elements/basic/button.go

@@ -121,7 +121,7 @@ func (element *Button) SetText (text string) {
 }
 
 func (element *Button) draw () {
-	bounds := element.core.Bounds()
+	bounds := element.Bounds()
 
 	pattern, inset := theme.ButtonPattern(theme.PatternState {
 		Case: buttonCase,
@@ -130,7 +130,7 @@ func (element *Button) draw () {
 		Pressed:  element.pressed,
 	})
 
-	artist.FillRectangle(element.core, pattern, bounds)
+	artist.FillRectangle(element, pattern, bounds)
 		
 	innerBounds := inset.Apply(bounds)
 
@@ -149,5 +149,5 @@ func (element *Button) draw () {
 		Case: buttonCase,
 		Disabled: !element.Enabled(),
 	})
-	element.drawer.Draw(element.core, foreground, offset)
+	element.drawer.Draw(element, foreground, offset)
 }

elements/basic/checkbox.go

@@ -133,13 +133,13 @@ func (element *Checkbox) SetText (text string) {
 }
 
 func (element *Checkbox) draw () {
-	bounds := element.core.Bounds()
+	bounds := element.Bounds()
 	boxBounds := image.Rect(0, 0, bounds.Dy(), bounds.Dy())
 
 	backgroundPattern, _ := theme.BackgroundPattern(theme.PatternState {
 		Case: checkboxCase,
 	})
-	artist.FillRectangle ( element.core, backgroundPattern, bounds)
+	artist.FillRectangle(element, backgroundPattern, bounds)
 
 	pattern, inset := theme.ButtonPattern(theme.PatternState {
 		Case: checkboxCase,
@@ -147,7 +147,7 @@ func (element *Checkbox) draw () {
 		Focused:  element.Focused(),
 		Pressed:  element.pressed,
 	})
-	artist.FillRectangle(element.core, pattern, boxBounds)
+	artist.FillRectangle(element, pattern, boxBounds)
 
 	textBounds := element.drawer.LayoutBounds()
 	offset := image.Point {
@@ -161,10 +161,10 @@ func (element *Checkbox) draw () {
 		Case: checkboxCase,
 		Disabled: !element.Enabled(),
 	})
-	element.drawer.Draw(element.core, foreground, offset)
+	element.drawer.Draw(element, foreground, offset)
 	
 	if element.checked {
 		checkBounds := inset.Apply(boxBounds).Inset(2)
-		artist.FillRectangle(element.core, foreground, checkBounds)
+		artist.FillRectangle(element, foreground, checkBounds)
 	}
 }

elements/basic/container.go

@@ -201,11 +201,11 @@ func (element *Container) redoAll () {
 	element.recalculate()
 
 	// draw a background
-	bounds := element.core.Bounds()
+	bounds := element.Bounds()
 	pattern, _ := theme.BackgroundPattern (theme.PatternState {
 		Case: containerCase,
 	})
-	artist.FillRectangle(element.core, pattern, bounds)
+	artist.FillRectangle(element, pattern, bounds)
 
 	// resize all elements, having them draw onto us
 	for _, entry := range element.children {

elements/basic/label.go

@@ -107,19 +107,19 @@ func (element *Label) updateMinimumSize () {
 }
 
 func (element *Label) draw () {
-	bounds := element.core.Bounds()
+	bounds := element.Bounds()
 
 	pattern, _ := theme.BackgroundPattern(theme.PatternState {
 		Case: labelCase,
 	})
-	artist.FillRectangle(element.core, pattern, bounds)
+	artist.FillRectangle(element, pattern, bounds)
 
 	textBounds := element.drawer.LayoutBounds()
 
 	foreground, _ := theme.ForegroundPattern (theme.PatternState {
 		Case: labelCase,
 	})
-	element.drawer.Draw (element.core, foreground, image.Point {
+	element.drawer.Draw (element, foreground, image.Point {
 		X: 0 - textBounds.Min.X,
 		Y: 0 - textBounds.Min.Y,
 	})

elements/basic/list.go

@@ -376,7 +376,7 @@ func (element *List) draw () {
 		Disabled: !element.Enabled(),
 		Focused: element.Focused(),
 	})
-	artist.FillRectangle(element.core, pattern, bounds)
+	artist.FillRectangle(element, pattern, bounds)
 
 	bounds = inset.Apply(bounds)
 	dot := image.Point {

elements/basic/progressbar.go

@@ -32,15 +32,15 @@ func (element *ProgressBar) SetProgress (progress float64) {
 }
 
 func (element *ProgressBar) draw () {
-	bounds := element.core.Bounds()
+	bounds := element.Bounds()
 
 	pattern, inset := theme.SunkenPattern(theme.PatternState { })
-	artist.FillRectangle(element.core, pattern, bounds)
+	artist.FillRectangle(element, pattern, bounds)
 	bounds = inset.Apply(bounds)
 	meterBounds := image.Rect (
 		bounds.Min.X, bounds.Min.Y,
 		bounds.Min.X + int(float64(bounds.Dx()) * element.progress),
 		bounds.Max.Y)
 	accent, _ := theme.AccentPattern(theme.PatternState { })
-	artist.FillRectangle(element.core, accent, meterBounds)
+	artist.FillRectangle(element, accent, meterBounds)
 }

