Merge pull request fyne-io#4560 from andydotxyz/fix/cursorcpu

Reduce CPU consumption of Entry cursor by around 80%

widget/entry.go

@@ -13,6 +13,7 @@ import (
 	"fyne.io/fyne/v2/data/binding"
 	"fyne.io/fyne/v2/driver/desktop"
 	"fyne.io/fyne/v2/driver/mobile"
+	"fyne.io/fyne/v2/internal/async"
 	"fyne.io/fyne/v2/internal/cache"
 	"fyne.io/fyne/v2/internal/widget"
 	"fyne.io/fyne/v2/theme"
@@ -96,6 +97,7 @@ type Entry struct {
 	binder          basicBinder
 	conversionError error
 	lastChange      time.Time
+	minCache        async.Size
 	multiLineRows   int // override global default number of visible lines
 
 	// undoStack stores the data necessary for undo/redo functionality
@@ -399,6 +401,11 @@ func (e *Entry) KeyUp(key *fyne.KeyEvent) {
 //
 // Implements: fyne.Widget
 func (e *Entry) MinSize() fyne.Size {
+	cached := e.minCache.Load()
+	if !cached.IsZero() {
+		return cached
+	}
+
 	e.ExtendBaseWidget(e)
 
 	min := e.BaseWidget.MinSize()
@@ -409,6 +416,7 @@ func (e *Entry) MinSize() fyne.Size {
 		min = min.Add(fyne.NewSize(theme.IconInlineSize()+theme.LineSpacing(), 0))
 	}
 
+	e.minCache.Store(min)
 	return min
 }
 
@@ -474,6 +482,12 @@ func (e *Entry) Redo() {
 	e.Refresh()
 }
 
+func (e *Entry) Refresh() {
+	e.minCache.Store(fyne.Size{})
+
+	e.BaseWidget.Refresh()
+}
+
 // SelectedText returns the text currently selected in this Entry.
 // If there is no selection it will return the empty string.
 func (e *Entry) SelectedText() string {
@@ -500,6 +514,7 @@ func (e *Entry) SelectedText() string {
 // Since: 2.2
 func (e *Entry) SetMinRowsVisible(count int) {
 	e.multiLineRows = count
+	e.Refresh()
 }
 
 // SetPlaceHolder sets the text that will be displayed if the entry is otherwise empty

widget/entry_cursor_anim.go

@@ -11,7 +11,11 @@ import (
 	"fyne.io/fyne/v2/theme"
 )
 
-const cursorInterruptTime = 300 * time.Millisecond
+const (
+	cursorInterruptTime = 300 * time.Millisecond
+	cursorFadeAlpha     = uint8(0x16)
+	cursorFadeRatio     = 0.1
+)
 
 type entryCursorAnimation struct {
 	mu                *sync.RWMutex
@@ -30,14 +34,26 @@ func newEntryCursorAnimation(cursor *canvas.Rectangle) *entryCursorAnimation {
 // creates fyne animation
 func (a *entryCursorAnimation) createAnim(inverted bool) *fyne.Animation {
 	cursorOpaque := theme.PrimaryColor()
-	r, g, b, _ := col.ToNRGBA(theme.PrimaryColor())
-	cursorDim := color.NRGBA{R: uint8(r), G: uint8(g), B: uint8(b), A: 0x16}
-	start, end := color.Color(cursorDim), cursorOpaque
+	ri, gi, bi, ai := col.ToNRGBA(theme.PrimaryColor())
+	r := uint8(ri >> 8)
+	g := uint8(gi >> 8)
+	b := uint8(bi >> 8)
+	endA := uint8(ai >> 8)
+	startA := cursorFadeAlpha
+	cursorDim := color.NRGBA{R: r, G: g, B: b, A: cursorFadeAlpha}
 	if inverted {
-		start, end = cursorOpaque, color.Color(cursorDim)
+		a.cursor.FillColor = cursorOpaque
+		startA, endA = endA, startA
+	} else {
+		a.cursor.FillColor = cursorDim
 	}
+
+	deltaA := endA - startA
+	fadeStart := float32(0.5 - cursorFadeRatio)
+	fadeStop := float32(0.5 + cursorFadeRatio)
+
 	interrupted := false
-	anim := canvas.NewColorRGBAAnimation(start, end, time.Second/2, func(c color.Color) {
+	anim := fyne.NewAnimation(time.Second/2, func(f float32) {
 		a.mu.RLock()
 		shouldInterrupt := a.timeNow().Sub(a.lastInterruptTime) <= cursorInterruptTime
 		a.mu.RUnlock()
@@ -67,7 +83,26 @@ func (a *entryCursorAnimation) createAnim(inverted bool) *fyne.Animation {
 			}()
 			return
 		}
-		a.cursor.FillColor = c
+
+		alpha := uint8(0)
+		if f < fadeStart {
+			if _, _, _, al := a.cursor.FillColor.RGBA(); uint8(al>>8) == cursorFadeAlpha {
+				return
+			}
+
+			a.cursor.FillColor = cursorDim
+		} else if f >= fadeStop {
+			if _, _, _, al := a.cursor.FillColor.RGBA(); al == 0xffff {
+				return
+			}
+
+			a.cursor.FillColor = cursorOpaque
+		} else {
+			fade := (f + cursorFadeRatio - 0.5) * (1 / (cursorFadeRatio * 2))
+			alpha = uint8(float32(deltaA) * fade)
+			a.cursor.FillColor = color.NRGBA{R: r, G: g, B: b, A: alpha}
+		}
+
 		a.cursor.Refresh()
 	})
 

widget/entry_cursor_anim_test.go

@@ -21,7 +21,7 @@ func TestEntryCursorAnim(t *testing.T) {
 	alphaEquals := func(color1, color2 color.Color) bool {
 		_, _, _, a1 := col.ToNRGBA(color1)
 		_, _, _, a2 := col.ToNRGBA(color2)
-		return a1 == a2
+		return uint8(a1>>8) == uint8(a2>>8) // only check 8bit colour channels
 	}
 
 	cursor := canvas.NewRectangle(color.Black)

widget/entry_test.go

@@ -438,6 +438,7 @@ func TestEntry_MinSize(t *testing.T) {
 
 	min = entry.MinSize()
 	entry.ActionItem = canvas.NewCircle(color.Black)
+	entry.Refresh()
 	assert.Equal(t, min.Add(fyne.NewSize(theme.IconInlineSize()+theme.Padding(), 0)), entry.MinSize())
 }
 
@@ -462,6 +463,7 @@ func TestEntryMultiline_MinSize(t *testing.T) {
 
 	min = entry.MinSize()
 	entry.ActionItem = canvas.NewCircle(color.Black)
+	entry.Refresh()
 	assert.Equal(t, min.Add(fyne.NewSize(theme.IconInlineSize()+theme.Padding(), 0)), entry.MinSize())
 }
 
@@ -1775,6 +1777,7 @@ func TestMultiLineEntry_MinSize(t *testing.T) {
 	assert.True(t, multiMin.Height > singleMin.Height)
 
 	multi.MultiLine = false
+	multi.Refresh()
 	multiMin = multi.MinSize()
 	assert.Equal(t, singleMin.Height, multiMin.Height)
 }