reason pinch zoom

init.lua

--[[
Pinch zoom script for Reason
This file should be put in the ~/.hammerspoon directory
or just click Open Config in the Hammerspoon menu and paste all of this in

To use, just pinch with the trackpad while in the sequencer.
Hold shift to zoom in on the playhead instead of the cursor
Hold command to zoom vertically
]]

pinchZoom = {}
pinchZoom.appName = 'Heptabase'
pinchZoom.threshold = 0.10   -- adjust to vary sensitivity - lower is faster
pinchZoom.zoomSum = 0
pinchZoom.lastZoomTime = 0

pinchZoom.eventtap = hs.eventtap.new({ hs.eventtap.event.types.gesture }, function(event)
    local gestureType = event:getType(true)
    if gestureType ~= hs.eventtap.event.types.magnify then return end
    local zoomTime = hs.timer.absoluteTime()
    if zoomTime - pinchZoom.lastZoomTime > 1000000000 then pinchZoom.zoomSum = 0 end
    pinchZoom.lastZoomTime = zoomTime

    -- the zoom key commands are much less sensitive than the scroll wheel
    -- so we lower the threshold when using them
    local threshold = pinchZoom.threshold
    if event:getFlags()['shift'] then threshold = threshold * 0.5 end

    local zoomLevel = event:getTouchDetails().magnification
    pinchZoom.zoomSum = pinchZoom.zoomSum + zoomLevel

    local offsets = {}
    if pinchZoom.zoomSum >= threshold then
        offsets = { 1, 0 }
        pinchZoom.zoomSum = 0
    elseif pinchZoom.zoomSum <= -threshold then
        offsets = { -1, 0 }
        pinchZoom.zoomSum = 0
    else
        return
    end

    if event:getFlags()['shift'] or event:getFlags()['cmd'] then
        local flags = { ['cmd'] = true, ['shift'] = true }
        if event:getFlags()['cmd'] then flags['alt'] = true end
        local key = offsets[1] == 1 and '=' or '-'
        hs.eventtap.event.newKeyEvent(key, true):setFlags(flags):post()
        hs.eventtap.event.newKeyEvent(key, false):setFlags(flags):post()
    else
        hs.eventtap.event.newScrollEvent(offsets, { 'cmd', 'shift' }, 'pixel'):post()
    end
end)

pinchZoom.watcher = hs.application.watcher.new(function(appName, eventType)
    if appName == pinchZoom.appName then
        if eventType == hs.application.watcher.activated then
            pinchZoom.eventtap:start()
        elseif eventType == hs.application.watcher.deactivated then
            pinchZoom.eventtap:stop()
        end
    end
end)
pinchZoom.watcher:start()

hs.alert('reloaded Hammerspoon')