How to pack a button in a HeaderBar using Genie?

问题

Background

My aim is to improve a little text editor as an exercise. It is running fine after the HeaderBar was added, however I can't find a way to pack buttons in it.

Code

uses
    Granite.Widgets
    Gtk

init
    Gtk.init (ref args)

    var app = new Application ()
    app.show_all ()
    Gtk.main ()

// This class holds all the elements from the GUI
class Application : Gtk.Window

    _view:Gtk.TextView

    construct ()

        // Prepare Gtk.Window:
        this.window_position = Gtk.WindowPosition.CENTER
        this.destroy.connect (Gtk.main_quit)
        this.set_default_size (400, 400)


        // Headerbar definition
        headerbar:Gtk.HeaderBar = new Gtk.HeaderBar()
        headerbar.show_close_button = true
        headerbar.set_title("My text editor")

        // Headerbar buttons
        var open_button = new ToolButton.from_stock(Stock.Open)

        // Add everything to the toolbar
        open_button.pack_start ()
        show_all ()
        this.set_titlebar(headerbar)

        // Box:
        box:Gtk.Box = new Gtk.Box (Gtk.Orientation.VERTICAL, 1)
        this.add (box)

        // A ScrolledWindow:
        scrolled:Gtk.ScrolledWindow = new Gtk.ScrolledWindow (null, null)
        box.pack_start (scrolled, true, true, 0)

        // The TextView:
        _view = new Gtk.TextView ()
        _view.set_wrap_mode (Gtk.WrapMode.WORD)
        _view.buffer.text = "Lorem Ipsum"
        scrolled.add (_view)

        // A Button:
        button:Gtk.Button = new Gtk.Button.with_label ("Print content to
                                                        stdout")
        box.pack_start (button, false, true, 0)
        button.clicked.connect (clicked)

    // This is a simple stub function to take care of the click
    def clicked ()
        stdout.puts (_view.buffer.text)
        stdout.putc ('\n')

Error

When pack_start (see below) is used, I get the error:

text_editor-exercise_7_1.gs:136.3-136.39: error: Access to instance member `Gtk.HeaderBar.pack_start' denied

Similar errors occur when I use HeaderBar.pack_start or button_name.pack_start.

Question

Am I wrong to believe that pack_start should be used with HeaderBars?

A second smaller problem is regarding the use of Stock icons. For some reason I can't access Stock.Open.

Finally, is there any other source of information on HeaderBar? Valadoc is sparse in this subject (there are no examples or templates).

回答1:

You are trying to call pack_start on the button, not on the headerbar:

// Add everything to the toolbar
open_button.pack_start ()

The correct code is:

headerbar.pack_start (open_button)

来源：https://stackoverflow.com/questions/36258764/how-to-pack-a-button-in-a-headerbar-using-genie

标签

gtk3

Vala

genie