Alembic import/export: added as_background_job option

The ABC_export and ABC_import functions both take a as_background_job
parameter, and return a boolean.

When as_background_job=true, returns false immediately after scheduling
a background job. This was the old behaviour of this function, which makes
it very hard for scripts to do something with the data after the import
or export completes.

When as_background_job=false, performs the export synchronously, and
returns true when the export was ok, and false if there were any errors.
This allows further processing.

The Scene.alembic_export() function is deprecated, and will be removed from
Blender 2.8 in favour of calling the bpy.ops.wm.alembic_export() operator.
As such, it has been hard-coded to the old background job behaviour.

1 files changed, 14 insertions, 4 deletions

diff --git a/source/blender/editors/io/io_alembic.c b/source/blender/editors/io/io_alembic.c
index 8651d89c403..62c36552048 100644
--- a/source/blender/editors/io/io_alembic.c
+++ b/source/blender/editors/io/io_alembic.c
@@ -133,9 +133,10 @@ static int wm_alembic_export_exec(bContext *C, wmOperator *op)
 	    .global_scale = RNA_float_get(op->ptr, "global_scale"),
 	};
 
-	ABC_export(CTX_data_scene(C), C, filename, &params);
+	const bool as_background_job = RNA_boolean_get(op->ptr, "as_background_job");
+	bool ok = ABC_export(CTX_data_scene(C), C, filename, &params, as_background_job);
 
-	return OPERATOR_FINISHED;
+	return as_background_job || ok ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 static void ui_alembic_export_settings(uiLayout *layout, PointerRNA *imfptr)
@@ -363,6 +364,9 @@ void WM_OT_alembic_export(wmOperatorType *ot)
 	RNA_def_boolean(ot->srna, "export_hair", 1, "Export Hair", "Exports hair particle systems as animated curves");
 	RNA_def_boolean(ot->srna, "export_particles", 1, "Export Particles", "Exports non-hair particle systems");
 
+	RNA_def_boolean(ot->srna, "as_background_job", true, "Run as Background Job",
+	                "Enable this to run the import in the background, disable to block Blender while importing");
+
 	/* This dummy prop is used to check whether we need to init the start and
      * end frame values to that of the scene's, otherwise they are reset at
      * every change, draw update. */
@@ -497,6 +501,7 @@ static int wm_alembic_import_exec(bContext *C, wmOperator *op)
 	const bool is_sequence = RNA_boolean_get(op->ptr, "is_sequence");
 	const bool set_frame_range = RNA_boolean_get(op->ptr, "set_frame_range");
 	const bool validate_meshes = RNA_boolean_get(op->ptr, "validate_meshes");
+	const bool as_background_job = RNA_boolean_get(op->ptr, "as_background_job");
 
 	int offset = 0;
 	int sequence_len = 1;
@@ -505,9 +510,11 @@ static int wm_alembic_import_exec(bContext *C, wmOperator *op)
 		sequence_len = get_sequence_len(filename, &offset);
 	}
 
-	ABC_import(C, filename, scale, is_sequence, set_frame_range, sequence_len, offset, validate_meshes);
+	bool ok = ABC_import(C, filename, scale, is_sequence, set_frame_range,
+	                     sequence_len, offset, validate_meshes,
+	                     as_background_job);
 
-	return OPERATOR_FINISHED;
+	return as_background_job || ok ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 void WM_OT_alembic_import(wmOperatorType *ot)
@@ -538,6 +545,9 @@ void WM_OT_alembic_import(wmOperatorType *ot)
 
 	RNA_def_boolean(ot->srna, "is_sequence", false, "Is Sequence",
 	                "Set to true if the cache is split into separate files");
+
+	RNA_def_boolean(ot->srna, "as_background_job", true, "Run as Background Job",
+	                "Enable this to run the export in the background, disable to block Blender while exporting");
 }
 
 #endif