2024-05-07 ToDo App Commit 4

labs/TodoAndroid/app/src/main/java/at/htl/todo/MainActivity.java

@@ -10,6 +10,7 @@
 
 import javax.inject.Inject;
 
+import at.htl.todo.model.TodoService;
 import dagger.hilt.android.AndroidEntryPoint;
 
 @AndroidEntryPoint
@@ -23,11 +24,14 @@ public class MainActivity extends ComponentActivity {
     @Inject
     MainUiBuilder mainUiBuilder;
 
+    @Inject
+    TodoService todoService;
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         var url = config.getValue("json.placeholder.baseurl", String.class);
-        Log.i(TAG,url);
+        todoService.getAll();
         mainUiBuilder.buildContent(this);
     }
 }

labs/TodoAndroid/app/src/main/java/at/htl/todo/MainUiBuilder.kt

@@ -9,6 +9,10 @@ import androidx.activity.compose.setContent
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
+import androidx.compose.runtime.State
+import androidx.compose.runtime.rxjava3.subscribeAsState
+import at.htl.todo.model.Model
+import at.htl.todo.model.ModelStore
 import at.htl.todo.ui.theme.TodoAndroidTheme
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -18,6 +22,9 @@ class MainUiBuilder  {
 
     @Inject constructor(){}
 
+    @Inject
+    lateinit var modelStore: ModelStore
+
     fun buildContent(activity: ComponentActivity) {
         activity.setContent {
             TodoAndroidTheme {
@@ -26,7 +33,8 @@ class MainUiBuilder  {
                     modifier = Modifier.fillMaxSize(),
                     color = MaterialTheme.colorScheme.background
                 ) {
-                    Greeting("Android")
+                    val state = modelStore.pipe.subscribeAsState(initial = Model())
+                    Greeting(state)
                 }
             }
         }
@@ -35,9 +43,11 @@ class MainUiBuilder  {
 }
 
 @Composable
-fun Greeting(name: String, modifier: Modifier = Modifier) {
+fun Greeting(state: State<Model>, modifier: Modifier = Modifier) {
+
+
     Text(
-        text = "Hello $name!",
+        text = "Hello ${state.value.todos.size}!",
         modifier = modifier
     )
 }
@@ -46,7 +56,7 @@ fun Greeting(name: String, modifier: Modifier = Modifier) {
 @Composable
 fun GreetingPreview() {
     TodoAndroidTheme {
-        Greeting("Android")
+        //Greeting("Android")
     }
 }
 

labs/TodoAndroid/app/src/main/java/at/htl/todo/model/ModelStore.java

@@ -0,0 +1,19 @@
+package at.htl.todo.model;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import at.htl.todo.util.store.Store;
+
+/** This is our Storage area for <a href="https://redux.js.org/understanding/thinking-in-redux/three-principles">single source of truth</a> {@link Model}. */
+@Singleton
+public class ModelStore extends Store<Model> {
+    @Inject
+    ModelStore() {
+        super(Model.class, new Model());
+    }
+    public void setTodos(Todo[] todos) {
+        apply(model -> model.todos = todos);
+    }
+}
+

labs/TodoAndroid/app/src/main/java/at/htl/todo/model/TodoService.java

@@ -1,30 +1,34 @@
 package at.htl.todo.model;
 
+import org.eclipse.microprofile.config.Config;
+
 import java.util.concurrent.CompletableFuture;
 
 import javax.inject.Inject;
 import javax.inject.Singleton;
 
-//@Singleton
-//public class TodoService {
-//
-//
-//    public static final String JSON_PLACEHOLDER_BASE_URL_SETTING = "json.placeholder.baseurl";
-//    public final String baseUrl;
-//    public final ToDoClient toDoClient;
-//    public final ModelStore store;
-//
-//    @Inject
-//    ToDoService(Config config, RestApiClientBuilder builder, ModelStore store) {
-//        this.baseUrl = config.getValue(JSON_PLACEHOLDER_BASE_URL_SETTING, String.class);
-//        toDoClient = builder.build(ToDoClient.class, baseUrl);
-//        this.store = store;
-//    }
-//
-//    public void getAll() {
-//        CompletableFuture
-//                .supplyAsync(() -> toDoClient.all())
-//                .thenAccept(store::setTodos);
-//    }
-//
-//}
+import at.htl.todo.util.resteasy.RestApiClientBuilder;
+
+@Singleton
+public class TodoService {
+
+    public static final String JSON_PLACEHOLDER_BASE_URL_SETTING = "json.placeholder.baseurl";
+    public final String baseUrl;
+    public final TodoClient todoClient;
+    public final ModelStore modelStore;
+
+    @Inject // Hilt verlangt Constructor Injection
+    TodoService(Config config, RestApiClientBuilder builder, ModelStore modelStore) {
+        this.baseUrl = config.getValue(JSON_PLACEHOLDER_BASE_URL_SETTING, String.class);
+        todoClient = builder.build(TodoClient.class, baseUrl);
+        this.modelStore = modelStore;
+    }
+
+    public void getAll() {
+        CompletableFuture
+                .supplyAsync(() -> todoClient.all())
+                .thenAccept(modelStore::setTodos);
+        //todoClient.all();  // NetworkOnMainThreadException
+    }
+
+}

