Fix T60554: Missing undo push changing color

Operators don't have a good way to skip undo,
for now check the button undo flag & return cancelled.

source/blender/editors/interface/interface_eyedropper_color.c

@@ -69,6 +69,7 @@ typedef struct Eyedropper {
 	PointerRNA ptr;
 	PropertyRNA *prop;
 	int index;
+	bool is_undo;
 
 	float init_col[3]; /* for resetting on cancel */
 
@@ -84,7 +85,7 @@ static bool eyedropper_init(bContext *C, wmOperator *op)
 	Eyedropper *eye = MEM_callocN(sizeof(Eyedropper), __func__);
 	eye->use_accum = RNA_boolean_get(op->ptr, "use_accumulate");
 
-	UI_context_active_but_prop_get(C, &eye->ptr, &eye->prop, &eye->index);
+	uiBut *but = UI_context_active_but_prop_get(C, &eye->ptr, &eye->prop, &eye->index);
 
 	if ((eye->ptr.data == NULL) ||
 	    (eye->prop == NULL) ||
@@ -97,6 +98,8 @@ static bool eyedropper_init(bContext *C, wmOperator *op)
 	}
 	op->customdata = eye;
 
+	eye->is_undo = UI_but_flag_is_set(but, UI_BUT_UNDO);
+
 	if (RNA_property_subtype(eye->prop) != PROP_COLOR) {
 		Scene *scene = CTX_data_scene(C);
 		const char *display_device;
@@ -259,11 +262,15 @@ static int eyedropper_modal(bContext *C, wmOperator *op, const wmEvent *event)
 				eyedropper_cancel(C, op);
 				return OPERATOR_CANCELLED;
 			case EYE_MODAL_SAMPLE_CONFIRM:
+			{
+				const bool is_undo = eye->is_undo;
 				if (eye->accum_tot == 0) {
 					eyedropper_color_sample(C, eye, event->x, event->y);
 				}
 				eyedropper_exit(C, op);
-				return OPERATOR_FINISHED;
+				/* Could support finished & undo-skip. */
+				return is_undo ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+			}
 			case EYE_MODAL_SAMPLE_BEGIN:
 				/* enable accum and make first sample */
 				eye->accum_start = true;
@@ -343,7 +350,7 @@ void UI_OT_eyedropper_color(wmOperatorType *ot)
 	ot->poll = eyedropper_poll;
 
 	/* flags */
-	ot->flag = OPTYPE_BLOCKING | OPTYPE_INTERNAL;
+	ot->flag = OPTYPE_UNDO | OPTYPE_BLOCKING | OPTYPE_INTERNAL;
 
 	/* properties */
 	PropertyRNA *prop;

source/blender/editors/interface/interface_eyedropper_colorband.c

@@ -72,6 +72,7 @@ typedef struct EyedropperColorband {
 	ColorBand *color_band;
 	PointerRNA ptr;
 	PropertyRNA *prop;
+	bool is_undo;
 } EyedropperColorband;
 
 /* For user-data only. */
@@ -110,6 +111,7 @@ static bool eyedropper_colorband_init(bContext *C, wmOperator *op)
 	eye->init_color_band = *eye->color_band;
 	eye->ptr = ((Colorband_RNAUpdateCb *)but->func_argN)->ptr;
 	eye->prop  = ((Colorband_RNAUpdateCb *)but->func_argN)->prop;
+	eye->is_undo = UI_but_flag_is_set(but, UI_BUT_UNDO);
 
 	op->customdata = eye;
 
@@ -192,10 +194,14 @@ static int eyedropper_colorband_modal(bContext *C, wmOperator *op, const wmEvent
 				eyedropper_colorband_cancel(C, op);
 				return OPERATOR_CANCELLED;
 			case EYE_MODAL_SAMPLE_CONFIRM:
+			{
+				const bool is_undo = eye->is_undo;
 				eyedropper_colorband_sample_segment(C, eye, event->x, event->y);
 				eyedropper_colorband_apply(C, op);
 				eyedropper_colorband_exit(C, op);
-				return OPERATOR_FINISHED;
+				/* Could support finished & undo-skip. */
+				return is_undo ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+			}
 			case EYE_MODAL_SAMPLE_BEGIN:
 				/* enable accum and make first sample */
 				eye->sample_start = true;
@@ -312,7 +318,7 @@ void UI_OT_eyedropper_colorband(wmOperatorType *ot)
 	ot->poll = eyedropper_colorband_poll;
 
