Add shortcut for Resource properties

Author: gilzoide

README.md

@@ -6,16 +6,12 @@ as a scripting language in [Godot](https://godotengine.org/).
 Being a GDNative library, recompiling the engine is not required, so anyone
 with a built release copied to their project can use it.
 Being a PluginScript language, Lua can seamlessly communicate with scripts
-written in GDScript/C#/Visual Script and vice-versa.
+written in GDScript / C# / Visual Script and vice-versa.
+This way, one can use the language that best suits the implementation for each
+script and all of them can understand each other.
 
-
-## Documentation
-The API is documented using [LDoc](https://stevedonovan.github.io/ldoc/manual/doc.md.html)
-and is available online at [github pages](https://gilzoide.github.io/godot-lua-pluginscript/topics/README.md.html).
-
-Generate the documentation with the following command:
-
-    # make docs
+Currently, only LuaJIT is supported, since the implementation is based on its
+[FFI](https://luajit.org/ext_ffi.html) library.
 
 
 ## Installing
@@ -25,14 +21,6 @@ Make sure the `lua_pluginscript.gdnlib` file is located at the
 `res://addons/godot-lua-pluginscript` folder.
 
 
-## Articles
-
-1. [Designing Godot Lua PluginScript](blog/1-design-en.md)
-2. [Implementing the library's skeleton](blog/2-infrastructure-en.md)
-3. [Integrating LuaJIT and FFI](blog/3-luajit-callbacks-en.md)
-4. Initializing and finalizing scripts (TODO)
-
-
 ## Goals
 
 - Provide support for Lua as a scripting language in Godot in a way that does
@@ -41,7 +29,7 @@ Make sure the `lua_pluginscript.gdnlib` file is located at the
   like GDScript, Visual Script and C#, in an idiomatic way
 - Simple script description interface that doesn't need `require`ing anything
 - Support for LuaJIT and Lua 5.2+
-- Support paths relative to `res://*` and exported game executable path for
+- Support paths relative to `res://*` and exported game/app executable path for
   `require`ing Lua modules
 - Have a simple build process, where anyone with the cloned source code and
   installed build system + toolchain can build the project in a single step
@@ -53,6 +41,23 @@ Make sure the `lua_pluginscript.gdnlib` file is located at the
 - Support multithreading on the Lua side
 
 
+## Documentation
+The API is documented using [LDoc](https://stevedonovan.github.io/ldoc/manual/doc.md.html)
+and is available online at [github pages](https://gilzoide.github.io/godot-lua-pluginscript/topics/README.md.html).
+
+Documentation may be generated with the following command:
+
+    # make docs
+
+
+## Articles
+
+1. [Designing Godot Lua PluginScript](https://github.com/gilzoide/godot-lua-pluginscript/blob/main/blog/1-design-en.md)
+2. [Implementing the library's skeleton](https://github.com/gilzoide/godot-lua-pluginscript/blob/main/blog/2-infrastructure-en.md)
+3. [Integrating LuaJIT and FFI](https://github.com/gilzoide/godot-lua-pluginscript/blob/main/blog/3-luajit-callbacks-en.md)
+4. Initializing and finalizing scripts (TODO)
+
+
 ## Script example
 
