simplify drag toggle operator, use BLI_rctf_isect_segment between mouse events rather then many calls to ui_but_find_mouse_over().

source/blender/editors/interface/interface_handlers.c

@@ -153,6 +153,7 @@ typedef struct uiHandleButtonData {
 	int maxlen, selextend, selstartx;
 
 	/* number editing / dragging */
+	/* coords are Window/uiBlock relative (depends on the button) */
 	int draglastx, draglasty;
 	int dragstartx, dragstarty;
 	int dragchange, draglock, dragsel;
@@ -5474,6 +5475,24 @@ static int ui_mouse_inside_button(ARegion *ar, uiBut *but, int x, int y)
 	return 1;
 }
 
+/**
+ * Can we mouse over the button or is it hidden/disabled/layout.
+ */
+bool ui_is_but_interactive(uiBut *but)
+{
+	/* note, LABEL is included for highlights, this allows drags */
+	if (but->type == LABEL && but->dragpoin == NULL)
+		return false;
+	if (ELEM3(but->type, ROUNDBOX, SEPR, LISTBOX))
+		return false;
+	if (but->flag & UI_HIDDEN)
+		return false;
+	if (but->flag & UI_SCROLLED)
+		return false;
+
+	return true;
+}
+
 uiBut *ui_but_find_mouse_over(ARegion *ar, int x, int y)
 {
 	uiBlock *block;
@@ -5491,17 +5510,11 @@ uiBut *ui_but_find_mouse_over(ARegion *ar, int x, int y)
 		ui_window_to_block(ar, block, &mx, &my);
 
 		for (but = block->buttons.first; but; but = but->next) {
-			/* note, LABEL is included for highlights, this allows drags */
+			if (ui_is_but_interactive(but)) {
-			if (but->type == LABEL && but->dragpoin == NULL)
+				if (ui_but_contains_pt(but, mx, my)) {
-				continue;
+					butover = but;
-			if (ELEM3(but->type, ROUNDBOX, SEPR, LISTBOX))
+				}
-				continue;
+			}
-			if (but->flag & UI_HIDDEN)
-				continue;
-			if (but->flag & UI_SCROLLED)
-				continue;
-			if (ui_but_contains_pt(but, mx, my))
-				butover = but;
 		}
 
 		/* CLIP_EVENTS prevents the event from reaching other blocks */
@@ -5843,12 +5856,13 @@ static void button_activate_exit(bContext *C, uiBut *but, uiHandleButtonData *da
 
 	/* redraw (data is but->active!) */
 	ED_region_tag_redraw(data->region);
-	
+
 	/* clean up button */
 	if (but->active) {
 		MEM_freeN(but->active);
 		but->active = NULL;
 	}
+
 	but->flag &= ~(UI_ACTIVE | UI_SELECT);
 	but->flag |= UI_BUT_LAST_ACTIVE;
 	if (!onfree)

source/blender/editors/interface/interface_intern.h

@@ -171,8 +171,8 @@ struct uiBut {
 	char *str;
 	char strdata[UI_MAX_NAME_STR];
 	char drawstr[UI_MAX_DRAW_STR];
-	
+
-	rctf rect;
+	rctf rect;  /* block relative coords */
 
 	char *poin;
 	float hardmin, hardmax, softmin, softmax;
@@ -225,7 +225,7 @@ struct uiBut {
 	void *rename_orig;
 
 	uiLink *link;
-	short linkto[2];
+	short linkto[2];  /* region relative coords */
 	
 	const char *tip, *lockstr;
 
@@ -410,6 +410,7 @@ extern int  ui_is_but_bool(uiBut *but);
 extern int  ui_is_but_unit(uiBut *but);
 extern int  ui_is_but_rna_valid(uiBut *but);
 extern int  ui_is_but_utf8(uiBut *but);
+extern bool ui_is_but_interactive(uiBut *but);
 
 extern void ui_bounds_block(uiBlock *block);
 extern void ui_block_translate(uiBlock *block, int x, int y);

source/blender/editors/interface/interface_ops.c

@@ -1081,64 +1081,46 @@ typedef struct DragOpInfo {
 	eButType but_type_start;
 } DragOpInfo;
 
