feat: add ability to select & move multiple units (closes #71)

tracker/gioui/draglist.go

@@ -15,6 +15,7 @@ import (
 
 type DragList struct {
 	SelectedItem  int
+	SelectedItem2 int
 	HoverItem     int
 	List          *layout.List
 	drag          bool
@@ -61,9 +62,9 @@ func (s *FilledDragListStyle) Layout(gtx C) D {
 
 	defer op.Offset(image.Point{}).Push(gtx.Ops).Pop()
 	defer clip.Rect(image.Rect(0, 0, gtx.Constraints.Max.X, gtx.Constraints.Max.Y)).Push(gtx.Ops).Pop()
-	keys := key.Set("↑|↓|Ctrl-↑|Ctrl-↓")
+	keys := key.Set("↑|↓|Ctrl-↑|Ctrl-↓|Shift-↑|Shift-↓")
 	if s.dragList.List.Axis == layout.Horizontal {
-		keys = key.Set("←|→|Ctrl-←|Ctrl-→")
+		keys = key.Set("←|→|Ctrl-←|Ctrl-→|Shift-←|Shift-→")
 	}
 	key.InputOp{Tag: &s.dragList.mainTag, Keys: keys}.Add(gtx.Ops)
 
@@ -78,6 +79,10 @@ func (s *FilledDragListStyle) Layout(gtx C) D {
 		key.FocusOp{Tag: &s.dragList.mainTag}.Add(gtx.Ops)
 	}
 
+	if !s.dragList.focused {
+		s.dragList.SelectedItem2 = s.dragList.SelectedItem
+	}
+
 	for _, ke := range gtx.Events(&s.dragList.mainTag) {
 		switch ke := ke.(type) {
 		case key.FocusEvent:
@@ -102,6 +107,9 @@ func (s *FilledDragListStyle) Layout(gtx C) D {
 					swap = delta
 				} else {
 					s.dragList.SelectedItem += delta
+					if !ke.Modifiers.Contain(key.ModShift) {
+						s.dragList.SelectedItem2 = s.dragList.SelectedItem
+					}
 				}
 			}
 		}
@@ -119,6 +127,8 @@ func (s *FilledDragListStyle) Layout(gtx C) D {
 				} else {
 					color = s.SelectedColor
 				}
+			} else if between(s.dragList.SelectedItem, index, s.dragList.SelectedItem2) {
+				color = s.SelectedColor
 			} else if s.dragList.HoverItem == index {
 				color = s.HoverColor
 			}
@@ -145,6 +155,9 @@ func (s *FilledDragListStyle) Layout(gtx C) D {
 						break
 					}
 					s.dragList.SelectedItem = index
+					if !e.Modifiers.Contain(key.ModShift) {
+						s.dragList.SelectedItem2 = index
+					}
 					key.FocusOp{Tag: &s.dragList.mainTag}.Add(gtx.Ops)
 				}
 			}
@@ -208,12 +221,41 @@ func (s *FilledDragListStyle) Layout(gtx C) D {
 		)
 	}
 	dims := s.dragList.List.Layout(gtx, s.Count, listElem)
-	if !s.dragList.swapped && swap != 0 && s.dragList.SelectedItem+swap >= 0 && s.dragList.SelectedItem+swap < s.Count {
+	a := intMin(s.dragList.SelectedItem, s.dragList.SelectedItem2)
-		s.swap(s.dragList.SelectedItem, s.dragList.SelectedItem+swap)
+	b := intMax(s.dragList.SelectedItem, s.dragList.SelectedItem2)
+	if !s.dragList.swapped && swap != 0 && a+swap >= 0 && b+swap < s.Count {
+		if swap < 0 {
+			for i := a; i <= b; i++ {
+				s.swap(i, i+swap)
+			}
+		} else {
+			for i := b; i >= a; i-- {
+				s.swap(i, i+swap)
+			}
+		}
 		s.dragList.SelectedItem += swap
+		s.dragList.SelectedItem2 += swap
 		s.dragList.swapped = true
 	} else {
 		s.dragList.swapped = false
 	}
 	return dims
 }
+
+func between(a, b, c int) bool {
+	return (a <= b && b <= c) || (c <= b && b <= a)
+}
+
+func intMax(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func intMin(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}

