Fix Drivers Editor showing playhead on the X Axis

Currently the Drivers Editor shows this (the blue thing can be dragged
to change frame):
{F10647661}

But the Drivers Editors X axis is the output of the driver [which can be
further tweaked by the curve] not time(frame).
So it seems better to not mix them here, it is just confusing to have
two different units on one axis.
Especially since what we really want to look at in X (the drivers output
value) can be in a totally unrelated range compared to frames, so e.g.
we might be interested in a drivers range from 0.0 to 1.0 and a
framerange of 100 to 200, so putting this on one axis just does not make
sense. Better to use a separate timeline for this.

Note 2.79 also did not do this.

Maniphest Tasks: T91157

Differential Revision: https://developer.blender.org/D12392

1 files changed, 8 insertions, 1 deletions

diff --git a/source/blender/editors/animation/anim_ops.c b/source/blender/editors/animation/anim_ops.c
index b4ea33920b2..3958c7f9e34 100644
--- a/source/blender/editors/animation/anim_ops.c
+++ b/source/blender/editors/animation/anim_ops.c
@@ -74,9 +74,16 @@ static bool change_frame_poll(bContext *C)
    * this shouldn't show up in 3D editor (or others without 2D timeline view) via search
    */
   if (area) {
-    if (ELEM(area->spacetype, SPACE_ACTION, SPACE_NLA, SPACE_SEQ, SPACE_CLIP, SPACE_GRAPH)) {
+    if (ELEM(area->spacetype, SPACE_ACTION, SPACE_NLA, SPACE_SEQ, SPACE_CLIP)) {
       return true;
     }
+    if (area->spacetype == SPACE_GRAPH) {
+      const SpaceGraph *sipo = area->spacedata.first;
+      /* Driver Editor's X axis is not time. */
+      if (sipo->mode != SIPO_MODE_DRIVERS) {
+        return true;
+      }
+    }
   }
 
   CTX_wm_operator_poll_msg_set(C, "Expected an animation area to be active");