UI: Animation editor scrubbing area

The main reason for this change is to allow setting the
active frame with the left mouse button, while still being
able to select e.g. keyframes with the same mouse button.

The solution is to introduce a new scrubbing region with
a specialized keymap. There are a couple of related todos,
that will be handled in separate commits.
Those are listed in D4654.

This solves T63193.

Differential Revision: https://developer.blender.org/D4654

Reviewers: brecht, billreynish

5 files changed, 18 insertions, 19 deletions

diff --git a/source/blender/editors/space_nla/nla_channels.c b/source/blender/editors/space_nla/nla_channels.c
index 3e4eb6af098..e5c116e85de 100644
--- a/source/blender/editors/space_nla/nla_channels.c
+++ b/source/blender/editors/space_nla/nla_channels.c
@@ -52,6 +52,8 @@
 #include "WM_api.h"
 #include "WM_types.h"
 
+#include "UI_interface.h"
+
 #include "DEG_depsgraph.h"
 #include "DEG_depsgraph_build.h"
 
@@ -389,7 +391,7 @@ static int nlachannels_mouseclick_invoke(bContext *C, wmOperator *op, const wmEv
   UI_view2d_listview_view_to_cell(NLACHANNEL_NAMEWIDTH,
                                   NLACHANNEL_STEP(snla),
                                   0,
-                                  NLACHANNEL_FIRST_TOP(snla),
+                                  NLACHANNEL_FIRST_TOP(&ac),
                                   x,
                                   y,
                                   NULL,
diff --git a/source/blender/editors/space_nla/nla_draw.c b/source/blender/editors/space_nla/nla_draw.c
index b821a246dc5..68cbfd76331 100644
--- a/source/blender/editors/space_nla/nla_draw.c
+++ b/source/blender/editors/space_nla/nla_draw.c
@@ -689,11 +689,11 @@ void draw_nla_main_data(bAnimContext *ac, SpaceNla *snla, ARegion *ar)
    * - offset of NLACHANNEL_HEIGHT*2 is added to the height of the channels, as first is for
    *   start of list offset, and the second is as a correction for the scrollers.
    */
-  int height = NLACHANNEL_TOT_HEIGHT(snla, items);
+  int height = NLACHANNEL_TOT_HEIGHT(ac, items);
   v2d->tot.ymin = -height;
 
   /* loop through channels, and set up drawing depending on their type  */
-  float ymax = NLACHANNEL_FIRST_TOP(snla);
+  float ymax = NLACHANNEL_FIRST_TOP(ac);
 
   for (bAnimListElem *ale = anim_data.first; ale; ale = ale->next, ymax -= NLACHANNEL_STEP(snla)) {
     float ymin = ymax - NLACHANNEL_HEIGHT(snla);
@@ -822,7 +822,7 @@ void draw_nla_channel_list(const bContext *C, bAnimContext *ac, ARegion *ar)
    * - offset of NLACHANNEL_HEIGHT*2 is added to the height of the channels, as first is for
    *  start of list offset, and the second is as a correction for the scrollers.
    */
-  int height = NLACHANNEL_TOT_HEIGHT(snla, items);
+  int height = NLACHANNEL_TOT_HEIGHT(ac, items);
   v2d->tot.ymin = -height;
 
   /* need to do a view-sync here, so that the keys area doesn't jump around
@@ -832,7 +832,7 @@ void draw_nla_channel_list(const bContext *C, bAnimContext *ac, ARegion *ar)
   /* draw channels */
   { /* first pass: just the standard GL-drawing for backdrop + text */
     size_t channel_index = 0;
-    float ymax = NLACHANNEL_FIRST_TOP(snla);
+    float ymax = NLACHANNEL_FIRST_TOP(ac);
 
     for (ale = anim_data.first; ale;
          ale = ale->next, ymax -= NLACHANNEL_STEP(snla), channel_index++) {
@@ -849,7 +849,7 @@ void draw_nla_channel_list(const bContext *C, bAnimContext *ac, ARegion *ar)
   { /* second pass: UI widgets */
     uiBlock *block = UI_block_begin(C, ar, __func__, UI_EMBOSS);
     size_t channel_index = 0;
-    float ymax = NLACHANNEL_FIRST_TOP(snla);
+    float ymax = NLACHANNEL_FIRST_TOP(ac);
 
