From 8560204c3975795e5aa44096adb390b69a2bdaa9 Mon Sep 17 00:00:00 2001
From: Sander Schobers <sander@schobers.eu>
Date: Sun, 17 May 2020 15:30:52 +0200
Subject: [PATCH] Added display move event. - The Allegro (alui) implementation
 only provides emulation of the event (comparing the position every time other
 events are handled).

---
 allg5ui/renderer.go | 15 ++++++++++++++-
 sdlui/renderer.go   |  2 ++
 ui/event.go         |  5 +++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/allg5ui/renderer.go b/allg5ui/renderer.go
index 92b08b3..0c2e71f 100644
--- a/allg5ui/renderer.go
+++ b/allg5ui/renderer.go
@@ -47,7 +47,7 @@ func NewRenderer(w, h int, opts allg5.NewDisplayOptions) (*Renderer, error) {
 	})
 	clean = nil
 
-	return &Renderer{disp, eq, nil, user, &ui.OSResources{}, ui.KeyState{}, ui.KeyModifierNone, ui.MouseCursorDefault}, nil
+	return &Renderer{disp, eq, nil, user, &ui.OSResources{}, dispPos(disp), ui.KeyState{}, ui.KeyModifierNone, ui.MouseCursorDefault}, nil
 }
 
 // Renderer implements ui.Renderer using Allegro 5.
@@ -58,6 +58,7 @@ type Renderer struct {
 	user *allg5.UserEventSource
 	res  ui.Resources
 
+	dispPos   geom.Point
 	keys      ui.KeyState
 	modifiers ui.KeyModifier
 	cursor    ui.MouseCursor
@@ -118,6 +119,13 @@ func (r *Renderer) PushEvents(t ui.EventTarget, wait bool) {
 		}
 		ev = r.eq.Get()
 	}
+	dispPos := dispPos(r.disp)
+	if dispPos != r.dispPos {
+		r.dispPos = dispPos
+		w := r.disp.Width()
+		h := r.disp.Height()
+		t.Handle(&ui.DisplayMoveEvent{Bounds: r.dispPos.RectRel2D(w, h).ToF32()})
+	}
 
 	if !unhandled && cursor != r.cursor {
 		switch r.cursor {
@@ -381,3 +389,8 @@ func newColor(c color.Color) allg5.Color {
 func snap(p geom.PointF32) (float32, float32) {
 	return float32(math.Round(float64(p.X))), float32(math.Round(float64(p.Y)))
 }
+
+func dispPos(disp *allg5.Display) geom.Point {
+	x, y := disp.Position()
+	return geom.Pt(x, y)
+}
diff --git a/sdlui/renderer.go b/sdlui/renderer.go
index 9dafdbb..45c385f 100644
--- a/sdlui/renderer.go
+++ b/sdlui/renderer.go
@@ -120,6 +120,8 @@ func (r *Renderer) PushEvents(t ui.EventTarget, wait bool) {
 			switch e.Event {
 			case sdl.WINDOWEVENT_CLOSE:
 				t.Handle(&ui.DisplayCloseEvent{EventBase: eventBase(e)})
+			case sdl.WINDOWEVENT_MOVED:
+				t.Handle(&ui.DisplayMoveEvent{EventBase: eventBase(e), Bounds: r.WindowBounds()})
 			case sdl.WINDOWEVENT_RESIZED:
 				t.Handle(&ui.DisplayResizeEvent{EventBase: eventBase(e), Bounds: r.WindowBounds()})
 			case sdl.WINDOWEVENT_ENTER:
diff --git a/ui/event.go b/ui/event.go
index 40af5e6..55f38c1 100644
--- a/ui/event.go
+++ b/ui/event.go
@@ -6,6 +6,11 @@ type DisplayCloseEvent struct {
 	EventBase
 }
 
+type DisplayMoveEvent struct {
+	EventBase
+	Bounds geom.RectangleF32
+}
+
 type DisplayResizeEvent struct {
 	EventBase
 	Bounds geom.RectangleF32