 This is an example of how a Lua script looks like. There are comments regarding
@@ -81,37 +86,32 @@ MyClass.some_prop = 42
 -- The `property` function adds metadata to defined properties,
 -- like setter and getter functions
 MyClass.some_prop_with_details = property {
-  -- [1] or ["default"] or ["default_value"] = property default value
+  -- ["default_value"] or ["default"] or [1] = property default value
   5,
-  -- [2] or ["type"] = variant type, optional, inferred from default value
+  -- ["type"] or [2] = variant type, optional, inferred from default value
   -- All Godot variant type names are defined globally as written in
   -- GDScript, like bool, int, float, String, Array, Vector2, etc...
   -- Notice that Lua <= 5.2 does not differentiate integers from float
   -- numbers, so we should always specify `int` where appropriate
   -- or use `int(5)` in the default value instead
   type = int,
-  -- ["set"] or ["setter"] = setter function, optional
-  set = function(self, value)
-    self.some_prop_with_details = value
-    -- Indexing `self` with keys undefined in script will search base
-    -- class for methods and properties
-    self:emit_signal("something_happened_with_args", "some_prop_with_details", value)
-  end,
-  -- ["get"] or ["getter"] = getter function, optional
+  -- ["get"] or ["getter"] = getter function or method name, optional
   get = function(self)
     return self.some_prop_with_details
   end,
-  -- ["usage"] = property usage, from enum godot_property_usage_flags
-  -- optional, default to GD.PROPERTY_USAGE_DEFAULT
-  usage = GD.PROPERTY_USAGE_DEFAULT,
-  -- ["hint"] = property hint, from enum godot_property_hint
-  -- optional, default to GD.PROPERTY_HINT_NONE
-  hint = GD.PROPERTY_HINT_RANGE,
+  -- ["set"] or ["setter"] = setter function or method name, optional
+  set = 'set_some_prop_with_details',
+  -- ["usage"] = property usage, from `enum godot_property_usage_flags`
+  -- optional, default to `PropertyUsage.DEFAULT`
+  usage = PropertyUsage.DEFAULT,
+  -- ["hint"] = property hint, from `enum godot_property_hint`
+  -- optional, default to `PropertyHint.NONE`
+  hint = PropertyHint.RANGE,
   -- ["hint_string"] = property hint text, only required for some hints
   hint_string = '1,10',
-  -- ["rset_mode"] = property remote set mode, from enum godot_method_rpc_mode
-  -- optional, default to GD.RPC_MODE_DISABLED
-  rset_mode = GD.RPC_MODE_MASTER,
+  -- ["rset_mode"] = property remote set mode, from `enum godot_method_rpc_mode`
+  -- optional, default to `RPCMode.DISABLED`
+  rset_mode = RPCMode.MASTER,
 }
 
 -- Functions defined in table are public methods
@@ -121,7 +121,14 @@ function MyClass:_ready()  -- `function t:f(...)` is an alias for `function t.f(
   print("MyClass instance is ready! Running on a " .. os_name .. " system")
 end
 
-function MyClass:some_prop_doubled()
+function MyClass:set_some_prop_with_details(value)
+    self.some_prop_with_details = value
+    -- Indexing `self` with keys undefined in script will search base
+    -- class for methods and properties
+    self:emit_signal("something_happened_with_args", "some_prop_with_details", value)
+end
+
+function MyClass:get_some_prop_doubled()
   return self.some_prop * 2
 end
 

src/godot_class.lua

@@ -80,6 +80,19 @@ local class_methods = {
 		Object_call(obj, '_init', ...)
 		return obj
 	end,
+	--- Returns whether this Class inherits a `parent` Class.
+	-- @function inherits
+	-- @param other  Other class name
+	-- @treturn bool
+	inherits = function(self, parent)
+		return ClassDB:is_parent_class(self.class_name, parent)
+	end,
+	--- Returns the parent class.
+	-- @function get_parent_class
+	-- @treturn String
+	get_parent_class = function(self)
+		return ClassDB:get_parent_class(self.class_name)
+	end,
 }
 local ClassWrapper = {
 	new = function(self, class_name)
@@ -114,8 +127,18 @@ local ClassWrapper = {
 			return constant
 		end
 	end,
+	--- Returns `class_name`
+	-- @function __tostring
+	-- @treturn string
+	__tostring = function(self)
+		return self.class_name
+	end,
 }
 
+local function is_class_wrapper(v)
+	return getmetatable(v) == ClassWrapper
+end
+
 --- MethodBind metatype, wrapper for `godot_method_bind`.
 -- These are returned by `ClassWrapper:__index` and GDNative's `godot_method_bind_get_method`.
 -- @type MethodBind

