diff --git a/include/QF/ui/canvas.h b/include/QF/ui/canvas.h
index 091b3465d..5ee3e8359 100644
--- a/include/QF/ui/canvas.h
+++ b/include/QF/ui/canvas.h
@@ -81,8 +81,19 @@ typedef struct canvas_system_s {
 struct view_s;
 struct view_pos_s;
 
-typedef void (*canvas_update_f) (struct view_s);
-typedef void (*canvas_func_f) (struct view_pos_s, struct view_pos_s);
+typedef void (*canvas_update_f) (struct view_s, void *data);
+typedef void (*canvas_func_f) (struct view_pos_s, struct view_pos_s,
+							   void *data);
+
+typedef struct canvas_update_s {
+	canvas_update_f update;
+	void       *data;
+} canvas_update_t;
+
+typedef struct canvas_func_s {
+	canvas_func_f func;
+	void       *data;
+} canvas_func_t;
 
 typedef struct canvas_subpic_s {
 	struct qpic_s *pic;
diff --git a/libs/client/cl_screen.c b/libs/client/cl_screen.c
index b46c60bec..d306e9038 100644
--- a/libs/client/cl_screen.c
+++ b/libs/client/cl_screen.c
@@ -134,23 +134,24 @@ clscr_set_cachepic (view_t view, const char *name)
 static void
 clscr_set_canvas_func (view_t view, canvas_func_f func)
 {
-	Ent_SetComponent (view.id, cl_canvas_sys.base + canvas_func, view.reg, &func);
+	Ent_SetComponent (view.id, cl_canvas_sys.base + canvas_func, view.reg,
+					  &(canvas_func_t) { .func = func });
 }
 
 static void
-cl_draw_crosshair (view_pos_t abs, view_pos_t len)
+cl_draw_crosshair (view_pos_t abs, view_pos_t len, void *data)
 {
 	r_funcs->Draw_Crosshair ();
 }
 
 static void
-cl_draw_centerprint (view_pos_t abs, view_pos_t len)
+cl_draw_centerprint (view_pos_t abs, view_pos_t len, void *data)
 {
 	Sbar_DrawCenterPrint ();
 }
 
 static void
-SCR_CShift (view_pos_t abs, view_pos_t len)
+SCR_CShift (view_pos_t abs, view_pos_t len, void *data)
 {
 	mleaf_t    *leaf;
 	int         contents = CONTENTS_EMPTY;
@@ -229,6 +230,18 @@ cl_vidsize_listener (void *data, const viddef_t *vdef)
 	cl_set_size ();
 }
 
+static void
+cl_timegraph (view_pos_t abs, view_pos_t len, void *data)
+{
+	R_TimeGraph (abs, len);
+}
+
+static void
+cl_zgraph (view_pos_t abs, view_pos_t len, void *data)
+{
+	R_ZGraph (abs, len);
+}
+
 static void
 cl_create_views (void)
 {
@@ -249,11 +262,11 @@ cl_create_views (void)
 	clscr_set_pic (net_view, pic);
 
 	timegraph_view = clscr_view (0, 0, vid->width, 100, grav_southwest);
-	clscr_set_canvas_func (timegraph_view, R_TimeGraph);
+	clscr_set_canvas_func (timegraph_view, cl_timegraph);
 	View_SetVisible (timegraph_view, r_timegraph);
 
 	zgraph_view = clscr_view (0, 0, vid->width, 100, grav_southwest);
-	clscr_set_canvas_func (zgraph_view, R_ZGraph);
+	clscr_set_canvas_func (zgraph_view, cl_zgraph);
 	View_SetVisible (zgraph_view, r_zgraph);
 
 	name = "gfx/loading.lmp";
diff --git a/libs/client/hud.c b/libs/client/hud.c
index 5edb06296..a183a76d2 100644
--- a/libs/client/hud.c
+++ b/libs/client/hud.c
@@ -309,7 +309,8 @@ sbar_remcomponent (view_t view, uint32_t comp)
 static inline void
 set_update (view_t view, canvas_update_f func)
 {
-	sbar_setcomponent (view, canvas_updateonce, &func);
+	sbar_setcomponent (view, canvas_updateonce,
+					   &(canvas_update_t) { .update = func });
 }
 
