VSE: Add precise drag and drop and strip previews

This patch adds the drag and drop strip previews in the VSE.
It also adds two new functions to the drag and drop API.

1. "draw_in_view" for callbacks that wants to draw elements in local viewport coordinates
2. "on_drag_start" that can be used for prefetching data only once at the start of the drag.

Reviewed By: Julian, Campbell

Differential Revision: http://developer.blender.org/D14560

1 files changed, 126 insertions, 17 deletions

diff --git a/source/blender/editors/space_sequencer/sequencer_add.c b/source/blender/editors/space_sequencer/sequencer_add.c
index 4672961543f..9298eb83b46 100644
--- a/source/blender/editors/space_sequencer/sequencer_add.c
+++ b/source/blender/editors/space_sequencer/sequencer_add.c
@@ -125,12 +125,20 @@ static void sequencer_generic_props__internal(wmOperatorType *ot, int flag)
       ot->srna, "channel", 1, 1, MAXSEQ, "Channel", "Channel to place this strip into", 1, MAXSEQ);
 
   RNA_def_boolean(
-      ot->srna, "replace_sel", 1, "Replace Selection", "Replace the current selection");
+      ot->srna, "replace_sel", true, "Replace Selection", "Replace the current selection");
 
   /* Only for python scripts which import strips and place them after. */
   prop = RNA_def_boolean(
-      ot->srna, "overlap", 0, "Allow Overlap", "Don't correct overlap on new sequence strips");
-  RNA_def_property_flag(prop, PROP_HIDDEN);
+      ot->srna, "overlap", false, "Allow Overlap", "Don't correct overlap on new sequence strips");
+  RNA_def_property_flag(prop, PROP_HIDDEN | PROP_SKIP_SAVE);
+
+  prop = RNA_def_boolean(
+      ot->srna,
+      "overlap_shuffle_override",
+      false,
+      "Override Overlap Shuffle Behaviour",
+      "Use the overlap_mode tool settings to determine how to shuffle overlapping strips");
+  RNA_def_property_flag(prop, PROP_HIDDEN | PROP_SKIP_SAVE);
 
   if (flag & SEQPROP_FIT_METHOD) {
     ot->prop = RNA_def_enum(ot->srna,
@@ -205,10 +213,13 @@ static void sequencer_generic_invoke_xy__internal(bContext *C, wmOperator *op, i
     RNA_int_set(op->ptr, "channel", sequencer_generic_invoke_xy_guess_channel(C, type));
   }
 
-  RNA_int_set(op->ptr, "frame_start", timeline_frame);
+  if (!RNA_struct_property_is_set(op->ptr, "frame_start")) {
+    RNA_int_set(op->ptr, "frame_start", timeline_frame);
+  }
 
   if ((flag & SEQPROP_ENDFRAME) && RNA_struct_property_is_set(op->ptr, "frame_end") == 0) {
-    RNA_int_set(op->ptr, "frame_end", timeline_frame + 25); /* XXX arbitrary but ok for now. */
+    RNA_int_set(
+        op->ptr, "frame_end", RNA_int_get(op->ptr, "frame_start") + DEFAULT_IMG_STRIP_LENGTH);
   }
 
   if (!(flag & SEQPROP_NOPATHS)) {
@@ -312,13 +323,53 @@ static void seq_load_apply_generic_options(bContext *C, wmOperator *op, Sequence
     SEQ_select_active_set(scene, seq);
   }
 
-  if (RNA_boolean_get(op->ptr, "overlap") == false) {
-    if (SEQ_transform_test_overlap(ed->seqbasep, seq)) {
-      SEQ_transform_seqbase_shuffle(ed->seqbasep, seq, scene);
-    }
+  if (RNA_boolean_get(op->ptr, "overlap") == true ||
+      !SEQ_transform_test_overlap(ed->seqbasep, seq)) {
+    /* No overlap should be handled or the strip is not overlapping, exit early. */
+    return;
+  }
+
+  if (RNA_boolean_get(op->ptr, "overlap_shuffle_override")) {
+    /* Use set overlap_mode to fix overlaps. */
+    SeqCollection *strip_col = SEQ_collection_create(__func__);
+    SEQ_collection_append_strip(seq, strip_col);
+
+    ScrArea *area = CTX_wm_area(C);
+    const bool use_sync_markers = (((SpaceSeq *)area->spacedata.first)->flag & SEQ_MARKER_TRANS) !=
+                                  0;
+    SEQ_transform_handle_overlap(scene, ed->seqbasep, strip_col, use_sync_markers);
+
+    SEQ_collection_free(strip_col);
+  }
+  else {
+    /* Shuffle strip channel to fix overlaps. */
+    SEQ_transform_seqbase_shuffle(ed->seqbasep, seq, scene);
   }
 }
 
+/* In this alternative version we only check for overlap, but do not do anything about them. */
+static bool seq_load_apply_generic_options_only_test_overlap(bContext *C,
+                                                             wmOperator *op,
+                                                             Sequence *seq,
+                                                             SeqCollection *strip_col)
+{
+  Scene *scene = CTX_data_scene(C);
+  Editing *ed = SEQ_editing_get(scene);
+
+  if (seq == NULL) {
+    return false;
+  }
+
+  if (RNA_boolean_get(op->ptr, "replace_sel")) {
+    seq->flag |= SELECT;
+    SEQ_select_active_set(scene, seq);
+  }
+
+  SEQ_collection_append_strip(seq, strip_col);
+
+  return SEQ_transform_test_overlap(ed->seqbasep, seq);
+}
+
 static bool seq_effect_add_properties_poll(const bContext *UNUSED(C),
                                            wmOperator *op,
                                            const PropertyRNA *prop)
@@ -634,6 +685,14 @@ static void sequencer_add_movie_multiple_strips(bContext *C,
   Main *bmain = CTX_data_main(C);
   Scene *scene = CTX_data_scene(C);
   const Editing *ed = SEQ_editing_ensure(scene);
+  bool overlap_shuffle_override = RNA_boolean_get(op->ptr, "overlap") == false &&
+                                  RNA_boolean_get(op->ptr, "overlap_shuffle_override");
+  bool has_seq_overlap = false;
+  SeqCollection *strip_col = NULL;
+
+  if (overlap_shuffle_override) {
+    strip_col = SEQ_collection_create(__func__);
+  }
 
