[haiku-development] Re: Obtaining mouse button type

James Kim <jkim202@xxxxxxxxxxxxxxxxx> wrote:
> Hi! I have come across another problem with mouse event handling. I 
> need
> to find out what button (left, right or none) is being pressed while
> BView::MouseMoved(). I have looked at GetMouse() but I cannot figure 
> out
> how to retrieve the button information from it because GetMouse()
> returns nothing. Any suggestions or a reference to an example would 
> be
> very appreciated. Thank you.

It's always a good idea to have a look at existing sample code; for 
example, we have tons of code in our repository that does this -- just 
take smaller apps like Sudoku.
Anyway, since you are in MouseMoved() anyway, you shouldn't need to use 
GetMouse(). Instead, you should have a look at the message that 
triggered the mouse move, it contains more information that just what 
has been passed to the method.
For example in SudokuView.cpp, in its MouseMoved() method you'll find 
the following code:

        int32 buttons = 0;
        if (Looper() != NULL && Looper()->CurrentMessage() != NULL)
                Looper()->CurrentMessage()->FindInt32("buttons", &buttons);

This is overly defensive (as the Looper() and CurrentMessage() would 
only be NULL if your own code called that function directly), but 
afterwards, you may find the B_{PRIMARY|SECONDARY|
TERTIARY}_MOUSE_BUTTON constants in "button" as described by Ryan.

Bye,
   Axel.

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