Scrollbar

A scrollbar that drives a scrollable widget — a Text, Listbox, Treeview, Canvas, or Entry. TScrollbar is the themed version (preferred); Scrollbar is the classic one.

Connecting a scrollbar

A scrollbar and its widget talk to each other in both directions: the widget tells the scrollbar how far it's scrolled, and the scrollbar tells the widget where to move. Wire the two callbacks once, after creating both:

const lb = app.Listbox();
const sb = app.TScrollbar({ orient: 'vertical' });

sb.pack.configure({ side: 'right', fill: 'y' });
lb.pack.configure({ side: 'left', fill: 'both', expand: true });

// widget → scrollbar (position) and scrollbar → widget (scroll command)
__native_tcl(lb._id, 'configure', '-yscrollcommand', `${sb._id} set`);
__native_tcl(sb._id, 'configure', '-command', `${lb._id} yview`);

lb.insert('end', ...Array.from({ length: 50 }, (_, i) => `Item ${i + 1}`));

For a horizontal scrollbar, use orient: 'horizontal' and the xScrollCommand / xview pair instead. The wiring uses the __native_tcl escape hatch because the two callbacks pass Tcl-level arguments between the widgets.

Options

The classic Scrollbar also takes width, troughColor, background, and relief.

Methods

A scrollbar has no methods you call directly — it's driven entirely by the two configure links above. It does support the inherited widget methods (layout, bind, …); see Widget basics.

See also

• Text, Listbox, Treeview — the widgets you scroll
• System & files — the __native_tcl escape hatch