Change property more than one time in an qml depend on input variables

petzold

no i have bit values and this i want transform to a number. not the matter if the number is hex, bin, dec.
i do it now in that way i think it will work
@
Text {
id: elevatorName
text: {
if(boCodePin3 == FALSE && boCodePin4 == FALSE) return "MEC1";
else if (boCodePin3 == TRUE && boCodePin4 == FALSE) return "MEC2";
else if (boCodePin3 == FALSE && boCodePin4 == TRUE) return "MEC3";
else if (boCodePin3 == TRUE && boCodePin4 == TRUE) return "MEC4";
}
}
@

andre

Huh? What you are doing now is not converting to a number, but to a string.

It seems you have a collection of booleans. I'd just make a simple element in C++ that you then expose to QML that has boolean properties for every bit position you want to support (8,16, perhaps more?) and an integer property for the numeric interpretation. You can then just bind your boolean values to this object hand use binding to the numeric value too. Or use it the other way around to set a number and get the induvidual bits directly. Edit: you could just make that component completely in QML too, if you want.

What you now write is feasible (but not recommended) if you have just two, maybe three bits. After that, it gets rather long and easy to make mistakes in quickly. Doing this for 8 bits will already require 256 of these with 8 checks each. Good luck with that...

p3c0

Still not able to understand. Can you give an example of what input you get and what you want it to be converted into ?

petzold

Andre:
i know this solutionwill just work in that simple case,and i don't want it too. that was the reason to post the problem. :-)
the solution will work because i just have 4 bits and so i can handle it.

your idea i don't understand fully. can you please detail it more or give a example, link etc?

p3c0:
a controller collect some differnt signals for controlling and visualization this are send over and interface to a control programm. some of this information are for the controlling, the rest is for visualization.
the problem is i don't want to change the programm code, the code should be the same becuase in other cases i need the bits.

this 4 bits are digital inputs and used for visualization.
this 4 bits are the coding of 16 sockets. and i will make a view where the user can see wich socket is used.

p3c0

So what numerical input you get when for eg socket no. 8 is used ? Do you get 1000 (considering each digit as a separate bit ofcourse)as the input ?

petzold

for socket 8 i get

boBit0 = FALSE
boBit1 = FALSE
boBit2 = FALSE
boBit4 = TRUE

andre

I'd do something like this:

Make new QML file BitField.qml, and put something like this in (untested):

@
import QtQuick 2.2

QtObject {
id: BitField
property bool bit0
property bool bit1
property bool bit2
property bool bit3

property int value;

onBit0Changed: updateValue()
onBit1Changed: updateValue()
onBit2Changed: updateValue()
onBit3Changed: updateValue()

function updateValue() {
int newVal = 0;
newVal |= bit0 ? 1 : 0;
newVal |= bit1 ? 2 : 0;
newVal |= bit2 ? 4 : 0;
newVal |= bit3 ? 8 : 0;
value = newVal;
}

onValueChanged: {
bit0 = value && 1;
bit1 = value && 2;
bit2 = value && 4;
bit3 = value && 8;
}
}
@

You can then use the BitField element in your QML, and just bind to the properties however you like.

Again: the code above is an idea only, I did not test it but just typed it into the forum editor directly.

petzold

this is my idea to solve it. (tested)

@
function iTransformtoInt(bit0, bit1, bit2, bit3, bit4, bit5, bit6, bit7) {
var calc = 0;
if (bit0 === true) { calc +=1};
if (bit1 === true) { calc +=2};
if (bit2 === true) { calc +=4};
if (bit3 === true) { calc +=8};
if (bit4 === true) { calc +=16};
if (bit5 === true) { calc +=32};
if (bit6 === true) { calc +=64};
if (bit7 === true) { calc +=128};
return calc;
}
Text {
id: elevatorName
text: iTransformtoInt(boCodePin1,boCodePin2, boCodePin3, boCodePin4,0,0,0,0)

}
@

petzold

thanks you both for give me some new ideas.

p3c0

Or may be this one
@
function convert(pinsArray) {
var all = ""
for(var i=0;i<pinsArray.length;i++)
all += (pinsArray[i]*1).toString()

console.log(all,parseInt(all, 2))

}

Component.onCompleted: {
var boCodePin1 = false
var boCodePin2 = false
var boCodePin3 = false
var boCodePin4 = true

var arr = [boCodePin4,boCodePin3,boCodePin2,boCodePin1];
convert(arr)

}
@

seems the earlier post was deleted.