1 files changed, 138 insertions, 15 deletions

diff --git a/go/ui/collection.go b/go/ui/collection.go
index 58cc4b85..bb7a4d53 100644
--- a/go/ui/collection.go
+++ b/go/ui/collection.go
@@ -8,10 +8,14 @@ import (
 	"golang.org/x/exp/slices"
 )
 
+// Container to organise multiple Widgets
+// A collection does implement the Widget interface and thus can be nested in
+// another Collection.
 type Collection struct {
 	Width, Height int
 	hoverDetector hoverDetector
 	widgets       []Widget
+	focused       Widget
 }
 
 func (c *Collection) Layout() (int, int) {
@@ -69,10 +73,17 @@ func (c *Collection) Draw(screen *ebiten.Image) {
 	}
 }
 
-func (c *Collection) Update() error {
-	x, y := ebiten.CursorPosition()
+func (c *Collection) Contains(x, y int) bool {
+	for _, w := range c.widgets {
+		if w.Contains(x, y) {
+			return true
+		}
+	}
+	return false
+}
+
+func (c *Collection) FindWidgetAt(x, y int) Widget {
 
-	var activeWidget Widget
 	// Iterate the widget in reverse order to ensure that upper widgets are
 	// considered first
 	for i := len(c.widgets) - 1; i >= 0; i-- {
@@ -80,37 +91,149 @@ func (c *Collection) Update() error {
 		if !w.Contains(x, y) {
 			continue
 		}
-		activeWidget = w
-		break
+		return w
+	}
+	return nil
+}
+
+func (c *Collection) FindObjectAt(x, y int) interface{} {
+
+	// Iterate the widget in reverse order to ensure that upper widgets are
+	// considered first
+	for i := len(c.widgets) - 1; i >= 0; i-- {
+		w := c.widgets[i]
+		if o := w.FindObjectAt(x, y); o != nil {
+			return o
+		}
+	}
+
+	return nil
+}
+
+func (c *Collection) switchFocus(fcsbl Widget) {
+	log.Printf("switch focus from %v to %v\n", c.focused, fcsbl)
+	if c.focused != nil {
+		c.focused.Focus(false)
+
+	}
+	if fcsbl != nil {
+		fcsbl.Focus(true)
+		c.focused = fcsbl
+	} else {
+		c.focused = nil
+	}
+}
+
+func (c *Collection) handleTouchInputs() error {
+	for _, tap := range TouchManager.Taps {
+		for i := len(c.widgets) - 1; i >= 0; i-- {
+			w := c.widgets[i]
+			if !w.Contains(tap.X, tap.Y) {
+				continue
+			}
+			if w.IsClickable() {
+				w.Click(tap.X, tap.Y)
+			}
+			if w.IsFocusable() {
+				c.switchFocus(w)
+			} else if c.focused != nil {
+				c.switchFocus(nil)
+			}
+			break
+		}
+	}
+
+	// TODO: handle pinching
+	if TouchManager.Pan != nil {
+		pan := TouchManager.Pan
+		iX, iY := pan.Incremental()
+
+		w := c.FindWidgetAt(int(pan.originX), (pan.originY))
+		if w != nil && w.IsScrollable() {
+			w.Scroll(int(iX)/10, int(iY)/10)
+		}
 	}
 
+	return nil
+}
+
+func passInput(textInput *TextInput) {
+	var input []rune
+	input = ebiten.AppendInputChars(input)
+	if len(input) > 0 {
+		textInput.AddInput(input)
+	}
+	textInput.HandleKey()
+}
+
+func (c *Collection) IsUpdatable() bool {
+	return true
+}
+
+func (c *Collection) Update() error {
+	// Update all updatables
+	for _, w := range c.widgets {
+		if w.IsUpdatable() {
+			if err := w.Update(); err != nil {
+				return err
+			}
+		}
+	}
+
+	if err := c.handleTouchInputs(); err != nil {
+		return err
+	}
+
+	x, y := ebiten.CursorPosition()
+
+	activeWidget := c.FindWidgetAt(x, y)
+
 	c.hoverDetector.update(c, x, y, activeWidget)
 
 	if activeWidget == nil {
+		if txt, ok := c.focused.(*TextInput); ok {
+			if ebiten.IsKeyPressed(ebiten.KeyA) {
+				txt.AddInput([]rune{'a'})
+			}
+			passInput(txt)
+		}
 		return nil
 	}
 
 	scrollX, scrollY := ebiten.Wheel()
 	if scrollX != 0 || scrollY != 0 {
-		if scrollable, ok := activeWidget.(Scrollable); ok {
-			scrollable.Scroll(int(scrollX), int(scrollY))
+		if activeWidget.IsScrollable() {
+			activeWidget.Scroll(int(scrollX), int(scrollY))
 		}
 	}
 
 	if textInput, ok := activeWidget.(*TextInput); ok {
-		var input []rune
-		input = ebiten.AppendInputChars(input)
-		if len(input) > 0 {
-			textInput.AddInput(input)
-		}
-		textInput.HandleKey()
+		passInput(textInput)
 	}
 
 	if inpututil.IsMouseButtonJustPressed(ebiten.MouseButtonLeft) {
-		if btn, ok := activeWidget.(Clickable); ok {
-			btn.Click(x, y)
+		if activeWidget.IsClickable() {
+			activeWidget.Click(x, y)
 		}
 	}
 
 	return nil
 }
+
+// The events for the contained widgets
+// are emitted during the collections
+// Update method.
+func (c *Collection) IsClickable() bool {
+	return false
+}
+func (c *Collection) Click(int, int) {}
+
+func (c *Collection) IsScrollable() bool {
+	return false
+}
+func (c *Collection) Scroll(int, int) {}
+
+func (c *Collection) IsFocusable() bool {
+	return false
+}
+func (c *Collection) Focus(bool) {}