Fix T53491: Absolute tablet motion detection fails

When using a tablet, detecting absolute motion only worked
when activating a tool with the tablet.

Pressing Enter to run a tool for e.g. would use relative motion.

Now store is_motion_absolute in the event,
set for new events based on the most recent motion events.

source/blender/editors/space_view3d/view3d_walk.c

@@ -699,7 +699,7 @@ static void walkEvent(bContext *C, wmOperator *op, WalkInfo *walk, const wmEvent
 			return;
 		}
 
-		if ((walk->is_cursor_absolute == false) && WM_event_is_absolute(event)) {
+		if ((walk->is_cursor_absolute == false) && event->is_motion_absolute) {
 			walk->is_cursor_absolute = true;
 			copy_v2_v2_int(walk->prev_mval, event->mval);
 			copy_v2_v2_int(walk->center_mval, event->mval);

source/blender/makesrna/intern/rna_wm.c

@@ -1766,6 +1766,11 @@ static void rna_def_event(BlenderRNA *brna)
 	RNA_def_property_boolean_funcs(prop, "rna_Event_is_tablet_get", NULL);
 	RNA_def_property_ui_text(prop, "Tablet Pressure", "The pressure of the tablet or 1.0 if no tablet present");
 
+	prop = RNA_def_property(srna, "is_mouse_absolute", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "is_motion_absolute", 1);
+	RNA_def_property_clear_flag(prop, PROP_EDITABLE);
+	RNA_def_property_ui_text(prop, "Absolute Motion", "The last motion event was an absolute an input");
+
 	/* modifiers */
 	prop = RNA_def_property(srna, "shift", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "shift", 1);

source/blender/windowmanager/WM_api.h

@@ -188,7 +188,6 @@ struct wmEventHandler *WM_event_add_dropbox_handler(ListBase *handlers, ListBase
 			/* mouse */
 void		WM_event_add_mousemove(struct bContext *C);
 bool		WM_event_is_modal_tweak_exit(const struct wmEvent *event, int tweak_event);
-bool		WM_event_is_absolute(const struct wmEvent *event);
 bool		WM_event_is_last_mousemove(const struct wmEvent *event);
 
 #ifdef WITH_INPUT_NDOF
@@ -206,11 +205,11 @@ void        WM_report_banner_show(void);
 void        WM_report(ReportType type, const char *message);
 void        WM_reportf(ReportType type, const char *format, ...) ATTR_PRINTF_FORMAT(2, 3);
 
-void wm_event_add_ex(
+struct wmEvent *wm_event_add_ex(
         struct wmWindow *win, const struct wmEvent *event_to_add,
         const struct wmEvent *event_to_add_after)
         ATTR_NONNULL(1, 2);
-void wm_event_add(
+struct wmEvent *wm_event_add(
         struct wmWindow *win, const struct wmEvent *event_to_add)
         ATTR_NONNULL(1, 2);
 

source/blender/windowmanager/WM_types.h

@@ -461,8 +461,9 @@ typedef struct wmEvent {
 	short keymodifier;				/* rawkey modifier */
 	
 	/* set in case a KM_PRESS went by unhandled */
-	short check_click;
-	
+	char check_click;
+	char is_motion_absolute;
+
 	/* keymap item, set by handler (weak?) */
 	const char *keymap_idname;
 

source/blender/windowmanager/intern/wm_cursors.c

@@ -213,13 +213,10 @@ void WM_cursor_grab_enable(wmWindow *win, bool wrap, bool hide, int bounds[4])
 	}
 	if ((G.debug & G_DEBUG) == 0) {
 		if (win->ghostwin) {
-			const GHOST_TabletData *tabletdata = GHOST_GetTabletData(win->ghostwin);
-			
 			/* Note: There is no tabletdata on Windows if no tablet device is connected. */
-			if (!tabletdata)
-				GHOST_SetCursorGrab(win->ghostwin, mode, bounds, NULL);
-			else if (tabletdata->Active == GHOST_kTabletModeNone)
+			if (win->eventstate->is_motion_absolute == false) {
 				GHOST_SetCursorGrab(win->ghostwin, mode, bounds, NULL);
+			}
 
 			win->grabcursor = mode;
 		}

source/blender/windowmanager/intern/wm_event_system.c

@@ -94,7 +94,7 @@ static int wm_operator_call_internal(bContext *C, wmOperatorType *ot, PointerRNA
 
