fix(app/library): add instance state handling

Signed-off-by: YuutaW <17158086+Trumeet@users.noreply.github.com>

1 files changed, 8 insertions, 7 deletions

diff --git a/library/src/main/java/moe/yuuta/flow/PageFragment.java b/library/src/main/java/moe/yuuta/flow/PageFragment.java
index dcc9f21..4e7996b 100644
--- a/library/src/main/java/moe/yuuta/flow/PageFragment.java
+++ b/library/src/main/java/moe/yuuta/flow/PageFragment.java
@@ -1,24 +1,25 @@
 package moe.yuuta.flow;
 
+import android.util.Log;
+
 import androidx.annotation.NonNull;
 import androidx.fragment.app.Fragment;
 
 public abstract class PageFragment extends Fragment {
-    private IFlowFragment mHostFragment;
-
     /**
      * Once mInfo is changed, you should call {@link IFlowFragment#notifyCurrentFlowInfoUpdated()} to publish it.
      * Note: it will be permanently change the recorded info.
      */
     protected FlowInfo mInfo;
 
-    final void setHostFragment(@NonNull IFlowFragment hostFragment) {
-        this.mHostFragment = hostFragment;
-    }
-
     @NonNull
     protected final IFlowFragment getHostFragment() {
-        return mHostFragment;
+        final Fragment parent = getParentFragment();
+        if (!(parent instanceof IFlowFragment)) {
+            throw new IllegalStateException("This fragment is not attached to a valid flow host");
+        }
+        Log.d("Page", "get");
+        return (IFlowFragment) parent;
     }
 
     /**