tracker/gioui/instrumenteditor.go

@@ -453,7 +453,6 @@ func (ie *InstrumentEditor) layoutInstrumentEditor(gtx C, t *Tracker) D {
 
 	defer op.Offset(image.Point{}).Push(gtx.Ops).Pop()
 	unitList := FilledDragList(t.Theme, ie.unitDragList, len(units), element, t.SwapUnits)
-	ie.unitDragList.SelectedItem = t.UnitIndex()
 	return Surface{Gray: 30, Focus: ie.wasFocused}.Layout(gtx, func(gtx C) D {
 		return layout.Flex{Axis: layout.Horizontal}.Layout(gtx,
 			layout.Rigid(func(gtx C) D {
@@ -477,24 +476,23 @@ func (ie *InstrumentEditor) layoutInstrumentEditor(gtx C, t *Tracker) D {
 										l := len(ie.unitTypeEditor.Text())
 										ie.unitTypeEditor.SetCaret(l, l)
 									case key.NameDeleteForward:
-										t.DeleteUnit(true)
+										t.DeleteUnits(true, ie.unitDragList.SelectedItem, ie.unitDragList.SelectedItem2)
-									case "C":
+									case "C", "X":
-										contents, err := yaml.Marshal(t.Unit())
+										units := t.DeleteUnits(true, ie.unitDragList.SelectedItem, ie.unitDragList.SelectedItem2)
+										contents, err := yaml.Marshal(units)
 										if err == nil {
 											clipboard.WriteOp{Text: string(contents)}.Add(gtx.Ops)
-											t.Alert.Update("Unit copied to clipboard", Notify, time.Second*3)
+											alertText := "Unit(s) copied to clipboard"
+											if e.Name == "X" {
+												alertText = "Unit(s) cut to clipboard"
 											}
-									case "X":
+											t.Alert.Update(alertText, Notify, time.Second*3)
-										contents, err := yaml.Marshal(t.Unit())
-										if err == nil {
-											clipboard.WriteOp{Text: string(contents)}.Add(gtx.Ops)
-											t.Alert.Update("Unit cut to clipboard", Notify, time.Second*3)
 										}
-										t.DeleteUnit(true)
+										ie.unitDragList.SelectedItem2 = t.UnitIndex()
 									case key.NameReturn:
 										if e.Modifiers.Contain(key.ModShortcut) {
 											t.AddUnit(true)
-											ie.unitDragList.SelectedItem = t.UnitIndex()
+											ie.unitDragList.SelectedItem2 = ie.unitDragList.SelectedItem
 											ie.unitTypeEditor.SetText("")
 										}
 										ie.unitTypeEditor.Focus()
@@ -504,7 +502,7 @@ func (ie *InstrumentEditor) layoutInstrumentEditor(gtx C, t *Tracker) D {
 								}
 							}
 						}
-
+						ie.unitDragList.SelectedItem = t.UnitIndex()
 						dims := unitList.Layout(gtx)
 						if t.UnitIndex() != ie.unitDragList.SelectedItem {
 							t.SetUnitIndex(ie.unitDragList.SelectedItem)

tracker/gioui/parameditor.go

@@ -179,7 +179,7 @@ func (pe *ParamEditor) layoutUnitFooter(t *Tracker) layout.Widget {
 			t.InstrumentEditor.unitDragList.Focus()
 		}
 		for pe.DeleteUnitBtn.Clickable.Clicked() {
-			t.DeleteUnit(false)
+			t.DeleteUnits(false, t.UnitIndex(), t.UnitIndex())
 			op.InvalidateOp{}.Add(gtx.Ops)
 			t.InstrumentEditor.unitDragList.Focus()
 		}

