GF/ST modifies no base image methods on any platform. For a full listing of added classes and methods, refer to the .SUM files supplied on the distribution media. Common protocol for GFGraphicObject is summarized in the description for that class, in the next section.GF/ST Class Hierarchy Common to All Platforms
(Other than PsiEventModel)GF/ST Classes Common
(PsiEventModel Hierarchy Only)In this section, we provide an alphabetically sorted list of all base GF/ST classes, together with a brief description of each. The descriptions should all be contained in the class COMMENT method, but you may find this alphabetical sort easier to use. We adhere to the ParcPlace commenting conventions in GF/ST, showing the kind of object expected in an instance variable in angle brackets (i.e., <>). Also, when we indicate that an object is an <Action>, we mean that it is a block or an EvaluableAction of some kind - anything that responds to the protocol of EvaluableAction. Like a block in Smalltalk, an EvaluableAction responds to value or more specifically for EvaluableActions, evaluate. See the class description in this section for more discussion.Description: An ActionSequence is a collection of EvaluableActions. ActionSequences respond to evaluate and return the result of the last EvaluableAction.Description: Color class is provided only for compatibility and centralized, convenient accessing methods for accessing and instantiating colors. For example, Color red returns an appropriate object for each platform.Description: The ColorDialog is a VA Smalltalk-only GF/ST-supplied dialog for displaying the color palette and allowing you to select a color. It is used from the Color class method pickAColor, which is invoked from various default menus.Description: EvaluableAction is an abstract class whose subclasses understand action-type protocol, such as evaluate, evaluateWithArgumentsEvaluableAction is a simple shell class used to group together GF constraint classes and support coercion methods. Blocks, while somewhat interchangeable in terms of their utility with EvaluableActions, are more “expensive” to use.Description: The GFButtonGO class wraps an image (or creates an image based on a GO) with a border, as specified by the selector held in borderSelector. It also knows how to create handles that will give the GO a “button-like” behavior when the action for the button is defined (use whenClickedSend:to: to define the clicked action). The GFButtonGO also has an offset that can be used for positioning where the image is displayed within the button border.connectedAction - <Action> The action to be evaluated after the connection has been made. The action accepts two arguments, the connection produced by the connectAction, and the location produced by the locationGenerationAction.Description: The GFGoEndPlug lets you supply an arbitrary graphic object as the line ending appropriate for a path GO. For examples and graphically displayed documentation, see the following class methods in GFDrawingInterface: rectangleLineEndExample, triangleLineEndExample, and circleLineEndExample.Rather than impose a heavyweight coordinate system on each graphic object, the framework relies on the drawing which contains the GO’s to supply a coordinate system. Therefore, GFGraphicObject supplies a protocol for converting between the native coordinate system and the actual coordinate system (user coordinate system). The default coordinate system is isomorphic to the native coordinate system. For more information on the coordinate system used, see the class GFCoordinateControl. When manipulating coordinate systems, you have to be very careful. It’s easy to get confused as to what coordinate system a point is defined in, as the point itself has no knowledge of this, nor should it. Points are always interpreted relative to a coordinate system, and you have to know which coordinate system you’re referencing when using a point. Be warned.Description: GFMemento allows for the recording of state information while trying to preserve encapsulation. It should only be created via one of the #originator:state: variants. GFMemento will only allow access to the type and state information if the conditions for allowing access are met. Those conditions are: if a key symbol is provided, the originator and the object requesting the information must respond to the symbol in an = test. If the key is nil, then the requesting object must be == to the originator.type - <Symbol | nil> Should be a selector that the restoring object will understand. If a type is specified, it is used as a selector sent to the restoring object with state as the parameter. An example of this would be if state was a Point, and the restoring object was a Rectangle, and type was #extent:. Given this setup, when the memento is restored, the restoring object (a Rectangle) is told to perform #extent: with the point as the argument.state - <OrderedCollection of: Message> When type is not nil, the restoring object is told there to perform the type selector with state as the argument. When type is nil, state is an OrderedCollection of Messages which are evaluated in order.Description: The GFPrintingGC is a specialization of the GFScalingGC used for printing. It ensures proper rounding of point values and bypasses the cache of pixelValueForColor.categories - <OrderedCollection of: GFCategory> Holds the available categories that can be selected.eventTable - <IdentityDictionary with key: Symbol and value: ActionSequence> Holds the equivalent of the class variable Dependents in Object. When you triggerEvent: aSymbol, the ActionSequence for aSymbol is evaluated.Many GF/ST classes, including GFGraphicObject and GFDrawingInterface, are subclasses of PsiEventModel. These classes always inherit all events from their superclass via the eventsTriggered class method. The list below summarizes the events which are added at each level of the PsiEventModel hierarchy.GFGraphicObject
attributeState
button1DoubleClick
damaged
deselect
generateHandles
getMenu
getMetaObject
needsPositionHandle
positionState
releasing
select
translateGFCompositeGO
resetVisibleArea
resizeGFDrawing
damageRegion
redrawGFHostWidgetGO
resizeGFToolPalette
addedCategory
addedToolToCategory
removedCategory
removedToolFromCategory
selectCategory
selectTool