Multi-window support

examples/hello-world/hello-world.go

@@ -14,8 +14,23 @@ func main() {
 		counter, setCounter := spot.UseState[int](ctx, 0)
 
 		buttonTitle := "Click me!"
+		var window spot.Component
 		if counter > 0 {
 			buttonTitle = fmt.Sprintf("Clicked %d times!", counter)
+			window = &ui.Window{
+				Title:  "Hello World 2",
+				Width:  200,
+				Height: 125,
+				Children: []spot.Component{
+					&ui.Button{
+						X: 25, Y: 50, Width: 150, Height: 25,
+						Title: "Close",
+						OnClick: func() {
+							setCounter(0)
+						},
+					},
+				},
+			}
 		}
 
 		return &ui.Window{
@@ -30,6 +45,7 @@ func main() {
 						setCounter(counter + 1)
 					},
 				},
+				window,
 			},
 		}
 	})

nodes.go

@@ -1,5 +1,7 @@
 package spot
 
+import "fmt"
+
 type Node struct {
 	Content  Control
 	Children []Node
@@ -11,40 +13,54 @@ func (n Node) Mount() {
 
 func (n Node) mount(parent Control) {
 	if n.Content != nil {
+		fmt.Printf("Mounting %T[%p]\n", n.Content, n.Content)
 		n.Content.Mount(parent)
 	}
 	for _, child := range n.Children {
+		fmt.Printf("Mounting child %T[%p] of %T[%p]\n", child.Content, child.Content, n.Content, n.Content)
 		child.mount(n.Content)
 	}
 }
 
-func (n Node) updateChild(idx int, new Control) {
+func (n Node) updateChild(idx int, other Node) {
+	n.Children[idx].Update(other, n.Content)
+	return
+	new := other.Content
+
 	old := n.Children[idx].Content
-	if old == nil && new == nil {
+	oldEmpty := isEmpty(old)
+	newEmpty := isEmpty(new)
+
+	fmt.Printf("Updating child #%d, %T[%p] <- %T[%p]\n", idx, old, old, new, new)
+	if oldEmpty && newEmpty {
+		fmt.Println("Both empty, nothing to do")
 		return
 	}
 
-	if old != nil && new == nil {
+	if !oldEmpty && newEmpty {
+		fmt.Println("Unmounting old child")
 		if unmountable, ok := old.(Unmountable); ok {
 			unmountable.Unmount()
 		}
 		n.Children[idx].Content = nil
 		return
 	}
 
-	if old == nil && new != nil {
+	if oldEmpty && !newEmpty {
+		fmt.Println("Mounting new child")
 		n.Children[idx].Content = new
-		new.Mount(n.Content)
+		n.Children[idx].mount(n.Content)
 		return
 	}
 
+	fmt.Println("Updating child")
 	ok := old.Update(new)
 	if !ok {
 		if unmountable, ok := old.(Unmountable); ok {
 			unmountable.Unmount()
 		}
 		n.Children[idx].Content = new
-		new.Mount(n.Content)
+		n.Children[idx].mount(n.Content)
 	}
 }
 
@@ -55,31 +71,47 @@ func (n Node) Update(other Node, parent Control) {
 		}
 		n.Content = nil
 	} else if n.Content == nil && other.Content != nil {
+		fmt.Printf("Will replace %T[%p] with %T[%p]\n", n.Content, n.Content, other.Content, other.Content)
 		n.Content = other.Content
-		n.Content.Mount(parent)
+		fmt.Printf("Mounting new Node %T[%p] with parent %T[%p])\n", n.Content, n.Content, parent, parent)
+		n.mount(parent)
 	} else if n.Content != nil && other.Content != nil {
+		fmt.Printf("Will update %T[%p] with new data\n", n.Content, n.Content)
 		ok := n.Content.Update(other.Content)
+		fmt.Printf("Update returned %v\n", ok)
 		if !ok {
 			if unmountable, ok := n.Content.(Unmountable); ok {
 				unmountable.Unmount()
 			}
 			n.Content = other.Content
-			n.Content.Mount(parent)
+			n.mount(parent)
 		}
 	}
 
