In C I have:
move = gtk_menu_item_new_with_label (name);
g_signal_connect(G_OBJECT(move), "activate", G_CALLBACK(MoveToNotepadCB), np);
In D I have tried:
auto move = new MenuItem (name);
Signals.connectData(view, "activate", &selectNotepad, &selectNotepad, null, ConnectFlags.SWAPPED);
(continued)
With the above D code, I get the error:
none of the overloads of connectData are callable using argument types
because
void delegate(Notepad np)
does not match
extern (C) void function() cHandler
connectData seems to be a low level function since most of the parameters are extern(C)
Should I subclass every button? I'd prefer to do what I do in C, set the callback and give it data (an object) to operate on.
I found a way:
auto view = new RadioMenuItem (group, name);
view.addOnActivate(delegate void(MenuItem foo) {this.selectNotepad();});
This is a bit awkward because view is a RadioMenuItem but since addOnActivate is defined in MenuItem, that's what the delegate parameter must be. Why doesn't inheritance make them equivalent?
I also saw an example that does:
view.addOnActivate(delegate void(_) {this.selectNotepad();});
It works, but I don't understand why.
On 23-12-2018 21:33, Chris Bare wrote:
I found a way:
auto view = new RadioMenuItem (group, name); view.addOnActivate(delegate void(MenuItem foo) {this.selectNotepad();});This is a bit awkward because view is a RadioMenuItem but since addOnActivate is defined in MenuItem, that's what the delegate parameter must be. Why doesn't inheritance make them equivalent?
Most of the time with GtkD you would use a delegate which has access to
it's context.
There is currently no connectData overload for D as there is for connect.
I also saw an example that does:
view.addOnActivate(delegate void(_) {this.selectNotepad();});It works, but I don't understand why.
It works because of type inference by the compiler, _ is the parameter
name and the compiler infers it's type from the definition of addOnActivate. You can also remove the delegate void part.
