Refactoring: View2DScrollers memory allocation

View2DScrollers used the memory manager to allocate memory. This isn't a
problem but in a upcoming change the scrollers will be drawn more often
than it used to (See {D8066}). To limit the number of allocations and
frees this patch will use the stack for allocation.

Reviewed By: Campbell Barton

Differential Revision: https://developer.blender.org/D8076

14 files changed, 60 insertions, 109 deletions

diff --git a/source/blender/editors/include/UI_view2d.h b/source/blender/editors/include/UI_view2d.h
index ffc06e94a90..0ddc45f4878 100644
--- a/source/blender/editors/include/UI_view2d.h
+++ b/source/blender/editors/include/UI_view2d.h
@@ -180,9 +180,10 @@ void UI_view2d_draw_scale_x__frames_or_seconds(const struct ARegion *region,
                                                int colorid);
 
 /* scrollbar drawing */
-View2DScrollers *UI_view2d_scrollers_calc(struct View2D *v2d, const struct rcti *mask_custom);
-void UI_view2d_scrollers_draw(struct View2D *v2d, View2DScrollers *scrollers);
-void UI_view2d_scrollers_free(View2DScrollers *scrollers);
+void UI_view2d_scrollers_calc(struct View2D *v2d,
+                              const struct rcti *mask_custom,
+                              struct View2DScrollers *r_scrollers);
+void UI_view2d_scrollers_draw(struct View2D *v2d, const struct rcti *mask_custom);
 
 /* list view tools */
 void UI_view2d_listview_view_to_cell(float columnwidth,
diff --git a/source/blender/editors/interface/view2d.c b/source/blender/editors/interface/view2d.c
index 8fee9df8706..1e1f4e1a55b 100644
--- a/source/blender/editors/interface/view2d.c
+++ b/source/blender/editors/interface/view2d.c
@@ -1413,17 +1413,15 @@ struct View2DScrollers {
 };
 
 /* Calculate relevant scroller properties */
-View2DScrollers *UI_view2d_scrollers_calc(View2D *v2d, const rcti *mask_custom)
+void UI_view2d_scrollers_calc(View2D *v2d,
+                              const rcti *mask_custom,
+                              struct View2DScrollers *r_scrollers)
 {
-  View2DScrollers *scrollers;
   rcti vert, hor;
   float fac1, fac2, totsize, scrollsize;
   int scroll = view2d_scroll_mapped(v2d->scroll);
   int smaller;
 
-  /* scrollers is allocated here... */
-  scrollers = MEM_callocN(sizeof(View2DScrollers), "View2DScrollers");
-
   /* Always update before drawing (for dynamically sized scrollers). */
   view2d_masks(v2d, mask_custom);
 
@@ -1456,8 +1454,8 @@ View2DScrollers *UI_view2d_scrollers_calc(View2D *v2d, const rcti *mask_custom)
   CLAMP(hor.xmin, hor.xmin, hor.xmax - V2D_SCROLL_HANDLE_SIZE_HOTSPOT);
 
   /* store in scrollers, used for drawing */
-  scrollers->vert = vert;
-  scrollers->hor = hor;
+  r_scrollers->vert = vert;
+  r_scrollers->hor = hor;
 
   /* scroller 'buttons':
    * - These should always remain within the visible region of the scrollbar
@@ -1475,30 +1473,30 @@ View2DScrollers *UI_view2d_scrollers_calc(View2D *v2d, const rcti *mask_custom)
 
     fac1 = (v2d->cur.xmin - v2d->tot.xmin) / totsize;
     if (fac1 <= 0.0f) {
-      scrollers->hor_min = hor.xmin;
+      r_scrollers->hor_min = hor.xmin;
     }
     else {
-      scrollers->hor_min = (int)(hor.xmin + (fac1 * scrollsize));
+      r_scrollers->hor_min = (int)(hor.xmin + (fac1 * scrollsize));
     }
 
     fac2 = (v2d->cur.xmax - v2d->tot.xmin) / totsize;
     if (fac2 >= 1.0f) {
-      scrollers->hor_max = hor.xmax;
+      r_scrollers->hor_max = hor.xmax;
     }
     else {
-      scrollers->hor_max = (int)(hor.xmin + (fac2 * scrollsize));
+      r_scrollers->hor_max = (int)(hor.xmin + (fac2 * scrollsize));
     }
 
