controlAdded event of activecanvas seems not to fire

in the constructor of grasshopper component, after the mybase.new call, i try to
hook an event like shown. but the event don't seem to fire.

shared cntr as integer = 0

Public Sub New()
MyBase.New("Surfaces", "Sur", "Description", "Ajay", "Surfaces")

If SurfacesComponent.cntr = 0 Then
AddHandler ActiveCanvas.ControlAdded, AddressOf Me.ctrladded

SurfacesComponent.cntr += 1
End if

End sub

Private Sub ctrladded(ByVal sender As Object, ByVal e As ControlEventArgs)
MsgBox("ctrl added")
End Sub

Any help will be appreciated, already spent two days frying my brains and eyeballs.

Replies to This Discussion

Permalink Reply by David Rutten on February 9, 2013 at 4:57pm

What controls are you looking for? The canvas typically doesn't contain winform controls (exceptions are when you double click sliders or scrollers, there will briefly be a textbox on the canvas).

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by ajay kakadia on February 12, 2013 at 12:09am

These are curve parameter components and custom created components. I am trying to automatically generate the input components like curve and then hook them to my custom created component when the user places my component on the canvas.

Permalink Reply by David Rutten on February 12, 2013 at 4:11am

Objects on the canvas (like IGH_Param and IGH_Component derived classes) are not winform controls. The canvas is completely owner-drawn and handles all mouse and key events from scratch (with the aforementioned exception of text input boxes when double clicking sliders or scrollers).

If you want to watch for the addition of objects to a document, then you need to handle the ObjectsAdded event on whatever GH_Document the canvas is currently displaying. Luckily the canvas retransmits this event so you can just handle Document_ObjectsAdded event on the ActiveCanvas and you don't have to worry about documents being switched about.

David Rutten

david@mcneel.com

Poprad, Slovakia

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