Add selected and unselected language header in LanguageActivity

app/src/main/java/org/kiwix/kiwixmobile/language/LanguageActivity.java

@@ -109,6 +109,7 @@ public class LanguageActivity extends BaseActivity implements LanguageContract.V
   public void notifyLanguagesFiltered(List<Language> languages) {
     this.languages.clear();
     this.languages.addAll(languages);
+    languageAdapter.categorizeLanguages();
     languageAdapter.notifyDataSetChanged();
   }
 }

app/src/main/java/org/kiwix/kiwixmobile/language/LanguageAdapter.java

@@ -12,27 +12,66 @@ import org.kiwix.kiwixmobile.R;
 import org.kiwix.kiwixmobile.models.Language;
 
 import java.util.ArrayList;
+import java.util.Collections;
 
 import butterknife.BindView;
 import butterknife.ButterKnife;
 
-class LanguageAdapter extends RecyclerView.Adapter<LanguageAdapter.ViewHolder> {
+class LanguageAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
+  private static final int TYPE_HEADER = 0;
+  private static final int TYPE_ITEM = 1;
   private final ArrayList<Language> languages;
+  private final ArrayList<Language> selectedLanguages = new ArrayList<>();
+  private final ArrayList<Language> unselectedLanguages = new ArrayList<>();
 
   LanguageAdapter(ArrayList<Language> languages) {
     this.languages = languages;
+    categorizeLanguages();
+  }
+
+  void categorizeLanguages() {
+    selectedLanguages.clear();
+    unselectedLanguages.clear();
+    for (Language language : languages) {
+      if (language.active != null && language.active.equals(true)) {
+        selectedLanguages.add(language);
+      } else {
+        language.active = false;
+        unselectedLanguages.add(language);
+      }
+    }
+    Collections.sort(selectedLanguages);
+    Collections.sort(unselectedLanguages);
   }
 
   @NonNull
   @Override
-  public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+  public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
-    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_language, parent, false);
+    if (viewType == TYPE_ITEM) {
-    return new ViewHolder(view);
+      View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_language, parent, false);
+      return new ViewHolder(view);
+    }
+    return new Header(LayoutInflater.from(parent.getContext()).inflate(R.layout.header_date, parent, false));
   }
 
   @Override
-  public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
+  public void onBindViewHolder(@NonNull RecyclerView.ViewHolder item, int position) {
-    Language language = languages.get(position);
+    if (item instanceof Header) {
+      Header header = (Header) item;
+      if (position == 0) {
+        header.header.setText(R.string.your_languages);
+      } else {
+        header.header.setText(R.string.other_languages);
+      }
+      return;
+    }
+    Language language;
+    if (position - 1 < selectedLanguages.size()) {
+      language = selectedLanguages.get(position - 1);
+    } else {
+      language = unselectedLanguages.get(position - selectedLanguages.size() - 2);
+    }
+    ViewHolder holder = (ViewHolder) item;
     holder.languageName.setText(language.language);
     holder.languageLocalizedName.setText(language.languageLocalized);
     holder.booksCount.setText(holder.booksCount.getContext().getResources()
@@ -43,7 +82,16 @@ class LanguageAdapter extends RecyclerView.Adapter<LanguageAdapter.ViewHolder> {
     holder.checkBox.setChecked(language.active);
     View.OnClickListener onClickListener = v -> {
       language.active = holder.checkBox.isChecked();
-      notifyItemChanged(position);
+      if (language.active) {
+        unselectedLanguages.remove(language);
+        selectedLanguages.add(language);
+      } else {
+        unselectedLanguages.add(language);
+        selectedLanguages.remove(language);
+      }
+      Collections.sort(selectedLanguages);
+      Collections.sort(unselectedLanguages);
+      notifyDataSetChanged();
     };
     holder.itemView.setOnClickListener(v -> {
       holder.checkBox.toggle();
@@ -52,9 +100,17 @@ class LanguageAdapter extends RecyclerView.Adapter<LanguageAdapter.ViewHolder> {
     holder.checkBox.setOnClickListener(onClickListener);
   }
 
+  @Override
+  public int getItemViewType(int position) {
+    if (position == 0 || position == selectedLanguages.size() + 1) {
+      return TYPE_HEADER;
+    }
+    return TYPE_ITEM;
+  }
+
   @Override
   public int getItemCount() {
-    return languages.size();
+    return selectedLanguages.size() + unselectedLanguages.size() + 2;
   }
 
   class ViewHolder extends RecyclerView.ViewHolder {
@@ -72,4 +128,14 @@ class LanguageAdapter extends RecyclerView.Adapter<LanguageAdapter.ViewHolder> {
       ButterKnife.bind(this, itemView);
     }
   }
+
+  class Header extends RecyclerView.ViewHolder {
+    @BindView(R.id.header_date)
+    TextView header;
+
+    Header(View itemView) {
+      super(itemView);
+      ButterKnife.bind(this, itemView);
+    }
+  }
 }

app/src/main/java/org/kiwix/kiwixmobile/models/Language.java

@@ -2,10 +2,11 @@ package org.kiwix.kiwixmobile.models;
 
 import android.os.Parcel;
 import android.os.Parcelable;
+import android.support.annotation.NonNull;
 
 import java.util.Locale;
 
-public class Language implements Parcelable {
+public class Language implements Parcelable, Comparable<Language> {
 
   public static final Creator<Language> CREATOR = new Creator<Language>() {
     @Override
@@ -62,4 +63,9 @@ public class Language implements Parcelable {
     dest.writeByte((byte) (active == null ? 0 : active ? 1 : 2));
     dest.writeInt(booksCount);
   }
+
+  @Override
+  public int compareTo(@NonNull Language o) {
+    return language.compareTo(o.language);
+  }
 }