_GUICtrlListView_Create() supports only 16 Child Guis

[adom]

Hello,

I need help in the following case:

I have a main GIU and 20 or more Childs. I want to put a ListView on each Child. 

For generating the Childs and the ListViews I use a FOR NEXT.

The issue:

20 or more Childs will be created. But only 16 ListViews will be placed in the first 16 Childs. 

I tried to reach the childs above the 16th instance with ControlMove to proof to have the right Handle. The Handle works.

So I suppose that _GUICtrlListView_Create(HWND, ..) doesnt manage HDNDs for Childs 16 + correct.

Does anyone has an Idea what is there the problem?

Greetings Andrew

_____code snippets below:

Creating Child=====================================

Local $modElem_window

 

Local $left_Next = 0

Local $title

 

For $i = 1 To 20

 

$modElem_window = 0

 

$title = String($i)

 

;~ If $i = 17 Then $title = -1

;~ If $i = 18 Then $title = -2

 

 

$modElem_window = GUICreate($title, 50, 300, $left_Next, 10, BitOr($WS_POPUP, $WS_BORDER))

GUICtrlSetResizing(-1, $GUI_DOCKALL)

GUISetBkColor(0x9900D1)

 

 

 

 

 

Creating List=====================================

Local $sHeaderText = "Done|CMD|RUN-Mode|ACK 2|ACK 1"

 

$List_CMDs_Modul_1 = _GUICtrlListView_Create($modElem_window, $sHeaderText, -1, -1, -1, -1)

_GUICtrlListView_SetExtendedListViewStyle($List_CMDs_Modul_1, BitOR($LVS_EX_GRIDLINES, $LVS_EX_FULLROWSELECT, $LVS_EX_INFOTIP, $LVS_EX_SUBITEMIMAGES, $LVS_EX_DOUBLEBUFFER)) ; $LVS_EX_SUBITEMIMAGES

GUICtrlSetResizing(-1, $GUI_DOCKALL)

 

_GUICtrlListView_SetColumnOrder($List_CMDs_Modul_1, "1|2|3|4|0")

 

[BrewManNH]

That would be correct from what I'm looking at in the code. In _GUICtrlListView_Create, there's a call to a function

Local $nCtrlID = __UDF_GetNextGlobalID($hWnd)

That function includes this loop.

For $iIndex = 0 To $_UDF_GlobalID_MAX_WIN - 1

$_UDF_GlobalID_MAX_WIN has a hard coded setting of 16 inside the UDFGlobalID.au3 file.

If $iUsedIndex = -1 And $fAllUsed Then Return SetError(16, 0, 0) ; used up all 16 window slots

[guinness]

As to why this limitation exists is anyone's guess I'm afraid.

[adom]

Hi BrewManNH,

that explains the Issue. What do you think: What will happen, when I modify the hardcoded 16? 

I guess its not recommended because of compatibility of new versions of Autoit.

Greetings

Andrew

[guinness]

The question we should be asking you is why do you need 16 UDF listviews? What is wrong with GUICtrlCreateListView?

[adom]

@guinness

I dont need only 16. I need it dynamically up to 30.

[Melba23]

adon,

Yes, but why do you want to use UDF-created ListViews (_GUICtrlListView_Create) in place of the native ones (GUICtrlCreateListView)?

M23

[guinness]

What Melba23 said. Why?

[adom]

No special reason.

[guinness]

There is no reason as to why you want 30 dynamically updating listviews? Seems like a pretty specific request to me.

[guinness]

It's also the >second time you have asked.

[adom]

I dont understand why you ask this. I explaned it in my first statement. If I need it I then need it. It may be more than 30 because its dynamic. Its a variable number.

[guinness]

Well you haven't mentioned why you don't use a native AutoIt listview and secondly, if you tell us your plan we can probably come up with a better approach, as 30 listviews does seem a little excessive.

Edited June 20, 2013 by guinness

[adom]

I now will try the normal ListView. I will share my experience with it.

So while thank you.

Greetings 

[guinness]

Good luck. If you get stuck post what you have and we can see what might be the problem.

[adom]

@guinness

Hello again.

One nice question. The problem of limitation of 16 is as brewmannh found out, is based on a constant in the UDF "__UDF_GetNextGlobalID".

This Func is written by Gary Frost. Is it possible to ask him directly, what will happen, if I turn it up to 30 or more? Is it allowed so send him a message? What is best procedure for that question?

In the meanwhile I tested it and it works. But because this UDF is also used generally in AUTOIT it will be good to get the opinion of Gary Frost.

[guinness]

I'm aware of the function, UDF, developer and issue, plus I work on the UDFs myself so there is nothing stopping me from committing the change to SVN. The question still remains the same though. Why?

Any requests should be posted to Trac, but before you do could you please answer the question Melba and I both asked.

[adom]

Why? First I was starting using the standard ListView. Then I get the feeling that I don't want to rewrite my code. 

Because my other code of 1500 rows is ready. Only issue with the limitation popped up. So I dont want to change my code. With this modification setting this const from 16 to 40 there is no problem.

Does this answer your question? 

I hope you no longer feel to be stressed by getting answers. In my mind I wrote all my ideas down now. 

Do you see anything wrong by doing my solution so?

BTW: I am a little confused by your questions like : Why 30? Why everything. Do you want to help me or do you want to fight me?

What is wrong on my decision to 30? And what I am missing is your answer why you ask me why 30? And this in consideration of my 1. post where I give the task I had to solve.

As I said I am a little confused about your strategie asking why but not why you ask why.

And what does it mean "I'm aware of the function,.." I asked you for the best way to communicate with the author. Should I now put in SVN without asking him?

 

[Melba23]

adom,

Please do not take this personally.

We were just wondering why you wanted so many ListViews when the number of UDF-created controls appears to be limited to 16. We have no idea why - although knowing Gary Frost I am sure there is a very good reason why this was the case. You say you have increased the number to 40 with no apparent ill effects - and I am delighted that you have found a solution to your immediate problem - but I hope that you appreciate that we are not going to change the AutoIt internal code without some good explanation as to why the limit was set at 16 rather then 40 in the first place.

Unfortunately Gary is an infrequent visitor to the forum these days. You might like to send him a PM asking why he set that constant to 16 when he wrote the UDF - please let us know if you get a response. Or you could start doing some detective work yourself and find a reference which indicates that a higher number is not going to cause problems later. Personally I can think of a number of reasons why 16 was chosen - when I see binary values like that I always feel that there is something in Windows which limits the value. An example is the 512 file handles per executable - the old DOS internal buffer would not hold any more.

So over to you - if you want us to modify the code, prove to us that it is safe to do so.

M23

[trancexx]

Uhm, that's not changing "AutoIt internal code", don't flatter yourself. 

@adom, you have a valid point, people asking "why" unfortunatly have the lack of knowledge to give you sensible answer. 

16 was a number that's not too big nor too small. It could have been 30, 32, 128, etc... just the same.

Changing from 16 to 32 makes the same sense as choosing 16 back then. Besides tomorrow there would be someone else asking for 52. Changing the value just for you makes even less sense.

AutoIt is currenly very low on "quality", so consider not using the stuff you don't really need because it'll be very long before that's changed.