Tech Tip: Get the best display width and height for the given text data

PRODUCT: 4D | VERSION: 17 | PLATFORM: Mac & Win

Published On: May 15, 2019

The command OBJECT GET BEST SIZE returns the bestWidth and bestHeight parameters, the “optimal” width and height of the form object. However, this command only works in a context of a form execution.

With the introduction of the dynamic forms, it is possible to build a simple form definition and dynamically load as offscreen window to allow execution of the OBJECT GET BEST SIZE command. The following method is written as a self-contained utility method that obtains the bestWidth and bestHeight for a given text without having to rely on a pre-constructed of a form.

  // ----------------------------------------------------
  // Method: TEXT_GET_DISPLAY_BEST_SIZE
  // Description
  // Get the best display width and height for the given text data
  //
  // Parameters
  // $1 - Text
  // $2 - Font name
  // $3 - Font size
  // $4 - (Optional) Maximum display width
  //
  // Return
  // $0 - Object { "bestWidth": 100, "bestHeight": 24 }
  // ----------------------------------------------------

C_TEXT($1;$data_t;$2;$fontName_t)
C_LONGINT($3;$fontSize_l;$4;$maxWidth_l;$win_l)

If (Count parameters>=3)
  $data_t:=$1
  $fontName_t:=$2
  $fontSize_l:=$3
  If (Count parameters>=4)
    $maxWidth_l:=$4
  End if

  C_OBJECT($0;$formDef_o;$formData_o)
  $formDef_o:=New object("destination";"detailScreen";"rightMargin";19;\
        "bottomMargin";20;"markerHeader";15;"markerBody";200;"markerBreak";\
        220;"markerFooter";240;"events";New collection("onLoad");"method";\
        Current method name;"pages";New collection("Null";New object("objects";\
        New object("Variable";New object("type";"input";"top";21;"left";16;\
        "width";65;"height";17;"fontFamily";$fontName_t;"fontSize";\
        $fontSize_l;"focusable";False;"enterable";False;"dragging";"none";\
        "dropping";"custom")))))

  $formData_o:=New object("data";$data_t;"maxWidth";$maxWidth_l)

  $win_l:=Open window(-10;-10;-10;-10)
  DIALOG($formDef_o;$formData_o)
  CLOSE WINDOW($win_l)

  $0:=New object("width";$formData_o.bestWidth;"height";$formData_o.bestHeight)

Else

  If (Form event=On Load) // Execution occurs within the context of the Form method
    C_LONGINT($bw;$bh)
    OBJECT Get pointer(Object named;"Variable")->:=Form.data
    If (Form.maxWidth>0)
      OBJECT GET BEST SIZE(*;"Variable";$bw;$bh;Form.maxWidth)
    Else
      OBJECT GET BEST SIZE(*;"Variable";$bw;$bh)
    End if
    Form.bestWidth:=$bw
    Form.bestHeight:=$bh
    CANCEL
  End if

End if