VSE: paste strips at mouse in preview

This PR makes it possible to paste strips directly at the mouse in the
VSE Preview, making it faster to paste strips directly at the position
the user wants the strip to be. It is still possible to paste the strip at the
original position with the `ctrl + shift + v` shortcut.

Pull Request: https://projects.blender.org/blender/blender/pulls/145008

source/blender/editors/space_sequencer/sequencer_clipboard.cc

@@ -11,6 +11,7 @@
 #include <algorithm>
 #include <cstring>
 
+#include "BLI_math_vector_types.hh"
 #include "BLO_readfile.hh"
 #include "BLO_writefile.hh"
 #include "MEM_guardedalloc.h"
@@ -42,6 +43,7 @@
 
 #include "SEQ_animation.hh"
 #include "SEQ_iterator.hh"
+#include "SEQ_relations.hh"
 #include "SEQ_select.hh"
 #include "SEQ_sequencer.hh"
 #include "SEQ_time.hh"
@@ -55,6 +57,7 @@
 #include "ANIM_action_legacy.hh"
 #include "ANIM_animdata.hh"
 
+#include "UI_view2d.hh"
 #include "WM_api.hh"
 #include "WM_types.hh"
 
@@ -396,6 +399,15 @@ static bool sequencer_paste_animation(Main *bmain_dst, Scene *scene_dst, Scene *
   return true;
 }
 
+wmOperatorStatus sequencer_clipboard_paste_invoke(bContext *C,
+                                                  wmOperator *op,
+                                                  const wmEvent *event)
+{
+  RNA_int_set(op->ptr, "x", event->mval[0]);
+  RNA_int_set(op->ptr, "y", event->mval[1]);
+  return sequencer_clipboard_paste_exec(C, op);
+}
+
 wmOperatorStatus sequencer_clipboard_paste_exec(bContext *C, wmOperator *op)
 {
   char filepath[FILE_MAX];
@@ -403,6 +415,14 @@ wmOperatorStatus sequencer_clipboard_paste_exec(bContext *C, wmOperator *op)
   const BlendFileReadParams params{};
   BlendFileReadReport bf_reports{};
   BlendFileData *bfd = BKE_blendfile_read(filepath, &params, &bf_reports);
+  const int mval[2] = {RNA_int_get(op->ptr, "x"), RNA_int_get(op->ptr, "y")};
+  float2 view_mval;
+  View2D *v2d = UI_view2d_fromcontext(C);
+  Scene *scene = CTX_data_sequencer_scene(C);
+  UI_view2d_region_to_view(v2d, mval[0], mval[1], &view_mval[0], &view_mval[1]);
+
+  /* For checking if region type is Preview. */
+  ARegion *region = CTX_wm_region(C);
 
   if (bfd == nullptr) {
     BKE_report(op->reports, RPT_INFO, "No data to paste");
@@ -440,7 +460,7 @@ wmOperatorStatus sequencer_clipboard_paste_exec(bContext *C, wmOperator *op)
   int ofs;
 
   deselect_all_strips(scene_dst);
-  if (RNA_boolean_get(op->ptr, "keep_offset")) {
+  if (RNA_boolean_get(op->ptr, "keep_offset") || (region->regiontype == RGN_TYPE_PREVIEW)) {
     ofs = scene_dst->r.cfra - scene_src->r.cfra;
   }
   else {
@@ -501,6 +521,7 @@ wmOperatorStatus sequencer_clipboard_paste_exec(bContext *C, wmOperator *op)
   /* Restore "first" pointer as BLI_movelisttolist sets it to nullptr */
   nseqbase.first = iseq_first;
 
+  int2 strip_mean_pos = {0, 0};
   LISTBASE_FOREACH (Strip *, istrip, &nseqbase) {
     if (istrip->name == active_seq_name) {
       seq::select_active_set(scene_dst, istrip);
@@ -508,8 +529,13 @@ wmOperatorStatus sequencer_clipboard_paste_exec(bContext *C, wmOperator *op)
     /* Make sure, that pasted strips have unique names. This has to be done after
      * adding strips to seqbase, for lookup cache to work correctly. */
     seq::ensure_unique_name(istrip, scene_dst);
+
+    strip_mean_pos += static_cast<int2>(
+        seq::image_transform_origin_offset_pixelspace_get(scene, istrip));
   }
 
+  strip_mean_pos /= BLI_listbase_count(&nseqbase);
+
   LISTBASE_FOREACH (Strip *, istrip, &nseqbase) {
     /* Translate after name has been changed, otherwise this will affect animdata of original
      * strip. */
@@ -518,6 +544,14 @@ wmOperatorStatus sequencer_clipboard_paste_exec(bContext *C, wmOperator *op)
     if (seq::transform_test_overlap(scene_dst, ed_dst->current_strips(), istrip)) {
       seq::transform_seqbase_shuffle(ed_dst->current_strips(), istrip, scene_dst);
     }
+    if (region->regiontype == RGN_TYPE_PREVIEW && !(RNA_boolean_get(op->ptr, "keep_offset"))) {
+      StripTransform *transform = istrip->data->transform;
+      const float2 mirror = seq::image_transform_mirror_factor_get(istrip);
+      const float2 origin = seq::image_transform_origin_offset_pixelspace_get(scene, istrip);
+      transform->xofs = (view_mval[0] - (strip_mean_pos[0] - origin[0])) * mirror[0];
+      transform->yofs = (view_mval[1] - (strip_mean_pos[1] - origin[1])) * mirror[1];
+      seq::relations_invalidate_cache(scene, istrip);
+    }
   }
 
   seq::animation_restore_original(scene_dst, &animation_backup);

source/blender/editors/space_sequencer/sequencer_edit.cc

@@ -2860,6 +2860,7 @@ void SEQUENCER_OT_paste(wmOperatorType *ot)
   ot->description = "Paste strips from the internal clipboard";
 
   /* API callbacks. */
+  ot->invoke = sequencer_clipboard_paste_invoke;
   ot->exec = sequencer_clipboard_paste_exec;
   ot->poll = ED_operator_sequencer_active;
 
@@ -2874,6 +2875,10 @@ void SEQUENCER_OT_paste(wmOperatorType *ot)
       "Keep Offset",
       "Keep strip offset relative to the current frame when pasting");
   RNA_def_property_flag(prop, PROP_SKIP_SAVE);
+  prop = RNA_def_int(ot->srna, "x", 0, INT_MIN, INT_MAX, "X", "", INT_MIN, INT_MAX);
+  RNA_def_property_flag(prop, PROP_HIDDEN | PROP_SKIP_SAVE);
+  prop = RNA_def_int(ot->srna, "y", 0, INT_MIN, INT_MAX, "Y", "", INT_MIN, INT_MAX);
+  RNA_def_property_flag(prop, PROP_HIDDEN | PROP_SKIP_SAVE);
 }
 
 /** \} */

source/blender/editors/space_sequencer/sequencer_intern.hh

@@ -406,6 +406,9 @@ blender::Vector<Strip *> sequencer_visible_strips_get(const Scene *scene, const
 /* `sequencer_clipboard.cc` */
 wmOperatorStatus sequencer_clipboard_copy_exec(bContext *C, wmOperator *op);
 wmOperatorStatus sequencer_clipboard_paste_exec(bContext *C, wmOperator *op);
+wmOperatorStatus sequencer_clipboard_paste_invoke(bContext *C,
+                                                  wmOperator *op,
+                                                  const wmEvent *event);
 
 /* `sequencer_add_menu_scene_assets.cc` */
 MenuType add_catalog_assets_menu_type();