[Help] How to use headerbar? How Gtk classes are translated into swift?

[lf-araujo]

Dear Tomas,

Thank you for this bindings! This is super useful.

I have a little experience in Vala, but on trying to use some elements from gtk I get errors. Specifically I am trying to use headerbars. How do this class translates into Swift? What am I doing wrong in the code below?

import SwiftGtk

let app = Application(applicationId: "com.example.application")

app.run { window in
    window.defaultSize = Size(width: 400, height: 400)
    window.resizable = true
    let headerbar = Headerbar()
    headerbar.set_title("My test")


    let button = Button(label: "Press Me")
    button.clicked = { _ in
        let newWindow = Window(windowType: .topLevel)
        newWindow.title = "Just a window"
        newWindow.defaultSize = Size(width: 200, height: 200)
        let labelPressed = Label(text: "Oh, you pressed the button.")
        newWindow.add(labelPressed)

        newWindow.showAll()
    }
    window.set_titlebar(headerbar)
    window.add(button)
}

[lf-araujo]

A better inspection of the source code and I found that these classes are implemented in the Sources directory. How would you recommend to approach creating a new one? Where you get the API or the methods that one should implement in the class source? I suppose those are the C Gtk methods, right?

[TomasLinhart]

I am away from a computer for a few days. Once I am back I will give you some information.

[TomasLinhart]

So...

First, you need to find documentation for API that you want to use. In your case it is https://developer.gnome.org/gtk3/stable/GtkHeaderBar.html Here you see all properties and methods that are available. To use them you need to create a new class and properties and methods for everything that you find the documentation.

I went ahead and created the binding for you so you can see how you would do it,
1801c74.

And you can use it in the following way.

let headerBar = HeaderBar()
headerBar.title = "Hello World"
headerBar.subtitle = "oh yea"
headerBar.showCloseButton = true
headerBar.spacing = 50

let label = Label(text: "1")

headerBar.packStart(child: label)
headerBar.packStart(child: Label(text: "2"))

headerBar.remove(label)

window.titlebar = headerBar
window.hideTitlebarWhenMaximized = true

I hope, it helps. 😄

[lf-araujo]

Thank you very much! I will contribute as soon as possible. Why don't you add this instruction into the README so others can get right at it?

[lf-araujo]

I have found a problem in the new code, the error is (I switched to Ubuntu):

/home/luis/Dropbox/Documentos/Coding/Swift/SwiftGtk/.build/checkouts/SwiftGtk--2571330441700638662/Sources/HeaderBar.swift:15:63: error: value of type 'UnsafePointer<gchar>' (aka 'UnsafePointer<Int8>') has no member 'toString'
        get { return gtk_header_bar_get_title(castedPointer())?.toString() }
                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^ ~~~~~~~~
/home/luis/Dropbox/Documentos/Coding/Swift/SwiftGtk/.build/checkouts/SwiftGtk--2571330441700638662/Sources/HeaderBar.swift:20:66: error: value of type 'UnsafePointer<gchar>' (aka 'UnsafePointer<Int8>') has no member 'toString'
        get { return gtk_header_bar_get_subtitle(castedPointer())?.toString() }
                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^ ~~~~~~~~
/home/luis/Dropbox/Documentos/Coding/Swift/SwiftGtk/.build/checkouts/SwiftGtk--2571330441700638662/Sources/HeaderBar.swift:41:75: error: value of type 'UnsafePointer<gchar>' (aka 'UnsafePointer<Int8>') has no member 'toString'
        get { return gtk_header_bar_get_decoration_layout(castedPointer())?.toString() }

The code I used was:

import SwiftGtk

let app = Application(applicationId: "com.example.application")

app.run { window in
    window.defaultSize = Size(width: 400, height: 400)
    window.resizable = true
    let headerBar = HeaderBar()
    headerBar.title = "Hello World"
    headerBar.subtitle = "oh yea"
    headerBar.showCloseButton = true
    headerBar.spacing = 50

    let label = Label(text: "1")

    headerBar.packStart(child: label)
    headerBar.packStart(child: Label(text: "2"))

    headerBar.remove(label)

    window.titlebar = headerBar
    window.hideTitlebarWhenMaximized = true


    let button = Button(label: "Press Me")
    button.clicked = { _ in
        let newWindow = Window(windowType: .topLevel)
        newWindow.title = "Just a window"
        newWindow.defaultSize = Size(width: 200, height: 200)
        let labelPressed = Label(text: "Oh, you pressed the button.")
        newWindow.add(labelPressed)

        newWindow.showAll()
    }


    window.add(button)
}

[TomasLinhart]

I see I will look into it.

[lf-araujo]

@TomasLinhart , nevermind, for some reason swift builder is not pulling the new files. I added UnsafePointerGChar and Window.swift; the issue was resolved. Sorry for the bother.

[lf-araujo]

Not related to your package, but I am doing something wrong. Perhaps @bmdelacruz can also help.

Any changes to main.swift requires .build folder to be deleted and the addition to the new files Window, UnsafePointerGChar, and HeaderBar. How can I instruct Swift build to detect the changes into main.swift without having to start over every run? It is probably something easy, but I cant find it!

Thank you.

[lf-araujo]

Found the solution for that too, the contents of Packages.swift:

import PackageDescription

let package = Package(
    name: "SwiftGtkApplication",
    dependencies: [
        .Package(url: "https://github.com/TomasLinhart/SwiftGtk", majorVersion: 1)
    ]
)

Source.

[lf-araujo]

Dear Tomas,

You should probably re-release the version with HeaderBar, the sourcefile is not in the assets for 0.3.1.

Best,

Luis