[mobile] try to fix fragment

app/src/main/java/com/fongmi/android/tv/ui/activity/BaseActivity.java

@@ -33,6 +33,7 @@ public abstract class BaseActivity extends AppCompatActivity {
         EventBus.getDefault().register(this);
         setWall();
         initView();
+        initView(savedInstanceState);
         initEvent();
     }
 
@@ -43,6 +44,9 @@ public abstract class BaseActivity extends AppCompatActivity {
     protected void initView() {
     }
 
+    protected void initView(Bundle savedInstanceState) {
+    }
+
     protected void initEvent() {
     }
 

app/src/mobile/java/com/fongmi/android/tv/ui/activity/MainActivity.java

@@ -1,6 +1,7 @@
 package com.fongmi.android.tv.ui.activity;
 
 import android.content.Intent;
+import android.os.Bundle;
 import android.view.MenuItem;
 
 import androidx.annotation.NonNull;
@@ -17,26 +18,24 @@ import com.fongmi.android.tv.databinding.ActivityMainBinding;
 import com.fongmi.android.tv.event.RefreshEvent;
 import com.fongmi.android.tv.net.Callback;
 import com.fongmi.android.tv.server.Server;
+import com.fongmi.android.tv.ui.custom.FragmentStateManager;
 import com.fongmi.android.tv.ui.fragment.SettingFragment;
 import com.fongmi.android.tv.ui.fragment.VodFragment;
 import com.fongmi.android.tv.utils.Notify;
 import com.google.android.material.navigation.NavigationBarView;
 
-import java.util.ArrayList;
-import java.util.List;
-
 public class MainActivity extends BaseActivity implements NavigationBarView.OnItemSelectedListener {
 
+    private FragmentStateManager mManager;
     private ActivityMainBinding mBinding;
-    private List<Fragment> mFragments;
     private boolean confirm;
 
     private VodFragment getVodFragment() {
-        return (VodFragment) getSupportFragmentManager().findFragmentByTag("0");
+        return (VodFragment) mManager.getFragment(0);
     }
 
     private SettingFragment getSettingFragment() {
-        return (SettingFragment) getSupportFragmentManager().findFragmentByTag("1");
+        return (SettingFragment) mManager.getFragment(1);
     }
 
     @Override
@@ -51,26 +50,31 @@ public class MainActivity extends BaseActivity implements NavigationBarView.OnIt
     }
 
     @Override
-    protected void initView() {
+    protected void initView(Bundle savedInstanceState) {
+        initFragment(savedInstanceState);
         Notify.progress(this);
         Updater.get().start();
         Server.get().start();
-        initFragment();
         initConfig();
     }
 
     @Override
     protected void initEvent() {
         mBinding.navigation.setOnItemSelectedListener(this);
-        mBinding.navigation.setSelectedItemId(R.id.vod);
     }
 
-    private void initFragment() {
-        if (mFragments != null) return;
-        mFragments = new ArrayList<>();
-        mFragments.add(VodFragment.newInstance());
-        mFragments.add(SettingFragment.newInstance());
-        for (int i = 0; i < mFragments.size(); i++) getSupportFragmentManager().beginTransaction().add(R.id.container, mFragments.get(i), String.valueOf(i)).hide(mFragments.get(i)).commitNowAllowingStateLoss();
+    private void initFragment(Bundle savedInstanceState) {
+        mManager = new FragmentStateManager(mBinding.container, getSupportFragmentManager()) {
+            @Override
+            public Fragment getItem(int position) {
+                if (position == 0) {
+                    return VodFragment.newInstance();
+                } else {
+                    return SettingFragment.newInstance();
+                }
+            }
+        };
+        if (savedInstanceState == null) mManager.change(0);
     }
 
     private void initConfig() {
@@ -111,10 +115,10 @@ public class MainActivity extends BaseActivity implements NavigationBarView.OnIt
     public boolean onNavigationItemSelected(@NonNull MenuItem item) {
         switch (item.getItemId()) {
             case R.id.vod:
-                getSupportFragmentManager().beginTransaction().hide(mFragments.get(1)).show(mFragments.get(0)).commitNowAllowingStateLoss();
+                mManager.change(0);
                 return true;
             case R.id.setting:
-                getSupportFragmentManager().beginTransaction().hide(mFragments.get(0)).show(mFragments.get(1)).commitNowAllowingStateLoss();
+                mManager.change(1);
                 return true;
             default:
                 return false;

app/src/mobile/java/com/fongmi/android/tv/ui/custom/FragmentStateManager.java

@@ -0,0 +1,40 @@
+package com.fongmi.android.tv.ui.custom;
+
+import android.view.ViewGroup;
+
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentManager;
+import androidx.fragment.app.FragmentTransaction;
+
+public abstract class FragmentStateManager {
+
+    private final FragmentManager fm;
+    private final ViewGroup container;
+
+    public FragmentStateManager(ViewGroup container, FragmentManager fm) {
+        this.container = container;
+        this.fm = fm;
+    }
+
+    public abstract Fragment getItem(int position);
+
+    public void change(int position) {
+        FragmentTransaction ft = fm.beginTransaction();
+        Fragment fragment = fm.findFragmentByTag(getTag(position));
+        if (fragment == null) ft.add(container.getId(), fragment = getItem(position), getTag(position));
+        else ft.show(fragment);
+        Fragment current = fm.getPrimaryNavigationFragment();
+        if (current != null) ft.hide(current);
+        ft.setPrimaryNavigationFragment(fragment);
+        ft.setReorderingAllowed(true);
+        ft.commitNowAllowingStateLoss();
+    }
+
+    public String getTag(long id) {
+        return "android:switcher:" + id;
+    }
+
+    public Fragment getFragment(long id) {
+        return fm.findFragmentByTag(getTag(id));
+    }
+}