 	/* flags */
-	ot->flag = OPTYPE_BLOCKING | OPTYPE_INTERNAL;
+	ot->flag = OPTYPE_UNDO | OPTYPE_BLOCKING | OPTYPE_INTERNAL;
 
 	/* properties */
 }
@@ -332,7 +338,7 @@ void UI_OT_eyedropper_colorband_point(wmOperatorType *ot)
 	ot->poll = eyedropper_colorband_poll;
 
 	/* flags */
-	ot->flag = OPTYPE_BLOCKING | OPTYPE_INTERNAL;
+	ot->flag = OPTYPE_UNDO | OPTYPE_BLOCKING | OPTYPE_INTERNAL;
 
 	/* properties */
 }

source/blender/editors/interface/interface_eyedropper_datablock.c

@@ -68,6 +68,7 @@ typedef struct DataDropper {
 	PropertyRNA *prop;
 	short idcode;
 	const char *idcode_name;
+	bool is_undo;
 
 	ID *init_id; /* for resetting on cancel */
 
@@ -97,7 +98,7 @@ static int datadropper_init(bContext *C, wmOperator *op)
 
 	DataDropper *ddr = MEM_callocN(sizeof(DataDropper), __func__);
 
-	UI_context_active_but_prop_get(C, &ddr->ptr, &ddr->prop, &index_dummy);
+	uiBut *but = UI_context_active_but_prop_get(C, &ddr->ptr, &ddr->prop, &index_dummy);
 
 	if ((ddr->ptr.data == NULL) ||
 	    (ddr->prop == NULL) ||
@@ -109,6 +110,8 @@ static int datadropper_init(bContext *C, wmOperator *op)
 	}
 	op->customdata = ddr;
 
+	ddr->is_undo = UI_but_flag_is_set(but, UI_BUT_UNDO);
+
 	ddr->art = art;
 	ddr->draw_handle_pixel = ED_region_draw_cb_activate(art, datadropper_draw_cb, ddr, REGION_DRAW_POST_PIXEL);
 
@@ -254,13 +257,12 @@ static int datadropper_modal(bContext *C, wmOperator *op, const wmEvent *event)
 				return OPERATOR_CANCELLED;
 			case EYE_MODAL_SAMPLE_CONFIRM:
 			{
-				bool success;
+				const bool is_undo = ddr->is_undo;
-
+				const bool success = datadropper_id_sample(C, ddr, event->x, event->y);
-				success = datadropper_id_sample(C, ddr, event->x, event->y);
 				datadropper_exit(C, op);
-
 				if (success) {
-					return OPERATOR_FINISHED;
+					/* Could support finished & undo-skip. */
+					return is_undo ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 				}
 				else {
 					BKE_report(op->reports, RPT_WARNING, "Failed to set value");
@@ -349,7 +351,7 @@ void UI_OT_eyedropper_id(wmOperatorType *ot)
 	ot->poll = datadropper_poll;
 
 	/* flags */
-	ot->flag = OPTYPE_BLOCKING | OPTYPE_INTERNAL;
+	ot->flag = OPTYPE_UNDO | OPTYPE_BLOCKING | OPTYPE_INTERNAL;
 
 	/* properties */
 }

source/blender/editors/interface/interface_eyedropper_depth.c

@@ -67,6 +67,7 @@
 typedef struct DepthDropper {
 	PointerRNA ptr;
 	PropertyRNA *prop;
+	bool is_undo;
 
 	float init_depth; /* for resetting on cancel */
 
@@ -99,7 +100,7 @@ static int depthdropper_init(bContext *C, wmOperator *op)
 
 	DepthDropper *ddr = MEM_callocN(sizeof(DepthDropper), __func__);
 
-	UI_context_active_but_prop_get(C, &ddr->ptr, &ddr->prop, &index_dummy);
+	uiBut *but = UI_context_active_but_prop_get(C, &ddr->ptr, &ddr->prop, &index_dummy);
 