 	if len(n.Children) != len(other.Children) {
 		for idx := range n.Children {
-			n.updateChild(idx, nil)
+			n.updateChild(idx, Node{})
 		}
 		n.Children = make([]Node, len(other.Children))
 		for idx := range n.Children {
-			n.updateChild(idx, other.Children[idx].Content)
+			n.updateChild(idx, other.Children[idx])
 		}
 		return
 	}
 
 	for idx := range n.Children {
-		n.updateChild(idx, other.Children[idx].Content)
+		n.updateChild(idx, other.Children[idx])
+	}
+}
+
+func (n Node) Unmount() {
+	for _, child := range n.Children {
+		child.Unmount()
+	}
+
+	if n.Content != nil {
+		if unmountable, ok := n.Content.(Unmountable); ok {
+			unmountable.Unmount()
+		}
 	}
 }

rendercontext.go

@@ -2,6 +2,7 @@ package spot
 
 import (
 	"fmt"
+	"reflect"
 	"strings"
 	"sync"
 )
@@ -14,10 +15,28 @@ type RenderContext struct {
 	mutex   sync.Mutex
 }
 
+// I love you, Go, but I hate you.
+func isEmpty(component Component) bool {
+	if component == nil {
+		return true
+	}
+
+	v := reflect.ValueOf(component)
+	k := v.Kind()
+	switch k {
+	case reflect.Chan, reflect.Func, reflect.Map, reflect.Pointer,
+		reflect.UnsafePointer, reflect.Interface, reflect.Slice:
+		return v.IsNil()
+	}
+
+	return false
+}
+
 // BuildNode recursively renders a component and its children into a tree
 // of UI controls.
 func (ctx *RenderContext) BuildNode(component Component) Node {
-	if component == nil {
+	fmt.Printf("[%p] Building node for component %T\n", ctx, component)
+	if isEmpty(component) {
 		return Node{}
 	}
 
@@ -38,7 +57,8 @@ func (ctx *RenderContext) BuildNode(component Component) Node {
 		return Node{Children: list}
 	}
 
-	if container, ok := component.(Container); ok {
+	if container, ok := component.(Container); ok && container != nil {
+		fmt.Println("It's a container!")
 		return container.BuildNode(ctx)
 	}
 

ui/button_test.go

@@ -0,0 +1,26 @@
+package ui
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/roblillack/spot"
+)
+
+func BenchmarkMeaninglessUpdates(b *testing.B) {
+	node := spot.Build(&Button{})
+	node.Mount()
+
+	for i := 0; i < b.N; i++ {
+		node.Update(spot.Build(&Button{}), nil)
+	}
+}
+
+func BenchmarkSimpleUpdates(b *testing.B) {
+	node := spot.Build(&Button{})
+	node.Mount()
+
+	for i := 0; i < b.N; i++ {
+		node.Update(spot.Build(&Button{Title: fmt.Sprintf("%d", i)}), nil)
+	}
+}

ui/window.go

@@ -1,6 +1,10 @@
 package ui
 
-import "github.com/roblillack/spot"
+import (
+	"fmt"
+
+	"github.com/roblillack/spot"
+)
 
 type Window struct {
 	Title     string
@@ -20,6 +24,7 @@ func (c *Window) Render(ctx *spot.RenderContext) spot.Component {
 }
 
 func (w *Window) BuildNode(ctx *spot.RenderContext) spot.Node {
+	fmt.Printf("Building %T[%p] for ctx %p\n", w, w, ctx)
 	kids := []spot.Node{}
 	for _, child := range w.Children {
 		kid := ctx.BuildNode(child)

ui/window_fltk.go

@@ -50,3 +50,11 @@ func (w *Window) Mount(parent spot.Control) any {
 	w.ref.Show()
 	return w.ref
 }
+
+func (w *Window) Unmount() {
+	if w.ref != nil {
+		w.ref.Hide()
+		w.ref.Destroy()
+		w.ref = nil
+	}
+}