Make library categories configurable

app/src/main/java/com/kabouzeid/gramophone/adapter/MusicLibraryPagerAdapter.java

@@ -10,14 +10,17 @@ import android.util.SparseArray;
 import android.view.ViewGroup;
 
 import com.kabouzeid.gramophone.R;
+import com.kabouzeid.gramophone.model.Category;
 import com.kabouzeid.gramophone.ui.fragments.mainactivity.library.pager.AlbumsFragment;
 import com.kabouzeid.gramophone.ui.fragments.mainactivity.library.pager.ArtistsFragment;
 import com.kabouzeid.gramophone.ui.fragments.mainactivity.library.pager.GenresFragment;
 import com.kabouzeid.gramophone.ui.fragments.mainactivity.library.pager.PlaylistsFragment;
 import com.kabouzeid.gramophone.ui.fragments.mainactivity.library.pager.SongsFragment;
+import com.kabouzeid.gramophone.util.PreferenceUtil;
 
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 
@@ -30,33 +33,29 @@ public class MusicLibraryPagerAdapter extends FragmentPagerAdapter {
     @NonNull
     private final Context mContext;
 
-    @NonNull
-    private final String[] titles;
-
     public MusicLibraryPagerAdapter(@NonNull final Context context, final FragmentManager fragmentManager) {
         super(fragmentManager);
         mContext = context;
-        titles = new String[]{
+        setCategories(PreferenceUtil.getInstance(context).getLibraryCategories());
-                context.getResources().getString(R.string.songs),
-                context.getResources().getString(R.string.albums),
-                context.getResources().getString(R.string.artists),
-                context.getResources().getString(R.string.genres),
-                context.getResources().getString(R.string.playlists)
-        };
-        final MusicFragments[] fragments = MusicFragments.values();
-        for (final MusicLibraryPagerAdapter.MusicFragments fragment : fragments) {
-            add(fragment.getFragmentClass(), null);
-        }
     }
 
-    @SuppressWarnings("synthetic-access")
+    public void setCategories(@NonNull ArrayList<Category> categories) {
-    public void add(@NonNull final Class<? extends Fragment> className, final Bundle params) {
+        mHolderList.clear();
-        final Holder mHolder = new Holder();
-        mHolder.mClassName = className.getName();
-        mHolder.mParams = params;
 
-        final int mPosition = mHolderList.size();
+        for (int i = 0, size = categories.size(); i < size; i++) {
-        mHolderList.add(mPosition, mHolder);
+            Category category = categories.get(i);
+            if (category.visible) {
+                MusicFragments fragment = MusicFragments.valueOf(category.id.toString());
+                Holder holder = new Holder();
+                holder.mClassName = fragment.getFragmentClass().getName();
+                holder.title = mContext.getResources()
+                        .getString(fragment.getResourceKey())
+                        .toUpperCase(Locale.getDefault());
+                mHolderList.add(holder);
+            }
+        }
+
+        alignCache();
         notifyDataSetChanged();
     }
 
@@ -68,6 +67,23 @@ public class MusicLibraryPagerAdapter extends FragmentPagerAdapter {
         return getItem(position);
     }
 
+    @Override
+    public int getItemPosition(@NonNull Object fragment) {
+        for (int i = 0, size = mHolderList.size(); i < size; i++) {
+            Holder holder = mHolderList.get(i);
+            if (holder.mClassName.equals(fragment.getClass().getName())) {
+                return i;
+            }
+        }
+        return POSITION_NONE;
+    }
+
+    @Override
+    public long getItemId(int position) {
+        // as fragment position is not fixed, we can't use position as id
+        return MusicFragments.of(getFragment(position).getClass()).ordinal();
+    }
+
     @NonNull
     @Override
     public Object instantiateItem(@NonNull final ViewGroup container, final int position) {
@@ -104,30 +120,75 @@ public class MusicLibraryPagerAdapter extends FragmentPagerAdapter {
     @NonNull
     @Override
     public CharSequence getPageTitle(final int position) {
-        return titles[position]
+        return mHolderList.get(position).title;
-                .toUpperCase(Locale.getDefault());
+    }
+
+    /**
+     * Aligns the fragment cache with the current category layout.
+     */
+    private void alignCache() {
+        if (mFragmentArray.size() == 0) return;
+
+        HashMap<String, WeakReference<Fragment>> mappings = new HashMap<>(mFragmentArray.size());
+
+        for (int i = 0, size = mFragmentArray.size(); i < size; i++) {
+            WeakReference<Fragment> ref = mFragmentArray.valueAt(i);
+            Fragment fragment = ref.get();
+            if (fragment != null) {
+                mappings.put(fragment.getClass().getName(), ref);
+            }
+        }
+        for (int i = 0, size = mHolderList.size(); i < size; i++) {
+            WeakReference<Fragment> ref = mappings.get(mHolderList.get(i).mClassName);
+            if (ref != null) {
+                mFragmentArray.put(i, ref);
+            } else {
+                mFragmentArray.remove(i);
+            }
+        }
     }
 
     public enum MusicFragments {
-        SONG(SongsFragment.class),
+        SONGS(SongsFragment.class, R.string.songs),
-        ALBUM(AlbumsFragment.class),
+        ALBUMS(AlbumsFragment.class, R.string.albums),
-        ARTIST(ArtistsFragment.class),
+        ARTISTS(ArtistsFragment.class, R.string.artists),
-        GENRES(GenresFragment.class),
+        GENRES(GenresFragment.class, R.string.genres),
-        PLAYLIST(PlaylistsFragment.class);
+        PLAYLISTS(PlaylistsFragment.class, R.string.playlists);
 
         private final Class<? extends Fragment> mFragmentClass;
+        private final int key;
 
