When you select show keypad, Deskcalc doesn't draw the keypad

[jscipione]

Steps to Reproduce:

1. Launch Deskcalc
2. Right click and hold on the text input box, select 'Show Keypad' which will hide the keypad (since it is on by default).
3. Right click and hold again on the text input box and select 'Show Keypad' again. This will show the keypad.
4. Observe that the keypad is not fully drawn.

If you resize the window the keypad is then drawn, but you shouldn't have to resize the window to make the keypad draw.