     /* prevent inverted sliders */
-    if (scrollers->hor_min > scrollers->hor_max) {
-      scrollers->hor_min = scrollers->hor_max;
+    if (r_scrollers->hor_min > r_scrollers->hor_max) {
+      r_scrollers->hor_min = r_scrollers->hor_max;
     }
     /* prevent sliders from being too small to grab */
-    if ((scrollers->hor_max - scrollers->hor_min) < V2D_SCROLL_THUMB_SIZE_MIN) {
-      scrollers->hor_max = scrollers->hor_min + V2D_SCROLL_THUMB_SIZE_MIN;
+    if ((r_scrollers->hor_max - r_scrollers->hor_min) < V2D_SCROLL_THUMB_SIZE_MIN) {
+      r_scrollers->hor_max = r_scrollers->hor_min + V2D_SCROLL_THUMB_SIZE_MIN;
 
-      CLAMP(scrollers->hor_max, hor.xmin + V2D_SCROLL_THUMB_SIZE_MIN, hor.xmax);
-      CLAMP(scrollers->hor_min, hor.xmin, hor.xmax - V2D_SCROLL_THUMB_SIZE_MIN);
+      CLAMP(r_scrollers->hor_max, hor.xmin + V2D_SCROLL_THUMB_SIZE_MIN, hor.xmax);
+      CLAMP(r_scrollers->hor_min, hor.xmin, hor.xmax - V2D_SCROLL_THUMB_SIZE_MIN);
     }
   }
 
@@ -1513,39 +1511,39 @@ View2DScrollers *UI_view2d_scrollers_calc(View2D *v2d, const rcti *mask_custom)
 
     fac1 = (v2d->cur.ymin - v2d->tot.ymin) / totsize;
     if (fac1 <= 0.0f) {
-      scrollers->vert_min = vert.ymin;
+      r_scrollers->vert_min = vert.ymin;
     }
     else {
-      scrollers->vert_min = (int)(vert.ymin + (fac1 * scrollsize));
+      r_scrollers->vert_min = (int)(vert.ymin + (fac1 * scrollsize));
     }
 
     fac2 = (v2d->cur.ymax - v2d->tot.ymin) / totsize;
     if (fac2 >= 1.0f) {
-      scrollers->vert_max = vert.ymax;
+      r_scrollers->vert_max = vert.ymax;
     }
     else {
-      scrollers->vert_max = (int)(vert.ymin + (fac2 * scrollsize));
+      r_scrollers->vert_max = (int)(vert.ymin + (fac2 * scrollsize));
     }
 
     /* prevent inverted sliders */
-    if (scrollers->vert_min > scrollers->vert_max) {
-      scrollers->vert_min = scrollers->vert_max;
+    if (r_scrollers->vert_min > r_scrollers->vert_max) {
+      r_scrollers->vert_min = r_scrollers->vert_max;
     }
     /* prevent sliders from being too small to grab */
-    if ((scrollers->vert_max - scrollers->vert_min) < V2D_SCROLL_THUMB_SIZE_MIN) {
-      scrollers->vert_max = scrollers->vert_min + V2D_SCROLL_THUMB_SIZE_MIN;
+    if ((r_scrollers->vert_max - r_scrollers->vert_min) < V2D_SCROLL_THUMB_SIZE_MIN) {
+      r_scrollers->vert_max = r_scrollers->vert_min + V2D_SCROLL_THUMB_SIZE_MIN;
 
-      CLAMP(scrollers->vert_max, vert.ymin + V2D_SCROLL_THUMB_SIZE_MIN, vert.ymax);
-      CLAMP(scrollers->vert_min, vert.ymin, vert.ymax - V2D_SCROLL_THUMB_SIZE_MIN);
+      CLAMP(r_scrollers->vert_max, vert.ymin + V2D_SCROLL_THUMB_SIZE_MIN, vert.ymax);
+      CLAMP(r_scrollers->vert_min, vert.ymin, vert.ymax - V2D_SCROLL_THUMB_SIZE_MIN);
     }
   }
-
-  return scrollers;
 }
 
