Cursive, callback to view seems to carry not enough info

help
#1

Hi everyone, I'm using cursive crate along with cursive_table_view crate.
I'm registering callback to each created table and yes, this callback is being triggered, but I believe that there is not enough info in that callback.

//The callback
    fn Enter_Fn(app: &mut cursive::Cursive, row: usize,index: usize)
    {
    //how am I suppose to know which view triggered that callback???
    }
    ////<<<later in the code
    for i in 0..10
    {
//create panels
    let mut panel_left = create_table();//see decl below, it is the same as in examples from the repo
    panel_left.set_on_submit(Enter_Fn);//register callback
    //here I have some code that defines layout etc, so the last line is "pseudo code"
    siv.add_layout(panel_left);
    }

    fn create_table() -> TableView<Foo, BasicColumn> ;//this is function that creates table
//end of code

How to know in the Enter_Fn function which table was active when the enter was pressed, that is, we are inside of the Enter_Fn callback but all we have is app, row and index but not the view which triggered that callback.

Thanks for any help

#2

Please use a code block instead of a quote block.

```
// your code here
```
#3

I'm not familiar with cursive and there might be a better way but it looks like that instead of calling Enter_fn directly you can call it from a lambda like

panel_left.set_on_submit(|siv, row, index| Enter_fn(siv, row, index));

Inside the lambda you have access to other local variables like panel_left or i so the lambda could call Enter_fn(siv, row, index, i, panel_left) or similar.

Most likely it won't compile without changes since passing panel_left would move the value and passing a reference will make Rust complain about lifetimes so you'll need to identify panels/views in some other way. Perhaps cursive already has something built in.

Not related but it's worth following Rust naming conventions.

#4

@qaopm Thanks for the answer. Unfortunately it doesn't compile. Really frustrating. Simple thing yet cannot make it working.
As far as I know cursive doesn't provide that functionality which is doubly frustrating as it seems to me that the cursive library is in very early stages...

#5

The simplest way might be to pass not the function directly, but the closure calling it:

fn enter_fn(app: &mut cursive::Cursive, row: usize, index: usize, i: usize) {
    todo!();
}

// later in the code
for i in 0..10 {
    let mut panel_left = create_table();
    // Next line does register the callback.
    panel_left.set_on_submit(|app, row, index| enter_fn(app, row, index, i));
    siv.add_layout(panel_left);
}
#6

@Cerberuser Hi and thanks for the answer.
In enter_fn I NEED access to the panel that the callback was called on. That seems to be the tricky part.

#7

In this case, you have to use so-called "named views". That means:

  • When creating your view, you wrap it in NamedView, preferably by importing Nameable and calling with_name.
  • Then, you pass the name into callback.
  • In callback, you invoke call_on_name on the provided Cursive instance.
  • call_on_name finds the view by name and passes the mutable reference to it into the next callback.
1 Like
#8

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