Help Enabling virtual scroll wheel on Sierra.

jeffmikels commented 7 years ago

I have a Logitech Marble Mouse, and I love it too much to switch to anything else, but having a scroll wheel is incredibly useful on a mac. Currently, I'm on El Capitan because Karabiner has a virtual scroll wheel feature where I can hold down CTL + CMD and then my trackball turns into a scroll wheel. It's the only thing preventing me from upgrading to Sierra.

I am a capable programmer, so I'd like to help development by enabling this one feature on Sierra, but I'd need some guidance. Can anyone help me enable virtual scroll wheel on Sierra?

dunkarooftop commented 7 years ago

I believe "Hammerspoon" can do it, just google "hammerspoon scroll wheel". Many people switch to hammerspoon after Sierra due to Karabiner is not supported in Sierra.

jeffmikels commented 7 years ago

Thanks!

jeffmikels commented 7 years ago

Following up on this: I have been able to successfully reproduce the Karabiner Virtual Scroll using Hammerspoon. For those who are interested, here is my hammerspoon code:

-- HANDLE SCROLLING
local oldmousepos = {}
local scrollmult = -4   -- negative multiplier makes mouse work like traditional scrollwheel

mousetap = hs.eventtap.new({5}, function(e)
    oldmousepos = hs.mouse.getAbsolutePosition()
    local mods = hs.eventtap.checkKeyboardModifiers()
    if mods['ctrl'] and mods['cmd'] then
        -- print ("will scroll")
        local dx = e:getProperty(hs.eventtap.event.properties['mouseEventDeltaX'])
        local dy = e:getProperty(hs.eventtap.event.properties['mouseEventDeltaY'])
        local scroll = hs.eventtap.event.newScrollEvent({dx * scrollmult, dy * scrollmult},{},'pixel')
        scroll:post()

        -- put the mouse back
        hs.mouse.setAbsolutePosition(oldmousepos)

        -- return true, {scroll}
        return true
    else
        return false, {}
    end
    -- print ("Mouse moved!")
    -- print (dx)
    -- print (dy)
end)
mousetap:start()

weitzj commented 7 years ago

If anyone is interested:

I have adopted the above answer, which allows me to scroll vertically/horizontally using my Logitech M570 (Trackball), while holding a mouse button (instead of ctrl + cmd)

-- HANDLE SCROLLING
local oldmousepos = {}
-- positive multiplier (== natural scrolling) makes mouse work like traditional scrollwheel
local scrollmult = 4 

-- The were all events logged, when using `{"all"}`
mousetap = hs.eventtap.new({0,3,5,14,25,26,27}, function(e)
    oldmousepos = hs.mouse.getAbsolutePosition()
    local mods = hs.eventtap.checkKeyboardModifiers()
    local pressedMouseButton = e:getProperty(hs.eventtap.event.properties['mouseEventButtonNumber'])

    -- If OSX button 4 is pressed, allow scrolling
    local shouldScroll = 3 == pressedMouseButton
    if shouldScroll then
        local dx = e:getProperty(hs.eventtap.event.properties['mouseEventDeltaX'])
        local dy = e:getProperty(hs.eventtap.event.properties['mouseEventDeltaY'])
        local scroll = hs.eventtap.event.newScrollEvent({dx * scrollmult, dy * scrollmult},{},'pixel')
        scroll:post()

        -- put the mouse back
        hs.mouse.setAbsolutePosition(oldmousepos)

        return true, {scroll}
    else
        return false, {}
    end
    -- print ("Mouse moved!")
    -- print (dx)
    -- print (dy)
end)
mousetap:start()

ghost commented 7 years ago

I had the same problem, but I prefer to use right mouse button to init scrolling, so I used your code and modified it to perform scroll during right mouse drag. There was some problems with deferring menuOpen on rightMouseDown, but I ended with this script, which works great.

Note: this will make right mouse dragging impossible, but who needs it anyway?

-- HANDLE SCROLLING

local deferred = false

overrideRightMouseDown = hs.eventtap.new({ hs.eventtap.event.types.rightMouseDown }, function(e)
    --print("down"))
    deferred = true
    return true
end)

overrideRightMouseUp = hs.eventtap.new({ hs.eventtap.event.types.rightMouseUp }, function(e)
    -- print("up"))
    if (deferred) then
        overrideRightMouseDown:stop()
        overrideRightMouseUp:stop()
        hs.eventtap.rightClick(e:location())
        overrideRightMouseDown:start()
        overrideRightMouseUp:start()
        return true
    end

    return false
end)

local oldmousepos = {}
local scrollmult = -4   -- negative multiplier makes mouse work like traditional scrollwheel
dragRightToScroll = hs.eventtap.new({ hs.eventtap.event.types.rightMouseDragged }, function(e)
    -- print("scroll");

    deferred = false

    oldmousepos = hs.mouse.getAbsolutePosition()    

    local dx = e:getProperty(hs.eventtap.event.properties['mouseEventDeltaX'])
    local dy = e:getProperty(hs.eventtap.event.properties['mouseEventDeltaY'])
    local scroll = hs.eventtap.event.newScrollEvent({dx * scrollmult, dy * scrollmult},{},'pixel')

    -- put the mouse back
    hs.mouse.setAbsolutePosition(oldmousepos)

    return true, {scroll}
end)

overrideRightMouseDown:start()
overrideRightMouseUp:start()
dragRightToScroll:start()

3rd3 commented 6 years ago

Can this be restricted to one particular device?

ghost commented 6 years ago

@3rd3 you can enable/disable Hammerspoon functions when device is un-/plugged from computer with hs.usb.watcher or as a result of launch/exit of some application with hs.application.watcher, but I could not find a way, how to limit functionality only to certain device, not the hs.eventtap nor the hs.eventtap.event seem to provide a information about device which triggered the mouse event.

randydod-teamunify commented 6 years ago

Yet another modification for using a Logitech Trackman Marble Trackball. weitzj's code above works as-is if you use the small left button to scroll. I use the trackball with my left hand, so I like using the right small button with my thumb to enable scrolling. I also like rolling down to scroll down, so I use the negative multiplier. For convenience, here's the code.

`

-- Enable virtual mouse scroll wheel with trackball while pressing small mouse button
local oldmousepos = {}
-- positive multiplier = natural scrolling, negative makes mouse work like traditional scroll wheel
local scrollmult = -4 

-- There were all events logged, when using `{"all"}`
mousetap = hs.eventtap.new({0,3,5,14,25,26,27}, function(e)
    oldmousepos = hs.mouse.getAbsolutePosition()
    local mods = hs.eventtap.checkKeyboardModifiers()
    local pressedMouseButton = e:getProperty(hs.eventtap.event.properties['mouseEventButtonNumber'])

    -- If small mouse button is pressed, allow scrolling with trackball
    -- 3 = left small button, 4 = right small button
    local shouldScroll = 4 == pressedMouseButton
    if shouldScroll then
        local dx = e:getProperty(hs.eventtap.event.properties['mouseEventDeltaX'])
        local dy = e:getProperty(hs.eventtap.event.properties['mouseEventDeltaY'])
        local scroll = hs.eventtap.event.newScrollEvent({dx * scrollmult, dy * scrollmult},{},'pixel')
        scroll:post()

        -- put the mouse back
        hs.mouse.setAbsolutePosition(oldmousepos)

        return true, {scroll}
    else
        return false, {}
    end
end)
mousetap:start()

`