how does a gadget recognize that it has the focus?

BlitzMax Forums/BlitzMax Programming/how does a gadget recognize that it has the focus?

Rozek

(Posted 2010) [#1]

Hello!

I am currently developing a few TProxyGadgets for my application. Now I have the problem that I would like to know when my gadgets gain/loose the keyboard focus in order to update their visual appearance

I could neither find any events informing about this state change nor a pair of functions (such as "ActivateGadget" - which exists - and "InactivateGadget" - which does not exist)

Is there any way to keep track of the focus?

Of course, I could regularly check "ActiveGadget" and update my gadget's state accordingly - but this does not sound like an efficient (and elegant) approach.

Is there any alternative?

Thanks in advance for any hint!

jsp	(Posted 2010) [#2]

Depends on the gadgets on top of the proxy gadget.
Textfields and Textarea produce a gadgetlostfocus event.
And for Panels and Canvas you could use the mouse enter and mouse leave event.
If you need more for some reason, you could also enable SetGadgetSensitivity( YourGadget:TGadget,SENSITIZE_MOUSE|SENSITIZE_KEYS )

Rozek

(Posted 2010) [#3]

Hello!

Thanks for your response!

Is the "GadgetLostFocus" event documented? I could not find any mention of it in the docs

And, unfortunately, mouse enter and mouse leave events must *not* be used for focus management (as you may also operate GUI-based applications with the keyboard only (the better ones, at least))

Currently, I see no other way as to observe the currently active gadget and inform the previous one about focus loss.

jsp	(Posted 2010) [#4]

Find below an example of the EVENT_GADGETLOSTFOCUS.

Currently, I see no other way as to observe the currently active gadget and inform the previous one about focus loss.

What do you change in case of focus / no focus.

SuperStrict

Import MaxGui.Drivers

Local Window3:TGadget = CreateWindow:TGadget("Window3",282,111,391,247,Null,WINDOW_TITLEBAR|WINDOW_RESIZABLE |WINDOW_STATUS |WINDOW_CLIENTCOORDS )
	Local TextField4:TGadget = CreateTextField:TGadget(30,108,80,18,Window3:TGadget,Null)
		SetGadgetText( TextField4:TGadget,"TextField4")
	Local TextField5:TGadget = CreateTextField:TGadget(30,151,80,18,Window3:TGadget,Null)
		SetGadgetText( TextField5:TGadget,"TextField5")
	Local Ok1:TGadget = CreateButton:TGadget("Ok1",282,210,75,23,Window3:TGadget,BUTTON_OK)
	Local Cancel2:TGadget = CreateButton:TGadget("Cancel2",30,210,75,23,Window3:TGadget,BUTTON_CANCEL)
	Local TextField2:TGadget = CreateTextField:TGadget(30,22,80,18,Window3:TGadget,Null)
		SetGadgetText( TextField2:TGadget,"TextField2")
	Local TextField3:TGadget = CreateTextField:TGadget(30,65,80,18,Window3:TGadget,Null)
		SetGadgetText( TextField3:TGadget,"TextField3")
	Local TextArea2:TGadget = CreateTextArea:TGadget(150,22,207,147,Window3:TGadget,Null)
		SetTextAreaText( TextArea2:TGadget , "TextArea2" )

Repeat
	WaitEvent()
	Select EventID()
		Case EVENT_WINDOWCLOSE
			Select EventSource()
				Case Window3	Window3_WC( Window3:TGadget )
			End Select

		Case EVENT_GADGETACTION
			Select EventSource()
				Case TextField4	TextField4_GA( TextField4:TGadget )
				Case TextField5	TextField5_GA( TextField5:TGadget )
				Case Ok1	Ok1_GA( Ok1:TGadget )
				Case Cancel2	Cancel2_GA( Cancel2:TGadget )
				Case TextField2	TextField2_GA( TextField2:TGadget )
				Case TextField3	TextField3_GA( TextField3:TGadget )
				Case TextArea2	TextArea2_GA( TextArea2:TGadget )
			End Select

		Case EVENT_GADGETLOSTFOCUS
			Select EventSource()
				Case TextField4	TextField4_GF( TextField4:TGadget )
				Case TextField5	TextField5_GF( TextField5:TGadget )
				Case TextField2	TextField2_GF( TextField2:TGadget )
				Case TextField3	TextField3_GF( TextField3:TGadget )
				Case TextArea2	TextArea2_GF( TextArea2:TGadget )
			End Select

	End Select
Forever

Function Window3_WC( Window:TGadget )
	DebugLog "Window Window3 wants to be closed"

	End
End Function

Function TextField4_GA( TextField:TGadget )
	DebugLog "TextField TextField4 was modified"
	DebugLog "Text = "+ TextFieldText$( TextField:TGadget )
	
End Function

Function TextField5_GA( TextField:TGadget )
	DebugLog "TextField TextField5 was modified"
	DebugLog "Text = "+ TextFieldText$( TextField:TGadget )
	
End Function

Function Ok1_GA( Button:TGadget )
	DebugLog "Button Ok1 was pressed"
	
End Function

Function Cancel2_GA( Button:TGadget )
	DebugLog "Button Cancel2 was pressed"
	
End Function

Function TextField2_GA( TextField:TGadget )
	DebugLog "TextField TextField2 was modified"
	DebugLog "Text = "+ TextFieldText$( TextField:TGadget )
	
End Function

Function TextField3_GA( TextField:TGadget )
	DebugLog "TextField TextField3 was modified"
	DebugLog "Text = "+ TextFieldText$( TextField:TGadget )
	
End Function

Function TextArea2_GA( TextArea:TGadget )
	DebugLog "TextArea TextArea2 was modified"
	
End Function

Function TextField4_GF( TextField:TGadget )
	DebugLog "TextField TextField4 lost focus"
	DebugLog "Text = "+ TextFieldText$( TextField:TGadget )
	
End Function

Function TextField5_GF( TextField:TGadget )
	DebugLog "TextField TextField5 lost focus"
	DebugLog "Text = "+ TextFieldText$( TextField:TGadget )
	
End Function

Function TextField2_GF( TextField:TGadget )
	DebugLog "TextField TextField2 lost focus"
	DebugLog "Text = "+ TextFieldText$( TextField:TGadget )
	
End Function

Function TextField3_GF( TextField:TGadget )
	DebugLog "TextField TextField3 lost focus"
	DebugLog "Text = "+ TextFieldText$( TextField:TGadget )
	
End Function

Function TextArea2_GF( TextArea:TGadget )
	DebugLog "TextArea TextArea2 lost focus"
	
End Function

Rozek

(Posted 2010) [#5]

Hello!

Thanks for the example code!

I want to provide some visual feedback in case while a gadget owns the keyboard focus - that's what I need these events for.