Layouts
#include "toolkit/layout.hpp"
All layouts derive from AbstractLayout (itself a Widget), which owns
margins/spacing and the shared plumbing (painting, mouse/key dispatch,
focus traversal) that delegates to each layout's for_each_child().
Children are owned via shared_ptr; every add_* call hands back a
weak_ptr to what it just stored, since a layout keeping a shared_ptr in
a sibling's callback would form a reference cycle that never frees.
- macOS
- Material
- Windows 11
- Windows 95
- Plasma 6
- GNOME
Example
auto root = std::make_unique<toolkit::VBoxLayout>();
root->set_margins({20, 20, 20, 20});
root->set_spacing(12);
root->add_widget(std::make_unique<toolkit::Label>("Hello, world!"));
AbstractLayout (common API)
| Member | Description |
|---|---|
set_margins(Margins const&) / get_margins() | Outer margins |
set_spacing(float) | Gap between children |
VBoxLayout / HBoxLayout
Stack children vertically or horizontally.
VBoxLayout();
HBoxLayout();
| Member | Description |
|---|---|
add_widget(shared_ptr<Widget>, int stretch = 0, Alignment align = ...) | Append a child; stretch distributes extra space, align is cross-axis alignment |
add<T>(int stretch = 0, Alignment align = ...) | Construct a T in place and add it, returning weak_ptr<T> |
insert_widget(...) (HBoxLayout only) | Insert at a specific index |
clear_items() | Remove all children |
release_item(int index) → shared_ptr<Widget> | Detach and return ownership of a child |
items() | Read-only access to {widget, stretch, alignment} entries |
GridLayout
Places children at (row, col), with optional row/column spans.
| Member | Description |
|---|---|
add_widget(widget, row, col, rowspan=1, colspan=1, h_align=Fill, v_align=Fill) | Place a child |
add<T>(row, col, ...) | Construct-and-place variant |
set_column_stretch(col, stretch) / set_row_stretch(row, stretch) | Extra-space distribution per row/column |
set_spacing(float) / set_column_spacing(float) / set_row_spacing(float) | Gaps |
StackedLayout
Shows exactly one child at a time (like a TabWidget's content area,
without the tab bar).
| Member | Description |
|---|---|
add_widget(shared_ptr<Widget>) / add<T>() | Add a page |
remove_widget(int index) / swap_widgets(int a, int b) | Manage pages |
set_current(int) / current() | Visible page index |
count() | Number of pages |
FormLayout
Two-column label/field rows.
| Member | Description |
|---|---|
add_row(shared_ptr<Widget> label, shared_ptr<Widget> field) → {weak_ptr label, weak_ptr field} | Add a row; either side may be null |
set_label_spacing(float) | Gap between the label and field columns |