Animation: Add GP layers in regular Dopesheet

Grease Pencil animation channels are now also shown in the Dopesheet
mode of the Dopesheet editor and in the Timeline.

Grease pencil related events are now listened not only by container
`SACTCONT_GPENCIL` (Grease Pencil Dopesheet), but also
`SACTCONT_DOPESHEET` (main Dopesheet), and `SACTCONT_TIMELINE`
(timeline).

A new Animation Filter flag was added: `ANIMFILTER_FCURVESONLY`. For now
this only filters out Grease Pencil Layer channels.

**Implemented:**

- Preview range set: now only considers selected Grease Pencil keyframes
  when `onlySel` parameter is true. Not only this allows the operator to
  work with grease pencil keyframes in main dopesheet, but it also fixes
  the operator in the Grease Pencil dopesheet.
- Translation: allocation (and freeing) of specific memory for
  translation of Grease Pencil keyframes.
- Copy/Paste: call to both Fcurve and GPencil operators, to allow for
  mixed selection. Errors are only reported when both the FCurve and
  GPencil functions fail to paste anything.
- Keyframe Type change and Insert Keyframe: removed some code here to
  unify Grease Pencil dopesheet and main dopesheet code.

- Jump, Snap, Mirror, Select all/box/lasso/circle, Select left/right,
  Clickselect: account for Grease Pencil channels within the channels
  loop, no need for `ANIMFILTER_FCURVESONLY` there.

**Not Implemented:**

- Graph-related operators. The filter `ANIMFILTER_FCURVESONLY` is
  naively added to all graph-related operators, meaning more-or-less all
  operators that used `ANIMFILTER_CURVE_VISIBLE`.
- Select linked: is for F-curves channel only
- Select more/less: not yet implemented for grease pencil layers.
- Clean Keys, Sample, Extrapolation, Interpolation, Easing, and Handle
  type change: work on Fcurve-channels only, so the
  `ANIMFILTER_FCURVESONLY` filter is activated

Graying out these operators (when no fcurve keyframe is selected) can be
done with custom poll functions BUT may affect performance. This is NOT
done in this patch.

**Dopesheet Summary Selection:**

The main summary of the dopesheet now also takes into account Grease
Pencil keyframes, using some nasty copy/pasting of code, as explained
[on devtalk](https://devtalk.blender.org/t/gpencil-layers-integration-in-main-dopesheet-selection-issue/24527).
It works, but may be improved, providing some deeper changes.

Reviewed By: mendio, pepeland, sybren

Maniphest Tasks: T97477

Differential Revision: https://developer.blender.org/D15003

1 files changed, 10 insertions, 5 deletions

diff --git a/source/blender/editors/space_graph/graph_ops.c b/source/blender/editors/space_graph/graph_ops.c
index 128925d4591..158f2eae88f 100644
--- a/source/blender/editors/space_graph/graph_ops.c
+++ b/source/blender/editors/space_graph/graph_ops.c
@@ -234,14 +234,16 @@ static int graphview_curves_hide_exec(bContext *C, wmOperator *op)
   /* get list of all channels that selection may need to be flushed to
    * - hierarchy must not affect what we have access to here...
    */
-  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_CHANNELS | ANIMFILTER_NODUPLIS);
+  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_FCURVESONLY | ANIMFILTER_LIST_CHANNELS |
+            ANIMFILTER_NODUPLIS);
   ANIM_animdata_filter(&ac, &all_data, filter, ac.data, ac.datatype);
 
   /* filter data
    * - of the remaining visible curves, we want to hide the ones that are
    *   selected/unselected (depending on "unselected" prop)
    */
-  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_CURVE_VISIBLE | ANIMFILTER_NODUPLIS);
+  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_FCURVESONLY | ANIMFILTER_CURVE_VISIBLE |
+            ANIMFILTER_NODUPLIS);
   if (unselected) {
     filter |= ANIMFILTER_UNSEL;
   }
@@ -275,7 +277,8 @@ static int graphview_curves_hide_exec(bContext *C, wmOperator *op)
   /* unhide selected */
   if (unselected) {
     /* turn off requirement for visible */
-    filter = ANIMFILTER_SEL | ANIMFILTER_NODUPLIS | ANIMFILTER_LIST_CHANNELS;
+    filter = ANIMFILTER_SEL | ANIMFILTER_NODUPLIS | ANIMFILTER_LIST_CHANNELS |
+             ANIMFILTER_FCURVESONLY;
 
     /* flushing has been done */
     ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);
@@ -344,13 +347,15 @@ static int graphview_curves_reveal_exec(bContext *C, wmOperator *op)
   /* get list of all channels that selection may need to be flushed to
    * - hierarchy must not affect what we have access to here...
    */
-  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_CHANNELS | ANIMFILTER_NODUPLIS);
+  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_CHANNELS | ANIMFILTER_NODUPLIS |
+            ANIMFILTER_FCURVESONLY);
   ANIM_animdata_filter(&ac, &all_data, filter, ac.data, ac.datatype);
 
   /* filter data
    * - just go through all visible channels, ensuring that everything is set to be curve-visible
    */
-  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_NODUPLIS);
+  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_NODUPLIS |
+            ANIMFILTER_FCURVESONLY);
   ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);
 
   for (ale = anim_data.first; ale; ale = ale->next) {