TouchGFX Wildcards: How to display a blank space

[KMew]

Hello,

I am using the TouchGFX application to display data gathered from CANbus communication, which I have verified is working. One feature I wanted to have is the following logic for fault error codes:

If a fault is present, display the error code in hexadecimal (with a user manual to outline the meaning of said error codes) in red.

If no fault is present, then I want NO text to be present. I do not want to show "0x00000000". I just want no text to be there at all.

I've attached a snippet of my code that writes the value into the wildcard currently. This solution does not work.

void Screen1View::UpdateFaults(uint64_t value){
	if(value != 0x00000000){
		Unicode::snprintf(textFaultSigBuffer, TEXTFAULTSIG_SIZE, "%x", value);
	}
	else{
		Unicode::snprintf(textFaultSigBuffer,TEXTFAULTSIG_SIZE, "%x","" );
	}
	  // Invalidate text area, which will result in it being redrawn in next tick.
	textFaultSig.invalidate();
}

Instead of displaying a blank space, it shows 8031650 (like in the picture).

Does anyone know how to make it just display no text at all?

[JTP1 · Accepted solution]

    void Screen1View::UpdateFaults(uint64_t value){
    	if(value != 0x00000000){
    		Unicode::snprintf(textFaultSigBuffer, TEXTFAULTSIG_SIZE, "%x", value);
    		textFaultSig.setVisible(1); // Shows to object
    	}
    	else{
//    		Unicode::snprintf(textFaultSigBuffer,TEXTFAULTSIG_SIZE, "%x","" );
    		textFaultSig.setVisible(0); // Hides to object
    	}
    	  // Invalidate text area, which will result in it being redrawn in next tick.
    	textFaultSig.invalidate();
    }

Just set it visible or not, if I understand right what you need ?

[KMew]

Hello JTP,

Yes, this is exactly what I needed! I just tried it and it worked exactly as I wanted.

Thank you!

[MM..1]

Your error is

Unicode::snprintf(textFaultSigBuffer,TEXTFAULTSIG_SIZE, "%x","" );

right is

Unicode::snprintf(textFaultSigBuffer,TEXTFAULTSIG_SIZE, "" );

or

Unicode::snprintf(textFaultSigBuffer,TEXTFAULTSIG_SIZE, "%s","" );

[KMew]

Ooohh interesting.

So if I did it your way, whatever was in the wildcard spot would go away and the non-wildcard part would stay, correct? For example:

"Fault: " - Non wildcard, so it would stay

But the wildcard part (the actual error code in hex) would be blank.

JTP's way gets rid of all wildcard and non-wildcard text, while yours gets rid of just the wildcard portion. This is most helpful! Now I can do both options.

Thank you MM!