Creating a Tab Action With Accelerators

[Cyncrovee]

So I'm creating a text editor, and want the ability to load a file into a specific tab. Now, the tab factory example shows how to communicate between a primary app window and the tab factory via the SendFront, MoveUp, and MoveDown outputs, however I can't find a way to bind the tab outputs to an action with accelerators. Does anyone know how to do this?

[zekefast]

@Cyncrovee Let me rephrase to see whether I understood what you want to do correctly.

Let's say you have tabs 1, 2 (current), 3. You want to press Ctrl+O and you want to make sure it calls load_file handler and opens file in tab 2. Essentially you want to wire actions to a specific tab (e.g. current), right?

[Cyncrovee]

Yes, that example is exactly what I'm trying to do.

[Cyncrovee]

You can do something like this as a solution but it's a tad verbose and doesn't feel very "Relm-like"

if let Some(selected_page) = self.tabs.widget().selected_page()
    && let Ok(page_box) = selected_page.child().downcast::<gtk4::Box>()
    && let Some(scroll_area) = page_box
        .first_child()
        .and_downcast::<gtk4::ScrolledWindow>()
    && let Some(editor) =
        scroll_area.child().and_downcast::<sourceview5::View>()
{
    let buf = editor.buffer();
    buf.set_text(file_content.as_str())
}

[zekefast]

@Cyncrovee I would do it something like that https://github.com/zekefast/relm4-tabbed-load-file-example

It supports two shortcuts <Ctrl> + O and <Ctrl> + <Shift> + O.

• <Ctrl> + O - opens files in new tabs and allows for multiples files selection
• <Ctrl> + <Shift> + O - opens file in currently selected tab. It allows to open only single file.

Shortcuts send two distinct messages Msg::OpenFileDialog and Msg::OpenFileInPlaceDialog which opens OpenDialogMulti or OpenDialog. Each dialog once files or file selected forward two distinct event Msg::OpenFiles or Msg::OpenFileInPlace. That's how app opens files in new tabs or replaces gtk::TextBuffer in active (i.e. selected) tab.

In order to replace gtk::TextBuffer inside gtk::TextView on active tab I use HashMap<TabPage, TextView> stored inside AppModel. It allows me to avoid fragile dependency on widgets' tree and simplify retrieval of gtk::TextView.

    if let Some(tab_page) = tab_view.selected_page()
        && let Some(text_view) = model.text_views.get(&tab_page)
    {
        tab_page.set_title(&entry.file_name);
        text_view.set_buffer(Some(&entry.text_buf));

        model.open_file_entries.push_back(entry);
    }

Your approach with widgets' tree traversal is also fine, but I personally prefer HashMap for simplicity and to avoid the need to change gtk:TextView lookup logic when widgets layout has changed.

I use simple widgets, i.e. gtk::TextView, gtk::Stack, adw::TabView and adw::TabBar, but obviously you can do similar thing with GtkSourceView.

I SKIP clean up of opened files in AppModel.open_file_entries and AppModel.text_views when tabs are closed. In real application it is something that you'll need to do. Although it is not complicated.

If you'll have any further questions about the topic of discussion or my example I'll be glad to answer them!

[Cyncrovee]

This is super helpful, thank you so much!/gen I'll have a look at implementing it in my project as soon as I get chance.

[Cyncrovee]

In order to replace gtk::TextBuffer inside gtk::TextView on active tab I use HashMap<TabPage, TextView> stored inside AppModel. It allows me to avoid fragile dependency on widgets' tree and simplify retrieval of gtk::TextView.

@zekefast
Would you be able to elaborate on how this works?\nf I've tried a quick test of this here but I've not managed to get it to find the view (I've never used hash maps before so you may have to bear with me there).

[zekefast]

HashMap is a data structure to associate keys to values. You definitely have to read a bit about how to use HashMap. Chapter from Rust By Example: HashMap can help you there.

Anyway, to get something from HashMap you need to put it there first. I didn't notice that you put anything into your HashMap.

In my example, when I load new tab I put a pair of TabPage as key and TextView as a value into HashMap. Then I lookup TextView by TabPage.

I see your lookup part, but I don't see insert part. I think that the problem.

[Cyncrovee]

Got it working!!!! Thank u again for your help :]