UI: allow off/on icons to be in reverse order.

The same icons are reused for "hide" and "show" properties, which need
to be in reverse order compared to each other.

3 files changed, 24 insertions, 3 deletions

diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index 92423d84c3f..ac463fe87a2 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -236,6 +236,8 @@ enum {
 	UI_BUT_ACTIVE_RIGHT      = (1 << 22), /* Active right part of number button */
 
 	UI_BUT_HAS_SHORTCUT      = (1 << 23), /* Button has shortcut text */
+
+	UI_BUT_ICON_REVERSE      = (1 << 24), /* Reverse order of consecutive off/on icons */
 };
 
 /* scale fixed button widths by this to account for DPI */
diff --git a/source/blender/editors/interface/interface.c b/source/blender/editors/interface/interface.c
index 3e8d32c0e2b..1e1c9c1fa3f 100644
--- a/source/blender/editors/interface/interface.c
+++ b/source/blender/editors/interface/interface.c
@@ -2985,7 +2985,11 @@ void ui_but_update_ex(uiBut *but, const bool validate)
 
 		case UI_BTYPE_ICON_TOGGLE:
 		case UI_BTYPE_ICON_TOGGLE_N:
-			if (!but->rnaprop || (RNA_property_flag(but->rnaprop) & PROP_ICONS_CONSECUTIVE)) {
+			if ((but->rnaprop == NULL) || (RNA_property_flag(but->rnaprop) & PROP_ICONS_CONSECUTIVE)) {
+				if (but->rnaprop && RNA_property_flag(but->rnaprop) & PROP_ICONS_REVERSE) {
+					but->drawflag |= UI_BUT_ICON_REVERSE;
+				}
+
 				but->iconadd = (but->flag & UI_SELECT) ? 1 : 0;
 			}
 			break;
diff --git a/source/blender/editors/interface/interface_widgets.c b/source/blender/editors/interface/interface_widgets.c
index 99022a14b6a..b8a661c5542 100644
--- a/source/blender/editors/interface/interface_widgets.c
+++ b/source/blender/editors/interface/interface_widgets.c
@@ -2016,6 +2016,21 @@ static void widget_draw_text(uiFontStyle *fstyle, uiWidgetColors *wcol, uiBut *b
 	}
 }
 
+static BIFIconID widget_icon_id(uiBut *but)
+{
+	if (!(but->flag & UI_HAS_ICON)) {
+		return ICON_NONE;
+	}
+
+	/* Consecutive icons can be toggle between. */
+	if (but->drawflag & UI_BUT_ICON_REVERSE) {
+		return but->icon - but->iconadd;
+	}
+	else {
+		return but->icon + but->iconadd;
+	}
+}
+
 /* draws text and icons for buttons */
 static void widget_draw_text_icon(uiFontStyle *fstyle, uiWidgetColors *wcol, uiBut *but, rcti *rect)
 {
@@ -2039,7 +2054,7 @@ static void widget_draw_text_icon(uiFontStyle *fstyle, uiWidgetColors *wcol, uiB
 
 	/* Big previews with optional text label below */
 	if (but->flag & UI_BUT_ICON_PREVIEW && ui_block_is_menu(but->block)) {
-		const BIFIconID icon = (but->flag & UI_HAS_ICON) ? but->icon + but->iconadd : ICON_NONE;
+		const BIFIconID icon = widget_icon_id(but);
 		int icon_size = BLI_rcti_size_y(rect);
 		int text_size = 0;
 
@@ -2076,7 +2091,7 @@ static void widget_draw_text_icon(uiFontStyle *fstyle, uiWidgetColors *wcol, uiB
 		}
 #endif
 
-		const BIFIconID icon = (but->flag & UI_HAS_ICON) ? but->icon + but->iconadd : ICON_NONE;
+		const BIFIconID icon = widget_icon_id(but);
 		int icon_size_init = is_tool ? ICON_DEFAULT_HEIGHT_TOOLBAR : ICON_DEFAULT_HEIGHT;
 		const float icon_size = icon_size_init / (but->block->aspect / UI_DPI_FAC);
 		const float icon_padding = 2 * UI_DPI_FAC;