.. csv-table::
    :escape: ^
    :widths: 20, 30

    "
    Generic variables, available for all ``AdafruitGFX_Helper`` enabled plugins, currently: :ref:`P095_page`, :ref:`P096_page`, :ref:`P116_page`, :ref:`P131_page` and :ref:`P141_page`.
    ","
    Generic notes:

    * If an argument has comma's or spaces, then that part should be 'wrapped' in either double quotes ``^"``, single quotes ``^'`` or back-ticks ``^```.
    * The ``<taskname>`` part is the name of the Device task.
    * True(1)/False(0) values can optionally return -1 to indicate an invalid request, like a missing Window Id.
    * All sizes, lengths etc. are returned in pixels.
    "
    "
    ``[<taskname>#win]``
    ","
    Get the currently active Window Id, expected range: 0..255.
    "
    "
    ``[<taskname>#iswin.<windowId>]``
    ","
    Is the request Window Id valid, expected result: 1 = true, 0 = false.
    "
    "
    ``[<taskname>#width]``
    ","
    Get the width of the currently active Window and rotation, expected range 0..<largest display dimension>.
    "
    "
    ``[<taskname>#height]``
    ","
    Get the height of the currently active Window and rotation, expected range 0..<largest display dimension>.
    "
    "
    ``[<taskname>#length.^"<text to measure>^"]``
    ","
    Get the length of the text in pixels for the current font and text scaling. Needs quotes if text contains space(s), comma(s) or quote(s).
    "
    "
    ``[<taskname>#textheight.^"<text to measure>^"]``
    ","
    Get the height of the text in pixels for the current font and text scaling. Needs quotes if the text contains space(s), comma(s) or quote(s).
    "
    "
    ``[<taskname>#rot]``
    ","
    Get the currently active rotation, expected range 0..3 (0 = 0 degrees, 1 = +90 degrees, 2 = +180 degrees, 3 = +270 degrees).
    "
    "
    ``[<taskname>#txs]``
    ","
    Get the currently active text scaling, expected range 1..10, limited to the max. font scaling allowed for the display.
    "
    "
    ``[<taskname>#tpm]``
    ","
    Get the currently active text print mode, expected range 0..3, see the ``tpm`` subcommand for details.
    "

.. csv-table::
    :escape: ^
    :widths: 20, 10

    "
    Example rules for centering a value (time) in a window:

    .. code:: none

      on centertime do  // NB: Comments & extra spaces should be removed to reduce rules size!
        if [st7796#iswin.%eventvalue1|2%]=1 // default window: 2
          let,120,[st7796#win]              // store current window
          st77xx,win,%eventvalue1|2%        // switch to window
          let,121,[st7796#txs]              // store textscaling
          st77xx,txs,3                      // set text scaling
          let,122,[st7796#rot]              // store rotation
          st77xx,rot,%eventvalue2|0%        // set rotation, default: 0
          let,123,([st7796#width]-[st7796#length.%systm_hm%])/2      // (width - textlength)/2
          let,124,([st7796#height]-[st7796#textheight.%systm_hm%])/2 // (height - textheight)/2
          st77xx,txtfull,[int#123],[int#124],3,red,black,%systm_hm%  // Display time red on black
          st77xx,rot,%v122%                 // restore rotation
          st77xx,txs,%v121%                 // restore text scaling
          st77xx,win,%v120%                 // restore window
        endif
      endon
      on Clock#Time=All,**:** do
        asyncevent,centertime=2             // Update the display every minute
      endon

    ","
    Display Task is named ``st7796``, using trigger ``st77xx``

    Usage: ``asyncevent,centertime[=<win>[,<rot>]]``
    "