Double click processing for roassal

[akevalion]

From discord Pavel said

looking into trustworthy Programming Windows 3.1 book , I found this:

If you want your window procedure to receive double-click mouse messages, you
must include the identifier CS-DBLCLKS when initializing the window style in the window
class structure before calling Register Class:

wndcl ass. style = CS_H REDRAW ! CS.VREDRAW ! CS_DBLCLKS ;

If you do not include CS_DBLCLKS in the window style and the user clicks the left mouse
button twice in quick succession, your window procedure receives these messages:
WM_LBUTTONDOWN, WM_LBUTTONUP, WM_LBUTTONDOWN, and WM-LBUT-
TONUP. (The window procedure might also receive other messages between these button
messages.) If you want to implement your own double-click logic, you can use the Win¬
dows function GetMessageTime to obtain the relative times of the WM-LBUTTONDOWN
messages. This function is discussed in more detail in Chapter 5.

If you include CS_DBLCLKS in your window class, the window procedure receives
these messages for a double-click: WM-LBUTTONDOWN, WM-LBUTTONUP, WM-
_LBUTTONDBLCLK, and WM_LBUTTONUP. The WM-LBUTTONDBLCLK message sim¬
ply replaces the second WM-LBUTTONDOWN message.

...this is nice and reasonable solution of double-click processing
instead of direct detection, it may just check if there is a handler for a double click

[akevalion]

moved to pharo-graphics/Roassal