Make library categories configurable

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;
+        }
+    }
+}