By default, the ToolBar is a raised bar stretched across the top of its parent form. You can alter its appearance using its EdgeStyle property and you can control its alignment with its Align property. Align can be set to Top (the default), Bottom, Left or Right and causes the ToolBar to be attached to the corresponding edge of the Form. A ToolBar aligned Top or Bottom will automatically stretch or shrink horizontally when its parent Form is resized, but it will remain fixed vertically. A ToolBar aligned Left or Right will stretch vertically but will remain fixed horizontally. By default a ToolBar occupies the entire width or length of the side of the Form to which it is attached and is 30 pixels high or wide. You can change these defaults using the Posn and Size properties.

A ToolBar organises its child controls in the order they are created. The way this is done is governed by the value of the Align property. If Align is Top or Bottom, the ToolBar arranges its controls in rows across the screen. If Align is Left or Right, the ToolBar arranges controls in columns.

The first control added to a ToolBar is automatically positioned 2 pixels down and 2 pixels across from its top left corner. The rule for positioning subsequent controls depends upon the value of the Align property.

If Align is 'Top' or 'Bottom', controls are positioned so as to be horizontally adjacent to one another. Whenever a control is added it is positioned relative to the one that immediately preceded it so that its top left corner meets the top right corner of the previous one. The HScroll property determines what happens when the end of the ToolBar is reached. If HScroll is 0 (the default) a control that would otherwise extend beyond the width of the ToolBar is instead positioned immediately below the first control in the ToolBar, thereby starting a new row. Note however that the ToolBar is not automatically resized vertically to accommodate a second row. If you want a multi-row ToolBar you have to set its height explicitly. If HScroll is ¯1 or ¯2, controls continue to be added along the ToolBar even though they extend beyond its right edge and may be scrolled into view using a mini scrollbar. If HScroll is ¯1, the scrollbar is shown whether or not any controls extend beyond the width of the ToolBar. If HScroll is ¯2, the scrollbar appears only if required and may appear or disappear when the user resizes the parent Form.

If Align is 'Left' or 'Right', controls are positioned so as to be vertically adjacent to one another. Whenever a control is added, its top left corner is positioned against the bottom left corner of the previous control. The VScroll property determines what happens when the bottom of the ToolBar is reached. If VScroll is 0 (the default) a control that would otherwise extend beyond the bottom of the ToolBar is instead positioned immediately to the right of the first one; thereby starting a new column. Note however that the ToolBar is not automatically resized horizontally to accommodate a second column. You must set the width of the ToolBar explicitly.

If VScroll is ¯1 or ¯2, controls continue to be added down the ToolBar even though they extend beyond its bottom edge and may be scrolled into view using a mini scrollbar. If VScroll is ¯1, the scrollbar is shown whether or not any controls extend beyond the bottom of the ToolBar. If VScroll is ¯2, the scrollbar appears only if required and may appear or disappear when the user resizes the parent Form.

VScroll and HScroll may only be set when the object is created and may not subsequently be changed.

If you specify a value for its Posn property, a control will be placed at the requested position regardless of the value of Style, VScroll or HScroll. However, the next control added will take its default position from the previous one according to the value of these properties. Thus if you wish to group your controls together with spaces between the groups, you need only specify the position of the first one in each group.

The ToolBar object was introduced in Dyalog APL before an appropriate standard Windows control existed. The ToolBar object should be considered as a legacy object and used only in old GUI applications. The ToolControl object should be used instead.