Problems with StyleSheet and QFontMetrics (see attached program)

[h123]

Hi,

Herewith I have attached a toy program in which it sets the stylesheet "* { font-size: 20pt; }" of app context.

After setting above style sheet, I am taking QFontMetrics to do some processing on fontmetrics.width() / fontmetrics.height() but both are getting wrong.

In toy program if you click "Print Font Info" button, I displays the correct information.
But when showing the fontmetrics of dialog (click on 'Show Dialog') or panel (click on 'Show Panel') it displays wrong.

In short: my aim is to set application font and subsequently I should get the correct fontmetrics info.

Please let me know if I am doing anthing wrong.

Thank you.
-Hiral