OpenEuphoria

2. Re: another setHandler() question

• Posted by Derek Parnell <ddparnell at bigpond.com> Sep 07, 2003
• 384 views

----- Original Message ----- 
From: "David Davis" <gdavis at hypercon.net>
To: "EUforum" <EUforum at topica.com>
Subject: another setHandler() question


> 
> 
> is it possible to pass a parameter through sethandler()?
> 
> code snippet:
> 
> procedure ASL_Cancel_onClick(integer self, integer event, sequence 
> params)
> closeWindow(ASL_Window)
> end procedure
> 
> procedure ASL_Add_onClick(integer self, integer event, sequence params)
> 
> -- item = getIndex(ItemsAvailable_List)
> -- addItem(Item_List, Products[item][2])
> -- addItem(Quantity_List, Products[item][3])
> -- addItem(Price_List, Products[item][4])
> 
> end procedure
> 
> procedure add_to_sale_list(integer self, integer event, sequence params)
> integer item
> atom Event
> sequence title
> 
> Event=params[1]
> if Event = LEFT_DOUBLECLICK  then
> item = getIndex(ItemsAvailable_List)
> title = Products[item][2] & "  " & Products[item][4] & "  " & 
> Products[item][3]
> ASL_Window = createEx( Window, title, 0, Default, Default, 331, 120, 
> 0, 0 )
> ASL_Button1 = createEx( PushButton, "Add", ASL_Window, 40, 60, 80, 30, 
> 0, 0 )
> ASL_Button2 = createEx( PushButton, "Cancel", ASL_Window, 195, 60, 80, 
> 30, 0, 0 )
> ASL_Edit = createEx( EditText, "", ASL_Window, 110, 15, 85, 25, 0, 0 )
> setHandler( ASL_Button1, w32HClick, routine_id("ASL_Add_onClick"))
> setHandler( ASL_Button2, w32HClick, routine_id("ASL_Cancel_onClick))
> openWindow(ASL_Window, Modal)
> setFocus(ASL_Edit)
> end if
> end procedure
> 
> 
> I need to pass 'item' (integer) to the ASL_Add_onClick routine, but 
> don't know if sethandler will let me, and I do not really want to make 
> it a file-wide variable. If I could do the entire operation in just one 
> procedure it would be even better. Hunting around the win32lib docs 
> hasn't helped, any ideas?
> 
> Thank You

Without knowing all the details, can I suggest you try using the User Property
feature.

Pick a suitable control, maybe the 'Add' button itself, and define a user
property for it.

  defineUserProperty(ASL_Button1, "item", -1) -- initial value of -1.

Then when you need to assign a value to 'item' ...

  setUserProperty(ASL_Button1, "item", newvalue)

Then in the 'ASL_Add_onClick' routine do this...

  item = getUserProperty(ASL_Button1, "item")

or even 

  item = getUserProperty(self, "item")

I know this is very similar to the file-wide variable idea, but the scope of the
user property is limited to the control.

The problem with passing parameters with setHandler is that you can only pass
the *value* of the item when setHandler is called, whereas you need the value at
the time the event happens.

I might consider this functionality when I add user-defined events to win32lib.

-- 
Derek