AddExec in compiled code

ROOT
1

I am confused about the use of AddExec in compiled code.

In a gui a TMarker is drawn on the Canvas, it’s y coordinate is shown in a TGTextEntry. Changing the entry will change the position of the TMarker.
However, I am trying to implement that you can also drag and drop the marker to a new position directly on the canvas. This is then supposed to update the member variables for the coordinates, and write the new value for y into the TextEntry field.
However, everytime I assign a new value to a member variable (y in that case) from within the Event member function (“MarkerClicked” in my example) I receive a segfault.
As long as I only output the new position as a new local variable everything is fine.

How to use AddExec properly in this context?

Cheers,

Maurits

I attach a minimal version of my working code. The dubious line(s) are commented out.
guiLinkDef.h (36 Bytes)
all.txt (135 Bytes)
MyMain.cxx (1.83 KB)
MyMain.h (702 Bytes)
main.cxx (245 Bytes)

2

Hi,

Please use this format:

instead of:

Cheers,
Bertrand.

3

Hi Bertrand.

It works like a charm. Thanks. Would you care to elaborate on the solution?

Maurits

4

Hi Maurits,

No problem. Here are more details:
At run time, this line:

gives (e.g.) this string:

0x0017fde4 being the address of MyMainFrame “this” pointer. This is then equal to:

Allowing the interpreter to properly call the MyMainFrame::MarkerClicked() method.

Cheers,
Bertrand.

5

Hi Bertrand.

I see. Thanks for your help.

Maurits