 #define STAT_MINUS		10			// num frame for '-' stats digit
@@ -585,7 +586,7 @@ draw_smallnum (view_t view, int n, int packed, int colored)
 }
 
 static void
-draw_miniammo (view_t view)
+draw_miniammo (view_t view, void *data)
 {
 	int         i, count;
 
@@ -598,7 +599,7 @@ draw_miniammo (view_t view)
 }
 
 static void
-draw_ammo (view_t view)
+draw_ammo (view_t view, void *data)
 {
 	qpic_t     *pic = 0;
 	if (sb_game) {
@@ -662,7 +663,7 @@ calc_flashon (float time, int mask, int base)
 }
 
 static void
-draw_weapons (view_t view)
+draw_weapons (view_t view, void *data)
 {
 	int         flashon, i;
 	static byte view_map[2][12] = {
@@ -705,7 +706,7 @@ draw_weapons (view_t view)
 }
 
 static void
-draw_items (view_t view)
+draw_items (view_t view, void *data)
 {
 	static byte ind_map[2][8] = {
 		{ 17, 18, 19, 20, 21, 22, 25, 26 },	// id/hipnotic
@@ -727,7 +728,7 @@ draw_items (view_t view)
 }
 
 static void
-draw_sigils (view_t view)
+draw_sigils (view_t view, void *data)
 {
 	for (int i = 0; i < 4; i++) {
 		view_t      sigil = View_GetChild (view, i);
@@ -934,7 +935,8 @@ set_frags_bar (view_t view, byte top, byte bottom, draw_charbuffer_t *buff,
 	sbar_setcomponent (View_GetChild (view, 1), canvas_fill, &bottom);
 	sbar_setcomponent (View_GetChild (view, 2), canvas_charbuff, &buff);
 	if (func) {
-		sbar_setcomponent (View_GetChild (view, 3), canvas_func, &func);
+		sbar_setcomponent (View_GetChild (view, 3), canvas_func,
+						   &(canvas_func_t) { .func = func });
 	} else {
 		sbar_remcomponent (View_GetChild (view, 3), canvas_func);
 	}
@@ -958,14 +960,14 @@ set_minifrags_bar (view_t view, byte top, byte bottom, draw_charbuffer_t *buff,
 }
 
 static void
-frags_marker (view_pos_t pos, view_pos_t len)
+frags_marker (view_pos_t pos, view_pos_t len, void *data)
 {
 	r_funcs->Draw_Character (pos.x, pos.y, 16);
 	r_funcs->Draw_Character (pos.x + len.x - 8, pos.y, 17);
 }
 
 static void
-draw_frags (view_t view)
+draw_frags (view_t view, void *data)
 {
 	if (sbar_maxplayers == 1) {
 		return;
@@ -993,7 +995,7 @@ draw_frags (view_t view)
 }
 
 static void
-draw_minifrags (view_t view)
+draw_minifrags (view_t view, void *data)
 {
 	if (sbar_maxplayers == 1) {
 		return;
@@ -1052,14 +1054,15 @@ set_miniteam_bar (view_t view, draw_charbuffer_t *team,
 	sbar_setcomponent (View_GetChild (view, 0), canvas_charbuff, &team);
 	sbar_setcomponent (View_GetChild (view, 1), canvas_charbuff, &frags);
 	if (func) {
-		sbar_setcomponent (View_GetChild (view, 2), canvas_func, &func);
+		sbar_setcomponent (View_GetChild (view, 2), canvas_func,
+						   &(canvas_func_t) { .func = func });
 	} else {
 		sbar_remcomponent (View_GetChild (view, 2), canvas_func);
 	}
 }
 
 static void
-draw_miniteam (view_t view)
+draw_miniteam (view_t view, void *data)
 {
 	if (!sbar_teamplay) {
 		return;
@@ -1091,7 +1094,7 @@ draw_miniteam (view_t view)
 }
 
 static void
-draw_face (view_t view)
+draw_face (view_t view, void *data)
 {
 	qpic_t     *face;
 
