Attempt to change textWidget to require parent context.

Less state in the text widget as our embedding Label and Entry widgets have the properties

widget/entry.go

@@ -84,11 +84,14 @@ func (e *entryRenderer) BackgroundColor() color.Color {
 }
 
 func (e *entryRenderer) Refresh() {
-	e.placeholder.Hide()
-	if e.text.len() == 0 {
+	if e.text.len() > 0 {
+		e.placeholder.Hide()
+	} else {
 		e.placeholder.Show()
+		e.placeholder.refreshTextRenderer()
 	}
 
+	e.text.refreshTextRenderer()
 	if e.entry.focused {
 		e.cursor.FillColor = theme.FocusColor()
 	} else {
@@ -154,8 +157,7 @@ func (e *Entry) SetText(text string) {
 // SetPlaceHolder sets the text that will be displayed if the entry is otherwise empty
 func (e *Entry) SetPlaceHolder(text string) {
 	e.PlaceHolder = text
-	e.placeholderWidget().SetText(text)
-	Renderer(e).Refresh()
+	e.placeholderWidget().SetText(text) // refreshes
 }
 
 // SetReadOnly sets whether or not the Entry should not be editable
@@ -331,22 +333,65 @@ func (e *Entry) placeholderWidget() *textWidget {
 	return Renderer(e).(*entryRenderer).placeholder
 }
 
-// textWidgetRenderer returns the renderer for the current text widget
-func (e *Entry) textWidgetRenderer() *textRenderer {
-	return Renderer(e.textWidget()).(*textRenderer)
+// textAlign tells the rendering textWidget our alignment
+func (e *Entry) textAlign() fyne.TextAlign {
+	return fyne.TextAlignLeading
+}
+
+// textStyle tells the rendering textWidget our style
+func (e *Entry) textStyle() fyne.TextStyle {
+	return fyne.TextStyle{}
+}
+
+// textColor tells the rendering textWidget our color
+func (e *Entry) textColor() color.Color {
+	return theme.TextColor()
+}
+
+// password tells the rendering textWidget if we are a password field
+func (e *Entry) password() bool {
+	return e.Password
+}
+
+// object returns the root object of the widget so it can be referenced
+func (e *Entry) object() fyne.Widget {
+	return nil
+}
+
+type placeholderParent struct {
+	e *Entry
+}
+
+// textAlign tells the rendering textWidget our alignment
+func (p *placeholderParent) textAlign() fyne.TextAlign {
+	return fyne.TextAlignLeading
+}
+
+// textStyle tells the rendering textWidget our style
+func (p *placeholderParent) textStyle() fyne.TextStyle {
+	return fyne.TextStyle{}
+}
+
+// textColor tells the rendering textWidget our color
+func (p *placeholderParent) textColor() color.Color {
+	return theme.PlaceHolderColor()
+}
+
+// password tells the rendering textWidget if we are a password field
+func (p *placeholderParent) password() bool {
+	return p.e.Password
+}
+
+// object returns the root object of the widget so it can be referenced
+func (p *placeholderParent) object() fyne.Widget {
+	return nil
 }
 
 // CreateRenderer is a private method to Fyne which links this widget to it's renderer
 func (e *Entry) CreateRenderer() fyne.WidgetRenderer {
-	text := &textWidget{
-		password: e.Password,
-	}
-	text.SetText(e.Text)
+	text := &textWidget{buffer: []rune(e.Text), parent: e}
+	placeholder := &textWidget{parent: &placeholderParent{e}, buffer: []rune(e.PlaceHolder)}
 
-	placeholder := &textWidget{
-		color: theme.PlaceHolderColor(),
-	}
-	placeholder.SetText(e.PlaceHolder)
 	box := canvas.NewRectangle(theme.BackgroundColor())
 	cursor := canvas.NewRectangle(theme.BackgroundColor())
 
@@ -358,7 +403,6 @@ func (e *Entry) CreateRenderer() fyne.WidgetRenderer {
 func NewEntry() *Entry {
 	e := &Entry{}
 
-	Renderer(e).Layout(e.MinSize())
 	Renderer(e).Refresh()
 	return e
 }
@@ -367,7 +411,6 @@ func NewEntry() *Entry {
 func NewMultiLineEntry() *Entry {
 	e := &Entry{MultiLine: true}
 
-	Renderer(e).Layout(e.MinSize())
 	Renderer(e).Refresh()
 	return e
 }
@@ -376,7 +419,6 @@ func NewMultiLineEntry() *Entry {
 func NewPasswordEntry() *Entry {
 	e := &Entry{Password: true}
 
-	Renderer(e).Layout(e.MinSize())
 	Renderer(e).Refresh()
 	return e
 }

widget/entry_test.go

@@ -4,12 +4,18 @@ import (
 	"testing"
 
 	"fyne.io/fyne"
+	"fyne.io/fyne/canvas"
 	"fyne.io/fyne/test"
 	"fyne.io/fyne/theme"
 
 	"github.com/stretchr/testify/assert"
 )
 
