Event handling: design problem

[merces]

In the current design, adding a new feature usually needs three things:

• A renderer function.
• An event handler function.
• Some data stored in struct App:
  

  dz6/src/app.rs

  Line 124 in 918d9a4

  pub struct App {

I was able to use a function pointer for the render function:

dz6/src/app.rs

Line 127 in 918d9a4

pub dialog_renderer: Option<fn(&mut App, &mut Frame)>,

So, the new feature under hex/, text/ or global/ sets this pointer and the main drawing function executes it here:

dz6/src/draw.rs

Line 67 in 918d9a4

if let Some(f) = app.dialog_renderer {

But I couldn't find a way to do the same for event handlers functions such as

dz6/src/hex/strings.rs

Line 208 in 918d9a4

pub fn dialog_strings_regex_events(app: &mut App, event: &Event) -> Result<bool> {

so I ended up creating a match arm for every dialog and explicitly calling the event handler function for the right feature in

dz6/src/events.rs

Line 22 in 918d9a4

pub fn handle_events(app: &mut App) -> Result<bool> {

but I'm sure there's a better way to do this I just don't know about. Maybe using traits? Not a Rust expert here, so I'd appreciate proposals to make the code smarter. :)