.. default-domain:: lua
.. highlight:: lua
.. currentmodule:: UI

Button
======


.. class:: Button

   A button that the user can click.
   Added to a :class:`UI.Canvas` or a :class:`UI.Panel`.

   .. attribute:: rect_transform: UI.RectTransform

      The rect transform for the UI object.

      :Attribute: Read-only, cannot be set
      :rtype: :class:`UI.RectTransform`

   .. attribute:: layout_element: UI.LayoutElement

      How much space the UI object asks a layout for.

      :Attribute: Read-only, cannot be set
      :rtype: :class:`UI.LayoutElement`

      .. note::

         Only has an effect when the object is in a panel that has a layout. A canvas is
         not inside a layout and does not have one.

   .. attribute:: visible: boolean

      Whether the UI object is visible.

      :Attribute: Can be read or written
      :rtype: boolean

      .. note::

         This is the object's own setting, which is what it was last set to. An object is
         only drawn when everything it is inside is visible as well, so an interface can
         be built with its parts visible, inside a panel that is not, and shown all at
         once by making that panel visible.

   .. attribute:: text: UI.Text

      The text for the button.

      :Attribute: Read-only, cannot be set
      :rtype: :class:`UI.Text`

   .. attribute:: clicked: boolean

      Whether the button has been clicked.

      :Attribute: Can be read or written
      :rtype: boolean

      .. note::

         This property is set to true when the user clicks the button.
         A client script should reset the property to false in order to detect subsequent button presses.

   .. attribute:: pressed: boolean

      Whether the user is holding the button down right now.

      :Attribute: Read-only, cannot be set
      :rtype: boolean

      .. note::

         True from the button being pressed until the pointer is released, however far
         it has moved by then. Polling this repeats an action for as long as the
         button is held, for nudging a value; :attr:`UI.Button.clicked` reports each
         completed click instead.

   .. attribute:: interactable: boolean

      Whether the control responds to the user.

      :Attribute: Can be read or written
      :rtype: boolean

      .. note::

         A control that is not interactable is drawn grayed out and ignores the user,
         but is still visible. Set its visibility to false to hide it instead.

   .. attribute:: color: StdLib.ColorRGBA

      The color the control is tinted with. White, the default, leaves the control drawn
      as the skin has it.

      :Attribute: Can be read or written
      :rtype: :class:`StdLib.ColorRGBA`

      .. note::

         The tint multiplies the sprite the control is drawn with, in every state, so
         a control can show a state of its own, an engaged autopilot for instance, by
         color. It is applied to the part of the control that responds to the user:
         the body of a button, dropdown or input field, the box of a toggle, and the
         handle of a slider. A control's label is tinted through the color of its
         text.

   .. attribute:: tooltip: string

      A short piece of text shown beside the pointer while it rests on the
      control. Empty, the default, shows nothing.

      :Attribute: Can be read or written
      :rtype: string

   .. method:: remove()

      Remove the UI object.