+func entryRenderTexts(e *Entry) []*canvas.Text {
+	textWid := Renderer(e).(*entryRenderer).text
+	return Renderer(textWid).(*textRenderer).texts
+}
+
 func TestEntry_MinSize(t *testing.T) {
 	entry := NewEntry()
 	min := entry.MinSize()
@@ -141,8 +147,8 @@ func TestEntry_OnKeyDown_Newline(t *testing.T) {
 	key.String = "o"
 	entry.OnKeyDown(key)
 	assert.Equal(t, "H\noi", entry.textWidget().String())
-	assert.Equal(t, "H", entry.textWidgetRenderer().texts[0].Text)
-	assert.Equal(t, "oi", entry.textWidgetRenderer().texts[1].Text)
+	assert.Equal(t, "H", entryRenderTexts(entry)[0].Text)
+	assert.Equal(t, "oi", entryRenderTexts(entry)[1].Text)
 }
 
 func TestEntry_OnKeyDown_Backspace(t *testing.T) {
@@ -439,5 +445,5 @@ func TestPasswordEntry_Obfuscation(t *testing.T) {
 	key.String = "Hié™שרה"
 	entry.OnKeyDown(key)
 	assert.Equal(t, "Hié™שרה", entry.Text)
-	assert.Equal(t, "*******", entry.textWidgetRenderer().texts[0].Text)
+	assert.Equal(t, "*******", entryRenderTexts(entry)[0].Text)
 }

widget/label.go

@@ -1,7 +1,10 @@
 package widget
 
 import (
+	"image/color"
+
 	"fyne.io/fyne"
+	"fyne.io/fyne/theme"
 )
 
 // Label widget is a label component with appropriate padding and layout.
@@ -25,27 +28,44 @@ func NewLabelWithStyle(text string, alignment fyne.TextAlign, style fyne.TextSty
 		TextStyle: style,
 	}
 
-	Renderer(l).Refresh()
 	return l
 }
 
 // SetText sets the text of the label
 func (l *Label) SetText(text string) {
 	l.Text = text
-	l.textWidget.SetText(text)
-	Renderer(l).Refresh()
+	l.textWidget.SetText(text) // calls refresh
+}
+
+// textAlign tells the rendering textWidget our alignment
+func (l *Label) textAlign() fyne.TextAlign {
+	return l.Alignment
+}
+
+// textStyle tells the rendering textWidget our style
+func (l *Label) textStyle() fyne.TextStyle {
+	return l.TextStyle
+}
+
+// textColor tells the rendering textWidget our color
+func (l *Label) textColor() color.Color {
+	return theme.TextColor()
+}
+
+// password tells the rendering textWidget if we are a password field
+func (l *Label) password() bool {
+	return false
+}
+
+// object returns the root object of the widget so it can be referenced
+func (l *Label) object() fyne.Widget {
+	return l
 }
 
 // CreateRenderer is a private method to Fyne which links this widget to it's renderer
 func (l *Label) CreateRenderer() fyne.WidgetRenderer {
-	l.textWidget = textWidget{
-		Alignment: l.Alignment,
-		TextStyle: l.TextStyle,
-	}
-	l.textWidget.SetText(l.Text)
-	r := l.textWidget.CreateRenderer()
-	r.Refresh()
-	return r
+	l.textWidget = newTextWidget(l.Text, l)
+	return l.textWidget.CreateRenderer()
 }
 
 // Resize sets a new size for a widget.

widget/label_test.go

@@ -18,9 +18,39 @@ func TestLabel_MinSize(t *testing.T) {
 	label.SetText("Longer")
 	assert.True(t, label.MinSize().Width > min.Width)
 }
+
+func TestLabel_Text(t *testing.T) {
+	label := &Label{Text: "Test"}
+	Renderer(label).Refresh()
+
+	assert.Equal(t, "Test", label.Text)
+	assert.Equal(t, "Test", textRenderTexts(label)[0].Text)
+}
+
+func TestLabel_SetText(t *testing.T) {
+	label := &Label{Text: "Test"}
+	Renderer(label).Refresh()
+	label.SetText("New")
+
+	assert.Equal(t, "New", label.Text)
+	assert.Equal(t, "New", textRenderTexts(label)[0].Text)
+}
+
 func TestLabel_Alignment(t *testing.T) {
 	label := &Label{Text: "Test", Alignment: fyne.TextAlignTrailing}
-	assert.Equal(t, fyne.TextAlignTrailing, Renderer(label).(*textRenderer).texts[0].Alignment)
+	Renderer(label).Refresh()
+
+	assert.Equal(t, fyne.TextAlignTrailing, textRenderTexts(label)[0].Alignment)
+}
+
+func TestLabel_Alignment_Later(t *testing.T) {
+	label := &Label{Text: "Test"}
+	Renderer(label).Refresh()
+	assert.Equal(t, fyne.TextAlignLeading, textRenderTexts(label)[0].Alignment)
+
+	label.Alignment = fyne.TextAlignTrailing
+	Renderer(label).Refresh()
+	assert.Equal(t, fyne.TextAlignTrailing, textRenderTexts(label)[0].Alignment)
 }
 
 func TestText_MinSize_MultiLine(t *testing.T) {