From f4c007264252253ae97a41036dcb2972a80804ce Mon Sep 17 00:00:00 2001
From: Drew Weymouth <dweymouth@gmail.com>
Date: Fri, 5 Apr 2024 08:17:31 -0700
Subject: [PATCH 1/3] add clean task for visualCache

---
 cmd/fyne_demo/main.go |  4 ++--
 widget/richtext.go    | 22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/cmd/fyne_demo/main.go b/cmd/fyne_demo/main.go
index 81deb5fcbb..1780a4390c 100644
--- a/cmd/fyne_demo/main.go
+++ b/cmd/fyne_demo/main.go
@@ -246,10 +246,10 @@ func makeNav(setTutorial func(tutorial tutorials.Tutorial), loadPrevious bool) f
 
 	themes := container.NewGridWithColumns(2,
 		widget.NewButton("Dark", func() {
-			a.Settings().SetTheme(&forcedVariant{Theme: theme.DefaultTheme(), variant: theme.VariantDark})
+			//a.Settings().SetTheme(&forcedVariant{Theme: theme.DefaultTheme(), variant: theme.VariantDark})
 		}),
 		widget.NewButton("Light", func() {
-			a.Settings().SetTheme(&forcedVariant{Theme: theme.DefaultTheme(), variant: theme.VariantLight})
+			//a.Settings().SetTheme(&forcedVariant{Theme: theme.DefaultTheme(), variant: theme.VariantLight})
 		}),
 	)
 
diff --git a/widget/richtext.go b/widget/richtext.go
index 007b8e3c67..23469c7725 100644
--- a/widget/richtext.go
+++ b/widget/richtext.go
@@ -225,6 +225,26 @@ func (t *RichText) cachedSegmentVisual(seg RichTextSegment, offset int) fyne.Can
 	return vis
 }
 
+func (t *RichText) cleanVisualCache() {
+	var deletingSegs []RichTextSegment
+	for seg1 := range t.visualCache {
+		found := false
+		for _, seg2 := range t.Segments {
+			if seg1 == seg2 {
+				found = true
+				break
+			}
+		}
+		if !found {
+			// cached segment is not currently in t.Segments, clear it
+			deletingSegs = append(deletingSegs, seg1)
+		}
+	}
+	for _, seg := range deletingSegs {
+		delete(t.visualCache, seg)
+	}
+}
+
 // insertAt inserts the text at the specified position
 func (t *RichText) insertAt(pos int, runes string) {
 	index := 0
@@ -726,6 +746,8 @@ func (r *textRenderer) Refresh() {
 
 	r.Layout(r.obj.Size())
 	canvas.Refresh(r.obj.super())
+
+	r.obj.cleanVisualCache()
 }
 
 func (r *textRenderer) layoutRow(texts []fyne.CanvasObject, align fyne.TextAlign, xPos, yPos, lineWidth float32) (float32, float32) {

From 77b6e423990542e974a65425cec9d3408cb6d818 Mon Sep 17 00:00:00 2001
From: Drew Weymouth <dweymouth@gmail.com>
Date: Fri, 5 Apr 2024 08:19:06 -0700
Subject: [PATCH 2/3] undo unintentional fyne_demo changes

---
 cmd/fyne_demo/main.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cmd/fyne_demo/main.go b/cmd/fyne_demo/main.go
index 1780a4390c..81deb5fcbb 100644
--- a/cmd/fyne_demo/main.go
+++ b/cmd/fyne_demo/main.go
@@ -246,10 +246,10 @@ func makeNav(setTutorial func(tutorial tutorials.Tutorial), loadPrevious bool) f
 
 	themes := container.NewGridWithColumns(2,
 		widget.NewButton("Dark", func() {
-			//a.Settings().SetTheme(&forcedVariant{Theme: theme.DefaultTheme(), variant: theme.VariantDark})
+			a.Settings().SetTheme(&forcedVariant{Theme: theme.DefaultTheme(), variant: theme.VariantDark})
 		}),
 		widget.NewButton("Light", func() {
-			//a.Settings().SetTheme(&forcedVariant{Theme: theme.DefaultTheme(), variant: theme.VariantLight})
+			a.Settings().SetTheme(&forcedVariant{Theme: theme.DefaultTheme(), variant: theme.VariantLight})
 		}),
 	)
 

From 6c7515e769ed993ada8162b8648024a6f77acb72 Mon Sep 17 00:00:00 2001
From: Drew Weymouth <dweymouth@gmail.com>
Date: Fri, 5 Apr 2024 08:49:49 -0700
Subject: [PATCH 3/3] add early return condition to cleanVisualCache

---
 widget/richtext.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/widget/richtext.go b/widget/richtext.go
index 23469c7725..3477953592 100644
--- a/widget/richtext.go
+++ b/widget/richtext.go
@@ -226,6 +226,9 @@ func (t *RichText) cachedSegmentVisual(seg RichTextSegment, offset int) fyne.Can
 }
 
 func (t *RichText) cleanVisualCache() {
+	if len(t.visualCache) <= len(t.Segments) {
+		return
+	}
 	var deletingSegs []RichTextSegment
 	for seg1 := range t.visualCache {
 		found := false