VSE: Strip drawing improvements

This patch include changes:
- Thicker and clearer selection indication
- Slimmer handles
- More transparent muted strips
- Trim frame number is drawn inside the strip
- Strip text is drawn in upper part of strip
- Color strips now have specific color, with chosen color drawn under strip text
- Transition strip will use color of input strips showing direction of transition
- Selecting effect strip will highlight input strips
- Selecting multicam strips will highlight target channel
- Missing media state is now indicated by a red line drawn on the top part of the strip
- A checkerboard pattern is now drawn on the outsides of the meta range
- Hold still regions are now always drawn if existent, with a darker shade of the strip’s background color

Author: Alessio Monti di Sopra <a.monti>

Reviewed By: ISS

Differential Revision: https://developer.blender.org/D6883

1 files changed, 3 insertions, 1 deletions

diff --git a/source/blender/editors/include/UI_resources.h b/source/blender/editors/include/UI_resources.h
index c1de697b0c5..7e510edd95b 100644
--- a/source/blender/editors/include/UI_resources.h
+++ b/source/blender/editors/include/UI_resources.h
@@ -205,10 +205,12 @@ typedef enum ThemeColorID {
   TH_SEQ_SCENE,
   TH_SEQ_AUDIO,
   TH_SEQ_EFFECT,
-  TH_SEQ_TRANSITION,
   TH_SEQ_META,
   TH_SEQ_TEXT,
   TH_SEQ_PREVIEW,
+  TH_SEQ_COLOR,
+  TH_SEQ_ACTIVE,
+  TH_SEQ_SELECTED,
 
   TH_EDGE_SHARP,
   TH_EDITMESH_ACTIVE,