Add recommended sizes and all that jazz

internal/system/box.go

@@ -128,6 +128,15 @@ func (this *box) borderSum () tomo.Inset {
 	return sum
 }
 
+func (this *box) borderAndPaddingSum () tomo.Inset {
+	sum := this.borderSum()
+	sum[0] += this.padding[0]
+	sum[1] += this.padding[1]
+	sum[2] += this.padding[2]
+	sum[3] += this.padding[3]
+	return sum
+}
+
 func (this *box) SetBounds (bounds image.Rectangle) {
 	if this.bounds == bounds { return }
 	this.bounds = bounds

internal/system/containerbox.go

@@ -73,6 +73,24 @@ func (this *containerBox) ScrollTo (point image.Point) {
 	this.invalidateLayout()
 }
 
+func (this *containerBox) RecommendedHeight (width int) int {
+	if this.layout == nil {
+		return this.MinimumSize().Y
+	} else {
+		return this.layout.RecommendedHeight(this.layoutHints(), this.children, width) +
+			this.borderAndPaddingSum().Vertical()
+	}
+}
+
+func (this *containerBox) RecommendedWidth (height int) int {
+	if this.layout == nil {
+		return this.MinimumSize().X
+	} else {
+		return this.layout.RecommendedWidth(this.layoutHints(), this.children, height) +
+			this.borderAndPaddingSum().Horizontal()
+	}
+}
+
 func (this *containerBox) OnContentBoundsChange (callback func()) event.Cookie {
 	return this.on.contentBoundsChange.Connect(callback)
 }

internal/system/textbox.go

@@ -65,6 +65,15 @@ func (this *textBox) ScrollTo (point image.Point) {
 	this.invalidateLayout()
 }
 
+func (this *textBox) RecommendedHeight (width int) int {
+	return this.drawer.ReccomendedHeightFor(width) + this.borderAndPaddingSum().Vertical()
+}
+
+func (this *textBox) RecommendedWidth (height int) int {
+	// TODO maybe not the best idea?
+	return this.MinimumSize().X
+}
+
 func (this *textBox) OnContentBoundsChange (callback func()) event.Cookie {
 	return this.on.contentBoundsChange.Connect(callback)
 }