Add a button to list all tabs in TabBar

Describe the project you are working on

Describe the problem or limitation you are having in your project

If you have many tabs, you will find it difficult to move quickly between them.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

To fix the problem we can add a button that will show Popup with a list of all tabs as it is done for example in Firefox.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

We need to add an enum and variable to TabBar for control the display policy of the button.

enum TabListButtonDisplayPolicy {
    TAB_LIST_BUTTON_SHOW_NEVER,
    TAB_LIST_BUTTON_SHOW_ALWAYS,
    // Displays the button only if not all tabs fit on the screen.
    TAB_LIST_BUTTON_SHOW_ONLY_OFFSET_BUTTONS_VISIBLE,
};

// By default, I think the `TAB_LIST_BUTTON_SHOW_NEVER` policy should be used.
TabListButtonDisplayPolicy tab_list_displaypolicy = TAB_LIST_BUTTON_SHOW_NEVER;

We need to add a child MenuButton for TabBar with a list of all tabs. And if a value of the variable is set as TAB_LIST_BUTTON_SHOW_ONLY_OFFSET_BUTTONS_VISIBLE or TAB_LIST_BUTTON_SHOW_ALWAYS allow the button to be displayed.

An example of what it looks like in my addon: test (2)

If this enhancement will not be used often, can it be worked around with a few lines of script?

Yes.

Is there a reason why this should be core and not an add-on in the asset library?

This solved a problem in the editor itself with many tabs. By default, the size of the tabs in the editor is very large, which makes the tabs with large names fit on the screen very small. And you have to scroll through the tabs a lot to navigate between scenes.

Example:

And adding such a button as I think would make navigation much easier.

godotengine / godot-proposals