共有ビューモデル実装

component/viewer/src/main/java/one/nem/lacerta/component/viewer/SharedViewModel.java

@@ -0,0 +1,19 @@
+package one.nem.lacerta.component.viewer;
+
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.ViewModel;
+
+public class SharedViewModel extends ViewModel {
+
+    private final MutableLiveData<Integer> currentFragmentPosition = new MutableLiveData<>();
+
+    public void setCurrentFragmentPosition(int position) {
+        currentFragmentPosition.setValue(position);
+    }
+
+    public int getCurrentFragmentPosition() {
+        assert currentFragmentPosition.getValue() != null;
+        return currentFragmentPosition.getValue();
+    }
+
+}