UI: support for popups starting with buttons activated

While this could already be done from C,
this is now exposed to Python

source/blender/editors/include/UI_interface.h

@@ -201,6 +201,8 @@ enum {
 	UI_BUT_LIST_ITEM       = 1 << 24,
 	/** edit this button as well as the active button (not just dragging) */
 	UI_BUT_DRAG_MULTI      = 1 << 25,
+	/** Use for popups to start editing the button on initialization. */
+	UI_BUT_ACTIVATE_ON_INIT = 1 << 26,
 
 	/** #uiBut.str contains #UI_SEP_CHAR, used for key shortcuts */
 	UI_BUT_HAS_SEP_CHAR    = 1 << 27,
@@ -631,6 +633,7 @@ void    UI_but_type_set_menu_from_pulldown(uiBut *but);
 
 /* special button case, only draw it when used actively, for outliner etc */
 bool    UI_but_active_only(const struct bContext *C, struct ARegion *ar, uiBlock *block, uiBut *but);
+bool    UI_block_active_only_flagged_buttons(const struct bContext *C, struct ARegion *ar, struct uiBlock *block);
 
 void    UI_but_execute(const struct bContext *C, uiBut *but);
 
@@ -1053,6 +1056,7 @@ void uiLayoutSetContextFromBut(uiLayout *layout, uiBut *but);
 
 void uiLayoutSetOperatorContext(uiLayout *layout, int opcontext);
 void uiLayoutSetActive(uiLayout *layout, bool active);
+void uiLayoutSetActivateInit(uiLayout *layout, bool active);
 void uiLayoutSetEnabled(uiLayout *layout, bool enabled);
 void uiLayoutSetRedAlert(uiLayout *layout, bool redalert);
 void uiLayoutSetAlignment(uiLayout *layout, char alignment);
@@ -1068,6 +1072,7 @@ int uiLayoutGetLocalDir(const uiLayout *layout);
 
 int uiLayoutGetOperatorContext(uiLayout *layout);
 bool uiLayoutGetActive(uiLayout *layout);
+bool uiLayoutGetActivateInit(uiLayout *layout);
 bool uiLayoutGetEnabled(uiLayout *layout);
 bool uiLayoutGetRedAlert(uiLayout *layout);
 int uiLayoutGetAlignment(uiLayout *layout);

source/blender/editors/interface/interface.c

@@ -823,6 +823,24 @@ bool UI_but_active_only(const bContext *C, ARegion *ar, uiBlock *block, uiBut *b
 	return true;
 }
 
+bool UI_block_active_only_flagged_buttons(const bContext *C, ARegion *ar, uiBlock *block)
+{
+	bool done = false;
+	for (uiBut *but = block->buttons.first; but; but = but->next) {
+		if (!done && ui_but_is_editable(but)) {
+			if (but->flag & UI_BUT_ACTIVATE_ON_INIT) {
+				if (UI_but_active_only(C, ar, block, but)) {
+					done = true;
+				}
+			}
+		}
+		but->flag &= ~UI_BUT_ACTIVATE_ON_INIT;
+	}
+	return done;
+}
+
+
+
 /* simulate button click */
 void UI_but_execute(const bContext *C, uiBut *but)
 {

source/blender/editors/interface/interface_layout.c

@@ -160,6 +160,7 @@ struct uiLayout {
 	short space;
 	bool align;
 	bool active;
+	bool activate_init;
 	bool enabled;
 	bool redalert;
 	bool keepaspect;
@@ -1818,6 +1819,9 @@ void uiItemFullR(uiLayout *layout, PointerRNA *ptr, PropertyRNA *prop, int index
 
 		if (layout->redalert)
 			UI_but_flag_enable(but, UI_BUT_REDALERT);
+
+		if (layout->activate_init)
+			UI_but_flag_enable(but, UI_BUT_ACTIVATE_ON_INIT);
 	}
 	/* single button */
 	else {
@@ -1831,6 +1835,9 @@ void uiItemFullR(uiLayout *layout, PointerRNA *ptr, PropertyRNA *prop, int index
 
 		if (layout->redalert)
 			UI_but_flag_enable(but, UI_BUT_REDALERT);
+
+		if (layout->activate_init)
+			UI_but_flag_enable(but, UI_BUT_ACTIVATE_ON_INIT);
 	}
 