-typedef struct DragOpPlotData {
-	bContext *C;
-	ARegion *ar;
-	bool is_set;
-	eButType but_type_start;
-	bool do_draw;
-	const uiBut *but_prev;
-} DragOpPlotData;
-
-static const uiBut *ui_but_set_xy(bContext *C, ARegion *ar, const bool is_set, const eButType but_type_start,
-                                  const int xy[2], const uiBut *but_prev)
-{
-	uiBut *but = ui_but_find_mouse_over(ar, xy[0], xy[1]);
-
-	if (but_prev == but) {
-		return but_prev;
-	}
-
-	if (but && ui_is_but_bool(but) && but->type == but_type_start) {
-		/* is it pressed? */
-		bool is_set_but = (ui_get_but_val(but) != 0.0);
-		BLI_assert(ui_is_but_bool(but) == true);
-		if (is_set_but != is_set) {
-			uiButExecute(C, but);
-			return but;
-		}
-	}
-
-	return but_prev;
-}
-
-static int ui_but_set_cb(int x, int y, void *data_v)
-{
-	DragOpPlotData *data = data_v;
-	int xy[2] = {x, y};
-	data->but_prev = ui_but_set_xy(data->C, data->ar, data->is_set, data->but_type_start, xy, data->but_prev);
-	return 1;  /* keep going */
-}
-
-/* operates on buttons between 2 mouse-points */
 static bool ui_but_set_xy_xy(bContext *C, ARegion *ar, const bool is_set, const eButType but_type_start,
                              const int xy_src[2], const int xy_dst[2])
 {
-	DragOpPlotData data;
+	bool change = false;
-	data.C = C;
+	uiBlock *block;
-	data.ar = ar;
-	data.is_set = is_set;
-	data.but_type_start = but_type_start;
-	data.do_draw = false;
-	data.but_prev = NULL;
 
+	for (block = ar->uiblocks.first; block; block = block->next) {
+		uiBut *but;
 
-	/* prevent dragging too fast loosing buttons */
+		float xy_a_block[2] = {UNPACK2(xy_src)};
-	plot_line_v2v2i(xy_src, xy_dst, ui_but_set_cb, &data);
+		float xy_b_block[2] = {UNPACK2(xy_dst)};
 
-	return data.do_draw;
+		ui_window_to_block_fl(ar, block, &xy_a_block[0], &xy_a_block[1]);
+		ui_window_to_block_fl(ar, block, &xy_b_block[0], &xy_b_block[1]);
+
+		for (but = block->buttons.first; but; but = but->next) {
+			if (ui_is_but_interactive(but)) {
+				if (BLI_rctf_isect_segment(&but->rect, xy_a_block, xy_b_block)) {
+
+					/* execute the button */
+					if (ui_is_but_bool(but) && but->type == but_type_start) {
+						/* is it pressed? */
+						bool is_set_but = (ui_get_but_val(but) != 0.0);
+						BLI_assert(ui_is_but_bool(but) == true);
+						if (is_set_but != is_set) {
+							uiButExecute(C, but);
+							change = true;
+						}
+					}
+					/* done */
+
+				}
+			}
+		}
+	}
+
+	return change;
 }
 
+
 static void ui_drag_but_set(bContext *C, wmOperator *op, const int xy_input[2])
 {
 	ARegion *ar = CTX_wm_region(C);
@@ -1307,4 +1289,3 @@ void UI_buttons_operatortypes(void)
 	WM_operatortype_append(UI_OT_reloadtranslation);
 	WM_operatortype_append(UI_OT_drag_toggle);
 }
-