Support custom preview number, Resolve #455

app/src/main/java/com/hippo/ehviewer/Settings.java

@@ -69,6 +69,8 @@ public class Settings {
     public static final int DEFAULT_DEFAULT_CATEGORIES = EhUtils.ALL_CATEGORY;
     public static final String KEY_EXCLUDED_TAG_NAMESPACES = "excluded_tag_namespaces";
     public static final String KEY_EXCLUDED_LANGUAGES = "excluded_languages";
+    private static final String KEY_PREVIEW_NUM = "preview_num";
+    private static final int DEFAULT_PREVIEW_NUM = 60;
     /********************
      ****** Privacy and Security
      ********************/
@@ -583,6 +585,10 @@ public class Settings {
         putBoolean(KEY_SHOW_TAG_TRANSLATIONS, value);
     }
 
+    public static int getPreviewNum() {
+        return getInt(KEY_PREVIEW_NUM, DEFAULT_PREVIEW_NUM);
+    }
+
     public static int getDefaultCategories() {
         return getInt(KEY_DEFAULT_CATEGORIES, DEFAULT_DEFAULT_CATEGORIES);
     }