Paul Emmerich [Paul Emmerich] - Beginning Lua with World of Warcraft Addons

This appendix contains information on all the frame types that you can create in World of Warcraft, with all the XML attributes and elements as well as all Lua methods and available script handlers. Frame types follow an object-oriented model, meaning that a frame type can inherit attributes and methods from another frame type. You can find an introduction to object-oriented programming in if you are not familiar with this topic.

You may wonder why there is such an appendix in this book, as you can probably find most of the information covered here on the Internet. WoWWiki has a few good pages that deal with exactly the same topic as this appendix. However, the information there is scattered over multiple pages and many of the articles are outdated or incomplete. This appendix is up to date as of patch 3.1 (the next patches probably won't change anything important in the frame API) and contains everything you need to know about a particular frame type in one place.

Object is an abstract frame type; that is, you cannot create frames from this type. But this type is the base class for all other frame types as every other type inherits from Object. This means that all of the methods, XML attributes, and XML elements listed here are available for all frames.

This frame type is sometimes also called UIObject, which is probably the type's internal name used in the C++ code of the game.

The Object type has the following XML attributes.

alpha

Defines the frame's transparency (0 1). Default: 1.

parent

Defines the frame's parent.

name

Defines the frame's name.

inherits

The template to use.

virtual

Creates a template. Default: false.

The Object type has the following Lua methods.

object:GetAlpha()

Returns the frame's alpha value.

object:GetEffectiveAlpha()

Returns the frame's effective alpha value by multiplying its alpha value with the parent's effective alpha.

object:GetName()

Returns the name of the frame.

object:GetObjectType()

Returns the type of the object.

object:GetParent()

Returns the parent of the frame.

object:IsObjectType(objType)

Returns 1 if object is of the type objType, or of a type that inherits from objType. For example, CreateFrame("CheckButton"):IsObjectType("Button") returns 1 because the type CheckButton inherits from the type Button.

object:SetAlpha()

Sets the frame's transparency (0 1).

object:SetParent(obj)

Sets the frame's parent.

Font is an object that inherits from Object and represents a font that can be used by FontStrings or Buttons.

The Font type has the following XML attributes.

font

The path to the font file you want to use.

justifyH

Sets the horizontal justification setting. This can either be LEFT, RIGHT, or CENTER. Default: CENTER.

justifyV

Sets the vertical justification setting. This can either be BOTTOM, TOP, or MIDDLE. Default: MIDDLE.

monochrome

Uses a monochrome font. Default: false.

outline

The outline to use; can be NONE, NORMAL, or THICK. Default: NONE.

spacing

The spacing between characters. Default: 0.

The Font type has the following XML elements.

FontHeight

Controls the height of the font with its Value attribute.

Color

Controls the color of the font with its r, g, b, and a attributes.

Shadow

Contains the two elements Color and Offset. Color controls the color with the attributes r, g, b, and a, and Offset controls the shadow offset with one of the elements AbsDimension or RelDimension.

The Font type has the following Lua methods.

font:CopyFontObject(otherObject)

Copies all settings from otherObject.

font:GetFont()

Returns the font file used.

font:GetFontObject()

Returns the font object itself. This method makes sense when called from a frame that inherits from Font.

font:GetJustifyH()

Returns the horizontal alignment of the text.

font:GetJustifyV()

Returns the vertical alignment of the text.

font:GetMultilineIndent()

Returns the multiline indention setting.

font:GetShadowColor()

Returns the color of the font's shadow.