-        MusicFragments(final Class<? extends Fragment> fragmentClass) {
+        MusicFragments(final Class<? extends Fragment> fragmentClass, int key) {
             mFragmentClass = fragmentClass;
+            this.key = key;
         }
 
         public Class<? extends Fragment> getFragmentClass() {
             return mFragmentClass;
         }
+
+        public int getResourceKey() {
+            return key;
+        }
+
+        public static MusicFragments of(Class<?> cl) {
+            MusicFragments[] fragments = All.FRAGMENTS;
+            for (int i = 0; i < fragments.length; i++) {
+                if (cl.equals(fragments[i].mFragmentClass))
+                    return fragments[i];
+            }
+
+            throw new IllegalArgumentException("Unknown music fragment " + cl);
+        }
+
+        private static class All {
+            public static final MusicFragments[] FRAGMENTS = values();
+        }
     }
 
     private final static class Holder {
         String mClassName;
         Bundle mParams;
+        String title;
     }
 }

app/src/main/java/com/kabouzeid/gramophone/model/Category.java

@@ -0,0 +1,65 @@
+package com.kabouzeid.gramophone.model;
+
+import com.kabouzeid.gramophone.R;
+
+import com.google.gson.annotations.SerializedName;
+
+public class Category {
+    @SerializedName("id")
+    public Id id;
+
+    @SerializedName("index")
+    public int index;
+
+    @SerializedName("checkBox")
+    public boolean visible;
+
+    public Category(Category category) {
+        this.id = category.id;
+        this.visible = category.visible;
+        this.index = index;
+    }
+
+    public Category(Id id, boolean visible, int index) {
+        this.id = id;
+        this.visible = visible;
+        this.index = index;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        Category category = (Category) o;
+
+        return id == category.id;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = 0;
+        result = 31 * result + id.hashCode();
+        return result;
+    }
+
+    public String toString()
+    {
+        return "{id:"+id + ", pos:"+ index + ", vis=" + visible + "}";
+    }
+
+    public static enum Id
+    {
+        SONGS(R.string.songs),
+        ALBUMS(R.string.albums),
+        ARTISTS(R.string.artists),
+        GENRES(R.string.genres),
+        PLAYLISTS(R.string.playlists);
+
+        public final int key;
+
+        private Id(int key) {
+            this.key = key;
+        }
+    }
+}

app/src/main/java/com/kabouzeid/gramophone/ui/fragments/mainactivity/library/LibraryFragment.java

@@ -3,6 +3,7 @@ package com.kabouzeid.gramophone.ui.fragments.mainactivity.library;
 
 import android.app.Activity;
 import android.content.Intent;
+import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
@@ -34,6 +35,7 @@ import com.kabouzeid.gramophone.ui.activities.MainActivity;
 import com.kabouzeid.gramophone.ui.activities.SearchActivity;
 import com.kabouzeid.gramophone.ui.fragments.mainactivity.AbsMainActivityFragment;
 import com.kabouzeid.gramophone.ui.fragments.mainactivity.library.pager.AbsLibraryPagerRecyclerViewCustomGridSizeFragment;
+import com.kabouzeid.gramophone.ui.fragments.mainactivity.library.pager.PlaylistsFragment;
 import com.kabouzeid.gramophone.util.PhonographColorUtil;
 import com.kabouzeid.gramophone.util.PreferenceUtil;
 import com.kabouzeid.gramophone.util.Util;
@@ -42,7 +44,7 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import butterknife.Unbinder;
 
-public class LibraryFragment extends AbsMainActivityFragment implements CabHolder, MainActivity.MainActivityFragmentCallbacks, ViewPager.OnPageChangeListener {
+public class LibraryFragment extends AbsMainActivityFragment implements CabHolder, MainActivity.MainActivityFragmentCallbacks, ViewPager.OnPageChangeListener, SharedPreferences.OnSharedPreferenceChangeListener {
     public static final String TAG = LibraryFragment.class.getSimpleName();
 
     private Unbinder unbinder;
@@ -75,6 +77,7 @@ public class LibraryFragment extends AbsMainActivityFragment implements CabHolde
 
