gwinPrintfSetText

[tubbutec]

An other small contribution to ugfx. This function is a sprintf wrapper for GWidget objects. It automatically allocates the memory needed for the formatted text. Can be used to display values in labels, in custom draw routines which display the current slider value, etc....

I use this with ARM-GCC in C99 mode, no idea if this compiles on other platforms...

Example:

int val = 100;
gwinPrintfSetText(ghLabel1,"The value is: %d", val);

 

Code:

#include <stdarg.h>
#define gw		((GWidgetObject *)gh)
void gwinPrintfSetText(GHandle gh, char * fmt,...)
{
    if (!(gh->flags & GWIN_FLG_WIDGET))
		return;

	// Dispose of the old string
	if ((gh->flags & GWIN_FLG_ALLOCTXT)) {
		gh->flags &= ~GWIN_FLG_ALLOCTXT;
		if (gw->text) {
			gfxFree((void *)gw->text);
			gw->text = "";
		}
	}

	// Alloc the new text
	char *str;
    va_list va;
    va_start (va, fmt);

    int size = vsnprintf(NULL, 0, fmt, va); //determine size used by printf

    if ((str = gfxAlloc(size+1))) {
        gh->flags |= GWIN_FLG_ALLOCTXT;
        vsprintf(str, fmt, va);
    }
    gw->text = (const char *)str;
    va_end (va);

	_gwinUpdate(gh);
}

 

[inmarket]

Thank you. That is a very useful contribution.

I will add it to the repository as soon as i get an opportunity although i will probably change snprintf to snprintg to avoid pulling all the full c library io overhead.

Well done.

[Joel Bodenmann]

Thank you very much for this awesome contribution!

[tubbutec]

Had not seen vsnprintg! thanks

[inmarket]

This has now been added to the repository as gwinPrintg().