Object Management Functions

 

Name 

Description 

 

GOLAddObject 

This function adds an object to the tail of the active list pointed to by _pGolObjects. The new list tail is set to point to NULL. 

 

GOLFindObject 

This function finds an object in the active list pointed to by _pGolObjects using the given object ID. 

 

GOLRedrawRec 

This function marks all objects in the active list intersected by the given rectangular area to be redrawn. 

 

GOLDraw 

This function loops through the active list and redraws objects that need to be redrawn. Partial redrawing or full redraw is performed depending on the drawing states of the objects. GOLDrawCallback() function is called by GOLDraw() when drawing of objects in the active list is completed. 

 

GOLDrawCallback 

GOLDrawCallback() function MUST BE implemented by the user. This is called inside the GOLDraw() function when the drawing of objects in the active list is completed. User drawing must be done here. Drawing color, line type, clipping region, graphic cursor position and current font will not be changed by GOL if this function returns a zero. To pass drawing control to GOL this function must return a non-zero value. If GOL messaging is not using the active link list, it is safe to modify the list here. 

 

GOLFree 

This function frees all the memory used by objects in the active list and initializes _pGolObjects pointer to NULL to start a new empty list. This function must be called only inside the GOLDrawCallback()function when using GOLDraw() and GOLMsg() functions. This requirement assures that primitive rendering settings are not altered by the rendering state machines of the objects. 

 

GOLDeleteObject 

deletes an object to the linked list objects for the current screen. 

 

GOLDeleteObjectByID 

Deletes an object in the current active linked list of objects using the ID parameter of the object. 

 

GOLSetFocus 

This function sets the keyboard input focus to the object. If the object cannot accept keyboard messages focus will not be changed. This function resets FOCUSED state for the object was in focus previously, set FOCUSED state for the required object and marks the objects to be redrawn. 

 

GOLInit 

This function initializes the graphics library and creates a default style scheme with default settings referenced by the global scheme pointer. GOLInit() function must be called before GOL functions can be used. It is not necessary to call GraphInit() function if this function is used. 

 

GOLCanBeFocused 

This function returns non-zero if the object can be focused. Only button, check box, radio button, slider, edit box, list box, scroll bar can accept focus. If the object is disabled it cannot be set to focused state. 

 

GOLGetFocusNext 

This function returns the pointer to the next object in the active linked list which is able to receive keyboard input. 

 

GOLGetFocusPrev 

This function returns the pointer to the previous object in the active linked list which is able to receive keyboard input. 

 

GOLPanelDrawTsk 

This function draws a panel on the screen with parameters set by GOLPanelDraw() macro. This function must be called repeatedly (depending on the return value) for a successful rendering of the panel. 

 

GOLTwoTonePanelDrawTsk 

This function draws a two tone panel on the screen with parameters set by GOLPanelDraw() macro. This function must be called repeatedly (depending on the return value) for a successful rendering of the panel.