Buttons: one callback for multiple sources

[fred]

Hi,

I'm implementing an on-screen keypad with buttons and I've stumbled on a problem. I have 12 buttons ([0..9] and a few control) and I want to register them with the same callback. At the callback I want to find out which button was pressed, but I'm unable to figure it out. In my callback I get a (void)* param and a Gevent; as far as I can tell all the button source can't be determined with the Gevent functions.

My second thought was to add a custom variable to the Button on initialisation which can then be querried from the Gevent, but which of them are used internally and which are available for custom data?

I'd like to add that I implemented it without buttons (use screen locations as in the Notepad example and get "button" events by filtering the touch coordinates) but I've abandoned that approach because the code turned out rather messy.

regards,

Fred

[Joel Bodenmann]

You should be able to retrieve the button information from the gevent structure that you get passed in your callback:

void _callback(void* param, GEvent *pe) 
{
    ...
    ((GEventGWinButton *)pe)->button
    ...
}

It's exactly the same as you do when handling the returned GEvent from geventEventWait() within the main(). Note that I did not try this code and it comes completely out of my mind. I'm on the bus.

I hope that helps a bit.

~ Tectu

[fred]

Thanks!

[Joel Bodenmann]

Please but me know whether it worked or not.

~ Tectu

[fred]

Hi,

works like a charm, here's some code if anyone wants to try it:

//Keypad  settings
#define KEYPAD_X			550	//keypad left border
#define KEYPAD_Y			100	//keypad top
#define KEYPAD_WIDTH		225	//
#define KEYPAD_HEIGHT		300	//
#define GLOBALVALUE_X		550
#define GLOBALVALUE_Y		60
#define GLOBALVALUE_WIDTH	225
#define GLOBALVALUE_HEIGHT	40	

//variables needed:
//globals keypad
GButtonObject	keypadGlobalsButton[12];
GHandle		keypadGlobalsButtonHandle[12];
GSourceHandle	keypadGlobalsButtonSource[12];
char* 		keypadGlobalsStrings[12] = {"1","2","3","4","5","6","7","8","9","BACK","0","CLR"};
GListener		keypadGlobalsCB;

//the variable we're editing
static uint32_t globalEditValue = 0;

font_t fontLarger;

void printGlobalVar(void){
	char globalValueText[12];

	chprintftostring(globalValueText, "%u", globalEditValue);
	gdispFillStringBox(GLOBALVALUE_X, GLOBALVALUE_Y, GLOBALVALUE_WIDTH, GLOBALVALUE_HEIGHT, globalValueText, fontLarger, Yellow, DarkGreen, justifyCenter);
	gdispDrawBox(GLOBALVALUE_X, GLOBALVALUE_Y, GLOBALVALUE_WIDTH, GLOBALVALUE_HEIGHT, Green);
}

//The shared button handler
void keypadGlobalsButtonHandler(void *param, GEvent *pe){
	GHandle pressed = ((GEventGWinButton *)pe)->button;
	uint8_t i = 0;

	for(i = 0; i < 12; i++){
		if(pressed == keypadGlobalsButtonHandle[i]){
			break;
		}
	}
	if(i == 9){//backspace .. divide by 10
		globalEditValue /= 10;
	}else if(i == 11){//clear
		globalEditValue = 0;
	}else if(i < 9){//x = 1..9, y(n+1) = 10*y(n) + x
		globalEditValue = 10 * globalEditValue + i + 1;
	}else if(i == 10){//x = 0, y(n+1) = 10*y(n)
		globalEditValue *= 10;
	}
	printGlobalVar();
}

//alloc of the buttons
void createGlobalsKeypadButtons(void){
	uint8_t x, y, i = 0;
	fontLarger = gdispOpenFont("Larger Double");
	geventListenerInit(&keypadGlobalsCB);
	keypadGlobalsCB.callback = &keypadGlobalsButtonHandler;

	//draw keypad: 0..9, backsp, "." and assign button
	for(y = 0; y < 4; y++){
		for(x = 0; x < 3; x++){
			keypadGlobalsButtonHandle[i] = gwinCreateButton(&keypadGlobalsButton[i], KEYPAD_X + x * 75 + 3, KEYPAD_Y + y * 75 + 3, 70, 70, fontLarger, GBTN_NORMAL);
			gwinSetButtonText(keypadGlobalsButtonHandle[i], keypadGlobalsStrings[i], FALSE);
			keypadGlobalsButtonSource[i] = gwinGetButtonSource(keypadGlobalsButtonHandle[i]);
			geventAttachSource(&keypadGlobalsCB, keypadGlobalsButtonSource[i], 0);//attach listener
			gwinAttachButtonMouse(keypadGlobalsButtonHandle[i], 0);
			i++;
		}
	}
}

//buttons de-activation
void disableGlobalsKeypad(void){
	uint8_t i = 0;
	GButtonObject *gb;

	for(i = 0; i < 12; i++){
		if(keypadGlobalsButtonHandle[i] != NULL){
			gb = &keypadGlobalsButton[i];
			gb->gwin.enabled = FALSE;
		}
	}
}

//buttons activation
void enableGlobalsKeypad(uint8_t draw){
	uint8_t i = 0;
	GButtonObject *gb;

	if(draw == TRUE){//start with a lightgrey square background
		gdispFillArea(KEYPAD_X, KEYPAD_Y, KEYPAD_WIDTH, KEYPAD_HEIGHT, LightGray);
	}
	for(i = 0; i < 12; i++){
		if(keypadGlobalsButtonHandle[i] != NULL){
			gb = &keypadGlobalsButton[i];
			gb->gwin.enabled = TRUE;
			if(draw == TRUE){
				gwinButtonDraw(keypadGlobalsButtonHandle[i]);
			}
		}
	}
}

In your init code call createGlobalsKeypadButtons(); followed by disableGlobalsKeypad();

The buttons are allocated, listening and calling the callback but they're not drawn - disableGlobalsKeypad() disables them altogether without destroying them. When you're ready to draw them you clear the screen and call enableGlobalsKeypad(TRUE);

BTW, everything is called xxxGlobalsxxx because I use this to edit and update global variables during runtime. If you have many buttons, don't forget to adjust GEVENT_MAX_SOURCE_LISTENERS.

regards,

Fred

[Joel Bodenmann]

Glad to hear that it works. Do you actually write a dedicated widget for the keypad? It would be nice if you'd contribute it so we can include it into the official repository.

~ Tectu

[fred]

I'm thinking about that, I'm currently implementing a second keypad to edit the RTC time/date and it would be nice to be able to reuse the code. But it's proving difficult to cover these two examples with the same code. I think I'll implement them seperately and see how they can be brought together in a widget.

[Joel Bodenmann]

What were the kinds of problems that you faced?

~ Tectu