Implement grouped undo option for operators

This option makes an operator to not push a task to the undo stack if the previous stored elemen is the same operator or part of the same undo group.

The main usage is for animation, so you can change frames to inspect the
poses, and revert the previous pose without having to roll back tons of
"change frame" operator, or even see the undo stack full.

This complements rB13ee9b8e
Design with help by Sergey Sharybin.

Reviewers: sergey, mont29

Reviewed By: mont29, sergey

Subscribers: pyc0d3r, hjalti, Severin, lowercase, brecht, monio, aligorith, hadrien, jbakker

Differential Revision: https://developer.blender.org/D2330

1 files changed, 42 insertions, 4 deletions

diff --git a/source/blender/makesrna/intern/rna_wm.c b/source/blender/makesrna/intern/rna_wm.c
index 90081a93188..35c9c9bcc89 100644
--- a/source/blender/makesrna/intern/rna_wm.c
+++ b/source/blender/makesrna/intern/rna_wm.c
@@ -419,6 +419,7 @@ static EnumPropertyItem keymap_modifiers_items[] = {
 static EnumPropertyItem operator_flag_items[] = {
 	{OPTYPE_REGISTER, "REGISTER", 0, "Register", "Display in the info window and support the redo toolbar panel"},
 	{OPTYPE_UNDO, "UNDO", 0, "Undo", "Push an undo event (needed for operator redo)"},
+	{OPTYPE_UNDO_GROUPED, "UNDO_GROUPED", 0, "Grouped Undo", "Push a single undo event for repetead instances of this operator"},
 	{OPTYPE_BLOCKING, "BLOCKING", 0, "Blocking", "Block anything else from using the cursor"},
 	{OPTYPE_MACRO, "MACRO", 0, "Macro", "Use to check if an operator is a macro"},
 	{OPTYPE_GRAB_CURSOR, "GRAB_CURSOR", 0, "Grab Pointer",
@@ -1139,6 +1140,7 @@ static char _operator_idname[OP_MAX_TYPENAME];
 static char _operator_name[OP_MAX_TYPENAME];
 static char _operator_descr[RNA_DYN_DESCR_MAX];
 static char _operator_ctxt[RNA_DYN_DESCR_MAX];
+static char _operator_undo_group[OP_MAX_TYPENAME];
 static StructRNA *rna_Operator_register(Main *bmain, ReportList *reports, void *data, const char *identifier,
                                         StructValidateFunc validate, StructCallbackFunc call, StructFreeFunc free)
 {
@@ -1153,10 +1155,11 @@ static StructRNA *rna_Operator_register(Main *bmain, ReportList *reports, void *
 	dummyot.name = _operator_name; /* only assigne the pointer, string is NULL'd */
 	dummyot.description = _operator_descr; /* only assigne the pointer, string is NULL'd */
 	dummyot.translation_context = _operator_ctxt; /* only assigne the pointer, string is NULL'd */
+	dummyot.undo_group = _operator_undo_group; /* only assigne the pointer, string is NULL'd */
 	RNA_pointer_create(NULL, &RNA_Operator, &dummyop, &dummyotr);
 
 	/* clear in case they are left unset */
-	_operator_idname[0] = _operator_name[0] = _operator_descr[0] = '\0';
+	_operator_idname[0] = _operator_name[0] = _operator_descr[0] = _operator_undo_group[0] = '\0';
 	/* We have to set default op context! */
 	strcpy(_operator_ctxt, BLT_I18NCONTEXT_OPERATOR_DEFAULT);
 
@@ -1210,9 +1213,10 @@ static StructRNA *rna_Operator_register(Main *bmain, ReportList *reports, void *
 			int namelen = strlen(_operator_name) + 1;
 			int desclen = strlen(_operator_descr) + 1;
 			int ctxtlen = strlen(_operator_ctxt) + 1;
+			int ugrouplen = strlen(_operator_undo_group) + 1;
 			char *ch;
 			/* 2 terminators and 3 to convert a.b -> A_OT_b */
-			ch = MEM_callocN(sizeof(char) * (idlen + namelen + desclen + ctxtlen), "_operator_idname");
+			ch = MEM_callocN(sizeof(char) * (idlen + namelen + desclen + ctxtlen + ugrouplen), "_operator_idname");
 			WM_operator_bl_idname(ch, _operator_idname); /* convert the idname from python */
 			dummyot.idname = ch;
 			ch += idlen;
@@ -1224,6 +1228,9 @@ static StructRNA *rna_Operator_register(Main *bmain, ReportList *reports, void *
 			ch += desclen;
 			strcpy(ch, _operator_ctxt);
 			dummyot.translation_context = ch;
+			ch += ctxtlen;
+			strcpy(ch, _operator_undo_group);
+			dummyot.undo_group = ch;
 		}
 	}
 
@@ -1280,10 +1287,11 @@ static StructRNA *rna_MacroOperator_register(Main *bmain, ReportList *reports, v
 	dummyot.name = _operator_name; /* only assigne the pointer, string is NULL'd */
 	dummyot.description = _operator_descr; /* only assigne the pointer, string is NULL'd */
 	dummyot.translation_context = _operator_ctxt; /* only assigne the pointer, string is NULL'd */
+	dummyot.undo_group = _operator_undo_group; /* only assigne the pointer, string is NULL'd */
 	RNA_pointer_create(NULL, &RNA_Macro, &dummyop, &dummyotr);
 
