Wiley-World.of.Warcraft.Programming.A.Guide.and.Reference.for.Creating.WoW.Addons

Chapter 12 ■ Interacting with Widgets 225Creating an EditBoxThe most prevalent edit box in the default user interface is the one that appearswhen you press Enter: the chat edit box. Using it you can input commands,type messages to friends, or even run Lua code. The edit box you use forBagBuddy won’t have all of these features because all it needs to do is accepttext from the user.You must exercise caution when working with an EditBox,whetheryouarecreating it in Lua or XML. It has an odd property that causes it to automaticallytake the keyboard’s focus when it is displayed and doesn’t (by default) have away to relinquish this control. As a result, if you don’t pay attention you couldwind up needing to restart your client to regain control of the keyboard.You can, however, set a property (via an XML attribute or Lua) and a framescript to provide better behavior. Open BagBuddy.xml and add the followingdefinition before the tag in the BagBuddy definition, but after thecode for the previous and next buttons:self:ClearFocus()BagBuddy_Update()The important part of this code is the autoFocus attribute being set to false.This ensures that the edit box won’t automatically try to steal the keyboardwhenever it is shown. It’s not enough, however, to ensure that there is aneasy way to get the keyboard’s focus away from the EditBox. Forthisyousetan OnEscapePressed script. This script handler fires anytime the edit box hasfocus and the player presses the escape key. Because most people are usedto pressing escape to clear the focus from an input box, whether it be on theWeb or in World of Warcraft, it’s a good behavior to emulate. The handlerbody simply calls the self:ClearFocus() method. This method is specific tothe EditBox type, and simply releases control of the keyboard so it can be usedelsewhere.