labs/TodoAndroid/app/src/main/java/at/htl/todo/util/immer/Immer.java

@@ -0,0 +1,36 @@
+package at.htl.todo.util.immer;
+
+import java.util.function.Consumer;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import at.htl.todo.util.mapper.Mapper;
+
+
+/** Immer simplifies handling immutable data structures.
+ * @see <a>https://immerjs.github.io/immer/</a>
+ * @see <a>https://redux.js.org/understanding/thinking-in-redux/motivation</a>
+ *
+ * @param <T> The type of the baseState
+ */
+@Singleton
+public class Immer<T> {
+    public final Mapper<T> mapper;
+
+    @Inject
+    public Immer(Class<? extends T> type) {
+        mapper = new Mapper<T>(type);
+    }
+
+    /**
+     * @param readonlyState the readonly readonlyState
+     * @param recipe the callback function that modifies the cloned state
+     * @return
+     */
+    public T produce(final T readonlyState, Consumer<T> recipe) {
+        var nextState = mapper.clone(readonlyState);
+        recipe.accept(nextState);
+        return nextState;
+    }
+}

labs/TodoAndroid/app/src/main/java/at/htl/todo/util/mapper/Mapper.java

@@ -0,0 +1,51 @@
+package at.htl.todo.util.mapper;
+
+import com.fasterxml.jackson.annotation.JsonAutoDetect;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+
+import java.io.IOException;
+
+/** A Mapper that maps types to their json representation and back.
+ * ... plus a convenient deep-clone function
+ * @param <T> the Class that is mapped
+ */
+public class Mapper<T> {
+    private Class<? extends T> clazz;
+    private ObjectMapper mapper;
+
+    public Mapper(Class<? extends T> clazz) {
+        this.clazz = clazz;
+        mapper = new ObjectMapper()
+                .configure(SerializationFeature.INDENT_OUTPUT, true)
+                .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+        mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY); // records
+    }
+    public String toResource(T model) {
+        try {
+            return mapper.writeValueAsString(model);
+        } catch (JsonProcessingException e) {
+            throw new RuntimeException(e);
+        }
+    }
+    public T fromResource(String json) {
+        T model = null;
+        try {
+            model = mapper.readValue(json.getBytes(), clazz);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        return model;
+    }
+    /** deep clone an object by converting it to its json representation and back.
+     *
+     * @param thing the thing to clone, unchanged
+     * @return the deeply cloned thing
+     */
+    public T clone(final T thing) {
+        return fromResource(toResource(thing));
+    }
+}

labs/TodoAndroid/app/src/main/java/at/htl/todo/util/store/Store.java

@@ -0,0 +1,24 @@
+package at.htl.todo.util.store;
+
+import java.util.concurrent.CompletionException;
+import java.util.function.Consumer;
+
+import at.htl.todo.util.immer.Immer;
+import io.reactivex.rxjava3.subjects.BehaviorSubject;
+
+public class Store<T> {
+    public final BehaviorSubject<T> pipe;
+    public final Immer<T> immer;
+
+    protected Store(Class<? extends T> type, T initialState) {
+        try {
+            pipe = BehaviorSubject.createDefault(initialState);
+            immer = new Immer<T>(type);
+        } catch (Exception e) {
+            throw new CompletionException(e);
+        }
+    }
+    public void apply(Consumer<T> recipe) {
+        pipe.onNext(immer.produce(pipe.getValue(), recipe));
+    }
+}

labs/TodoAndroid/build.gradle.kts

@@ -3,4 +3,5 @@ plugins {
     alias(libs.plugins.androidApplication) apply false
     alias(libs.plugins.jetbrainsKotlinAndroid) apply false
     id("com.google.dagger.hilt.android") version "2.44" apply false
+    //id("org.jetbrains.kotlin.jvm") version "1.9.0"
 }