 	/* clear in case they are left unset */
-	_operator_idname[0] = _operator_name[0] = _operator_descr[0] = '\0';
+	_operator_idname[0] = _operator_name[0] = _operator_descr[0] = _operator_undo_group[0] = '\0';
 	/* We have to set default op context! */
 	strcpy(_operator_ctxt, BLT_I18NCONTEXT_OPERATOR_DEFAULT);
 
@@ -1297,9 +1305,10 @@ static StructRNA *rna_MacroOperator_register(Main *bmain, ReportList *reports, v
 		int namelen = strlen(_operator_name) + 1;
 		int desclen = strlen(_operator_descr) + 1;
 		int ctxtlen = strlen(_operator_ctxt) + 1;
+		int ugrouplen = strlen(_operator_undo_group) + 1;
 		char *ch;
 		/* 2 terminators and 3 to convert a.b -> A_OT_b */
-		ch = MEM_callocN(sizeof(char) * (idlen + namelen + desclen + ctxtlen), "_operator_idname");
+		ch = MEM_callocN(sizeof(char) * (idlen + namelen + desclen + ctxtlen + ugrouplen), "_operator_idname");
 		WM_operator_bl_idname(ch, _operator_idname); /* convert the idname from python */
 		dummyot.idname = ch;
 		ch += idlen;
@@ -1311,6 +1320,9 @@ static StructRNA *rna_MacroOperator_register(Main *bmain, ReportList *reports, v
 		ch += desclen;
 		strcpy(ch, _operator_ctxt);
 		dummyot.translation_context = ch;
+		ch += ctxtlen;
+		strcpy(ch, _operator_undo_group);
+		dummyot.undo_group = ch;
 	}
 
 	if (strlen(identifier) >= sizeof(dummyop.idname)) {
@@ -1401,6 +1413,16 @@ static void rna_Operator_bl_description_set(PointerRNA *ptr, const char *value)
 		assert(!"setting the bl_description on a non-builtin operator");
 }
 
+static void rna_Operator_bl_undo_group_set(PointerRNA *ptr, const char *value)
+{
+	wmOperator *data = (wmOperator *)(ptr->data);
+	char *str = (char *)data->type->undo_group;
+	if (!str[0])
+		BLI_strncpy(str, value, OP_MAX_TYPENAME);    /* utf8 already ensured */
+	else
+		assert(!"setting the bl_undo_group on a non-builtin operator");
+}
+
 static void rna_KeyMapItem_update(Main *UNUSED(bmain), Scene *UNUSED(scene), PointerRNA *ptr)
 {
 	wmKeyMapItem *kmi = ptr->data;
@@ -1509,6 +1531,14 @@ static void rna_def_operator(BlenderRNA *brna)
 	RNA_def_property_flag(prop, PROP_REGISTER_OPTIONAL);
 	RNA_def_property_clear_flag(prop, PROP_NEVER_NULL); /* check for NULL */
 
+	prop = RNA_def_property(srna, "bl_undo_group", PROP_STRING, PROP_NONE);
+	RNA_def_property_string_sdna(prop, NULL, "type->undo_group");
+	RNA_def_property_string_maxlength(prop, OP_MAX_TYPENAME); /* else it uses the pointer size! */
+	RNA_def_property_string_funcs(prop, NULL, NULL, "rna_Operator_bl_undo_group_set");
+	/* RNA_def_property_clear_flag(prop, PROP_EDITABLE); */
+	RNA_def_property_flag(prop, PROP_REGISTER_OPTIONAL);
+	RNA_def_property_clear_flag(prop, PROP_NEVER_NULL); /* check for NULL */
+
 	prop = RNA_def_property(srna, "bl_options", PROP_ENUM, PROP_NONE);
 	RNA_def_property_enum_sdna(prop, NULL, "type->flag");
 	RNA_def_property_enum_items(prop, operator_flag_items);
@@ -1587,6 +1617,14 @@ static void rna_def_macro_operator(BlenderRNA *brna)
 	RNA_def_property_flag(prop, PROP_REGISTER_OPTIONAL);
 	RNA_def_property_clear_flag(prop, PROP_NEVER_NULL); /* check for NULL */
 
+	prop = RNA_def_property(srna, "bl_undo_group", PROP_STRING, PROP_NONE);
+	RNA_def_property_string_sdna(prop, NULL, "type->undo_group");
+	RNA_def_property_string_maxlength(prop, OP_MAX_TYPENAME); /* else it uses the pointer size! */
+	RNA_def_property_string_funcs(prop, NULL, NULL, "rna_Operator_bl_undo_group_set");
+	/* RNA_def_property_clear_flag(prop, PROP_EDITABLE); */
+	RNA_def_property_flag(prop, PROP_REGISTER_OPTIONAL);
+	RNA_def_property_clear_flag(prop, PROP_NEVER_NULL); /* check for NULL */
+
 	prop = RNA_def_property(srna, "bl_options", PROP_ENUM, PROP_NONE);
 	RNA_def_property_enum_sdna(prop, NULL, "type->flag");
 	RNA_def_property_enum_items(prop, operator_flag_items);