 /* Draw scrollbars in the given 2d-region */
-void UI_view2d_scrollers_draw(View2D *v2d, View2DScrollers *vs)
+void UI_view2d_scrollers_draw(View2D *v2d, const rcti *mask_custom)
 {
+  View2DScrollers scrollers;
+  UI_view2d_scrollers_calc(v2d, mask_custom, &scrollers);
   bTheme *btheme = UI_GetTheme();
   rcti vert, hor;
   const int scroll = view2d_scroll_mapped(v2d->scroll);
@@ -1556,8 +1554,8 @@ void UI_view2d_scrollers_draw(View2D *v2d, View2DScrollers *vs)
   UI_GetThemeColor4ubv(TH_BACK, scrollers_back_color);
 
   /* make copies of rects for less typing */
-  vert = vs->vert;
-  hor = vs->hor;
+  vert = scrollers.vert;
+  hor = scrollers.hor;
 
   /* horizontal scrollbar */
   if (scroll & V2D_SCROLL_HORIZONTAL) {
@@ -1566,8 +1564,8 @@ void UI_view2d_scrollers_draw(View2D *v2d, View2DScrollers *vs)
     rcti slider;
     int state;
 
-    slider.xmin = vs->hor_min;
-    slider.xmax = vs->hor_max;
+    slider.xmin = scrollers.hor_min;
+    slider.xmax = scrollers.hor_max;
     slider.ymin = hor.ymin;
     slider.ymax = hor.ymax;
 
@@ -1602,8 +1600,8 @@ void UI_view2d_scrollers_draw(View2D *v2d, View2DScrollers *vs)
 
     slider.xmin = vert.xmin;
     slider.xmax = vert.xmax;
-    slider.ymin = vs->vert_min;
-    slider.ymax = vs->vert_max;
+    slider.ymin = scrollers.vert_min;
+    slider.ymax = scrollers.vert_max;
 
     state = (v2d->scroll_ui & V2D_SCROLL_V_ACTIVE) ? UI_SCROLL_PRESSED : 0;
 
@@ -1631,12 +1629,6 @@ void UI_view2d_scrollers_draw(View2D *v2d, View2DScrollers *vs)
   btheme->tui.widget_emboss[3] = emboss_alpha;
 }
 
-/* free temporary memory used for drawing scrollers */
-void UI_view2d_scrollers_free(View2DScrollers *scrollers)
-{
-  MEM_freeN(scrollers);
-}
-
 /** \} */
 
 /* -------------------------------------------------------------------- */
diff --git a/source/blender/editors/interface/view2d_ops.c b/source/blender/editors/interface/view2d_ops.c
index 34108853c61..0585f7cf7cd 100644
--- a/source/blender/editors/interface/view2d_ops.c
+++ b/source/blender/editors/interface/view2d_ops.c
@@ -2011,7 +2011,7 @@ static void scroller_activate_init(bContext *C,
                                    const char in_scroller)
 {
   v2dScrollerMove *vsm;
-  View2DScrollers *scrollers;
+  View2DScrollers scrollers;
   ARegion *region = CTX_wm_region(C);
   View2D *v2d = &region->v2d;
   rctf tot_cur_union;
@@ -2032,7 +2032,7 @@ static void scroller_activate_init(bContext *C,
   /* 'zone' depends on where mouse is relative to bubble
    * - zooming must be allowed on this axis, otherwise, default to pan
    */
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
+  UI_view2d_scrollers_calc(v2d, NULL, &scrollers);
 
   /* Use a union of 'cur' & 'tot' in case the current view is far outside 'tot'. In this cases
    * moving the scroll bars has far too little effect and the view can get stuck T31476. */
@@ -2049,15 +2049,15 @@ static void scroller_activate_init(bContext *C,
 
     /* get 'zone' (i.e. which part of scroller is activated) */
     vsm->zone = mouse_in_scroller_handle(
-        event->mval[0], v2d->hor.xmin, v2d->hor.xmax, scrollers->hor_min, scrollers->hor_max);
+        event->mval[0], v2d->hor.xmin, v2d->hor.xmax, scrollers.hor_min, scrollers.hor_max);
 
     if ((v2d->keepzoom & V2D_LOCKZOOM_X) && ELEM(vsm->zone, SCROLLHANDLE_MIN, SCROLLHANDLE_MAX)) {
       /* default to scroll, as handles not usable */
       vsm->zone = SCROLLHANDLE_BAR;
     }
 
