[BOOK] Various minor issues

[valentingoebel]

It's death by a thousand cuts so I won't bother making multiple issues.

"GObject Concepts > Memory Management" starts off with a comment // Create two buttons for the single button listing. The same comment appears later again for Cell where it is still superfluous, because the Cell example is for a single button. That comment becomes necessary in the listing that introduces Rc but for some reason the code for the second button is in the hidden part of the listing when it should be shown.

At the very end of the "Settings" chapter, the book binds the setting to the active property which works exactly as you expect, but the example before that uses the state property which for me only changes the background color without moving the toggle. Changing .state(is_switch_enabled) to .active(is_switch_enabled) changes both the background color and moves the toggle.

I personally jumped straight to using libadwaita for the entire book and libadwaita introduces datastructures that have names identical to the gtk4 ones and it is not clear at all which ones you should choose. If you use the ApplicationWindow from libadwaita, you will run into an issue when adding a button via .child(&button). The error message is highly unintuitive and appears like an unsurmountable obstacle until you realize that you can just use the ApplicationWindow from gtk4. Since the To-Do app uses xml files to define the UI, you never get to see a simple code based UI listing for how to get libadwaita working with the earlier chapters of the book.

[valentingoebel]

Building a Simple To-Do App > Window: The code listings (mod.rs, imp.rs, resources.gresource.xml) in the "Window" section reference TaskRow which will be defined in the next section. This means you cannot compile the application and get the same result as the screenshot. You'll either have to remove the TaskRow references or proceed to the next section without compiling and running the application.

[valentingoebel]

12. Actions > Settings: Actions7.gschema.xml listing has changed the APP_ID to org.gtk_rs.Actions7 without mentioning it. This leads to the error:

GLib-GIO-ERROR **: 14:39:29.142: Settings schema 'org.gtk_rs.Actions1' is not installed

"Again, we install the schema as described in the settings chapter." should include a notice that the APP_ID needs to be changed as well.

[valentingoebel]

13. Manipulating State of To-Do App: Since I went through the entire guide, I got tired of making new Rust source files for the window.ui so I ended up overwriting the same file over and over again. Since this chapter was interrupted by the previous "Actions" chapter, I ended up overwriting the code for the To-Do App.

To my surprise, the code listings show you a code diff and expected you to have kept the code around, which I didn't do. This means I had to go back and forth between the chapters.

The imp.rs and mod.rs for the window.ui file do contain a full listing, but due to the poor separation between Filtering Tasks and Saving and Restoring Tasks, you end up copying code that references serdes before the serdes section has begun, so now you have to fix it manually again.

Once you have done that, you run into another small issue. Since the window.ui file has moved under Todo2 inside the .gresource.xml, you also have to adjust your pre-existing TaskRow to reference the task_row.ui inside Todo2.

Either the code listings have to be re-written or there needs to be a big warning in the actions chapter to keep the To-Do app code around.

[valentingoebel]

13. Manipulating State of To-Do App: TaskData needs to be clonable but this isn't mentioned. Furthermore, the location for the data.json file isn't mentioned so you cannot inspect the file. On Arch Linux, the file was stored under ~/.local/share/<APP_ID>/data.json.

[valentingoebel]

The 14. CSS chapter starts off with

    let button = Button::builder()
        .label("Press me!")
        .margin_top(12)
        .margin_bottom(12)
        .margin_start(12)
        .margin_end(12)
        .build();

As someone who despises hard coded margins in Rust code and window.ui files, I would have expected that the example look more like this CSS instead:

button {
    margin-top: 12px;
    margin-bottom: 12px;
    margin-left: 12px;
    margin-right: 12px;
}

the value proposition is obvious. No more hard coding of margins and the margins are defined in a central location if you wanted more than one button. It also missed an opportunity to explain how to find the equivalent CSS properties because GtkWidget defines margin-start and margin-end which obviously aren't the same properties as in a web browser.