   RNA_BEGIN (op->ptr, itemptr, "files") {
     char dir_only[FILE_MAX];
@@ -645,9 +704,8 @@ static void sequencer_add_movie_multiple_strips(bContext *C,
     Sequence *seq_movie = NULL;
     Sequence *seq_sound = NULL;
 
-    load_data->channel++;
     seq_movie = SEQ_add_movie_strip(bmain, scene, ed->seqbasep, load_data);
-    load_data->channel--;
+
     if (seq_movie == NULL) {
       BKE_reportf(op->reports, RPT_ERROR, "File '%s' could not be loaded", load_data->path);
     }
@@ -655,15 +713,40 @@ static void sequencer_add_movie_multiple_strips(bContext *C,
       if (RNA_boolean_get(op->ptr, "sound")) {
         seq_sound = SEQ_add_sound_strip(bmain, scene, ed->seqbasep, load_data);
         sequencer_add_movie_clamp_sound_strip_length(scene, ed->seqbasep, seq_movie, seq_sound);
+
+        if (seq_sound) {
+          /* The video has sound, shift the video strip up a channel to make room for the sound
+           * strip. */
+          seq_movie->machine++;
+        }
       }
 
       load_data->start_frame += seq_movie->enddisp - seq_movie->startdisp;
-      seq_load_apply_generic_options(C, op, seq_sound);
-      seq_load_apply_generic_options(C, op, seq_movie);
+      if (overlap_shuffle_override) {
+        has_seq_overlap |= seq_load_apply_generic_options_only_test_overlap(
+            C, op, seq_sound, strip_col);
+        has_seq_overlap |= seq_load_apply_generic_options_only_test_overlap(
+            C, op, seq_movie, strip_col);
+      }
+      else {
+        seq_load_apply_generic_options(C, op, seq_sound);
+        seq_load_apply_generic_options(C, op, seq_movie);
+      }
       SEQ_collection_append_strip(seq_movie, r_movie_strips);
     }
   }
   RNA_END;
+
+  if (overlap_shuffle_override) {
+    if (has_seq_overlap) {
+      ScrArea *area = CTX_wm_area(C);
+      const bool use_sync_markers = (((SpaceSeq *)area->spacedata.first)->flag &
+                                     SEQ_MARKER_TRANS) != 0;
+      SEQ_transform_handle_overlap(scene, ed->seqbasep, strip_col, use_sync_markers);
+    }
+
+    SEQ_collection_free(strip_col);
+  }
 }
 
 static bool sequencer_add_movie_single_strip(bContext *C,
@@ -678,9 +761,7 @@ static bool sequencer_add_movie_single_strip(bContext *C,
   Sequence *seq_movie = NULL;
   Sequence *seq_sound = NULL;
 
-  load_data->channel++;
   seq_movie = SEQ_add_movie_strip(bmain, scene, ed->seqbasep, load_data);
-  load_data->channel--;
 
   if (seq_movie == NULL) {
     BKE_reportf(op->reports, RPT_ERROR, "File '%s' could not be loaded", load_data->path);
@@ -689,9 +770,37 @@ static bool sequencer_add_movie_single_strip(bContext *C,
   if (RNA_boolean_get(op->ptr, "sound")) {
     seq_sound = SEQ_add_sound_strip(bmain, scene, ed->seqbasep, load_data);
     sequencer_add_movie_clamp_sound_strip_length(scene, ed->seqbasep, seq_movie, seq_sound);
+    if (seq_sound) {
+      /* The video has sound, shift the video strip up a channel to make room for the sound
+       * strip. */
+      seq_movie->machine++;
+    }
+  }
+
+  bool overlap_shuffle_override = RNA_boolean_get(op->ptr, "overlap") == false &&
+                                  RNA_boolean_get(op->ptr, "overlap_shuffle_override");
+  if (overlap_shuffle_override) {
+    SeqCollection *strip_col = SEQ_collection_create(__func__);
+    bool has_seq_overlap = false;
+
+    has_seq_overlap |= seq_load_apply_generic_options_only_test_overlap(
+        C, op, seq_sound, strip_col);
+    has_seq_overlap |= seq_load_apply_generic_options_only_test_overlap(
+        C, op, seq_movie, strip_col);
+
+    if (has_seq_overlap) {
+      ScrArea *area = CTX_wm_area(C);
+      const bool use_sync_markers = (((SpaceSeq *)area->spacedata.first)->flag &
+                                     SEQ_MARKER_TRANS) != 0;
+      SEQ_transform_handle_overlap(scene, ed->seqbasep, strip_col, use_sync_markers);
+    }
+
+    SEQ_collection_free(strip_col);
+  }
+  else {
+    seq_load_apply_generic_options(C, op, seq_sound);
+    seq_load_apply_generic_options(C, op, seq_movie);
   }
-  seq_load_apply_generic_options(C, op, seq_sound);
-  seq_load_apply_generic_options(C, op, seq_movie);
   SEQ_collection_append_strip(seq_movie, r_movie_strips);
 
   return true;