 /* ************ event management ************** */
 
-void wm_event_add_ex(wmWindow *win, const wmEvent *event_to_add, const wmEvent *event_to_add_after)
+wmEvent *wm_event_add_ex(wmWindow *win, const wmEvent *event_to_add, const wmEvent *event_to_add_after)
 {
 	wmEvent *event = MEM_mallocN(sizeof(wmEvent), "wmEvent");
 	
@@ -102,6 +102,13 @@ void wm_event_add_ex(wmWindow *win, const wmEvent *event_to_add, const wmEvent *
 
 	update_tablet_data(win, event);
 
+	if (ELEM(event->type, MOUSEMOVE, INBETWEEN_MOUSEMOVE)) {
+		/* We could have a preference to support relative tablet motion (we can't detect that). */
+		event->is_motion_absolute = (
+		        (event->tablet_data != NULL) &&
+		        (event->tablet_data->Active != GHOST_kTabletModeNone));
+	}
+
 	if (event_to_add_after == NULL) {
 		BLI_addtail(&win->queue, event);
 	}
@@ -109,11 +116,12 @@ void wm_event_add_ex(wmWindow *win, const wmEvent *event_to_add, const wmEvent *
 		/* note, strictly speaking this breaks const-correctness, however we're only changing 'next' member */
 		BLI_insertlinkafter(&win->queue, (void *)event_to_add_after, event);
 	}
+	return event;
 }
 
-void wm_event_add(wmWindow *win, const wmEvent *event_to_add)
+wmEvent *wm_event_add(wmWindow *win, const wmEvent *event_to_add)
 {
-	wm_event_add_ex(win, event_to_add, NULL);
+	return wm_event_add_ex(win, event_to_add, NULL);
 }
 
 void wm_event_free(wmEvent *event)
@@ -624,11 +632,6 @@ void WM_report_banner_show(void)
 	wm_reports->reporttimer->customdata = rti;
 }
 
-bool WM_event_is_absolute(const wmEvent *event)
-{
-	return (event->tablet_data != NULL);
-}
-
 bool WM_event_is_last_mousemove(const wmEvent *event)
 {
 	while ((event = event->next)) {
@@ -3196,7 +3199,7 @@ static bool wm_event_is_double_click(wmEvent *event, const wmEvent *event_state)
 	return false;
 }
 
-static void wm_event_add_mousemove(wmWindow *win, const wmEvent *event)
+static wmEvent *wm_event_add_mousemove(wmWindow *win, const wmEvent *event)
 {
 	wmEvent *event_last = win->queue.last;
 
@@ -3206,16 +3209,13 @@ static void wm_event_add_mousemove(wmWindow *win, const wmEvent *event)
 	if (event_last && event_last->type == MOUSEMOVE)
 		event_last->type = INBETWEEN_MOUSEMOVE;
 
-	wm_event_add(win, event);
-
-	{
-		wmEvent *event_new = win->queue.last;
-		if (event_last == NULL) {
-			event_last = win->eventstate;
-		}
-
-		copy_v2_v2_int(&event_new->prevx, &event_last->x);
+	wmEvent *event_new = wm_event_add(win, event);
+	if (event_last == NULL) {
+		event_last = win->eventstate;
 	}
+
+	copy_v2_v2_int(&event_new->prevx, &event_last->x);
+	return event_new;
 }
 
 /* windows store own event queues, no bContext here */
@@ -3245,8 +3245,11 @@ void wm_event_add_ghostevent(wmWindowManager *wm, wmWindow *win, int type, int U
 			wm_stereo3d_mouse_offset_apply(win, &event.x);
 
 			event.type = MOUSEMOVE;
-			wm_event_add_mousemove(win, &event);
-			copy_v2_v2_int(&evt->x, &event.x);
+			{
+				wmEvent *event_new = wm_event_add_mousemove(win, &event);
+				copy_v2_v2_int(&evt->x, &event_new->x);
+				evt->is_motion_absolute = event_new->is_motion_absolute;
+			}
 			
 			/* also add to other window if event is there, this makes overdraws disappear nicely */
 			/* it remaps mousecoord to other window in event */
@@ -3258,8 +3261,11 @@ void wm_event_add_ghostevent(wmWindowManager *wm, wmWindow *win, int type, int U
 
 				copy_v2_v2_int(&oevent.x, &event.x);
 				oevent.type = MOUSEMOVE;
-				wm_event_add_mousemove(owin, &oevent);
-				copy_v2_v2_int(&oevt->x, &oevent.x);
+				{
+					wmEvent *event_new = wm_event_add_mousemove(owin, &oevent);
+					copy_v2_v2_int(&oevt->x, &event_new->x);
+					oevt->is_motion_absolute = event_new->is_motion_absolute;
+				}
 			}
 				
 			break;