@@ -1132,7 +1135,7 @@ draw_face (view_t view)
 }
 
 static void
-draw_spectator (view_t view)
+draw_spectator (view_t view, void *data)
 {
 	view_t      tracking = View_GetChild (view, 0);
 	view_t      back = View_GetChild (view, 1);
@@ -1162,7 +1165,7 @@ draw_spectator (view_t view)
 }
 
 static void
-hide_spectator (view_t view)
+hide_spectator (view_t view, void *data)
 {
 	for (int i = 0; i < 4; i++) {
 		sbar_remcomponent (View_GetChild (view, i), canvas_charbuff);
@@ -1171,7 +1174,7 @@ hide_spectator (view_t view)
 }
 
 static void
-draw_armor (view_t view)
+draw_armor (view_t view, void *data)
 {
 	view_t      armor = View_GetChild (view, 0);
 	view_t      num[3] = {
@@ -1195,7 +1198,7 @@ draw_armor (view_t view)
 }
 
 static void
-draw_health (view_t view)
+draw_health (view_t view, void *data)
 {
 	view_t      num[3] = {
 		View_GetChild (view, 0),
@@ -1206,7 +1209,7 @@ draw_health (view_t view)
 }
 
 static void
-draw_rogue_ctf_face (view_t view)
+draw_rogue_ctf_face (view_t view, void *data)
 {
 	__auto_type p = &sbar_players[sbar_viewplayer];
 	byte        top = Sbar_ColorForMap (p->topcolor);
@@ -1457,7 +1460,7 @@ dmo_line_type (void)
 }
 
 static void
-draw_deathmatch (view_t view)
+draw_deathmatch (view_t view, void *data)
 {
 	Sbar_SortFrags (0);
 	Sbar_SortTeams ();
@@ -1507,7 +1510,7 @@ draw_status (void )
 
 
 	if (sbar_gametype) {
-		draw_deathmatch (deathmatch_view);
+		draw_deathmatch (deathmatch_view, nullptr);
 	} else {
 		if (sbar_spectator) {
 			if (sbar_autotrack < 0) {
@@ -1624,7 +1627,7 @@ Sbar_LogFrags (double completed_time)
 }
 
 static void
-draw_time (view_t *view)
+draw_time (view_t view, void *data)
 {
 	struct tm  *local = 0;
 	time_t      utc = 0;
@@ -1652,7 +1655,7 @@ draw_time (view_t *view)
 }
 
 static void
-draw_fps (view_t view)
+draw_fps (view_t view, void *data)
 {
 	static char   st[80];
 	double        t;
@@ -1736,20 +1739,20 @@ Sbar_DrawCenterString (view_t view, unsigned remaining)
 }
 
 static void
-clear_views (view_t view)
+clear_views (view_t view, void *data)
 {
 	sbar_remcomponent (view, canvas_cachepic);
 	sbar_remcomponent (view, canvas_pic);
 
 	for (uint32_t i = 0; i < View_ChildCount (view); i++) {
-		clear_views (View_GetChild (view, i));
+		clear_views (View_GetChild (view, i), nullptr);
 	}
 }
 
 static void
-draw_intermission (view_t view)
+draw_intermission (view_t view, void *data)
 {
-	clear_views (view);
+	clear_views (view, nullptr);
 	const char *n;
 	n = "gfx/complete.lmp";
 	sbar_setcomponent (View_GetChild (view, 0), canvas_cachepic, &n);
@@ -1798,9 +1801,9 @@ draw_intermission (view_t view)
 }
 
 static void
-draw_finale (view_t view)
+draw_finale (view_t view, void *data)
 {
-	clear_views (view);
+	clear_views (view, nullptr);
 
 	r_data->scr_copyeverything = 1;
 
@@ -1809,9 +1812,9 @@ draw_finale (view_t view)
 }
 
 static void
-draw_cutscene (view_t view)
+draw_cutscene (view_t view, void *data)
 {
-	clear_views (view);
+	clear_views (view, nullptr);
 }
 
 void
@@ -1872,9 +1875,9 @@ Sbar_Update (double time)
 	if (sb_updates < r_data->vid->numpages) {
 		//FIXME find a better way to support animations
 		sb_updates++;
-		draw_weapons (sbar_weapons);
-		draw_items (sbar_items);
-		draw_face (sbar_face);
+		draw_weapons (sbar_weapons, nullptr);
+		draw_items (sbar_items, nullptr);
+		draw_face (sbar_face, nullptr);
 	}
 }
 
