On Wed, Sep 8, 2010 at 2:31 PM, Alec Chapman <archapm@fas.harvard.edu> wrote:
Robert Ramey wrote:
To make progress in this area. Someone has to:
a) define a doable task b) do it c) submit it for everyone to pick at it d) go back and re-do it e) loop until it's accepted.
Completely agree. Here would be my shot at this. I know it's very manageable in scope and would still be useful in my projects, but those aren't very demanding. The question is if people think it could be more broadly useful.
Initially the library would simply provide a general method for binding data and broadly specifying layout. To actually render the controls, it would internally wrap an existing third party library and provide a way of accessing the underlying controls for low level display settings (actually, it would offer a choice of existing third party libraries to make it easy to use in existing projects).
+1
To give a quick idea of what I'm proposing, the closest analog seems to be data binding in WPF, though I'm not terribly familiar with this so people may know of better examples. The basic idea is that any class that models something like the property map concept or iterator concept would automatically have a reasonable default view which could also be completely changed. More complex dialogs could easily be created by nesting these types inside each other.
A view basically consists of a list of subviews (eg particular controls) and a layout for them (eg vertical list). I think this is a fairly well established idea already. What would be nice is if I could define default views for arbitrary classes through template specialization. For example, suppose I had an existing employee class:
struct Employee { int id, string name };
Then defining a default view might go something like this:
template<> View default_view(Employee& e) { View v; v.set_layout(vertical_list); //accepts certain predefined layouts or an arbitrary function v << employee.id; //add the first subview; this calls default_view<int> v.add_sub_view(default_view(employee.name)); //the previous line could equivalently be written like this return v; }
Suppose I have an object of type Employee: Employee employee = { 999, "Joe Smith" }; I could then call show(employee) or equivalently show(default_view(employee)) to pop up a window for display/editing.
The Mirror reflection library (http://bit.ly/bn7iYM), does something similar for input dialogs for constructing new instances of nested types with possibly multiple constructors. Look for the factory generator utility in the docs. Here (http://bit.ly/bqNqah) can also be found some images of gui dialogs automatically generated by this lib. Besides this factory generator I'm also working on a similar generator for viewers/manipulators of existing instances. These would create a reusable gui object that would accept instances of a given type and would allow to view or even manipulate them. I'm planning to add this utility in the next release of the library. [snip] BR Matus