 	/* Mark non-embossed textfields inside a listbox. */
@@ -3949,6 +3956,11 @@ void uiLayoutSetActive(uiLayout *layout, bool active)
 	layout->active = active;
 }
 
+void uiLayoutSetActivateInit(uiLayout *layout, bool activate_init)
+{
+	layout->activate_init = activate_init;
+}
+
 void uiLayoutSetEnabled(uiLayout *layout, bool enabled)
 {
 	layout->enabled = enabled;
@@ -4019,6 +4031,11 @@ bool uiLayoutGetActive(uiLayout *layout)
 	return layout->active;
 }
 
+bool uiLayoutGetActivateInit(uiLayout *layout)
+{
+	return layout->activate_init;
+}
+
 bool uiLayoutGetEnabled(uiLayout *layout)
 {
 	return layout->enabled;

source/blender/editors/interface/interface_region_popover.c

@@ -302,16 +302,24 @@ int UI_popover_panel_invoke(
 		return (OPERATOR_CANCELLED | OPERATOR_PASS_THROUGH);
 	}
 
+	uiBlock *block = NULL;
 	if (keep_open) {
-		ui_popover_panel_create(C, NULL, NULL, ui_item_paneltype_func, pt);
+		uiPopupBlockHandle *handle = ui_popover_panel_create(C, NULL, NULL, ui_item_paneltype_func, pt);
+		uiPopover *pup = handle->popup_create_vars.arg;
+		block = pup->block;
+
 	}
 	else {
 		uiPopover *pup = UI_popover_begin(C, U.widget_unit * pt->ui_units_x);
 		layout = UI_popover_layout(pup);
 		UI_paneltype_draw(C, pt, layout);
 		UI_popover_end(C, pup, NULL);
+		block = pup->block;
 	}
 
+	if (block) {
+		UI_block_active_only_flagged_buttons(C, CTX_wm_region(C), block);
+	}
 	return OPERATOR_INTERFACE;
 }
 

source/blender/makesrna/intern/rna_ui.c

@@ -881,6 +881,16 @@ static void rna_UILayout_active_set(PointerRNA *ptr, bool value)
 	uiLayoutSetActive(ptr->data, value);
 }
 
+static bool rna_UILayout_activate_init_get(PointerRNA *ptr)
+{
+	return uiLayoutGetActivateInit(ptr->data);
+}
+
+static void rna_UILayout_activate_init_set(PointerRNA *ptr, bool value)
+{
+	uiLayoutSetActivateInit(ptr->data, value);
+}
+
 static bool rna_UILayout_alert_get(PointerRNA *ptr)
 {
 	return uiLayoutGetRedAlert(ptr->data);
@@ -1056,6 +1066,13 @@ static void rna_def_ui_layout(BlenderRNA *brna)
 	prop = RNA_def_property(srna, "active", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_funcs(prop, "rna_UILayout_active_get", "rna_UILayout_active_set");
 
+	prop = RNA_def_property(srna, "activate_init", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_funcs(prop, "rna_UILayout_activate_init_get", "rna_UILayout_activate_init_set");
+	RNA_def_property_ui_text(
+	        prop, "Activate on Init",
+	        "When true, buttons defined in popups will be activated on first display "
+	        "(use so you can type into a field without having to click on it first)");
+
 	prop = RNA_def_property(srna, "operator_context", PROP_ENUM, PROP_NONE);
 	RNA_def_property_enum_items(prop, rna_enum_operator_context_items);
 	RNA_def_property_enum_funcs(prop, "rna_UILayout_op_context_get", "rna_UILayout_op_context_set", NULL);

source/blender/windowmanager/intern/wm_operators.c

@@ -1154,6 +1154,8 @@ static uiBlock *wm_block_dialog_create(bContext *C, ARegion *ar, void *userData)
 	/* center around the mouse */
 	UI_block_bounds_set_popup(block, 4, (const int[2]){data->width / -2, data->height / 2});
 
+	UI_block_active_only_flagged_buttons(C, ar, block);
+
 	return block;
 }
 
@@ -1179,6 +1181,8 @@ static uiBlock *wm_operator_ui_create(bContext *C, ARegion *ar, void *userData)
 
 	UI_block_bounds_set_popup(block, 4, NULL);
 
+	UI_block_active_only_flagged_buttons(C, ar, block);
+
 	return block;
 }