Buttons

GTK defines many button and button-like widgets.

GtkButton

We have already encountered the widget GtkButton, which defines a "clicked" signal that can be used to let the user trigger callback functions.

The button holds a child widget that can be a GtkLabel in the case of text, an image-displaying widget in the case of an icon, or potentially anything else you want. The child widget can be set and accessed using getindex(b::GtkButton) and setindex!(b::GtkButton, child_widget::GtkWidget):

b = GtkButton()
b[] = my_widget
child_widget = b[]

You can also associate an action (see Actions) with a button by setting its property "action-name".

Selected signals:

signal	arguments	returns
"clicked"	self::GtkButton	`Nothing`	Emitted when the button is clicked

GtkToggleButton

This widget looks like a button but it stays pressed when the user clicks it. The state of the button can be accessed or set using its property "active", which is true when the button is pressed.

A toggle button can be added to a group using the method group, in which case it can be used to select from mutually exclusive options:

using Gtk4

red_button = GtkToggleButton("red")
green_button = GtkToggleButton("green")
blue_button = GtkToggleButton("blue")
win = GtkWindow("choose one color")
win[] = box = GtkBox(:v)
push!(box, red_button)
push!(box, green_button)
push!(box, blue_button)

group(green_button, red_button)
group(blue_button, red_button)
# now only one button can be active at a time

Selected signals:

signal	arguments	returns
"toggled"	self::GtkToggleButton	`Nothing`	Emitted when the button state is changed

GtkCheckButton

This widget is a checkbox that can be used to control whether something is active (true) or inactive (false). Functionally it is identical to a GtkToggleButton but it is rendered differently. There is typically a label that is rendered next to the checkbox.

Like a toggle button, a check button can also be added to a group, in which case it is rendered as a "radio button" that can be used to choose from a few mutually exclusive options.

Selected signals:

signal	arguments	returns
"toggled"	self::GtkCheckButton	`Nothing`	Emitted when the button state is changed

GtkSwitch

This widget is very much like a check button but looks like a switch.

Like GtkCheckButton, its "active" property can be used to get and set the switch's state.

GtkLinkButton

This widget can be used to open a URL:

lb = GtkLinkButton("https://julialang.org","Julia website")