feat(gioui): flip the unit parameter slider scroll wheel behaviour

Closes #112.

CHANGELOG.md

@@ -24,6 +24,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Warn user about sample rate being other than 44100 Hz, as this lead to weird
   behaviour. Sointu assumes the samplerate always to be 44100 Hz. ([#129][i129])
 
+### Changed
+- The scroll wheel behavior for unit integer parameters was flipped: scrolling
+  up now increases the value, while scrolling down decreases the value. It was
+  vice versa. ([#112][i112])
+
 ## v0.3.0
 ### Added
 - Scroll bars to menus, shown when a menu is too long to fit.
@@ -129,6 +134,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 [0.3.0]: https://github.com/vsariola/sointu/compare/v0.2.0...v0.3.0
 [0.2.0]: https://github.com/vsariola/sointu/compare/v0.1.0...v0.2.0
 [0.1.0]: https://github.com/vsariola/sointu/compare/4klang-3.11...v0.1.0
+[i112]: https://github.com/vsariola/sointu/issues/112
 [i116]: https://github.com/vsariola/sointu/issues/116
 [i120]: https://github.com/vsariola/sointu/issues/120
 [i121]: https://github.com/vsariola/sointu/issues/121

tracker/gioui/unit_editor.go

@@ -235,7 +235,7 @@ func (p ParameterStyle) Layout(gtx C) D {
 				for _, e := range gtx.Events(&p.w.floatWidget) {
 					if ev, ok := e.(pointer.Event); ok && ev.Type == pointer.Scroll {
 						delta := math.Min(math.Max(float64(ev.Scroll.Y), -1), 1)
-						tracker.Int{IntData: p.w.Parameter}.Add(int(delta))
+						tracker.Int{IntData: p.w.Parameter}.Add(-int(delta))
 					}
 				}
 				gtx.Constraints.Min.X = gtx.Dp(unit.Dp(200))