elements/basic/scrollcontainer.go

@@ -358,7 +358,7 @@ func (element *ScrollContainer) recalculate () {
 }
 
 func (element *ScrollContainer) draw () {
-	artist.Paste(element.core, element.child, image.Point { })
+	artist.Paste(element, element.child, image.Point { })
 	deadPattern, _ := theme.DeadPattern(theme.PatternState {
 		Case: scrollContainerCase,
 	})

elements/basic/spacer.go

@@ -34,19 +34,19 @@ func (element *Spacer) SetLine (line bool) {
 }
 
 func (element *Spacer) draw () {
-	bounds := element.core.Bounds()
+	bounds := element.Bounds()
 
 	if element.line {
 		pattern, _ := theme.ForegroundPattern(theme.PatternState {
 			Case: spacerCase,
 			Disabled: true,
 		})
-		artist.FillRectangle(element.core, pattern, bounds)
+		artist.FillRectangle(element, pattern, bounds)
 	} else {
 		pattern, _ := theme.BackgroundPattern(theme.PatternState {
 			Case: spacerCase,
 			Disabled: true,
 		})
-		artist.FillRectangle(element.core, pattern, bounds)
+		artist.FillRectangle(element, pattern, bounds)
 	}
 }

elements/basic/switch.go

@@ -140,13 +140,13 @@ func (element *Switch) calculateMinimumSize () {
 }
 
 func (element *Switch) draw () {
-	bounds := element.core.Bounds()
+	bounds := element.Bounds()
 	handleBounds := image.Rect(0, 0, bounds.Dy(), bounds.Dy())
 	gutterBounds := image.Rect(0, 0, bounds.Dy() * 2, bounds.Dy())
 	backgroundPattern, _ := theme.BackgroundPattern(theme.PatternState {
 		Case: switchCase,
 	})
-	artist.FillRectangle ( element.core, backgroundPattern, bounds)
+	artist.FillRectangle (element, backgroundPattern, bounds)
 
 	if element.checked {
 		handleBounds.Min.X += bounds.Dy()
@@ -168,7 +168,7 @@ func (element *Switch) draw () {
 		Focused:  element.Focused(),
 		Pressed:  element.pressed,
 	})
-	artist.FillRectangle(element.core, gutterPattern, gutterBounds)
+	artist.FillRectangle(element, gutterPattern, gutterBounds)
 	
 	handlePattern, _ := theme.HandlePattern(theme.PatternState {
 		Case: switchCase,
@@ -176,7 +176,7 @@ func (element *Switch) draw () {
 		Focused:  element.Focused(),
 		Pressed:  element.pressed,
 	})
-	artist.FillRectangle(element.core, handlePattern, handleBounds)
+	artist.FillRectangle(element, handlePattern, handleBounds)
 
 	textBounds := element.drawer.LayoutBounds()
 	offset := image.Point {
@@ -190,5 +190,5 @@ func (element *Switch) draw () {
 		Case: switchCase,
 		Disabled: !element.Enabled(),
 	})
-	element.drawer.Draw(element.core, foreground, offset)
+	element.drawer.Draw(element, foreground, offset)
 }

elements/basic/textbox.go

@@ -257,7 +257,7 @@ func (element *TextBox) runOnChange () {
 func (element *TextBox) scrollToCursor () {
 	if !element.core.HasImage() { return }
 
-	bounds := element.core.Bounds().Inset(theme.Padding())
+	bounds := element.Bounds().Inset(theme.Padding())
 	bounds.Max.X -= element.valueDrawer.Em().Round()
 	cursorPosition := element.valueDrawer.PositionOf(element.cursor)
 	cursorPosition.X -= element.scroll
@@ -272,7 +272,7 @@ func (element *TextBox) scrollToCursor () {
 }
 
 func (element *TextBox) draw () {
-	bounds := element.core.Bounds()
+	bounds := element.Bounds()
 
 	// FIXME: take index into account
 	pattern, inset := theme.InputPattern(theme.PatternState {
@@ -280,7 +280,7 @@ func (element *TextBox) draw () {
 		Disabled: !element.Enabled(),
 		Focused:  element.Focused(),
 	})
-	artist.FillRectangle(element.core, pattern, bounds)
+	artist.FillRectangle(element, pattern, bounds)
 
 	if len(element.text) == 0 && !element.Focused() {
 		// draw placeholder
@@ -294,7 +294,7 @@ func (element *TextBox) draw () {
 			Disabled: true,
 		})
 		element.placeholderDrawer.Draw (
-			element.core,
+			element,
 			foreground,
 			offset.Sub(textBounds.Min))
 	} else {
@@ -309,7 +309,7 @@ func (element *TextBox) draw () {
 			Disabled: !element.Enabled(),
 		})
 		element.valueDrawer.Draw (
-			element.core,
+			element,
 			foreground,
 			offset.Sub(textBounds.Min))
 
