Layout Group

• Apr 02, 2024
• 3 minutes to read

The base elements of the ExpressLayout Control are items and groups. Groups are divided into three categories: standard, tabbed, and hidden. This topic covers the capabilities of standard groups. To learn about tabbed or hidden groups, refer to the Tabbed Layout Group and Hidden Group topics.

Groups can nest other groups and items. All immediate child groups and items have one parent group, which is accessible via the Parent property. The ExpressLayout Control maintains the root (base) group automatically. This group is displayed in the Layout Tree View pane of the Customization Form. At runtime, it can be accessed via the layout control’s Items property.

To create a new group at design time, click the “Add Group…” button within the Customization Form‘s Available Items pane.

At runtime, you can call the CreateGroup) method.

To learn more about group creation capabilities, refer to the How to Create Layout Items and Groups topic.

Groups that are already arranged within the ExpressLayout Control are displayed within the Customization Form‘s Layout Tree View pane:

Elements inside each group can be laid out in the following ways: horizontally, vertically or within tabs. The group layout is specified using the group’s LayoutDirection property (the root group layout is specified by the control’s LayoutDirection property).

A group can have both a caption and a border. Use the group’s CaptionOptions.Visible and ShowBorder properties to display its caption and border. Layout, caption and border types depend on the container’s style. Refer to the corresponding topic to learn about available styles.

Item width/height may be fixed or calculated automatically within a group, based on the size of the group and other items. To improve the appearance, you can adjust horizontal and vertical offsets inside groups and items.

You can force a group and its content to be considered as a single element in customization mode using the group’s Locked property. Set this property to True to prohibit end-users from changing the internal group layout (adding/removing group elements) in customization mode. However, end-users still can change the external layout of any group – move it to another group or change its visibility.

The table below lists the main properties that relate to layout groups.

Visibility	A group’s Visible property.
Position	A group’s Index, VisibleIndex, AlignHorz, AlignVert, AlignmentConstraint, and Offsets properties. A parent group’s LayoutDirection and UseIndent properties.
Appearance	A group’s LayoutLookAndFeel property. A parent group’s LayoutLookAndFeelException property. The layout control’s LayoutLookAndFeel property.
Contents	A group’s Expanded, ButtonOptions, CaptionOptions.VisibleElements, and ShowBorder properties.
Behavior	A group’s CaptionOptions.Hint, SizeOptions.SizableHorz, SizeOptions.SizableVert, AllowFloating, AllowQuickCustomize, AllowRemove, Enabled, Hidden, Locked, and WrapItemsMode properties. The layout control’s OptionsItem.AllowFloatingGroups, OptionsItem.AllowGroupWrapItems, OptionsItem.AllowQuickCustomize, OptionsItem.SizableHorz, and OptionsItem.SizableVert properties.
Size	A group’s SizeOptions.Height, SizeOptions.Width, SizeOptions.MaxHeight, and SizeOptions.MaxWidth properties.
Context Menu	Refer to the Runtime Customization Context Menus topic.
Hints	Use a button’s Hint property to specify hints for a group’s check box, expand button and action buttons.
HitTest Information	For standard layout groups, the layout control’s GetHitTest function returns a TdxLayoutGroupHitTest object.