Slider widgets (aka GtkScale) and dynamic adjustments

The following example creates two sliders using GtkScale. The callback function for the 1st slider dynamically changes the value of the 2nd slider to force it to match, and also dynamically changes the range of the 1st slider if the value reaches 10.

This example illustrates that one can use GAccessor.value both to access a widget value and to alter that value.

using Gtk: GtkGrid, GtkScale, GtkWindow, GAccessor
using Gtk: signal_connect, set_gtk_property!, showall

win = GtkWindow("Sliders", 500, 200)
slider1 = GtkScale(false, 0:10)
slider2 = GtkScale(false, 0:30)
signal_connect(slider1, "value-changed") do widget, others...
    value = GAccessor.value(slider1)
    GAccessor.value(slider2, value) # dynamic value adjustment
    println("slider value is $value")
    if value == 10
        GAccessor.range(slider1, 1, 20) # dynamic range adjustment
g = GtkGrid()
g[1,1] = slider1
g[1,2] = slider2
set_gtk_property!(g, :column_homogeneous, true)
push!(win, g)