GOLDrawCallback Function

Microchip Graphics Library

WORD GOLDrawCallback();

Overview

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.

Returns

Return a one if GOLDraw() will have drawing control on the active list. Return a zero if user wants to keep the drawing control.

Preconditions

none

Side Effects

none

Example

Copy Code

#define SIG_STATE_SET   0
#define SIG_STATE_DRAW  1
WORD GOLDrawCallback(){
    static BYTE state = SIG_STATE_SET;
    if(state == SIG_STATE_SET){
        // Draw the button with disabled colors
        GOLPanelDraw(SIG_PANEL_LEFT,SIG_PANEL_TOP,
                     SIG_PANEL_RIGHT,SIG_PANEL_BOTTOM, 0,
                     WHITE, altScheme->EmbossLtColor,
                     altScheme->EmbossDkColor,
                     NULL, GOL_EMBOSS_SIZE);

        state = SIG_STATE_DRAW;
    }
    
    if(!GOLPanelDrawTsk()){
        // do not return drawing control to GOL
        // drawing is not complete
        return 0;
    }else{
        state = SIG_STATE_SET;
        // return drawing control to GOL, drawing is complete
        return 1;
    }
}

Library API > Graphics Object Layer API > Object Management > GOLDrawCallback Function

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