-    vsm->scrollbarwidth = scrollers->hor_max - scrollers->hor_min;
-    vsm->scrollbar_orig = ((scrollers->hor_max + scrollers->hor_min) / 2) + region->winrct.xmin;
+    vsm->scrollbarwidth = scrollers.hor_max - scrollers.hor_min;
+    vsm->scrollbar_orig = ((scrollers.hor_max + scrollers.hor_min) / 2) + region->winrct.xmin;
   }
   else {
     /* vertical scroller - calculate adjustment factor first */
@@ -2069,18 +2069,17 @@ static void scroller_activate_init(bContext *C,
 
     /* get 'zone' (i.e. which part of scroller is activated) */
     vsm->zone = mouse_in_scroller_handle(
-        event->mval[1], v2d->vert.ymin, v2d->vert.ymax, scrollers->vert_min, scrollers->vert_max);
+        event->mval[1], v2d->vert.ymin, v2d->vert.ymax, scrollers.vert_min, scrollers.vert_max);
 
     if ((v2d->keepzoom & V2D_LOCKZOOM_Y) && ELEM(vsm->zone, SCROLLHANDLE_MIN, SCROLLHANDLE_MAX)) {
       /* default to scroll, as handles not usable */
       vsm->zone = SCROLLHANDLE_BAR;
     }
 
-    vsm->scrollbarwidth = scrollers->vert_max - scrollers->vert_min;
-    vsm->scrollbar_orig = ((scrollers->vert_max + scrollers->vert_min) / 2) + region->winrct.ymin;
+    vsm->scrollbarwidth = scrollers.vert_max - scrollers.vert_min;
+    vsm->scrollbar_orig = ((scrollers.vert_max + scrollers.vert_min) / 2) + region->winrct.ymin;
   }
 
-  UI_view2d_scrollers_free(scrollers);
   ED_region_tag_redraw_no_rebuild(region);
 }
 
diff --git a/source/blender/editors/screen/area.c b/source/blender/editors/screen/area.c
index 1adf7f84bbf..63366044f88 100644
--- a/source/blender/editors/screen/area.c
+++ b/source/blender/editors/screen/area.c
@@ -2795,9 +2795,7 @@ void ED_region_panels_draw(const bContext *C, ARegion *region)
     mask_buf.xmax -= UI_PANEL_CATEGORY_MARGIN_WIDTH;
     mask = &mask_buf;
   }
-  View2DScrollers *scrollers = UI_view2d_scrollers_calc(v2d, mask);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, mask);
 }
 
 void ED_region_panels_ex(
diff --git a/source/blender/editors/space_action/space_action.c b/source/blender/editors/space_action/space_action.c
index 1e4919761a1..a8b3ec9cdf6 100644
--- a/source/blender/editors/space_action/space_action.c
+++ b/source/blender/editors/space_action/space_action.c
@@ -181,7 +181,6 @@ static void action_main_region_draw(const bContext *C, ARegion *region)
   Object *obact = CTX_data_active_object(C);
   bAnimContext ac;
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
   short marker_flag = 0;
   short cfra_flag = 0;
 
@@ -240,9 +239,7 @@ static void action_main_region_draw(const bContext *C, ARegion *region)
   ED_time_scrub_draw(region, scene, saction->flag & SACTION_DRAWTIME, true);
 
   /* scrollers */
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
diff --git a/source/blender/editors/space_clip/space_clip.c b/source/blender/editors/space_clip/space_clip.c
index 6ec99730e09..54da00a132d 100644
--- a/source/blender/editors/space_clip/space_clip.c
+++ b/source/blender/editors/space_clip/space_clip.c
@@ -1045,7 +1045,6 @@ static void clip_preview_region_init(wmWindowManager *wm, ARegion *region)
 static void graph_region_draw(const bContext *C, ARegion *region)
 {
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
   SpaceClip *sc = CTX_wm_space_clip(C);
   Scene *scene = CTX_data_scene(C);
   short cfra_flag = 0;
@@ -1076,9 +1075,7 @@ static void graph_region_draw(const bContext *C, ARegion *region)
   ED_time_scrub_draw(region, scene, sc->flag & SC_SHOW_SECONDS, true);
 