tracker/gioui/tracker.go

@@ -67,13 +67,13 @@ type Tracker struct {
 }
 
 func (t *Tracker) UnmarshalContent(bytes []byte) error {
-	var unit sointu.Unit
+	var units []sointu.Unit
-	if errJSON := json.Unmarshal(bytes, &unit); errJSON == nil {
+	if errJSON := json.Unmarshal(bytes, &units); errJSON == nil {
-		t.PasteUnit(unit)
+		t.PasteUnits(units)
 		return nil
 	}
-	if errYaml := yaml.Unmarshal(bytes, &unit); errYaml == nil {
+	if errYaml := yaml.Unmarshal(bytes, &units); errYaml == nil {
-		t.PasteUnit(unit)
+		t.PasteUnits(units)
 		return nil
 	}
 	var instr sointu.Instrument

tracker/model.go

@@ -641,18 +641,20 @@ func (m *Model) SetUnitType(t string) {
 	m.notifyPatchChange()
 }
 
-func (m *Model) PasteUnit(unit sointu.Unit) {
+func (m *Model) PasteUnits(units []sointu.Unit) {
-	m.saveUndo("PasteUnit", 0)
+	m.saveUndo("PasteUnits", 0)
-	newUnits := make([]sointu.Unit, len(m.Instrument().Units)+1)
+	newUnits := make([]sointu.Unit, len(m.Instrument().Units)+len(units))
 	m.unitIndex++
 	copy(newUnits, m.Instrument().Units[:m.unitIndex])
-	copy(newUnits[m.unitIndex+1:], m.Instrument().Units[m.unitIndex:])
+	copy(newUnits[m.unitIndex+len(units):], m.Instrument().Units[m.unitIndex:])
+	for _, unit := range units {
 		if _, ok := m.usedIDs[unit.ID]; ok {
 			m.maxID++
 			unit.ID = m.maxID
 		}
 		m.usedIDs[unit.ID] = true
-	newUnits[m.unitIndex] = unit
+	}
+	copy(newUnits[m.unitIndex:m.unitIndex+len(units)], units)
 	m.song.Patch[m.instrIndex].Units = newUnits
 	m.paramIndex = 0
 	m.clampPositions()
@@ -724,23 +726,38 @@ func (m *Model) DeleteOrderRow(forward bool) {
 	m.notifyScoreChange()
 }
 
-func (m *Model) DeleteUnit(forward bool) {
+func (m *Model) DeleteUnits(forward bool, a, b int) []sointu.Unit {
-	if !m.CanDeleteUnit() {
-		return
-	}
 	instr := m.Instrument()
-	m.saveUndo("DeleteUnit", 0)
+	m.saveUndo("DeleteUnits", 0)
-	delete(m.usedIDs, instr.Units[m.unitIndex].ID)
+	a, b = intMin(a, b), intMax(a, b)
-	newUnits := make([]sointu.Unit, len(instr.Units)-1)
+	if a < 0 {
-	copy(newUnits, instr.Units[:m.unitIndex])
+		a = 0
-	copy(newUnits[m.unitIndex:], instr.Units[m.unitIndex+1:])
+	}
-	m.song.Patch[m.instrIndex].Units = newUnits
+	if b > len(instr.Units)-1 {
-	if !forward && m.unitIndex > 0 {
+		b = len(instr.Units) - 1
+	}
+	for i := a; i <= b; i++ {
+		delete(m.usedIDs, instr.Units[i].ID)
+	}
+	var newUnits []sointu.Unit
+	if a == 0 && b == len(instr.Units)-1 {
+		newUnits = make([]sointu.Unit, 1)
+		m.unitIndex = 0
+	} else {
+		newUnits = make([]sointu.Unit, len(instr.Units)-(b-a+1))
+		copy(newUnits, instr.Units[:a])
+		copy(newUnits[a:], instr.Units[b+1:])
+		m.unitIndex = a
+		if forward {
 			m.unitIndex--
 		}
+	}
+	deletedUnits := instr.Units[a : b+1]
+	m.song.Patch[m.instrIndex].Units = newUnits
 	m.paramIndex = 0
 	m.clampPositions()
 	m.notifyPatchChange()
+	return deletedUnits
 }
 
 func (m *Model) CanDeleteUnit() bool {
@@ -1377,3 +1394,17 @@ func clamp(a, min, max int) int {
 	}
 	return a
 }
+
+func intMax(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func intMin(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}