From 22caa5e502f50bd399643df28ea127783f0374eb Mon Sep 17 00:00:00 2001
From: Pietro Gagliardi <pietro10@mac.com>
Date: Tue, 25 Oct 2016 00:34:12 -0400
Subject: [PATCH] Implemented the window drag stuff on GTK+. It works!

---
 test/page15.c |  2 +-
 ui.h          |  3 ++
 unix/area.c   | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+), 1 deletion(-)

diff --git a/test/page15.c b/test/page15.c
index 99e402e3..2c9728bf 100644
--- a/test/page15.c
+++ b/test/page15.c
@@ -107,7 +107,7 @@ static void handlerMouseEvent(uiAreaHandler *a, uiArea *area, uiAreaMouseEvent *
 #define resize(cond, edge) if (cond) { uiAreaBeginUserWindowResize(area, edge); return; }
 	resize(ta.leftresize.in, uiWindowResizeEdgeLeft)
 	resize(ta.topresize.in, uiWindowResizeEdgeTop)
-	resize((ta.rightresize.in, uiWindowResizeEdgeRight)
+	resize(ta.rightresize.in, uiWindowResizeEdgeRight)
 	resize(ta.bottomresize.in, uiWindowResizeEdgeBottom)
 	resize(ta.topleftresize.in, uiWindowResizeEdgeTopLeft)
 	resize(ta.toprightresize.in, uiWindowResizeEdgeTopRight)
diff --git a/ui.h b/ui.h
index 9dbc32b6..518d366a 100644
--- a/ui.h
+++ b/ui.h
@@ -301,6 +301,8 @@ _UI_ENUM(uiWindowResizeEdge) {
 	uiWindowResizeEdgeBottomLeft,
 	uiWindowResizeEdgeBottomRight,
 	// TODO have one for keyboard resizes?
+	// TODO GDK doesn't seem to have any others, including for keyboards...
+	// TODO way to bring up the system menu instead?
 };
 
 #define uiArea(this) ((uiArea *) (this))
@@ -312,6 +314,7 @@ _UI_EXTERN void uiAreaQueueRedrawAll(uiArea *a);
 _UI_EXTERN void uiAreaScrollTo(uiArea *a, double x, double y, double width, double height);
 // TODO document these can only be called within Mouse() handlers
 // TODO should these be allowed on scrolling areas?
+// TODO decide which mouse events should be accepted; Down is the only one guaranteed to work right now
 _UI_EXTERN void uiAreaBeginUserWindowMove(uiArea *a);
 _UI_EXTERN void uiAreaBeginUserWindowResize(uiArea *a, uiWindowResizeEdge edge);
 _UI_EXTERN uiArea *uiNewArea(uiAreaHandler *ah);
diff --git a/unix/area.c b/unix/area.c
index c5b490d6..c46447cc 100644
--- a/unix/area.c
+++ b/unix/area.c
@@ -46,6 +46,9 @@ struct uiArea {
 
 	// note that this is a pointer; see above
 	clickCounter *cc;
+
+	// for user window drags
+	GdkEventButton *dragevent;
 };
 
 G_DEFINE_TYPE(areaWidget, areaWidget, GTK_TYPE_DRAWING_AREA)
@@ -261,7 +264,11 @@ static gboolean areaWidget_button_press_event(GtkWidget *w, GdkEventButton *e)
 
 	me.Down = e->button;
 	me.Up = 0;
+
+	// and set things up for window drags
+	a->dragevent = e;
 	finishMouseEvent(a, &me, e->button, e->x, e->y, e->state, e->window);
+	a->dragevent = NULL;
 	return GDK_EVENT_PROPAGATE;
 }
 
@@ -505,6 +512,76 @@ void uiAreaScrollTo(uiArea *a, double x, double y, double width, double height)
 	// TODO adjust adjustments and find source for that
 }
 
+void uiAreaBeginUserWindowMove(uiArea *a)
+{
+	GtkWidget *toplevel;
+
+	if (a->dragevent == NULL)
+		userbug("cannot call uiAreaBeginUserWindowMove() outside of a Mouse() with Down != 0");
+	// TODO don't we have a libui function for this? did I scrap it?
+	// TODO widget or areaWidget?
+	toplevel = gtk_widget_get_toplevel(a->widget);
+	if (toplevel == NULL) {
+		// TODO
+		return;
+	}
+	// the docs say to do this
+	if (!gtk_widget_is_toplevel(toplevel)) {
+		// TODO
+		return;
+	}
+	if (!GTK_IS_WINDOW(toplevel)) {
+		// TODO
+		return;
+	}
+	gtk_window_begin_move_drag(GTK_WINDOW(toplevel),
+		a->dragevent->button,
+		a->dragevent->x_root,		// TODO are these correct?
+		a->dragevent->y_root,
+		a->dragevent->time);
+}
+
+static const GdkWindowEdge edges[] = {
+	[uiWindowResizeEdgeLeft] = GDK_WINDOW_EDGE_WEST,
+	[uiWindowResizeEdgeTop] = GDK_WINDOW_EDGE_NORTH,
+	[uiWindowResizeEdgeRight] = GDK_WINDOW_EDGE_EAST,
+	[uiWindowResizeEdgeBottom] = GDK_WINDOW_EDGE_SOUTH,
+	[uiWindowResizeEdgeTopLeft] = GDK_WINDOW_EDGE_NORTH_WEST,
+	[uiWindowResizeEdgeTopRight] = GDK_WINDOW_EDGE_NORTH_EAST,
+	[uiWindowResizeEdgeBottomLeft] = GDK_WINDOW_EDGE_SOUTH_WEST,
+	[uiWindowResizeEdgeBottomRight] = GDK_WINDOW_EDGE_SOUTH_EAST,
+};
+
+void uiAreaBeginUserWindowResize(uiArea *a, uiWindowResizeEdge edge)
+{
+	GtkWidget *toplevel;
+
+	if (a->dragevent == NULL)
+		userbug("cannot call uiAreaBeginUserWindowResize() outside of a Mouse() with Down != 0");
+	// TODO don't we have a libui function for this? did I scrap it?
+	// TODO widget or areaWidget?
+	toplevel = gtk_widget_get_toplevel(a->widget);
+	if (toplevel == NULL) {
+		// TODO
+		return;
+	}
+	// the docs say to do this
+	if (!gtk_widget_is_toplevel(toplevel)) {
+		// TODO
+		return;
+	}
+	if (!GTK_IS_WINDOW(toplevel)) {
+		// TODO
+		return;
+	}
+	gtk_window_begin_resize_drag(GTK_WINDOW(toplevel),
+		edges[edge],
+		a->dragevent->button,
+		a->dragevent->x_root,		// TODO are these correct?
+		a->dragevent->y_root,
+		a->dragevent->time);
+}
+
 uiArea *uiNewArea(uiAreaHandler *ah)
 {
 	uiArea *a;