   /* scrollers */
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 
   /* scale indicators */
   {
@@ -1095,7 +1092,6 @@ static void dopesheet_region_draw(const bContext *C, ARegion *region)
   SpaceClip *sc = CTX_wm_space_clip(C);
   MovieClip *clip = ED_space_clip_get_clip(sc);
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
   short cfra_flag = 0;
 
   if (clip) {
@@ -1127,9 +1123,7 @@ static void dopesheet_region_draw(const bContext *C, ARegion *region)
   ED_time_scrub_draw(region, scene, sc->flag & SC_SHOW_SECONDS, true);
 
   /* scrollers */
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 }
 
 static void clip_preview_region_draw(const bContext *C, ARegion *region)
diff --git a/source/blender/editors/space_console/space_console.c b/source/blender/editors/space_console/space_console.c
index 775159fbd79..3c62aeb1759 100644
--- a/source/blender/editors/space_console/space_console.c
+++ b/source/blender/editors/space_console/space_console.c
@@ -208,7 +208,6 @@ static void console_main_region_draw(const bContext *C, ARegion *region)
   /* draw entirely, view changes should be handled here */
   SpaceConsole *sc = CTX_wm_space_console(C);
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
 
   if (BLI_listbase_is_empty(&sc->scrollback)) {
     WM_operator_name_call((bContext *)C, "CONSOLE_OT_banner", WM_OP_EXEC_DEFAULT, NULL);
@@ -230,9 +229,7 @@ static void console_main_region_draw(const bContext *C, ARegion *region)
   UI_view2d_view_restore(C);
 
   /* scrollers */
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 }
 
 static void console_operatortypes(void)
diff --git a/source/blender/editors/space_file/space_file.c b/source/blender/editors/space_file/space_file.c
index 21b705cbb44..56f3fd08bae 100644
--- a/source/blender/editors/space_file/space_file.c
+++ b/source/blender/editors/space_file/space_file.c
@@ -449,7 +449,6 @@ static void file_main_region_draw(const bContext *C, ARegion *region)
   FileSelectParams *params = ED_fileselect_get_params(sfile);
 
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
   float col[3];
 
   /* Needed, because filelist is not initialized on loading */
@@ -509,9 +508,7 @@ static void file_main_region_draw(const bContext *C, ARegion *region)
   /* scrollers */
   rcti view_rect;
   ED_fileselect_layout_maskrect(sfile->layout, v2d, &view_rect);
-  scrollers = UI_view2d_scrollers_calc(v2d, &view_rect);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, &view_rect);
 }
 
 static void file_operatortypes(void)
diff --git a/source/blender/editors/space_graph/space_graph.c b/source/blender/editors/space_graph/space_graph.c
index b9c7c529620..30c7e5288d6 100644
--- a/source/blender/editors/space_graph/space_graph.c
+++ b/source/blender/editors/space_graph/space_graph.c
@@ -200,7 +200,6 @@ static void graph_main_region_draw(const bContext *C, ARegion *region)
   Scene *scene = CTX_data_scene(C);
   bAnimContext ac;
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
   float col[3];
   short cfra_flag = 0;
 
@@ -319,9 +318,7 @@ static void graph_main_region_draw(const bContext *C, ARegion *region)
 
   /* scrollers */
   // FIXME: args for scrollers depend on the type of data being shown...
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 
   /* scale numbers */
   {
@@ -358,7 +355,6 @@ static void graph_channel_region_draw(const bContext *C, ARegion *region)
 {
   bAnimContext ac;
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
   float col[3];
 
   /* clear and setup matrix */
@@ -380,9 +376,7 @@ static void graph_channel_region_draw(const bContext *C, ARegion *region)
   UI_view2d_view_restore(C);
 
   /* scrollers */
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
diff --git a/source/blender/editors/space_info/space_info.c b/source/blender/editors/space_info/space_info.c
index ddf45eb4dce..836830916ed 100644
--- a/source/blender/editors/space_info/space_info.c
+++ b/source/blender/editors/space_info/space_info.c
@@ -139,7 +139,6 @@ static void info_main_region_draw(const bContext *C, ARegion *region)
   /* draw entirely, view changes should be handled here */
   SpaceInfo *sinfo = CTX_wm_space_info(C);
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
@@ -161,9 +160,7 @@ static void info_main_region_draw(const bContext *C, ARegion *region)
   UI_view2d_view_restore(C);
 
