Lua: Allow clearing an aspects MacroExpander

Adds a value "Null" to simpletypes to allow setting null values in
Tables:

Settings.BoolAspect.create({
  -- ...
  macroExpander = Null
})

Adds Macro.globalExpander() to retrieve the global expander.

Changes the result of MacroExpander.value() to (ok, value).

Change-Id: I2e2577b8d2f6acd447a3701f7ecaf835504768da
Reviewed-by: <lie@spyro-soft.com>
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/plugins/lua/bindings/macro.cpp

@@ -12,12 +12,28 @@ void setupMacroModule()
     registerProvider("Macro", [](sol::state_view lua) {
         sol::table module = lua.create_table();
 
-        module.set_function("expand", [](const QString &s) -> QString {
+        module.new_usertype<Utils::MacroExpander>(
+            "MacroExpander",
+            sol::no_constructor,
+            "expand",
+            [](Utils::MacroExpander *self, const QString &str) { return self->expand(str); },
+            "value",
+            [](Utils::MacroExpander *self, const QByteArray &str) {
+                bool found = false;
+                const QString res = self->value(str, &found);
+                return std::make_pair(found, res);
+            });
+
+        module.set_function("globalExpander", [] { return Utils::globalMacroExpander(); });
+
+        module.set_function("expand", [](const QString &s) {
             return Utils::globalMacroExpander()->expand(s);
         });
 
-        module.set_function("value", [](const QString &s) -> QString {
-            return Utils::globalMacroExpander()->value(s.toUtf8());
+        module.set_function("value", [](const QString &s) {
+            bool found = false;
+            const QString res = Utils::globalMacroExpander()->value(s.toUtf8(), &found);
+            return std::make_pair(found, res);
         });
 
         return module;

src/plugins/lua/bindings/settings.cpp

@@ -112,7 +112,12 @@ void baseAspectCreate(BaseAspect *aspect, const std::string &key, const sol::obj
                          [func = value.as<sol::function>()] { void_safe_call(func); });
     } else if (key == "enabler")
         aspect->setEnabler(value.as<BoolAspect *>());
-    else
+    else if (key == "macroExpander") {
+        if (value.is<Null>())
+            aspect->setMacroExpander(nullptr);
+        else
+            aspect->setMacroExpander(value.as<MacroExpander *>());
+    } else
         qWarning() << "Unknown key:" << key.c_str();
 }
 

src/plugins/lua/luaengine.cpp

@@ -421,6 +421,11 @@ void setupLuaEngine(QObject *guard)
 {
     QTC_ASSERT(!d, return);
     d = new LuaInterfaceImpl(guard);
+
+    autoRegister([](sol::state_view lua) {
+        lua.new_usertype<Null>("NullType", sol::no_constructor);
+        lua.set("Null", Null{});
+    });
 }
 
 } // namespace Lua

src/plugins/lua/luaengine.h

@@ -109,4 +109,7 @@ sol::protected_function_result runFunction(
 
 void setupLuaEngine(QObject *guard);
 
+class Null
+{};
+
 } // namespace Lua

src/plugins/lua/meta/macro.lua

@@ -2,13 +2,34 @@
 -- SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 
 ---@meta Macro
-
 local macro = {}
+---@class MacroExpander
+local MacroExpander = {}
+
+---Expands all variables in the given string.
+---@param stringWithVariables string The string with variables to expand.
+---@return string The expanded string.
+function MacroExpander:expand(stringWithVariables) end
+
+---Returns the value of the given variable.
+---@param variableName string The name of the variable.
+---@return boolean ok Whether the variable was found.
+---@return string value The value of the variable.
+function MacroExpander:value(variableName) end
+
+---Returns the global Macro expander
+---@return MacroExpander
+function macro.globalExpander() end
 
 ---Returns globalExpander():value(variableName).
+---@param variableName string The name of the variable.
+---@return boolean ok Whether the variable was found.
+---@return string value The value of the variable.
 function macro.value(variableName) end
 
 ---Returns globalExpander():expand(stringWithVariables).
+---@param stringWithVariables string The string with variables to expand.
+---@return string The expanded string.
 function macro.expand(stringWithVariables) end
 
 return macro

src/plugins/lua/meta/settings.lua

@@ -1,6 +1,7 @@
 ---@meta Settings
 
 ---@module 'Qt'
+---@module 'SimpleTypes'
 
 local settings = {}
 
@@ -19,6 +20,7 @@ function settings.BaseAspect:apply() end
 ---@field enabler? BoolAspect Enable / Disable this aspect based on the state of the `enabler`.
 ---@field onValueChanged? function () Called when the value of the aspect changes.
 ---@field onVolatileValueChanged? function () Called when the volatile value of the aspect changes.
+---@field macroExpander? MacroExpander|NullType The macro expander to use, or nil to disable macro expansion.
 local AspectCreate = {}
 
 ---The base class of most typed aspects.

src/plugins/lua/meta/simpletypes.lua

@@ -1,4 +1,4 @@
----@meta
+---@meta SimpleTypes
 
 ---@class QRect
 ---@field x integer The x position of the rectangle.
@@ -28,9 +28,19 @@ QPointF = {}
 ---@field height number The height of the floating point size.
 QSizeF = {}
 
----@class QRectF
+---@class QRectF A rectangle with floating point coordinates.
 ---@field x number The x position of the floating point rectangle.
 ---@field y number The y position of the floating point rectangle.
 ---@field width number The width of the floating point rectangle.
 ---@field height number The height of the floating point rectangle.
 QRectF = {}
+
+---@class NullType
+NullType = {}
+
+---Just a workaround to let "Null" show the correct type in the documentation.
+---@return NullType null
+local function null() end
+
+---A special object to represent a nullptr value.
+Null = null()