
 import androidx.core.net.toUri
 import androidx.databinding.BindingAdapter
 import androidx.recyclerview.widget.RecyclerView
 import com.bumptech.glide.Glide
 import com.bumptech.glide.request.RequestOptions
 import com.example.android.marsphotos.network.MarsPhoto
+import com.example.android.marsphotos.overview.MarsApiStatus
 import com.example.android.marsphotos.overview.PhotoGridAdapter
 
 @BindingAdapter("imageUrl")
@@ -26,4 +28,21 @@ fun bindImage(imgView: ImageView, imgUrl: String?) {
 fun bindRecyclerView(recyclerView: RecyclerView, data: List<MarsPhoto>?) {
     val adapter = recyclerView.adapter as PhotoGridAdapter
     adapter.submitList(data)
+}
+
+@BindingAdapter("marsApiStatus")
+fun bindStatus(statusImageView: ImageView, status: MarsApiStatus?) {
+    when (status) {
+        MarsApiStatus.LOADING -> {
+            statusImageView.visibility = View.VISIBLE
+            statusImageView.setImageResource(R.drawable.loading_animation)
+        }
+        MarsApiStatus.ERROR -> {
+            statusImageView.visibility = View.VISIBLE
+            statusImageView.setImageResource(R.drawable.ic_connection_error)
+        }
+        MarsApiStatus.DONE -> {
+            statusImageView.visibility = View.GONE
+        }
+    }
 }

10-mars-photos/app/src/main/java/com/example/android/marsphotos/BindingAdapters.kt

@@ -24,16 +24,19 @@ import com.example.android.marsphotos.network.MarsApi
 import com.example.android.marsphotos.network.MarsPhoto
 import kotlinx.coroutines.launch
 
+enum class MarsApiStatus { LOADING, ERROR, DONE }
+
 /**
  * The [ViewModel] that is attached to the [OverviewFragment].
  */
 class OverviewViewModel : ViewModel() {
 
     // The internal MutableLiveData that stores the status of the most recent request
-    private val _status = MutableLiveData<String>()
+    private val _status = MutableLiveData<MarsApiStatus>()
 
     // The external immutable LiveData for the request status
-    val status: LiveData<String> = _status
+    val status: LiveData<MarsApiStatus>
+        get() = _status
 
     // LiveData for a single MarsProperty object
     /*private val _property = MutableLiveData<MarsPhoto>()
@@ -58,16 +61,18 @@ class OverviewViewModel : ViewModel() {
      */
     private fun getMarsPhotos() {
         viewModelScope.launch {
+            _status.value = MarsApiStatus.LOADING
             try {
 //                val listResult = MarsApi.retrofitService.getPhotos()
 //                _status.value = "Success: ${listResult.size} Mars photos retrieved"
                 /*if (listResult.isNotEmpty()) {
                     //_property.value = listResult[0]
                 }*/
                 _properties.value = MarsApi.retrofitService.getPhotos()
-                _status.value = "Success: Mars properties retrived"
+                _status.value = MarsApiStatus.DONE
             } catch (e: Exception) {
-                _status.value = "Failure: ${e.message}"
+                _status.value = MarsApiStatus.ERROR
+                _properties.value = ArrayList()
             }
         }
     }

10-mars-photos/app/src/main/java/com/example/android/marsphotos/overview/OverviewViewModel.kt

@@ -53,6 +53,14 @@
             app:spanCount="2"
             tools:itemCount="16"
             tools:listitem="@layout/grid_view_item"/>
-
+        <ImageView
+            android:id="@+id/status_image"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintLeft_toLeftOf="parent"
+            app:layout_constraintRight_toRightOf="parent"
+            app:layout_constraintTop_toTopOf="parent"
+            app:marsApiStatus="@{viewModel.status}" />
     </androidx.constraintlayout.widget.ConstraintLayout>
 </layout>