   /* scrollers */
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 }
 
 static void info_operatortypes(void)
diff --git a/source/blender/editors/space_nla/space_nla.c b/source/blender/editors/space_nla/space_nla.c
index 9ec38a2e9eb..aeb5c30c809 100644
--- a/source/blender/editors/space_nla/space_nla.c
+++ b/source/blender/editors/space_nla/space_nla.c
@@ -191,7 +191,6 @@ static void nla_channel_region_draw(const bContext *C, ARegion *region)
 {
   bAnimContext ac;
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
@@ -211,9 +210,7 @@ static void nla_channel_region_draw(const bContext *C, ARegion *region)
   UI_view2d_view_restore(C);
 
   /* scrollers */
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
@@ -237,7 +234,6 @@ static void nla_main_region_draw(const bContext *C, ARegion *region)
   Scene *scene = CTX_data_scene(C);
   bAnimContext ac;
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
   short cfra_flag = 0;
 
   /* clear and setup matrix */
@@ -292,9 +288,7 @@ static void nla_main_region_draw(const bContext *C, ARegion *region)
   ED_time_scrub_draw(region, scene, snla->flag & SNLA_DRAWTIME, true);
 
   /* scrollers */
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
diff --git a/source/blender/editors/space_node/node_draw.c b/source/blender/editors/space_node/node_draw.c
index 43d844df900..c3823d8eb27 100644
--- a/source/blender/editors/space_node/node_draw.c
+++ b/source/blender/editors/space_node/node_draw.c
@@ -1772,7 +1772,6 @@ static void draw_group_overlay(const bContext *C, ARegion *region)
 void drawnodespace(const bContext *C, ARegion *region)
 {
   wmWindow *win = CTX_wm_window(C);
-  View2DScrollers *scrollers;
   SpaceNode *snode = CTX_wm_space_node(C);
   View2D *v2d = &region->v2d;
 
@@ -1921,7 +1920,5 @@ void drawnodespace(const bContext *C, ARegion *region)
   draw_tree_path(snode);
 
   /* scrollers */
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 }
diff --git a/source/blender/editors/space_outliner/space_outliner.c b/source/blender/editors/space_outliner/space_outliner.c
index 540e2405758..aa1663dff01 100644
--- a/source/blender/editors/space_outliner/space_outliner.c
+++ b/source/blender/editors/space_outliner/space_outliner.c
@@ -84,7 +84,6 @@ static void outliner_main_region_init(wmWindowManager *wm, ARegion *region)
 static void outliner_main_region_draw(const bContext *C, ARegion *region)
 {
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
 
   /* clear */
   UI_ThemeClearColor(TH_BACK);
@@ -96,9 +95,7 @@ static void outliner_main_region_draw(const bContext *C, ARegion *region)
   UI_view2d_view_restore(C);
 
   /* scrollers */
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 }
 
 static void outliner_main_region_free(ARegion *UNUSED(region))
diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index 1f06ab68516..433abe1ade7 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -2257,7 +2257,6 @@ void draw_timeline_seq(const bContext *C, ARegion *region)
   Editing *ed = BKE_sequencer_editing_get(scene, false);
   SpaceSeq *sseq = CTX_wm_space_seq(C);
   View2D *v2d = &region->v2d;
-  View2DScrollers *scrollers;
   short cfra_flag = 0;
   float col[3];
 
@@ -2345,9 +2344,7 @@ void draw_timeline_seq(const bContext *C, ARegion *region)
   ED_region_draw_cb_draw(C, region, REGION_DRAW_POST_VIEW);
   UI_view2d_view_restore(C);
   ED_time_scrub_draw(region, scene, !(sseq->flag & SEQ_DRAWFRAMES), true);
-  scrollers = UI_view2d_scrollers_calc(v2d, NULL);
-  UI_view2d_scrollers_draw(v2d, scrollers);
-  UI_view2d_scrollers_free(scrollers);
+  UI_view2d_scrollers_draw(v2d, NULL);
 
   /* Draw channel numbers. */
   {