Labels may request an expanding height change

elements/basic/label.go

@@ -27,6 +27,7 @@ func NewLabel (text string, wrap bool) (element *Label) {
 	return
 }
 
+// Resize resizes the label and re-wraps the text if wrapping is enabled.
 func (element *Label) Resize (width, height int) {
 	element.core.AllocateCanvas(width, height)
 	if element.wrap {
@@ -37,6 +38,17 @@ func (element *Label) Resize (width, height int) {
 	return
 }
 
+// MinimumHeightFor returns the reccomended height for this element based on the
+// given width in order to allow the text to wrap properly.
+func (element *Label) MinimumHeightFor (width int) (height int) {
+	if element.wrap {
+		return element.drawer.ReccomendedHeightFor(width)
+	} else {
+		_, height = element.MinimumSize()
+		return
+	}
+}
+
 // SetText sets the label's text.
 func (element *Label) SetText (text string) {
 	if element.text == text { return }
@@ -76,6 +88,7 @@ func (element *Label) updateMinimumSize () {
 		if em < 1 { em = theme.Padding() }
 		element.core.SetMinimumSize (
 			em, element.drawer.LineHeight().Round())
+		element.core.NotifyExpandingHeightChange()
 	} else {
 		bounds := element.drawer.LayoutBounds()
 		element.core.SetMinimumSize(bounds.Dx(), bounds.Dy())

elements/core/core.go

@@ -144,6 +144,12 @@ func (control CoreControl) SetMinimumSize (width, height int) {
 	}
 }
 
+// NotifyExpandingHeightChange notifies the parent element that this element's
+// expanding height has changed.
+func (control CoreControl) NotifyExpandingHeightChange () {
+	control.core.hooks.RunExpandingHeightChange()
+}
+
 // ConstrainSize contstrains the specified width and height to the minimum width
 // and height, and returns wether or not anything ended up being constrained.
 func (control CoreControl) ConstrainSize (