Code Order

Projects Programming
1

Hi All. First post and a newbie so be gentle please :slight_smile: :slight_smile:

I am in the process of learning coding as well as trying to get to grips with a Nextion display. I have got the basic grasp of what i need to do but when i come to "declare objects",

  • Do you list the objects in page/object order?
  • List the objects by type?
  • It dosent matter?
NexButton b0 = NexButton(2, 1, "b0");  // Button added
NexButton b1 = NexButton(2, 2, "b1");  // Button added
NexButton b2 = NexButton(2, 3, "b2");  // Button added
NexButton b3 = NexButton(2, 4, "b3");  // Button added
NexButton b4 = NexButton(2, 5, "b4");  // Button added
NexButton b5 = NexButton(2, 6, "b5");  // Button added
NexButton b6 = NexButton(2, 7, "b6");  // Button added
NexButton b7 = NexButton(2, 8, "b7");  // Button added
NexButton b8 = NexButton(2, 9, "b8");  // Button added
NexButton b9 = NexButton(2, 10, "b9");  // Button added
NexButton b10 = NexButton(2, 11, "b10");  // Button added

NexButton b1 = NexButton(0, 9, "b1");  // Button added
NexButton b0 = NexButton(0, 1, "b0");  // Button added
NexButton b4 = NexButton(0, 11, "b4");  // Button added
NexDSButton bt0 = NexDSButton(0, 8, "bt0");  // Dual state button added
NexSlider h0 = NexSlider(0, 4, "h0");  // Slider added
NexText t5 = NexText(2, 12, "t5");  // Text box added, so we can read it
NexText t6 = NexText(2, 13, "t6");  // Text box added, so we can read it
NexText t7 = NexText(2, 14, "t7");  // Text box added, so we can read it
NexRadio r0 = NexRadio(2, 4, "r0");  // Radio checkbox added
NexRadio r1 = NexRadio(2, 5, "r1");  // Radio checkbox added
2

In most cases the declaration order isn’t important, as long as any dependencies are accommodated.
They’re often arranged into meaningful / logical blocks for readability - or on occasion - tidiness!

One observation... when you start ‘numbering’ objects you should start considering arrays of that object. Your code will almost inevitably be shorter and more readable.

3

One observation... when you start 'numbering' objects you should start considering arrays of that object. Your code will almost inevitably be shorter and more readable.

Sorry, as i said, i am a newbie to programming. Can you explain a bit more or give an example.

Many thanks

4

I’ll help —- when you fix your initial post with code tags !

5

Is that better? :slight_smile:

6 
// there are 'clever' ways to expand on this 
// - but since you had sequential single digit button names, this is the easiest

//========================================================
#define BUTTON_TYPE 2
const int NUM_BUTTONS = 12;
// create array of buttons
NexButton myButton[NUM_BUTTONS];

// initialise each button member
for (int index = 0; index < NUM_BUTTONS; index++) {
 char button_name[4] = {"b"}; // button name prefix
// myBad ! // strcat(button_name, index + 0x30); // add the index number as ASCII digit
 strcat(button_name, '0' + index);  // I SHOULD have done this first time !
 myButton[index] = NexButton(BUTTON_TYPE, index+1, button_name);  // Add button 
}
// - to reference these buttons - exacgtly the same as you did before - with a new name
myButton[n] // being the index of the button

//========================================================

// You can extend the same idea over to other objects as needed.
// It's no always the sweetest, but in many cases it is---

// ----------------------------------------------
// Curious - why are you RE-declaring these ?
/*
NexButton b1 = NexButton(0, 9, "b1");  // Button added
NexButton b0 = NexButton(0, 1, "b0");  // Button added
NexButton b4 = NexButton(0, 11, "b4");  // Button added
*/
// ----------------------------------------------
// if there's only one or two of a type - just leave them as is
// you could generate them programmatically, but that's
// beyond the scope of this answer !

NexDSButton bt0 = NexDSButton(0, 8, "bt0");  // Dual state button added
NexSlider h0 = NexSlider(0, 4, "h0");  // Slider added

NexText t5 = NexText(2, 12, "t5");  // Text box added, so we can read it
NexText t6 = NexText(2, 13, "t6");  // Text box added, so we can read it
NexText t7 = NexText(2, 14, "t7");  // Text box added, so we can read it

NexRadio r0 = NexRadio(2, 4, "r0");  // Radio checkbox added
NexRadio r1 = NexRadio(2, 5, "r1");  // Radio checkbox added

// ----------------------------------------------
// Curious - why are you RE-declaring these ?
/*
NexDSButton bt0 = NexDSButton(0, 8, "bt0");  // Dual state button added
NexSlider h0 = NexSlider(0, 4, "h0");  // Slider added
NexText t5 = NexText(2, 12, "t5");  // Text box added, so we can read it
NexText t6 = NexText(2, 13, "t6");  // Text box added, so we can read it
NexText t7 = NexText(2, 14, "t7");  // Text box added, so we can read it
NexRadio r0 = NexRadio(2, 4, "r0");  // Radio checkbox added
NexRadio r1 = NexRadio(2, 5, "r1");  // Radio checkbox added
*/

BTW in your code - the button instances have the a same name as the NexButton class...
NOT a good idea o several levels... note - I usedmyButton

7

strcat(button_name, index + 0x40); sp. "0x30"

8

Thanks - oops, finger slip! ('0' not 'A') !

9

lastchancename:
Thanks - oops, finger slip! ('0' not 'A') !

sp. "('0' not '@')"

10

It's been a while !
:frowning:

11

I am trying to do this to iterate through text actually. But tried the button sketch as a starting point. When I try to compile I get the following error:

no matching function for call to 'NexButton::NexButton()'

The only thing I added to the sketch above was:

#include <Nextion.h>

to add the library.

My plan is to build a display with 16 different names and I would like to be able to "for" through each one but having difficulty initialized the array of items.
Any help would be appreciated.
Thanks