@@ -2243,8 +2246,8 @@ static void
 hud_fps_f (void *data, const cvar_t *cvar)
 {
 	if (hud_fps) {
-		void       *f = draw_fps;
-		sbar_setcomponent (hud_fps_view, canvas_update, &f);
+		sbar_setcomponent (hud_fps_view, canvas_update,
+						   &(canvas_update_t) { .update = draw_fps });
 		sbar_setcomponent (hud_fps_view, canvas_charbuff, &fps_buff);
 	} else {
 		sbar_remcomponent (hud_fps_view, canvas_update);
@@ -2276,8 +2279,8 @@ static void
 hud_time_f (void *data, const cvar_t *cvar)
 {
 	if (hud_time) {
-		void       *f = draw_time;
-		sbar_setcomponent (hud_time_view, canvas_update, &f);
+		sbar_setcomponent (hud_time_view, canvas_update,
+						   &(canvas_update_t) { .update = draw_time });
 		sbar_setcomponent (hud_time_view, canvas_charbuff, &time_buff);
 	} else {
 		sbar_remcomponent (hud_time_view, canvas_update);
diff --git a/libs/console/client.c b/libs/console/client.c
index a46d1376a..9e3b05d41 100644
--- a/libs/console/client.c
+++ b/libs/console/client.c
@@ -254,7 +254,8 @@ con_setcomponent (view_t view, uint32_t comp, void *data)
 static void
 con_setfunc (view_t view, uint32_t comp, canvas_update_f func)
 {
-	con_setcomponent (view, canvas_base + comp, &func);
+	con_setcomponent (view, canvas_base + comp,
+					  &(canvas_update_t) { .update = func });
 }
 
 static void
@@ -712,7 +713,7 @@ draw_con_scrollback (void)
 }
 
 static void
-draw_cursor (view_t view)
+draw_cursor (view_t view, void *data)
 {
 	float       t = *con_data.realtime * con_cursorspeed;
 	int         ch = 10 + ((int) (t) & 1);
diff --git a/libs/ui/canvas.c b/libs/ui/canvas.c
index 8700361dc..260f1e9f1 100644
--- a/libs/ui/canvas.c
+++ b/libs/ui/canvas.c
@@ -88,12 +88,12 @@ canvas_canvas_destroy (void *_canvas, ecs_registry_t *reg)
 
 const component_t canvas_components[canvas_comp_count] = {
 	[canvas_update] = {
-		.size = sizeof (canvas_update_f),
+		.size = sizeof (canvas_update_t),
 		.name = "update",
 		.rangeid = canvas_update_rangeid,
 	},
 	[canvas_updateonce] = {
-		.size = sizeof (canvas_update_f),
+		.size = sizeof (canvas_update_t),
 		.name = "updateonce",
 		.rangeid = canvas_updateonce_rangeid,
 	},
@@ -143,12 +143,12 @@ const component_t canvas_components[canvas_comp_count] = {
 		.rangeid = canvas_glyphs_rangeid,
 	},
 	[canvas_func] = {
-		.size = sizeof (canvas_func_f),
+		.size = sizeof (canvas_func_t),
 		.name = "func",
 		.rangeid = canvas_func_rangeid,
 	},
 	[canvas_lateupdate] = {
-		.size = sizeof (canvas_update_f),
+		.size = sizeof (canvas_update_t),
 		.name = "lateupdate",
 		.rangeid = canvas_lateupdate_rangeid,
 	},
@@ -181,9 +181,10 @@ draw_update (canvas_system_t *canvas_sys, ecs_pool_t *pool, ecs_range_t range)
 	ecs_system_t viewsys = { canvas_sys->reg, canvas_sys->view_base };
 	uint32_t    count = range.end - range.start;
 	uint32_t   *ent = pool->dense + range.start;
-	__auto_type func = (canvas_update_f *) pool->data + range.start;
+	auto func = (canvas_update_t *) pool->data + range.start;
 	while (count-- > 0) {
-		(*func++) (View_FromEntity (viewsys, *ent++));
+		func->update (View_FromEntity (viewsys, *ent++), func->data);
+		func++;
 	}
 }
 
