[ adavis ] I am developing an application which requires a third mouse button; However, the two button mouse seems by far to be the most common variety. I've put together something which emulates a third mouse button by pressing both mouse buttons together. I've searched but haven't found an existing solution (though I guess there must be one) so I'm posting my version. It seems to work OK but I presume there is a neater solution...
I've decided to call the system button13 which generates the following virtual events:-
Buttons one and three must be pressed within 200ms of each other (This value can be set as a parameter).
proc button13 {widget {ms 200}} { bind $widget <Button-1> "button13proc1 $widget 1 $ms" bind $widget <Button-3> "button13proc1 $widget 3 $ms" } proc button13proc1 {widget button ms} { global button13 if {[info exists button13($widget)] && ! [string equal $button13($widget) $button]} { event generate $widget <<Button-13>> catch "unset button13($widget)" return } set button13($widget) $button after $ms "button13proc2 $widget $button" } proc button13proc2 {widget button} { global button13 if {! [info exists button13($widget)]} { return } if {[info exists button13($widget)] && ! [string equal $button13($widget) $button]} { event generate $widget <<Button-13>> } else { event generate $widget <<Button-$button>> } catch "unset button13($widget)" } #===================# # Example of usage. # #===================# label .lab1 -text "Click on this label" button13 .lab1 bind .lab1 <<Button-1>> "puts Button-1" bind .lab1 <<Button-3>> "puts Button-3" bind .lab1 <<Button-13>> "puts Button-13" pack .lab1
While this is clearly useful, I disagree that the majority of mice are two-button. 80% of mice sold have a mouse wheel (which doubles as a middle button), and I'm sure a good deal of the others have a standard button for the third. -FW
GPS: This seems simpler:
bind . <Button-1><Button-3> {puts 2} bind . <Button-3><Button-1> {puts 2}
In practice I would proc'ify it, but you probably get the idea. It would need a single variable to record the state, because if 1 and 3 are activated and then released, and 1 is pressed again the <Button-3><Button-1> binding will be invoked.