Politically correct terrible consequencer changes

This patch includes the work done in the terrible consequencer branch
that hasn't been merged to master minus a few controversial and WIP
stuff, like strip parenting, new sequence data structs and cuddly
widgets.

What is included:

* Strip extensions only when slipping. It can very easily be made an
option but with a few strips with overlapping durations it makes view
too crowded and difficult to make out.
* Threaded waveform loading + code that restores waveforms on undo (not
used though, since sound_load recreates everything. There's a patch for
review D876)
* Toggle to enable backdrop in the strip sequence editor
* Toggle to easily turn on/off waveform display
* Snapping during transform on sequence boundaries. Snapping to start or
end of selection depends on position of mouse when invoking the operator
* Snapping of timeline indicator in sequencer to strip boundaries. To
use just press and hold ctrl while dragging.

Reviewers: campbellbarton

Differential Revision: https://developer.blender.org/D904

1 files changed, 9 insertions, 0 deletions

diff --git a/source/blender/editors/transform/transform.h b/source/blender/editors/transform/transform.h
index 67d55639528..c2891b50321 100644
--- a/source/blender/editors/transform/transform.h
+++ b/source/blender/editors/transform/transform.h
@@ -173,6 +173,13 @@ typedef struct TransDataSeq {
 
 } TransDataSeq;
 
+typedef struct TransSeq {
+	TransDataSeq *tdseq;
+	int min;
+	int max;
+	bool snap_left;
+} TransSeq;
+
 /* for NLA transform (stored in td->extra pointer) */
 typedef struct TransDataNla {
 	ID *id;						/* ID-block NLA-data is attached to */
@@ -588,6 +595,8 @@ typedef enum {
 void snapGridIncrement(TransInfo *t, float *val);
 void snapGridIncrementAction(TransInfo *t, float *val, GearsType action);
 
+int snapSequenceBounds(TransInfo *t, const int mval[2]);
+
 bool activeSnap(TransInfo *t);
 bool validSnap(TransInfo *t);