     @Override
     public void onDestroyView() {
+        PreferenceUtil.getInstance(getActivity()).unregisterOnSharedPreferenceChangedListener(this);
         super.onDestroyView();
         pager.removeOnPageChangeListener(this);
         unbinder.unbind();
@@ -82,6 +85,7 @@ public class LibraryFragment extends AbsMainActivityFragment implements CabHolde
 
     @Override
     public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
+        PreferenceUtil.getInstance(getActivity()).registerOnSharedPreferenceChangedListener(this);
         setStatusbarColorAuto(view);
         getMainActivity().setNavigationbarColorAuto();
         getMainActivity().setTaskDescriptionColorAuto();
@@ -90,6 +94,20 @@ public class LibraryFragment extends AbsMainActivityFragment implements CabHolde
         setUpViewPager();
     }
 
+    @Override
+    public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {
+        if (PreferenceUtil.LIBRARY_CATEGORIES.equals(key)) {
+            Fragment current = getCurrentFragment();
+            pagerAdapter.setCategories(PreferenceUtil.getInstance(getActivity()).getLibraryCategories());
+            pager.setOffscreenPageLimit(pagerAdapter.getCount() - 1);
+            int position = pagerAdapter.getItemPosition(current);
+            pager.setCurrentItem(position > -1 ? position : 0);
+
+            // hide the tab bar with single tab
+            tabs.setVisibility(pagerAdapter.getCount() == 1 ? View.GONE : View.VISIBLE);
+        }
+    }
+
     private void setUpToolbar() {
         int primaryColor = ThemeStore.primaryColor(getActivity());
         appbar.setBackgroundColor(primaryColor);
@@ -125,7 +143,7 @@ public class LibraryFragment extends AbsMainActivityFragment implements CabHolde
     }
 
     private boolean isPlaylistPage() {
-        return pager.getCurrentItem() == MusicLibraryPagerAdapter.MusicFragments.PLAYLIST.ordinal();
+        return getCurrentFragment() instanceof PlaylistsFragment;
     }
 
     @NonNull

app/src/main/java/com/kabouzeid/gramophone/util/PreferenceUtil.java

@@ -9,10 +9,17 @@ import android.support.annotation.StyleRes;
 
 import com.kabouzeid.gramophone.R;
 import com.kabouzeid.gramophone.helper.SortOrder;
+import com.kabouzeid.gramophone.model.Category;
 import com.kabouzeid.gramophone.ui.fragments.mainactivity.folders.FoldersFragment;
 import com.kabouzeid.gramophone.ui.fragments.player.NowPlayingScreen;
 
 import java.io.File;
+import java.util.Collections;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Set;
+
+import com.google.gson.Gson;
 
 public final class PreferenceUtil {
     public static final String GENERAL_THEME = "general_theme";
@@ -74,6 +81,8 @@ public final class PreferenceUtil {
 
     public static final String INITIALIZED_BLACKLIST = "initialized_blacklist";
 
+    public static final String LIBRARY_CATEGORIES = "library_categories";
+
     private static PreferenceUtil sInstance;
 
     private final SharedPreferences mPreferences;
@@ -426,4 +435,55 @@ public final class PreferenceUtil {
     public final boolean initializedBlacklist() {
         return mPreferences.getBoolean(INITIALIZED_BLACKLIST, false);
     }
+
+    public void setLibraryCategories(ArrayList<Category> categories) {
+        Gson gson = new Gson();
+
+        Set<String> data = new HashSet<>(categories.size());
+
+        for (int i = 0, size = categories.size(); i < size; i++) {
+            Category category = categories.get(i);
+            category.index = i;
+            data.add(gson.toJson(category));
+        }
+
+        SharedPreferences.Editor editor = mPreferences.edit();
+        editor.putStringSet(LIBRARY_CATEGORIES, data);
+        editor.commit();
+    }
+
+    public ArrayList<Category> getLibraryCategories() {
+        Set<String> data = mPreferences.getStringSet(LIBRARY_CATEGORIES, null);
+        if (data != null) {
+            Gson gson = new Gson();
+            ArrayList<Category> result = new ArrayList<>(Collections.nCopies(data.size(), (Category) null));
+
+            for (String json : data) {
+                Category category = gson.fromJson(json, Category.class);
+                result.set(category.index, category);
+            }
+
+            return result;
+        }
+
+        return LibraryCategories.DEFAULTS;
+    }
+
+    public ArrayList<Category> getDefaultLibraryCategories() {
+        return LibraryCategories.DEFAULTS;
+    }
+
+    private static class LibraryCategories {
+        public final static ArrayList<Category> DEFAULTS = getDefaults();
+
+        private static ArrayList<Category> getDefaults() {
+            ArrayList<Category> result = new ArrayList<>();
+            result.add(new Category(Category.Id.SONGS, true, 0));
+            result.add(new Category(Category.Id.ALBUMS, true, 1));
+            result.add(new Category(Category.Id.ARTISTS, true, 2));
+            result.add(new Category(Category.Id.GENRES, true, 3));
+            result.add(new Category(Category.Id.PLAYLISTS, true, 4));
+            return result;
+        }
+    }
 }