FormSpec: Add universal style selector `*` (#9718)

2 files changed, 20 insertions, 6 deletions

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 948e0f89e..961e1ff37 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -2567,7 +2567,7 @@ Elements
 
 * Set the style for the element(s) matching `selector` by name.
 * `selector` can be one of:
-    * `<name>` - An element name.
+    * `<name>` - An element name. Includes `*`, which represents every element.
     * `<name>:<state>` - An element name, a colon, and one or more states.
 * `state` is a list of states separated by the `+` character.
     * If a state is provided, the style will only take effect when the element is in that state.
@@ -2580,7 +2580,7 @@ Elements
 
 * Set the style for the element(s) matching `selector` by type.
 * `selector` can be one of:
-    * `<type>` - An element type.
+    * `<type>` - An element type. Includes `*`, which represents every element.
     * `<type>:<state>` - An element type, a colon, and one or more states.
 * `state` is a list of states separated by the `+` character.
     * If a state is provided, the style will only take effect when the element is in that state.
@@ -2647,6 +2647,8 @@ A name/type can optionally be a comma separated list of names/types, like so:
     world_delete,world_create,world_configure
     button,image_button
 
+A `*` type can be used to select every element in the formspec.
+
 Any name/type in the list can also be accompanied by a `+`-separated list of states, like so:
 
     world_delete:hovered+pressed
diff --git a/src/gui/guiFormSpecMenu.cpp b/src/gui/guiFormSpecMenu.cpp
index 567f0ca7e..72095a86e 100644
--- a/src/gui/guiFormSpecMenu.cpp
+++ b/src/gui/guiFormSpecMenu.cpp
@@ -4609,20 +4609,32 @@ StyleSpec GUIFormSpecMenu::getDefaultStyleForElement(const std::string &type,
 	return getStyleForElement(type, name, parent_type)[StyleSpec::STATE_DEFAULT];
 }
 
-std::array<StyleSpec, StyleSpec::NUM_STATES> GUIFormSpecMenu::getStyleForElement(const std::string &type,
-		const std::string &name, const std::string &parent_type)
+std::array<StyleSpec, StyleSpec::NUM_STATES> GUIFormSpecMenu::getStyleForElement(
+	const std::string &type, const std::string &name, const std::string &parent_type)
 {
 	std::array<StyleSpec, StyleSpec::NUM_STATES> ret;
 
+	auto it = theme_by_type.find("*");
+	if (it != theme_by_type.end()) {
+		for (const StyleSpec &spec : it->second)
+			ret[(u32)spec.getState()] |= spec;
+	}
+
+	it = theme_by_name.find("*");
+	if (it != theme_by_name.end()) {
+		for (const StyleSpec &spec : it->second)
+			ret[(u32)spec.getState()] |= spec;
+	}
+
 	if (!parent_type.empty()) {
-		auto it = theme_by_type.find(parent_type);
+		it = theme_by_type.find(parent_type);
 		if (it != theme_by_type.end()) {
 			for (const StyleSpec &spec : it->second)
 				ret[(u32)spec.getState()] |= spec;
 		}
 	}
 
-	auto it = theme_by_type.find(type);
+	it = theme_by_type.find(type);
 	if (it != theme_by_type.end()) {
 		for (const StyleSpec &spec : it->second)
 			ret[(u32)spec.getState()] |= spec;