10277 - Listbox.ColumnFromXY when cursor over header

General
1

I need to know when the mouse cursor is over a header cell or if it has just been clicked.
I though I could do it with “Column and Row FromXY”, and as I couldn’t do it I went to the Feedback just in case there was a reported bug about this subject. But what I found was a feature request from 2009 (#10277). The status is “verified”, but it seems that nothing has been done.

Of course, I can create my function to get the column of the header from XY, but I wanted to ask you all if you had already done it in an easier way.
Thanks for any help.

2

IIRC

If Y < me.headheight

3

Well, I’ve created this function and it works

Function HeaderColumn(extends LB as ListBox, X as Integer, Y as integer) As Integer
  
  'Returns the Header column according to X,Y
  'If X,Y is not on the Header it returns -1
  
  If LB = Nil Then Return -1
  If Y > LB.HeaderHeight Then Return -1
  
  Var LeftLB As Integer = LB.Window.Left + LB.Left
  Var Left As Integer
  
  For c As Integer = 0 To LB.LastColumnIndex
    Left = Left + LB.ColumnAt(c).WidthActual
    If Left > x Then Return c
  Next c
  
  Return -1
  
End Function

I don’t know if it works with ContainerControls, but fortunately it is not a problem now.

4

The followng in MouseDown of a standard ListBox:

System.DebugLog "ColumnFromXY:: " + Str(Me.ColumnFromXY(x,y))
System.DebugLog "RowFromXY:: " + Str(Me.RowFromXY(x,y))

Returns -1 (x and y) if click in the ListBox Header.

5

Exactly. This is the problem. I think that in the ListBox Header it should return the column number, not -1.

6

You still are able to determine that using System.MouseX and System.MouseY compared to ListBox location on the Window.

7

And the headerpressed event fires and gives you the column. What else do you need?

1 Like
8

Thank you Tim. You are right and, in fact, I was not aware of this event.
However my situation is a bit different. I was hovering the mouse over the header and I wanted to use the X,Y of the MouseMove event to know over which Header column I was. Without “pressing” it.

9

Yes, sorry, only later did I read the first post or two. There is unfortunately no MouseOverHeader AFAIK.

But you could do:

if  (Y<me.HeaderHeight)  Then
  yy = Y + me.HeaderHeight
  col = Me.ColumnFromXY(x,yy)
else
  col = Me.ColumnFromXY(x,y)
end if
10

:+1:

11

http://documentation.xojo.com/api/os/system.html#system-mousex

12

Or even:

col = if  (Y<me.HeaderHeight, Me.ColumnFromXY (x, me.HeaderHeight + 1), Me.ColumnFromXY (x, y))
13

That is basically what I have done in the past… but be aware that only works if the listbox is not empty to get the column.

If the listbox has no entries then col = -1 and one would need to use his original way…

As an aside, his original code does not account for the horizontal scroll position for the general case.

-Karen

1 Like