VSE: Move remove gaps operator logic to module code

Logic was broken into finding gaps and ofsetting strips.
Functions were modified so they work on explicitly defined seqbase,
so they can be used as python API functions.

Functional changes:
 - Improve performance by calculating gap length and offseting strips
   at once. Previously strips were offset by one frame.
 - Calculate gap from start frame. Previously gap was considered only
   inbetween strips.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D9730

1 files changed, 35 insertions, 0 deletions

diff --git a/source/blender/sequencer/intern/strip_edit.c b/source/blender/sequencer/intern/strip_edit.c
index 3137a471470..a29810cc9ee 100644
--- a/source/blender/sequencer/intern/strip_edit.c
+++ b/source/blender/sequencer/intern/strip_edit.c
@@ -38,6 +38,8 @@
 #include "BKE_scene.h"
 #include "BKE_sound.h"
 
+#include "strip_time.h"
+
 #include "SEQ_sequencer.h"
 
 int BKE_sequence_swap(Sequence *seq_a, Sequence *seq_b, const char **error_str)
@@ -319,3 +321,36 @@ Sequence *SEQ_edit_strip_split(Main *bmain,
   BKE_sequence_calc(scene, right_seq);
   return right_seq;
 }
+
+/**
+ * Find gap after initial_frame and move strips on right side to close the gap
+ *
+ * \param scene: Scene in which strips are located
+ * \param seqbase: ListBase in which strips are located
+ * \param initial_frame: frame on timeline from where gaps are searched for
+ * \param remove_all_gaps: remove all gaps instead of one gap
+ * \return true if gap is removed, otherwise false
+ */
+bool SEQ_edit_remove_gaps(Scene *scene,
+                          ListBase *seqbase,
+                          const int initial_frame,
+                          const bool remove_all_gaps)
+{
+  GapInfo gap_info = {0};
+  seq_time_gap_info_get(scene, seqbase, initial_frame, &gap_info);
+
+  if (!gap_info.gap_exists) {
+    return false;
+  }
+
+  if (remove_all_gaps) {
+    while (gap_info.gap_exists) {
+      SEQ_offset_after_frame(scene, seqbase, -gap_info.gap_length, gap_info.gap_start_frame);
+      seq_time_gap_info_get(scene, seqbase, initial_frame, &gap_info);
+    }
+  }
+  else {
+    SEQ_offset_after_frame(scene, seqbase, -gap_info.gap_length, gap_info.gap_start_frame);
+  }
+  return true;
+}