Added changing the mouse cursor.

allg5/display.go

@@ -78,6 +78,10 @@ func (d *Display) SetIcon(i *Bitmap) {
 	C.al_set_display_icon(d.display, i.bitmap)
 }
 
+func (d *Display) SetMouseCursor(c MouseCursor) {
+	C.al_set_system_mouse_cursor(d.display, C.ALLEGRO_SYSTEM_MOUSE_CURSOR(c))
+}
+
 func (d *Display) SetMousePosition(x, y int) {
 	C.al_set_mouse_xy(d.display, C.int(x), C.int(y))
 }

allg5/mouse.go

@@ -11,6 +11,31 @@ const (
 	MouseButtonMiddle             = 3
 )
 
+type MouseCursor uint
+
+const (
+	MouseCursorNone        MouseCursor = 0
+	MouseCursorDefault                 = 1
+	MouseCursorArrow                   = 2
+	MouseCursorBusy                    = 3
+	MouseCursorQuestion                = 4
+	MouseCursorEdit                    = 5
+	MouseCursorMove                    = 6
+	MouseCursorResizeN                 = 7
+	MouseCursorResizeW                 = 8
+	MouseCursorResizeS                 = 9
+	MouseCursorResizeE                 = 10
+	MouseCursorResizeNW                = 11
+	MouseCursorResizeSW                = 12
+	MouseCursorResizeSE                = 13
+	MouseCursorResizeNE                = 14
+	MouseCursorProgress                = 15
+	MouseCursorPrecision               = 16
+	MouseCursorLink                    = 17
+	MouseCursorAltSelect               = 18
+	MouseCursorUnavailable             = 19
+)
+
 func IsMouseButtonDown(b MouseButton) bool {
 	var state C.ALLEGRO_MOUSE_STATE
 	C.al_get_mouse_state(&state)

ui/allg5ui/renderer.go

@@ -34,15 +34,17 @@ func NewRenderer(w, h int, opts allg5.NewDisplayOptions) (*Renderer, error) {
 	eq.RegisterDisplay(disp)
 	eq.RegisterUserEvents(user)
 
-	return &Renderer{disp, eq, map[string]*font{}, user}, nil
+	return &Renderer{disp, eq, map[string]*font{}, user, ui.MouseCursorDefault, ui.MouseCursorDefault}, nil
 }
 
 // Renderer implements ui.Renderer using Allegro 5.
 type Renderer struct {
-	disp *allg5.Display
-	eq   *allg5.EventQueue
-	ft   map[string]*font
-	user *allg5.UserEventSource
+	disp      *allg5.Display
+	eq        *allg5.EventQueue
+	ft        map[string]*font
+	user      *allg5.UserEventSource
+	cursor    ui.MouseCursor
+	newCursor ui.MouseCursor
 }
 
 // Renderer implementation (events)
@@ -50,6 +52,7 @@ type Renderer struct {
 func (r *Renderer) PushEvents(t ui.EventTarget, wait bool) {
 	r.disp.Flip()
 
+	r.newCursor = ui.MouseCursorDefault
 	var ev = eventWait(r.eq, wait)
 	for nil != ev {
 		switch e := ev.(type) {
@@ -68,6 +71,22 @@ func (r *Renderer) PushEvents(t ui.EventTarget, wait bool) {
 		}
 		ev = r.eq.Get()
 	}
+
+	if r.newCursor != r.cursor {
+		r.cursor = r.newCursor
+		switch r.cursor {
+		case ui.MouseCursorNone:
+			r.disp.SetMouseCursor(allg5.MouseCursorNone)
+		case ui.MouseCursorDefault:
+			r.disp.SetMouseCursor(allg5.MouseCursorDefault)
+		case ui.MouseCursorNotAllowed:
+			r.disp.SetMouseCursor(allg5.MouseCursorUnavailable)
+		case ui.MouseCursorPointer:
+			r.disp.SetMouseCursor(allg5.MouseCursorLink)
+		case ui.MouseCursorText:
+			r.disp.SetMouseCursor(allg5.MouseCursorEdit)
+		}
+	}
 }
 
 func (r *Renderer) Refresh() {
@@ -183,6 +202,10 @@ func (r *Renderer) SetIcon(im ui.Image) {
 	r.disp.SetIcon(bmp)
 }
 
+func (r *Renderer) SetMouseCursor(c ui.MouseCursor) {
+	r.newCursor = c
+}
+
 func (r *Renderer) SetWindowTitle(t string) {
 	r.disp.SetWindowTitle(t)
 }

ui/button.go

@@ -25,6 +25,13 @@ func (b *Button) DesiredSize(ctx Context) geom.PointF32 {
 	return geom.PtF32(width+pad*2, height+pad*2)
 }
 
+func (b *Button) Handle(ctx Context, e Event) {
+	b.ControlBase.Handle(ctx, e)
+	if b.over {
+		ctx.Renderer().SetMouseCursor(MouseCursorPointer)
+	}
+}
+
 func (b *Button) Render(ctx Context) {
 	var fore = b.FontColor
 	var style = ctx.Style()

ui/mouse.go

@@ -0,0 +1,11 @@
+package ui
+
+type MouseCursor int
+
+const (
+	MouseCursorNone MouseCursor = iota
+	MouseCursorDefault
+	MouseCursorNotAllowed
+	MouseCursorPointer
+	MouseCursorText
+)

ui/renderer.go

@@ -27,6 +27,7 @@ type Renderer interface {
 	Rectangle(r geom.RectangleF32, c color.Color, thickness float32)
 	RenderTo(Image)
 	RenderToDisplay()
+	SetMouseCursor(c MouseCursor)
 	Size() geom.PointF32
 	Target() Image
 	Text(p geom.PointF32, font string, color color.Color, text string)