elements/basic/container.go

@@ -59,8 +59,6 @@ func (element *Container) Adopt (child tomo.Element, expand bool) {
 		child0.OnSelectionRequest (func () (granted bool) {
 			return element.childSelectionRequestCallback(child0)
 		})
-	}
-	if child0, ok := child.(tomo.Selectable); ok {
 		child0.OnSelectionMotionRequest (
 			func (direction tomo.SelectionDirection) (granted bool) {
 				if element.onSelectionMotionRequest == nil { return }

elements/basic/scrollcontainer.go

@@ -24,7 +24,8 @@ type ScrollContainer struct {
 		bounds image.Rectangle
 	}
 
-	// TODO event handlers
+	onSelectionRequest func () (granted bool)
+	onSelectionMotionRequest func (tomo.SelectionDirection) (granted bool)
 }
 
 // NewScrollContainer creates a new scroll container with the specified scroll
@@ -60,12 +61,14 @@ func (element *ScrollContainer) Adopt (child tomo.Scrollable) {
 	// adopt new child
 	element.child = child
 	if child != nil {
-		// child.SetParentHooks (tomo.ParentHooks {
-			// Draw: window.childDrawCallback,
-			// MinimumSizeChange: window.childMinimumSizeChangeCallback,
-			// FlexibleHeightChange: window.resizeChildToFit,
-			// SelectionRequest: window.childSelectionRequestCallback,
-		// })
+		child.OnDamage(element.childDamageCallback)
+		child.OnMinimumSizeChange(element.updateMinimumSize)
+		if newChild, ok := child.(tomo.Selectable); ok {
+			newChild.OnSelectionRequest (
+				element.childSelectionRequestCallback)
+			newChild.OnSelectionMotionRequest (
+				element.childSelectionMotionRequestCallback)
+		}
 
 		// TODO: somehow inform the core that we do not in fact want to
 		// redraw the element.
@@ -81,6 +84,89 @@ func (element *ScrollContainer) Adopt (child tomo.Scrollable) {
 	}
 }
 
+func (element *ScrollContainer) HandleKeyDown (
+	key tomo.Key,
+	modifiers tomo.Modifiers,
+	repeated bool,
+) {
+	if child, ok := element.child.(tomo.KeyboardTarget); ok {
+		child.HandleKeyDown(key, modifiers, repeated)
+	}
+}
+
+func (element *ScrollContainer) HandleKeyUp (key tomo.Key, modifiers tomo.Modifiers) {
+	if child, ok := element.child.(tomo.KeyboardTarget); ok {
+		child.HandleKeyUp(key, modifiers)
+	}
+}
+
+func (element *ScrollContainer) Selected () (selected bool) {
+	return element.selected
+}
+
+func (element *ScrollContainer) Select () {
+	if element.onSelectionRequest != nil {
+		element.onSelectionRequest()
+	}
+}
+
+func (element *ScrollContainer) HandleSelection (
+	direction tomo.SelectionDirection,
+) (
+	accepted bool,
+) {
+	if child, ok := element.child.(tomo.Selectable); ok {
+		element.selected = true
+		return child.HandleSelection(direction)
+	} else {
+		element.selected = false
+		return false
+	}
+}
+
+func (element *ScrollContainer) HandleDeselection () {
+	if child, ok := element.child.(tomo.Selectable); ok {
+		child.HandleDeselection()
+	}
+	element.selected = false
+}
+
+func (element *ScrollContainer) OnSelectionRequest (callback func () (granted bool)) {
+	element.onSelectionRequest = callback
+}
+
+func (element *ScrollContainer) OnSelectionMotionRequest (
+	callback func (direction tomo.SelectionDirection) (granted bool),
+) {
+	element.onSelectionMotionRequest = callback
+}
+
+func (element *ScrollContainer) childDamageCallback (region tomo.Canvas) {
+	element.core.DamageRegion(artist.Paste(element, region, image.Point { }))
+}
+
+func (element *ScrollContainer) childSelectionRequestCallback () (granted bool) {
+	child, ok := element.child.(tomo.Selectable)
+	if !ok { return false }
+	if element.onSelectionRequest != nil && element.onSelectionRequest() {
+		child.HandleSelection(tomo.SelectionDirectionNeutral)
+		return true
+	} else {
+		return false
+	}
+}
+
+func (element *ScrollContainer) childSelectionMotionRequestCallback (
+	direction tomo.SelectionDirection,
+) (
+	granted bool,
+) {
+	if element.onSelectionMotionRequest == nil {
+		 return
+	}
+	return element.onSelectionMotionRequest(direction)
+}
+
 func (element *ScrollContainer) clearChildEventHandlers (child tomo.Element) {
 	child.OnDamage(nil)
 	child.OnMinimumSizeChange(nil)

elements/basic/textbox.go

@@ -273,6 +273,10 @@ func (element *TextBox) ScrollAxes () (horizontal, vertical bool) {
 	return true, false
 }
 
+func (element *TextBox) OnScrollBoundsChange (callback func ()) {
+	element.onScrollBoundsChange = callback
+}
+
 func (element *TextBox) updateMinimumSize () {
 	textBounds := element.placeholderDrawer.LayoutBounds()
 	element.core.SetMinimumSize (