Controls

All controls from AppCUI follow a tree-like organization: a control has a parent control and may have multiple child controls.

Remarks:

• There is only one Desktop control. AppCUI provides a default one, but a custom desktop can be created as well.
• A Desktop control can have one or more windows.
• All events emitted by any control are processed at window level.
• A control may contain other child controls.

Every control has a set of common characteristics:

1. Layout (how it is positioned relative to its parent). The only exception in this case is the Desktop control, which always takes the entire terminal space. More details are in the Layout section.
2. Visibility (a control can be visible or not). The only exception is the Desktop control that will always be visible. A hidden control does not receive any input events and it is not drawn.
3. Enabled (a control can be enabled or not). The only exceptions are the Desktop and Window controls, which are always enabled. If a control is not enabled, it will not receive any input events (key presses or mouse events), but it will still be drawn.
4. HotKey (a combination of keys usually in the following form: Alt+<Letter|Number> that will automatically move the focus to the current control and execute a default action for it—for example, for a checkbox, pressing that combination will check or uncheck the checkbox).

Besides this, a set of commonly available methods exists for all controls. These methods allow changing or accessing some attributes like visibility, layout, hotkeys, etc. More details can be found in the Common methods for all Controls section.