src/godot_enums.lua

@@ -241,19 +241,19 @@ for k, v in pairs(RPCMode) do RPCMode[v] = k end
 --- Enum `godot_property_hint`, mapping UPPER_CASED names to ordinal values and vice-versa.
 -- @table PropertyHint
 -- @field NONE  None
--- @field RANGE  Range
--- @field EXP_RANGE  Exp Range
--- @field ENUM  Enum
+-- @field RANGE  Range (hint_string = `"min,max,step,slider"`; step and slider are optional)
+-- @field EXP_RANGE  Exp Range (hint_string = `"min,max,step"`; exponential edit)
+-- @field ENUM  Enum (hint_string = `"val1,val2,val3,etc"`)
 -- @field EXP_EASING  Exp Easing
--- @field LENGTH  Length
--- @field SPRITE_FRAME  Sprite Frame
--- @field KEY_ACCEL  Key Accel
--- @field FLAGS  Flags
+-- @field LENGTH  Length (hint_string = `"length"`; as integer)
+-- @field SPRITE_FRAME  Sprite Frame (Obsolete)
+-- @field KEY_ACCEL  Key Accel (hint_string = `"length"`; as integer)
+-- @field FLAGS  Flags (hint_string = `"flag1,flag2,etc"`; as bit flags)
 -- @field LAYERS_2D_RENDER  Layers 2D Render
 -- @field LAYERS_2D_PHYSICS  Layers 2D Physics
 -- @field LAYERS_3D_RENDER  Layers 3D Render
 -- @field LAYERS_3D_PHYSICS  Layers 3D Physics
--- @field FILE  File
+-- @field FILE  File (optional hint_string: file filter, e.g. `"\*.png,\*.wav"`)
 -- @field DIR  Dir
 -- @field GLOBAL_FILE  Global File
 -- @field GLOBAL_DIR  Global Dir
@@ -264,7 +264,7 @@ for k, v in pairs(RPCMode) do RPCMode[v] = k end
 -- @field IMAGE_COMPRESS_LOSSY  Image Compress Lossy
 -- @field IMAGE_COMPRESS_LOSSLESS  Image Compress Lossless
 -- @field OBJECT_ID  Object Id
--- @field TYPE_STRING  Type String
+-- @field TYPE_STRING  Type String (hint_string = `"base class name"`)
 -- @field NODE_PATH_TO_EDITED_NODE  Node Path To Edited Node
 -- @field METHOD_OF_VARIANT_TYPE  Method Of Variant Type
 -- @field METHOD_OF_BASE_TYPE  Method Of Base Type
@@ -323,8 +323,8 @@ for k, v in pairs(PropertyHint) do PropertyHint[v] = k end
 -- @field INTERNATIONALIZED  Internationalized
 -- @field GROUP  Group
 -- @field CATEGORY  Category
--- @field STORE_IF_NONZERO  Store If Nonzero
--- @field STORE_IF_NONONE  Store If Nonone
+-- @field STORE_IF_NONZERO  Store If Nonzero (Obsolete)
+-- @field STORE_IF_NONONE  Store If Nonone (Obsolete)
 -- @field NO_INSTANCE_STATE  No Instance State
 -- @field RESTART_IF_CHANGED  Restart If Changed
 -- @field SCRIPT_VARIABLE  Script Variable

src/godot_string_name.lua

@@ -22,7 +22,7 @@
 -- IN THE SOFTWARE.
 
 --- StringName metatype, wrapper for `godot_string_name`.
--- Construct using the idiom `StringName(...)`, which calls `__new`.
+-- Construct using the idiom `StringName(name)`, which calls `__new`.
 -- @classmod StringName
 
 local methods = {

src/pluginscript_callbacks.lua

@@ -128,17 +128,10 @@ clib.lps_script_init_cb = wrap_callback(function(manifest, path, source, err)
 			prop.name = String(k)
 			-- Maintain default value directly for __indexing
 			metadata[k] = default_value
-			-- TODO: support strings for get/set
 			if get then
-				if is_a_string(get) then
-					get = MethodBindByName:new(get)
-				end
 				getter[k] = get
 			end
 			if set then
-				if is_a_string(set) then
-					set = MethodBindByName:new(set)
-				end
 				setter[k] = set
 			end
 			manifest.properties:append(prop)

src/pluginscript_class_metadata.lua

@@ -21,7 +21,11 @@
 -- FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 -- IN THE SOFTWARE.
 
