Windows (forms) two-step construction

[rossanoparis]

I've noticed that for wxDialog and wxPanel, the genrated code uses two-step construction only, for wxFrame the genrated code don't use two-step construction.
Talking about windows (forms) constructions, as I see it, two-step construction shouldn't be imposed by the used RAD tool.
In my opinion, windows construction shuld be decided by the developer by using an option for each window (form) used; not a common option for the entire project, but such option shuld be present for each inserted form.
The current way used by wxUIEditor is "stiff" and forces developer to follow its way to generate code, generally speaking should be the opposite.

[KeyWorksRW]

Most of the wxWidgets classes work that way. The ctor with no parameters simply calls Init() and the ctor with all the parameters calls Init() and then calls Create(). Or put another way:

    wxDialog dlg(parent, id, title);

the above will first call wxDialog::Init() and then immediately call wxDialog::Create(parent, id, title). If you use wxUE to create MyDialogBase and enter:

    MyDialogBase dlg(parent, id, title);

the above will automatically call wxDialog::Init() and then calls:

    if (!wxDialog::Create(parent, id, title))
        return false;

before creating the additional content. So whether you are creating wxDialog or MyDialogBase, you can create them with no parameters MyDialogBase dlg followed by a call to Create or you can call it with parameters MyDialogBase dlg(...) and it will call Create for you -- the same as would happen if you simply created a pure wxDialog instance.

With a Dialog or Panel form, you have two ways to create an instance of the form, the same as you do with the wxWidget class it inherits from. With a Frame form, you only have one way to create an instance. In my mind, it is the Frame which is "stiff" and forces the dev to only have one way to create an instance of the frame.

I actually plan at some point to change the Frame form to two-step creation as well since it should be compatible with all existing code unless an inherited class overrides the Create method and doesn't call the base class Create method.

All that said, I don't think ever tried this, but I assume given a MyDialogBase base class and a MyDialog inherited class you could simply create a ctor using:

MyDialog::MyDialog(wxWindow* parent) : MyDialogBase(parent) {}

The downside is that you can't do anything before Create is called, whereas

MyDialog::MyDialog(wxWindow* parent)
{
    // Insert pre-creation initialization code here

    Create(parent);

    // Insert post-creation initialization code here
}

Does all of this make sense or am I overlooking something?

[rossanoparis]

Thank you, of course it makes sense, except for wxFrame construction which doesn't follow the same principle.
I'd suggest to permit wxFrame two-step construction too, as wxFrame window could be used in many different way within an application, not only as main application frame.

[KeyWorksRW]

Pull request #963 adds 2-step construction to wxFrame and the form version of wxPanel. This will be in the 1.1.1 release.

[rossanoparis]

well done!