@@ -321,7 +321,7 @@ func (element *TextBox) draw () {
 				Case: textBoxCase,
 			})
 			artist.Line (
-				element.core,
+				element,
 				foreground, 1,
 				cursorPosition.Add(offset),
 				image.Pt (

elements/core/core.go

@@ -65,6 +65,9 @@ func (core *Core) MinimumSize () (width, height int) {
 // overridden.
 func (core *Core) DrawTo (canvas tomo.Canvas) {
 	core.canvas = canvas
+	if core.drawSizeChange != nil {
+		core.drawSizeChange()
+	}
 }
 
 // OnDamage fulfils the tomo.Element interface. This should not need to be
@@ -84,28 +87,27 @@ func (core *Core) OnMinimumSizeChange (callback func ()) {
 // instead kept as a private member. When a Core struct is created, a
 // corresponding CoreControl struct is linked to it and returned alongside it.
 type CoreControl struct {
-	tomo.BasicCanvas
 	core *Core
 }
 
 // HasImage returns true if the core has an allocated image buffer, and false if
 // it doesn't.
 func (control CoreControl) HasImage () (has bool) {
-	return control.core.canvas != nil
+	return control.core.canvas != nil && !control.core.canvas.Bounds().Empty()
 }
 
 // DamageRegion pushes the selected region of pixels to the parent element. This
 // does not need to be called when responding to a resize event.
 func (control CoreControl) DamageRegion (bounds image.Rectangle) {
 	if control.core.onDamage != nil {
-		control.core.onDamage(tomo.Cut(control, bounds))
+		control.core.onDamage(tomo.Cut(control.core, bounds))
 	}
 }
 
 // DamageAll pushes all pixels to the parent element. This does not need to be
 // called when redrawing in response to a change in size.
 func (control CoreControl) DamageAll () {
-	control.DamageRegion(control.Bounds())
+	control.DamageRegion(control.core.Bounds())
 }
 
 // SetMinimumSize sets the minimum size of this element, notifying the parent

elements/fun/clock.go

@@ -35,7 +35,7 @@ func (element *AnalogClock) SetTime (newTime time.Time) {
 }
 
 func (element *AnalogClock) draw () {
-	bounds := element.core.Bounds()
+	bounds := element.Bounds()
 
 	pattern, inset := theme.SunkenPattern(theme.PatternState {
 		Case: clockCase,
@@ -81,7 +81,7 @@ func (element *AnalogClock) radialLine (
 	outer  float64,
 	radian float64,
 ) {
-	bounds := element.core.Bounds()
+	bounds := element.Bounds()
 	width  := float64(bounds.Dx()) / 2
 	height := float64(bounds.Dy()) / 2
 	min := image.Pt (
@@ -91,5 +91,5 @@ func (element *AnalogClock) radialLine (
 		int(math.Cos(radian) * outer * width + width),
 		int(math.Sin(radian) * outer * height + height))
 	// println(min.String(), max.String())
-	artist.Line(element.core, source, 1, min, max)
+	artist.Line(element, source, 1, min, max)
 }

elements/testing/mouse.go

@@ -29,17 +29,17 @@ func NewMouse () (element *Mouse) {
 func (element *Mouse) draw () {
 	bounds := element.Bounds()
 	pattern, _ := theme.AccentPattern(theme.PatternState { })
-	artist.FillRectangle(element.core, pattern, bounds)
+	artist.FillRectangle(element, pattern, bounds)
 	artist.StrokeRectangle (
-		element.core,
+		element,
 		artist.NewUniform(color.Black), 1,
 		bounds)
 	artist.Line (
-		element.core, artist.NewUniform(color.White), 1,
+		element, artist.NewUniform(color.White), 1,
 		image.Pt(1, 1),
 		image.Pt(bounds.Dx() - 2, bounds.Dy() - 2))
 	artist.Line (
-		element.core, artist.NewUniform(color.White), 1,
+		element, artist.NewUniform(color.White), 1,
 		image.Pt(1, bounds.Dy() - 2),
 		image.Pt(bounds.Dx() - 2, 1))
 }
@@ -53,7 +53,7 @@ func (element *Mouse) HandleMouseUp (x, y int, button tomo.Button) {
 	element.drawing = false
 	mousePos := image.Pt(x, y)
 	element.core.DamageRegion (artist.Line (
-		element.core, element.color, 1,
+		element, element.color, 1,
 		element.lastMousePos, mousePos))
 	element.lastMousePos = mousePos
 }
@@ -62,7 +62,7 @@ func (element *Mouse) HandleMouseMove (x, y int) {
 	if !element.drawing { return }
 	mousePos := image.Pt(x, y)
 	element.core.DamageRegion (artist.Line (
-		element.core, element.color, 1,
+		element, element.color, 1,
 		element.lastMousePos, mousePos))
 	element.lastMousePos = mousePos
 }