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, 56 insertions, 10 deletions

diff --git a/source/blender/editors/include/ED_anim_api.h b/source/blender/editors/include/ED_anim_api.h
index 6342a8b26d9..cd68981dee3 100644
--- a/source/blender/editors/include/ED_anim_api.h
+++ b/source/blender/editors/include/ED_anim_api.h
@@ -403,7 +403,8 @@ typedef enum eAnimFilter_Flags {
 /* -------------- Channel Defines -------------- */
 
 /* channel heights */
-#define ACHANNEL_FIRST_TOP(ac) (-0.4f * (ac)->yscale_fac * U.widget_unit)
+#define ACHANNEL_FIRST_TOP(ac) \
+  (UI_view2d_scale_get_y(&(ac)->ar->v2d) * -UI_SCRUBBING_MARGIN_Y - ACHANNEL_SKIP)
 #define ACHANNEL_HEIGHT(ac) (0.8f * (ac)->yscale_fac * U.widget_unit)
 #define ACHANNEL_SKIP (0.1f * U.widget_unit)
 #define ACHANNEL_STEP(ac) (ACHANNEL_HEIGHT(ac) + ACHANNEL_SKIP)
@@ -420,14 +421,15 @@ typedef enum eAnimFilter_Flags {
 /* -------------- NLA Channel Defines -------------- */
 
 /* NLA channel heights */
-#define NLACHANNEL_FIRST_TOP(snla) (-0.4f * U.widget_unit)
+#define NLACHANNEL_FIRST_TOP(ac) \
+  (UI_view2d_scale_get_y(&(ac)->ar->v2d) * -UI_SCRUBBING_MARGIN_Y - NLACHANNEL_SKIP)
 #define NLACHANNEL_HEIGHT(snla) \
   ((snla && (snla->flag & SNLA_NOSTRIPCURVES)) ? (0.8f * U.widget_unit) : (1.2f * U.widget_unit))
 #define NLACHANNEL_SKIP (0.1f * U.widget_unit)
 #define NLACHANNEL_STEP(snla) (NLACHANNEL_HEIGHT(snla) + NLACHANNEL_SKIP)
 /* Additional offset to give some room at the end. */
-#define NLACHANNEL_TOT_HEIGHT(snla, item_amount) \
-  (-NLACHANNEL_FIRST_TOP(snla) + NLACHANNEL_STEP(snla) * (item_amount + 1))
+#define NLACHANNEL_TOT_HEIGHT(ac, item_amount) \
+  (-NLACHANNEL_FIRST_TOP(ac) + NLACHANNEL_STEP(((SpaceNla *)(ac)->sl)) * (item_amount + 1))
 
 /* channel widths */
 #define NLACHANNEL_NAMEWIDTH (10 * U.widget_unit)
diff --git a/source/blender/editors/include/ED_screen.h b/source/blender/editors/include/ED_screen.h
index 264eb6abdf1..6734342b880 100644
--- a/source/blender/editors/include/ED_screen.h
+++ b/source/blender/editors/include/ED_screen.h
@@ -436,12 +436,11 @@ enum {
   ED_KEYMAP_GIZMO = (1 << 2),
   ED_KEYMAP_TOOL = (1 << 3),
   ED_KEYMAP_VIEW2D = (1 << 4),
-  ED_KEYMAP_MARKERS = (1 << 5),
-  ED_KEYMAP_ANIMATION = (1 << 6),
-  ED_KEYMAP_FRAMES = (1 << 7),
-  ED_KEYMAP_HEADER = (1 << 8),
-  ED_KEYMAP_GPENCIL = (1 << 9),
-  ED_KEYMAP_FOOTER = (1 << 10),
+  ED_KEYMAP_ANIMATION = (1 << 5),
+  ED_KEYMAP_FRAMES = (1 << 6),
+  ED_KEYMAP_HEADER = (1 << 7),
+  ED_KEYMAP_GPENCIL = (1 << 8),
+  ED_KEYMAP_FOOTER = (1 << 9),
 };
 
 /* SCREEN_OT_space_context_cycle direction */
diff --git a/source/blender/editors/include/ED_scrubbing.h b/source/blender/editors/include/ED_scrubbing.h
new file mode 100644
index 00000000000..cc225723f64
--- /dev/null
+++ b/source/blender/editors/include/ED_scrubbing.h
@@ -0,0 +1,40 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2019 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup editors
+ */
+
+#ifndef __ED_SCRUBBING_H__
+#define __ED_SCRUBBING_H__
+
+struct bContext;
+struct View2DGrid;
+struct bDopeSheet;
+
+void ED_scrubbing_draw(const struct ARegion *ar,
+                       const struct Scene *scene,
+                       bool display_seconds,
+                       bool discrete_frames);
+
+void ED_channel_search_draw(const struct bContext *C,
+                            struct ARegion *ar,
+                            struct bDopeSheet *dopesheet);
+
+#endif /* __ED_SCRUBBING_H__ */
diff --git a/source/blender/editors/include/UI_resources.h b/source/blender/editors/include/UI_resources.h
index af94889a1bb..0c2090b2c91 100644
--- a/source/blender/editors/include/UI_resources.h
+++ b/source/blender/editors/include/UI_resources.h
@@ -105,6 +105,7 @@ typedef enum ThemeColorID {
   TH_FACE_DOT,
   TH_FACEDOT_SIZE,
   TH_CFRAME,
+  TH_SCRUBBING_BACKGROUND,
   TH_TIME_KEYFRAME,
   TH_TIME_GP_KEYFRAME,
   TH_NURB_ULINE,
@@ -267,6 +268,8 @@ typedef enum ThemeColorID {
   TH_ICON_MODIFIER,
   TH_ICON_SHADING,
 
+  TH_SCROLL_TEXT,
+
   TH_NLA_TWEAK,       /* 'tweaking' track in NLA */
   TH_NLA_TWEAK_DUPLI, /* error/warning flag for other strips referencing dupli strip */
 
diff --git a/source/blender/editors/include/UI_view2d.h b/source/blender/editors/include/UI_view2d.h
index 064951d40ed..6e9675f4c63 100644
--- a/source/blender/editors/include/UI_view2d.h
+++ b/source/blender/editors/include/UI_view2d.h
@@ -258,6 +258,8 @@ void UI_view2d_smooth_view(struct bContext *C,
                            struct ARegion *ar,
                            const struct rctf *cur,
                            const int smooth_viewtx);
+
 #define UI_MARKER_MARGIN_Y (42 * UI_DPI_FAC)
+#define UI_SCRUBBING_MARGIN_Y (23 * UI_DPI_FAC)
 
 #endif /* __UI_VIEW2D_H__ */