/**
* Sets the display mode.
*
* @param displayMode the mode to set
*/
public synchronized void setDisplayMode(BookShelfFragment.DisplayMode displayMode) {
sp.edit().putString(PREF_KEY_DISPLAY_MODE, displayMode.name()).apply();
}
/** @return the display mode that has been set or the default. */
public synchronized BookShelfFragment.DisplayMode getDisplayMode() {
return BookShelfFragment.DisplayMode.valueOf(
sp.getString(PREF_KEY_DISPLAY_MODE, BookShelfFragment.DisplayMode.GRID.name()));
}