     /* set blending again, as may not be set in previous step */
     GPU_blend_set_func_separate(
diff --git a/source/blender/editors/space_nla/nla_edit.c b/source/blender/editors/space_nla/nla_edit.c
index 07853e5850a..cf1794cd2c7 100644
--- a/source/blender/editors/space_nla/nla_edit.c
+++ b/source/blender/editors/space_nla/nla_edit.c
@@ -429,7 +429,7 @@ static bool nla_channels_get_selected_extents(bAnimContext *ac, float *min, floa
   ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
 
   /* loop through all channels, finding the first one that's selected */
-  float ymax = NLACHANNEL_FIRST_TOP(snla);
+  float ymax = NLACHANNEL_FIRST_TOP(ac);
 
   for (ale = anim_data.first; ale; ale = ale->next, ymax -= NLACHANNEL_STEP(snla)) {
     const bAnimChannelType *acf = ANIM_channel_get_typeinfo(ale);
diff --git a/source/blender/editors/space_nla/nla_select.c b/source/blender/editors/space_nla/nla_select.c
index accd82525f5..0de9acfec25 100644
--- a/source/blender/editors/space_nla/nla_select.c
+++ b/source/blender/editors/space_nla/nla_select.c
@@ -47,6 +47,7 @@
 #include "WM_types.h"
 
 #include "UI_view2d.h"
+#include "UI_interface.h"
 
 #include "nla_intern.h"  // own include
 
@@ -542,7 +543,7 @@ static void mouse_nla_strips(
    * (i.e a row in the list) where keyframe was */
   UI_view2d_region_to_view(v2d, mval[0], mval[1], &x, &y);
   UI_view2d_listview_view_to_cell(
-      0, NLACHANNEL_STEP(snla), 0, NLACHANNEL_FIRST_TOP(snla), x, y, NULL, &channel_index);
+      0, NLACHANNEL_STEP(snla), 0, NLACHANNEL_FIRST_TOP(ac), x, y, NULL, &channel_index);
 
   /* x-range to check is +/- 7 (in screen/region-space) on either side of mouse click
    * (that is the size of keyframe icons, so user should be expecting similar tolerances)
diff --git a/source/blender/editors/space_nla/space_nla.c b/source/blender/editors/space_nla/space_nla.c
index ba660945d32..123f34a3c43 100644
--- a/source/blender/editors/space_nla/space_nla.c
+++ b/source/blender/editors/space_nla/space_nla.c
@@ -40,6 +40,7 @@
 #include "ED_anim_api.h"
 #include "ED_markers.h"
 #include "ED_screen.h"
+#include "ED_scrubbing.h"
 
 #include "WM_api.h"
 #include "WM_types.h"
@@ -201,6 +202,9 @@ static void nla_channel_region_draw(const bContext *C, ARegion *ar)
     draw_nla_channel_list(C, &ac, ar);
   }
 
+  /* channel filter next to scrubbing area */
+  ED_channel_search_draw(C, ar, ac.ads);
+
   /* reset view matrix */
   UI_view2d_view_restore(C);
 
@@ -284,20 +288,12 @@ static void nla_main_region_draw(const bContext *C, ARegion *ar)
   /* reset view matrix */
   UI_view2d_view_restore(C);
 
+  ED_scrubbing_draw(ar, 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);
-
-  /* frame numbers */
-  UI_view2d_draw_scale_x__discrete_frames_or_seconds(
-      ar, v2d, &v2d->hor, scene, snla->flag & SNLA_DRAWTIME, TH_TEXT);
-
-  /* draw current frame number-indicator on top of scrollers */
-  if ((snla->flag & SNLA_NODRAWCFRANUM) == 0) {
-    UI_view2d_view_orthoSpecial(ar, v2d, 1);
-    ANIM_draw_cfra_number(C, v2d, cfra_flag);
-  }
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
@@ -614,7 +610,7 @@ void ED_spacetype_nla(void)
   art->draw = nla_main_region_draw;
   art->listener = nla_main_region_listener;
   art->message_subscribe = nla_main_region_message_subscribe;
-  art->keymapflag = ED_KEYMAP_VIEW2D | ED_KEYMAP_MARKERS | ED_KEYMAP_ANIMATION | ED_KEYMAP_FRAMES;
+  art->keymapflag = ED_KEYMAP_VIEW2D | ED_KEYMAP_ANIMATION | ED_KEYMAP_FRAMES;
 
   BLI_addhead(&st->regiontypes, art);