UI: allow shrinking panel height to zero when open.

Currently if a panel becomes empty (draw simply returns), it stays
at the last non-empty height. This seems to be caused by some legacy
checks that may be completely obsolete, but the safest fix is to at
least allow resetting height when the panel is open.

1 files changed, 9 insertions, 9 deletions

diff --git a/source/blender/editors/interface/interface_panel.c b/source/blender/editors/interface/interface_panel.c
index aa7ff015bad..14e880c927a 100644
--- a/source/blender/editors/interface/interface_panel.c
+++ b/source/blender/editors/interface/interface_panel.c
@@ -367,7 +367,7 @@ Panel *UI_panel_begin(
   return pa;
 }
 
-void UI_panel_end(uiBlock *block, int width, int height)
+void UI_panel_end(uiBlock *block, int width, int height, bool open)
 {
   Panel *pa = block->panel;
 
@@ -390,21 +390,21 @@ void UI_panel_end(uiBlock *block, int width, int height)
     pa->sizey = height;
   }
   else {
-    /* check if we need to do an animation */
-    if (!ELEM(width, 0, pa->sizex) || !ELEM(height, 0, pa->sizey)) {
-      pa->runtime_flag |= PNL_ANIM_ALIGN;
-      if (height != 0) {
-        pa->ofsy += pa->sizey - height;
-      }
-    }
+    int old_sizex = pa->sizex, old_sizey = pa->sizey;
 
     /* update width/height if non-zero */
     if (width != 0) {
       pa->sizex = width;
     }
-    if (height != 0) {
+    if (height != 0 || open) {
       pa->sizey = height;
     }
+
+    /* check if we need to do an animation */
+    if (pa->sizex != old_sizex || pa->sizey != old_sizey) {
+      pa->runtime_flag |= PNL_ANIM_ALIGN;
+      pa->ofsy += old_sizey - pa->sizey;
+    }
   }
 }