B4J Question Pane with dimension of a A4 sheet

[micro]

Hi to all
how i can add a pane to run time or by designer
with the dimensions of an A4 sheet (210x297 mm)?
It is necessary to have the dimensions of a single pixel
of the screen?
How do I get this?
Thanks

 

[Erel]

After making some tests it seems like the screen dpi reported by windows is not accurate so it is impossible to accurately set the display size based on a physical size.

I haven't searched a lot however this discussion might be relevant: https://social.msdn.microsoft.com/F...ize-is-incorrect-in-windows-7?forum=vcgeneral

 

[Daestrum]

I use the following ( on my display it matches an A4 page to less than .5mm)

This is a cut down example - it uses javaobject library

Sub AppStart (Form1 As Form, Args() As String)
 MainForm = Form1
 MainForm.SetFormStyle("UNDECORATED")
 MainForm.Show
 asJO(Me).RunMethod("makeA4Page",Array(MainForm))
End Sub
Sub asJO(o As JavaObject)As JavaObject
 Return o
End Sub
'Return true to allow the default exceptions handler to handle the uncaught exception.
Sub Application_Error (Error As Exception, StackTrace As String) As Boolean
 Return True
End Sub
#if java
import javafx.stage.Stage;
public static void makeA4Page(anywheresoftware.b4j.objects.Form s){
 Double dpi = javafx.stage.Screen.getPrimary().getDpi();
 Double dpmm = dpi/25.4;
 s.setWindowHeight(297 * dpmm);
 s.setWindowWidth(210 * dpmm);
}
#End If

 

[micro]

Thanks for the tips.

 

[Erel]

This is similar to what I tried. The difference here is about 2cm.

Note that you can simplify it:

Dim jo As JavaObject = fx.PrimaryScreen
Dim dpi As Double = jo.RunMethod("getDpi", Null)
Dim dpmm As Double = dpi / 25.4
MainForm.WindowWidth = 210 * dpmm
MainForm.WindowHeight = 297 * dpmm