refactor(tracker): change so that all icon initialization is a lazy & cache in iconcache

tracker/iconcache.go

@@ -0,0 +1,22 @@
+package tracker
+
+import (
+	"log"
+
+	"gioui.org/widget"
+)
+
+var iconCache = map[*byte]*widget.Icon{}
+
+// widgetForIcon returns a widget for IconVG data, but caching the results
+func widgetForIcon(icon []byte) *widget.Icon {
+	if widget, ok := iconCache[&icon[0]]; ok {
+		return widget
+	}
+	widget, err := widget.NewIcon(icon)
+	if err != nil {
+		log.Fatal(err)
+	}
+	iconCache[&icon[0]] = widget
+	return widget
+}

tracker/instruments.go

@@ -11,6 +11,7 @@ import (
 	"gioui.org/unit"
 	"gioui.org/widget"
 	"gioui.org/widget/material"
+	"golang.org/x/exp/shiny/materialdesign/icons"
 )
 
 type C = layout.Context
@@ -25,7 +26,7 @@ func (t *Tracker) updateInstrumentScroll() {
 }
 
 func (t *Tracker) layoutInstruments() layout.Widget {
-	btnStyle := material.IconButton(t.Theme, t.NewInstrumentBtn, addIcon)
+	btnStyle := material.IconButton(t.Theme, t.NewInstrumentBtn, widgetForIcon(icons.ContentAdd))
 	btnStyle.Background = transparent
 	btnStyle.Inset = layout.UniformInset(unit.Dp(6))
 	if t.song.Patch.TotalVoices() < 32 {
@@ -57,7 +58,7 @@ func (t *Tracker) layoutInstrumentHeader() layout.Widget {
 		return layout.Dimensions{Size: gtx.Constraints.Min}
 	}
 	header := func(gtx C) D {
-		deleteInstrumentBtnStyle := material.IconButton(t.Theme, t.DeleteInstrumentBtn, deleteIcon)
+		deleteInstrumentBtnStyle := material.IconButton(t.Theme, t.DeleteInstrumentBtn, widgetForIcon(icons.ActionDelete))
 		deleteInstrumentBtnStyle.Background = transparent
 		deleteInstrumentBtnStyle.Inset = layout.UniformInset(unit.Dp(6))
 		if len(t.song.Patch.Instruments) > 1 {

tracker/layout.go

@@ -3,7 +3,6 @@ package tracker
 import (
 	"image"
 	"image/color"
-	"log"
 
 	"gioui.org/layout"
 	"gioui.org/op"
@@ -12,50 +11,9 @@ import (
 	"gioui.org/unit"
 	"gioui.org/widget"
 	"gioui.org/widget/material"
-
 	"golang.org/x/exp/shiny/materialdesign/icons"
 )
 
-var upIcon *widget.Icon
-var downIcon *widget.Icon
-var addIcon *widget.Icon
-var loadIcon *widget.Icon
-var saveIcon *widget.Icon
-var clearIcon *widget.Icon
-var deleteIcon *widget.Icon
-
-func init() {
-	var err error
-	upIcon, err = widget.NewIcon(icons.NavigationArrowUpward)
-	if err != nil {
-		log.Fatal(err)
-	}
-	downIcon, err = widget.NewIcon(icons.NavigationArrowDownward)
-	if err != nil {
-		log.Fatal(err)
-	}
-	addIcon, err = widget.NewIcon(icons.ContentAdd)
-	if err != nil {
-		log.Fatal(err)
-	}
-	loadIcon, err = widget.NewIcon(icons.FileFolder)
-	if err != nil {
-		log.Fatal(err)
-	}
-	saveIcon, err = widget.NewIcon(icons.ContentSave)
-	if err != nil {
-		log.Fatal(err)
-	}
-	clearIcon, err = widget.NewIcon(icons.ContentClear)
-	if err != nil {
-		log.Fatal(err)
-	}
-	deleteIcon, err = widget.NewIcon(icons.ActionDelete)
-	if err != nil {
-		log.Fatal(err)
-	}
-}
-
 func smallButton(icStyle material.IconButtonStyle) material.IconButtonStyle {
 	icStyle.Size = unit.Dp(14)
 	icStyle.Inset = layout.UniformInset(unit.Dp(1))
@@ -178,7 +136,7 @@ func (t *Tracker) layoutTracks(gtx layout.Context) layout.Dimensions {
 		subtractOctaveBtnStyle.Color = primaryColor
 		subtractOctaveBtnStyle.Background = transparent
 		subtractOctaveBtnStyle.Inset = layout.UniformInset(unit.Dp(6))
-		newTrackBtnStyle := material.IconButton(t.Theme, t.NewTrackBtn, addIcon)
+		newTrackBtnStyle := material.IconButton(t.Theme, t.NewTrackBtn, widgetForIcon(icons.ContentAdd))
 		newTrackBtnStyle.Background = transparent
 		newTrackBtnStyle.Inset = layout.UniformInset(unit.Dp(6))
 		if t.song.TotalTrackVoices() < t.song.Patch.TotalVoices() {

tracker/songpanel.go

@@ -9,6 +9,7 @@ import (
 	"gioui.org/op/paint"
 	"gioui.org/unit"
 	"gioui.org/widget/material"
+	"golang.org/x/exp/shiny/materialdesign/icons"
 )
 
 func (t *Tracker) layoutSongPanel(gtx C) D {
@@ -36,17 +37,17 @@ func (t *Tracker) layoutSongButtons(gtx C) D {
 		t.SaveSongFile()
 	}
 
-	newBtnStyle := material.IconButton(t.Theme, t.NewSongFileBtn, clearIcon)
+	newBtnStyle := material.IconButton(t.Theme, t.NewSongFileBtn, widgetForIcon(icons.ContentClear))
 	newBtnStyle.Background = transparent
 	newBtnStyle.Inset = layout.UniformInset(unit.Dp(6))
 	newBtnStyle.Color = primaryColor
 
-	loadBtnStyle := material.IconButton(t.Theme, t.LoadSongFileBtn, loadIcon)
+	loadBtnStyle := material.IconButton(t.Theme, t.LoadSongFileBtn, widgetForIcon(icons.FileFolder))
 	loadBtnStyle.Background = transparent
 	loadBtnStyle.Inset = layout.UniformInset(unit.Dp(6))
 	loadBtnStyle.Color = primaryColor
 
-	saveBtnStyle := material.IconButton(t.Theme, t.SaveSongFileBtn, saveIcon)
+	saveBtnStyle := material.IconButton(t.Theme, t.SaveSongFileBtn, widgetForIcon(icons.ContentSave))
 	saveBtnStyle.Background = transparent
 	saveBtnStyle.Inset = layout.UniformInset(unit.Dp(6))
 	saveBtnStyle.Color = primaryColor