Toolbox: Layouts

Toolbox Layouts

Layouts are invisible objects whose purpose is to group other widgets together so that their location is well-defined (including when the form is resized). The Layouts toolbox contains the following objects:

	Vertical and Horizontal Layouts: the simplest way to arrange objects on a form is to place them in a horizontal or vertical layout. Horizontal layouts ensure that the widgets within are aligned horizontally; vertical layouts ensure that they are aligned vertically. Horizontal and vertical layouts can be combined and nested to any depth. However, if you need more control over the placement of objects, consider using the grid layout.
	Grid Layout: complex form layouts can be created by placing objects in a grid layout. This kind of layout gives the form designer much more freedom to arrange widgets on the form, but can result in a much less flexible layout. However, for some kinds of form layout, a grid arrangement is much more suitable than a nested arrangement of horizontal and vertical layouts.
	Form Layout: this class manages widgets in a two-column form; the left column holds labels and the right column holds field widgets such as line edits, spin boxes, etc.

There are two ways to relate widgets to a layout:

• Place a Layout object on the form, and then place other widgets inside it: Figure 65: Dragging an Integer Editor into a layout

• Select several objects on the form and right-click to group them into a layout:

Once widgets have been inserted into a layout, it is not possible to move and resize them individually, because the layout itself controls the geometry of each widget within it, taking account of the hints provided by spacers. Instead, you must either break the layout and adjust each objects geometry manually, or you can influence the widgets geometry by resizing the layout.

To break the layout you have applied, press Ctrl+O, or select Break Layout in the contextual menu. You can then drag the various widgets freely around the form to position them as you require, before selecting the layout option you need. You can also add and remove spacers from the layout to influence the geometries of the widgets.