Disable list editing on export, optimize size

It was possible to delete or create lists during export which also made
the UI much harder to use, as swiping could delete a list.
Expands viewpager to allow passing a bundle.
Also optimizes arraylist size for viewpager.

Signed-off-by: Aron Heinecke <aron.heinecke@t-online.de>

Author: 0xpr03

app/src/main/java/vocabletrainer/heinecke/aron/vocabletrainer/activity/ExImportActivity.java

@@ -35,6 +35,8 @@
 import vocabletrainer.heinecke.aron.vocabletrainer.lib.Storage.GenericSpinnerEntry;
 import vocabletrainer.heinecke.aron.vocabletrainer.lib.ViewModel.FormatViewModel;
 
+import static vocabletrainer.heinecke.aron.vocabletrainer.fragment.ListPickerFragment.K_SELECT_ONLY;
+
 /**
  * Activity for import/export
  */
@@ -85,7 +87,7 @@ protected void onCreate(@Nullable Bundle savedInstanceState) {
      * Init ViewPager
      */
     private void initViewPager(){
-        viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager(),this);
+        viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager(),this,4);
         Intent intent = getIntent();
         boolean showImport = intent.getBooleanExtra(PARAM_IMPORT, true);
         if(showImport){
@@ -95,7 +97,9 @@ private void initViewPager(){
         } else {
             getSupportActionBar().setTitle(R.string.Export_Title);
             viewPagerAdapter.addFragment(ExportFragment.class, R.string.Export_Tab_Main);
-            viewPagerAdapter.addFragment(ListPickerFragment.class,R.string.Export_Tab_List);
+            Bundle args = new Bundle();
+            args.putBoolean(K_SELECT_ONLY,true);
+            viewPagerAdapter.addFragment(ListPickerFragment.class,R.string.Export_Tab_List,args);
         }
         viewPagerAdapter.addFragment(FormatFragment.class, R.string.ExImport_Tab_CustomFormat);
         viewPager.setAdapter(viewPagerAdapter);

app/src/main/java/vocabletrainer/heinecke/aron/vocabletrainer/fragment/ListPickerFragment.java

@@ -52,7 +52,7 @@ public class ListPickerFragment extends PagerFragment implements ListRecyclerAda
     private static final String P_KEY_SORTING_DIALOG = "sorting_dialog_list";
     private static final String K_PRESELECT = "preselect";
     private static final String K_MULTISELECT = "multiSelect";
-    private static final String K_SELECT_ONLY = "select_only";
+    public static final String K_SELECT_ONLY = "select_only";
     private static final int CODE_NEW_LIST = 1001;
 
     private View view;

app/src/main/java/vocabletrainer/heinecke/aron/vocabletrainer/lib/Adapter/ViewPagerAdapter.java

@@ -2,10 +2,13 @@
 
 import android.content.Context;
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.annotation.StringRes;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentPagerAdapter;
+
+import android.os.Bundle;
 import android.util.Log;
 
 import java.util.ArrayList;
@@ -16,31 +19,52 @@
 public class ViewPagerAdapter extends FragmentPagerAdapter {
     private final static String TAG = "ViewPagerAdapter";
 
-    private final ArrayList<Class<? extends Fragment>> mFragmentClassList = new ArrayList<>();
-    private final ArrayList<String> mFragmentTitleList = new ArrayList<>();
+    private final ArrayList<Class<? extends Fragment>> mFragmentClassList;
+    private final ArrayList<String> mFragmentTitleList;
+    private final ArrayList<Bundle> mFragmentArguments;
     private Context context;
 
     /**
      * Creates a new ViewPagerAdapter
      * @param manager FragmentManager
      * @param context Context required for StringRes resolve
      */
-    public ViewPagerAdapter(FragmentManager manager, Context context) {
+    public ViewPagerAdapter(FragmentManager manager, Context context, int size) {
         super(manager);
         this.context = context;
+        mFragmentClassList = new ArrayList<>(size);
+        mFragmentTitleList = new ArrayList<>(size);
+        mFragmentArguments = new ArrayList<>(size);
     }
 
     @Override
     public Fragment getItem(int position) {
         Fragment frag = null;
         try {
             frag = mFragmentClassList.get(position).newInstance();
+            Bundle args;
+            if((args = mFragmentArguments.get(position)) != null) {
+                frag.setArguments(args);
+            }
         } catch (InstantiationException | IllegalAccessException e) {
             Log.wtf(TAG,"Error on fragment instantiation in ViewPagerAdapter",e);
         }
         return frag;
     }
 
+
+    /**
+     * Add Fragment instance to ViewPagerAdapter<br>
+     *     <b>Note:</b> the Fragment passed is not used directly, a new Instance will be used
+     * @param frag
+     * @param title
+     * @param args
+     */
+    @SuppressWarnings("unused")
+    public void addFragment(Class<? extends Fragment> frag,@StringRes int title, Bundle args ){
+        addFragment(frag,context.getString(title), args);
+    }
+
     /**
      * Add Fragment instance to ViewPagerAdapter<br>
      *     <b>Note:</b> the Fragment passed is not used directly, a new Instance will be used
@@ -49,19 +73,21 @@ public Fragment getItem(int position) {
      */
     @SuppressWarnings("unused")
     public void addFragment(Class<? extends Fragment> frag,@StringRes int title ){
-        addFragment(frag,context.getString(title));
+        addFragment(frag,title, null);
     }
 
     /**
      * Add Fragment instance to ViewPagerAdapter<br>
      *     <b>Note:</b> the Fragment passed is not used directly, a new Instance will be used
      * @param frag
      * @param title
+     * @param arguments
      */
     @SuppressWarnings("unused")
-    public void addFragment(Class<? extends Fragment> frag, @NonNull String title) {
+    public void addFragment(Class<? extends Fragment> frag, @NonNull String title, @Nullable Bundle arguments) {
         mFragmentClassList.add(frag);
         mFragmentTitleList.add(title);
+        mFragmentArguments.add(arguments);
     }
 
     @Override