Re: [XForms] Single and double-click

[Alessandro Basili]

Jens Thoms Toerring writes:

> Three (FL_SELECT_BROWSER, FL_HOLD_BROWSER and FL_MULTI_BROWSER)
> of the four browser types react to single mouse clicks with the
> left mouse button, none of them to double clicks per default. If
> you don't want a reaction to single but only double clicks I guess
> that using a FL_NORMAL_BROWSER (which doesn't react to single
> clicks) and installing a callback for double clicks, using the
> fl_set_browser_dblclick_callback() function, should do the trick.

We normally use a FL_HOLD_BROWSER type of browser in order to highlight the 
single mouse action of the user and then a dblclick_callback to perform the 
action we want. We found that an intermediate step would help focusing user 
attention and helped him effectively use the browser.

IMHO the action should be clear depending on the layout of the GUI. If it's 
a directory search browser the user would expect that the action would be 
'opening' a file or a directory. Giving cues about what's next will enable 
the user to use effectively the object and since the user may not know if he 
needs a single click or a double, having a visual feedback on a single click 
may help the user.

> At least that's how it should work according to my current un-
> derstanding of the documentation and the code but I did not do
> any tests yet.

We are extensively using browsers but unfortunately we are still using 
version 1.0 Released on december 8, 2002! Plus a couple of minor 
modifications which do affected browser behavior.
I do not know if browser behavior has changed since that release, but I 
believe that the main principles behind still do apply.

> clicks you didn't program in yourself. If you want e.g. a line
> to be highlighted in some way on a double click you will have
> to take care of that yourself (since it's imposible to forsee
> what people expect to happen on a double click into a browser).

Using the FL_HOLD_BROWSER you'll get highlighting automatically, but you 
still need a dblclick_callback to react on double clicks.

What I noticed is not effectively working is the reaction to wheel inputs 
when there's a slide vertical bar. It seems the reaction is not as smooth as 
one would expect but I must say I haven't spent a whole lot of time on that.

Al