@@ -331,13 +332,13 @@ draw_func_views (canvas_system_t *canvas_sys, ecs_pool_t *pool,
 	ecs_system_t viewsys = { canvas_sys->reg, canvas_sys->view_base };
 	uint32_t    count = range.end - range.start;
 	uint32_t   *ent = pool->dense + range.start;
-	__auto_type func = (canvas_func_f *) pool->data + range.start;
+	auto func = (canvas_func_t *) pool->data + range.start;
 	while (count-- > 0) {
 		view_t      view = View_FromEntity (viewsys, *ent++);
 		if (View_GetVisible (view)) {
 			view_pos_t  pos = View_GetAbs (view);
 			view_pos_t  len = View_GetLen (view);
-			(*func) (pos, len);
+			func->func (pos, len, func->data);
 		}
 		func++;
 	}
diff --git a/libs/ui/imui.c b/libs/ui/imui.c
index 7babe2fc6..a8c9cdeaf 100644
--- a/libs/ui/imui.c
+++ b/libs/ui/imui.c
@@ -1176,7 +1176,7 @@ IMUI_Labelf (imui_ctx_t *ctx, const char *fmt, ...)
 }
 
 static void
-passage_update (view_t psgview)
+passage_update (view_t psgview, void *data)
 {
 	auto reg = psgview.reg;
 	auto href = View_GetRef (psgview);
@@ -1235,8 +1235,8 @@ IMUI_Passage (imui_ctx_t *ctx, const char *name, struct passage_s *passage)
 	Ent_RemoveComponent (psg_view.id, c_updateonce, reg);
 	Ent_SetComponent (psg_view.id, c_passage_glyphs, reg,
 					  Ent_GetComponent (psg_view.id, t_passage_glyphs, reg));
-	void *update = passage_update;
-	Ent_SetComponent (psg_view.id, c_updateonce, reg, &update);
+	Ent_SetComponent (psg_view.id, c_updateonce, reg,
+					  &(canvas_update_t) { .update = passage_update });
 	*View_Control (psg_view) = (viewcont_t) {
 		.gravity = grav_northwest,
 		.visible = 1,
diff --git a/qw/source/cl_ngraph.c b/qw/source/cl_ngraph.c
index 4ffb7f56e..137ff9b2c 100644
--- a/qw/source/cl_ngraph.c
+++ b/qw/source/cl_ngraph.c
@@ -111,7 +111,7 @@ cl_netgraph_height_f (void *data, const cvar_t *cvar)
 }
 
 static void
-CL_NetGraph (view_pos_t abs, view_pos_t len)
+CL_NetGraph (view_pos_t abs, view_pos_t len, void *data)
 {
 	int         lost, a, l, x, y, i, o;
 	int         timings[NET_TIMINGS];
@@ -165,9 +165,9 @@ CL_NetGraph_Init (void)
 	View_SetPos (cl_netgraph_view, 0, 64);
 	View_SetLen (cl_netgraph_view, NET_TIMINGS + 16, cl_netgraph_height + 25);
 	View_SetGravity (cl_netgraph_view, grav_southwest);
-	void       *f = CL_NetGraph;
 	Ent_SetComponent (cl_netgraph_view.id, cl_canvas_sys.base + canvas_func,
-					  cl_netgraph_view.reg, &f);
+					  cl_netgraph_view.reg,
+					  &(canvas_func_t) { .func = CL_NetGraph });
 	View_SetVisible (cl_netgraph_view, cl_netgraph);
 }
 
diff --git a/ruamoko/include/imui.h b/ruamoko/include/imui.h
index d795ef2a9..f7274d79f 100644
--- a/ruamoko/include/imui.h
+++ b/ruamoko/include/imui.h
@@ -85,6 +85,7 @@ void IMUI_EndWindow (imui_ctx_t ctx);
 int IMUI_StartScrollBox (imui_ctx_t ctx, string name);
 void IMUI_EndScrollBox (imui_ctx_t ctx);
 
+void IMUI_ScrollBar (imui_ctx_t ctx, string name);
 
 #define IMUI_DeferLoop(begin, end) \
 	for (int _i_ = (begin); !_i_; _i_++, (end))
@@ -145,6 +146,9 @@ void IMUI_EndScrollBox (imui_ctx_t ctx);
 #define UI_ScrollBox(name) \
 	IMUI_DeferLoop (IMUI_StartScrollBox (IMUI_context, name), \
 					IMUI_EndScrollBox (IMUI_context))
+#define UI_ScrollBar(name) \
+	IMUI_ScrollBar (IMUI_context, name)
+
 
 #define UI_Style(style) \
 	IMUI_DeferLoop (IMUI_PushStyle (IMUI_context, style), \