Added Android code

[wl-app.git] / Android / app / src / main / java / com / moiseum / wolnelektury / base / DataProvider.java

diff --git a/Android/app/src/main/java/com/moiseum/wolnelektury/base/DataProvider.java b/Android/app/src/main/java/com/moiseum/wolnelektury/base/DataProvider.java
new file mode 100644 (file)
index 0000000..a0663ba
--- /dev/null
+++ b/Android/app/src/main/java/com/moiseum/wolnelektury/base/DataProvider.java
@@ -0,0 +1,75 @@
+package com.moiseum.wolnelektury.base;
+
+import android.util.Log;
+
+import com.moiseum.wolnelektury.connection.RestClientCallback;
+
+import javax.annotation.Nullable;
+
+import retrofit2.Call;
+
+/**
+ * @author golonkos.
+ */
+
+public abstract class DataProvider<T, S> extends RestClientCallback<T, S> {
+
+       private final static String TAG = DataProvider.class.getSimpleName();
+
+       protected DataObserver<T> dataObserver;
+       protected String lastKeySlug = null;
+       private Call<T> call;
+
+       public DataProvider() {
+       }
+
+       public void setDataObserver(DataObserver<T> dataObserver) {
+               this.dataObserver = dataObserver;
+       }
+
+       @Override
+       public void onSuccess(T data) {
+               if (dataObserver != null) {
+                       dataObserver.onLoadSuccess(data);
+               }
+       }
+
+       @Override
+       public void onFailure(Exception e) {
+               Log.e(TAG, "Failed to load data", e);
+               if (dataObserver != null) {
+                       dataObserver.onLoadFailed(e);
+               }
+       }
+
+       @Override
+       public void onCancel() {
+               //nop
+       }
+
+       /**
+        * Invoked in order to load data.
+        * @param lastKey Last book slug for pagination. Can be null if there is no pagination.
+        */
+       public void load(@Nullable String lastKey) {
+               cancel();
+               lastKeySlug = lastKey;
+               call = WLApplication.getInstance().getRestClient().call(this, getServiceClass());
+               if (dataObserver != null) {
+                       dataObserver.onLoadStarted();
+               }
+       }
+
+       public void cancel() {
+               if (call != null) {
+                       call.cancel();
+                       call = null;
+               }
+       }
+
+       public void release() {
+               dataObserver = null;
+       }
+
+       protected abstract Class<S> getServiceClass();
+}