--- Map names and ctypes to godot_variant_type
+--- Scripts metadata.
+-- This includes properties, signals and methods.
+-- @module script_metadata
+
+-- Map names and types to godot_variant_type
 local property_types = {
 	bool = VariantType.Bool, [bool] = VariantType.Bool,
 	int = VariantType.Int, [int] = VariantType.Int,
@@ -85,23 +89,69 @@ local function property_to_dictionary(prop)
 		default_value = prop
 		dict.type = get_property_type(prop)
 	else
-		default_value = prop[1] or prop.default or prop.default_value
-		local explicit_type = prop[2] or prop.type
-		dict.type = property_types[explicit_type] or explicit_type or get_property_type(default_value)
-		dict.hint = prop.hint
-		dict.hint_string = prop.hint_string
+		default_value = prop.default_value or prop.default or prop[1]
+		local explicit_type = prop.type or prop[2]
+		if is_class_wrapper(explicit_type) and explicit_type:inherits('Resource') then
+			dict.type = VariantType.Object
+			dict.hint = PropertyHint.RESOURCE_TYPE
+			dict.hint_string = explicit_type.class_name
+		else
+			dict.type = property_types[explicit_type] or explicit_type or get_property_type(default_value)
+			dict.hint = prop.hint
+			dict.hint_string = prop.hint_string
+		end
 		dict.usage = prop.usage
 		dict.rset_mode = prop.rset_mode
 		get = prop.get or prop.getter
+		if is_a_string(get) then
+			get = MethodBindByName:new(get)
+		end
 		set = prop.set or prop.setter
+		if is_a_string(set) then
+			set = MethodBindByName:new(set)
+		end
 	end
 	dict.default_value = default_value
 	return dict, default_value, get, set
 end
 
+--- Adds `metadata` to a property.
+-- If `metadata` is not a table, creates a table with this value as `default_value`.
+-- The `metadata` table may include the following fields:
+--
+-- * `default_value` or `default` or `1`: default property value, returned when
+--   Object has no other value set for it.
+-- * (*optional*) `type` or `2`: property type. If absent, it is inferred from `default_value`.
+--   May be a `Enumerations.VariantType` (`VariantType.Vector2`), the type directly (`Vector2`),
+--   or a Resource class (`AudioStream`)
+-- * (*optional*) `get` or `getter`: getter function. May be a string with the method name
+--   to be called or any callable value, like functions and tables with a `__call`
+--   metamethod.
+-- * (*optional*) `set` or `setter`: setter function. May be a string with the method name
+--   to be called or any callable value, like functions and tables with a `__call`
+--   metamethod.
+-- * (*optional*) `hint`: one of `Enumerations.PropertyHint`. Default to `PropertyHint.NONE`.
+-- * (*optional*) `hint_string`: the hint text, required for some hints like `RANGE`.
+-- * (*optional*) `usage`: one of `Enumerations.PropertyUsage`. Default to `PropertyUsage.DEFAULT`.
+-- * (*optional*) `rset_mode`: one of `Enumerations.RPCMode`. Default to `RPCMode.DISABLED`.
+--
+-- TODO: accept hints directly (`range = '1,10'`; `enum = 'value1,value2,value3'`; `file = '*.png'`, etc...).
+-- @usage
+--     MyClass.some_prop = property(42)
+--     MyClass.some_prop_with_metadata = property {
+--         type = int,
+--         set = function(self, value)
+--             self.some_prop_with_metadata = value
+--             self:emit('some_prop_with_metadata_changed', value)
+--         end,
+--         hint = PropertyHint.RANGE,
+--         hint_text = '1,100',
+--     }
+-- @treturn table
+-- @see lps_coroutine.lua
 function property(metadata)
 	if type(metadata) ~= 'table' then
-		metadata = { metadata }
+		metadata = { default_value = metadata }
 	end
 	return setmetatable(metadata, Property)
 end
@@ -122,6 +172,14 @@ local function signal_to_dictionary(sig)
 	return dict
 end
 
+--- Create a signal table.
+-- This is only useful for declaring scripts' signals.
+-- @usage
+--     MyClass.something_happened = signal()
+--     MyClass.something_happened_with_args = signal('arg1', 'arg2', 'etc')
+-- @param ...  Signal argument names
+-- @treturn table
+-- @see lps_coroutine.lua
 function signal(...)
 	return setmetatable({ ... }, Signal)
 end