 	/* fallback to the active camera's dof */
 	if (ddr->prop == NULL) {
@@ -123,6 +124,8 @@ static int depthdropper_init(bContext *C, wmOperator *op)
 	}
 	op->customdata = ddr;
 
+	ddr->is_undo = UI_but_flag_is_set(but, UI_BUT_UNDO);
+
 	ddr->art = art;
 	ddr->draw_handle_pixel = ED_region_draw_cb_activate(art, depthdropper_draw_cb, ddr, REGION_DRAW_POST_PIXEL);
 	ddr->init_depth = RNA_property_float_get(&ddr->ptr, ddr->prop);
@@ -268,6 +271,8 @@ static int depthdropper_modal(bContext *C, wmOperator *op, const wmEvent *event)
 				depthdropper_cancel(C, op);
 				return OPERATOR_CANCELLED;
 			case EYE_MODAL_SAMPLE_CONFIRM:
+			{
+				const bool is_undo = ddr->is_undo;
 				if (ddr->accum_tot == 0) {
 					depthdropper_depth_sample(C, ddr, event->x, event->y);
 				}
@@ -275,7 +280,9 @@ static int depthdropper_modal(bContext *C, wmOperator *op, const wmEvent *event)
 					depthdropper_depth_set_accum(C, ddr);
 				}
 				depthdropper_exit(C, op);
-				return OPERATOR_FINISHED;
+				/* Could support finished & undo-skip. */
+				return is_undo ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+			}
 			case EYE_MODAL_SAMPLE_BEGIN:
 				/* enable accum and make first sample */
 				ddr->accum_start = true;
@@ -380,7 +387,7 @@ void UI_OT_eyedropper_depth(wmOperatorType *ot)
 	ot->poll = depthdropper_poll;
 
 	/* flags */
-	ot->flag = OPTYPE_BLOCKING | OPTYPE_INTERNAL;
+	ot->flag = OPTYPE_UNDO | OPTYPE_BLOCKING | OPTYPE_INTERNAL;
 
 	/* properties */
 }

source/blender/editors/interface/interface_eyedropper_driver.c

@@ -64,6 +64,7 @@ typedef struct DriverDropper {
 	PointerRNA ptr;
 	PropertyRNA *prop;
 	int index;
+	bool is_undo;
 
 	// TODO: new target?
 } DriverDropper;
@@ -85,6 +86,8 @@ static bool driverdropper_init(bContext *C, wmOperator *op)
 	}
 	op->customdata = ddr;
 
+	ddr->is_undo = UI_but_flag_is_set(but, UI_BUT_UNDO);
+
 	return true;
 }
 
@@ -153,18 +156,24 @@ static void driverdropper_cancel(bContext *C, wmOperator *op)
 /* main modal status check */
 static int driverdropper_modal(bContext *C, wmOperator *op, const wmEvent *event)
 {
+	DriverDropper *ddr = op->customdata;
+
 	/* handle modal keymap */
 	if (event->type == EVT_MODAL_MAP) {
 		switch (event->val) {
 			case EYE_MODAL_CANCEL:
+			{
 				driverdropper_cancel(C, op);
 				return OPERATOR_CANCELLED;
-
+			}
 			case EYE_MODAL_SAMPLE_CONFIRM:
+			{
+				const bool is_undo = ddr->is_undo;
 				driverdropper_sample(C, op, event);
 				driverdropper_exit(C, op);
-
+				/* Could support finished & undo-skip. */
-				return OPERATOR_FINISHED;
+				return is_undo ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+			}
 		}
 	}
 
@@ -224,7 +233,7 @@ void UI_OT_eyedropper_driver(wmOperatorType *ot)
 	ot->poll = driverdropper_poll;
 
 	/* flags */
-	ot->flag = OPTYPE_BLOCKING | OPTYPE_INTERNAL | OPTYPE_UNDO;
+	ot->flag = OPTYPE_UNDO | OPTYPE_BLOCKING | OPTYPE_INTERNAL;
 
 	/* properties */
 	RNA_def_enum(ot->srna, "mapping_type", prop_driver_create_mapping_types, 0,