Trait ScriptInstance
pub trait ScriptInstance: Sized {
type Base: GodotClass;
Show 18 methods
// Required methods
fn class_name(&self) -> GString;
fn set_property(
this: SiMut<'_, Self>,
name: StringName,
value: &Variant,
) -> bool;
fn get_property(&self, name: StringName) -> Option<Variant>;
fn get_property_list(&self) -> Vec<PropertyInfo>;
fn get_method_list(&self) -> Vec<MethodInfo>;
fn call(
this: SiMut<'_, Self>,
method: StringName,
args: &[&Variant],
) -> Result<Variant, u32>;
fn is_placeholder(&self) -> bool;
fn has_method(&self, method: StringName) -> bool;
fn get_script(&self) -> &Gd<Script>;
fn get_property_type(&self, name: StringName) -> VariantType;
fn to_string(&self) -> GString;
fn get_property_state(&self) -> Vec<(StringName, Variant)>;
fn get_language(&self) -> Gd<ScriptLanguage>;
fn on_refcount_decremented(&self) -> bool;
fn on_refcount_incremented(&self);
fn property_get_fallback(&self, name: StringName) -> Option<Variant>;
fn property_set_fallback(
this: SiMut<'_, Self>,
name: StringName,
value: &Variant,
) -> bool;
fn get_method_argument_count(&self, _method: StringName) -> Option<u32>;
}
Expand description
Implement custom scripts that can be attached to objects in Godot.
To use script instances, implement this trait for your own type.
You can use the create_script_instance()
function to create a low-level pointer to your script instance.
This pointer should then be returned from IScriptExtension::instance_create()
.
§Example
use godot::prelude::*;
use godot::classes::{Script, ScriptExtension};
use godot::extras::{IScriptExtension, ScriptInstance};
// 1) Define the script.
// This needs #[class(tool)] since the script extension runs in the editor.
#[derive(GodotClass)]
#[class(init, base=ScriptExtension, tool)]
struct MyScript {
base: Base<ScriptExtension>,
// ... other fields
}
// 2) Define the script _instance_, and implement the trait for it.
struct MyInstance;
impl MyInstance {
fn from_gd(script: Gd<Script>) -> Self {
Self { /* ... */ }
}
}
impl ScriptInstance for MyInstance {
// Implement all the methods...
}
// 3) Implement the script's virtual interface to wire up 1) and 2).
#[godot_api]
impl IScriptExtension for MyScript {
// Implement all the methods...
}
Required Associated Types§
type Base: GodotClass
Required Methods§
fn class_name(&self) -> GString
fn class_name(&self) -> GString
Name of the new class the script implements.
fn set_property(
this: SiMut<'_, Self>,
name: StringName,
value: &Variant,
) -> bool
fn set_property( this: SiMut<'_, Self>, name: StringName, value: &Variant, ) -> bool
Property setter for Godot’s virtual dispatch system.
The engine will call this function when it wants to change a property on the script.
fn get_property(&self, name: StringName) -> Option<Variant>
fn get_property(&self, name: StringName) -> Option<Variant>
Property getter for Godot’s virtual dispatch system.
The engine will call this function when it wants to read a property on the script.
fn get_property_list(&self) -> Vec<PropertyInfo>
fn get_property_list(&self) -> Vec<PropertyInfo>
A list of all the properties a script exposes to the engine.
fn get_method_list(&self) -> Vec<MethodInfo>
fn get_method_list(&self) -> Vec<MethodInfo>
A list of all the methods a script exposes to the engine.
fn call(
this: SiMut<'_, Self>,
method: StringName,
args: &[&Variant],
) -> Result<Variant, u32>
fn call( this: SiMut<'_, Self>, method: StringName, args: &[&Variant], ) -> Result<Variant, u32>
Method invoker for Godot’s virtual dispatch system. The engine will call this function when it wants to call a method on the script.
All method calls are taking a mutable reference of the script instance, as the engine does not differentiate between immutable and mutable method calls like rust.
It’s important that the script does not cause a second call to this function while executing a method call. This would result in a panic.
fn is_placeholder(&self) -> bool
fn is_placeholder(&self) -> bool
Identifies the script instance as a placeholder. If this function and
IScriptExtension::is_placeholder_fallback_enabled return true,
Godot will call Self::property_set_fallback
instead of Self::set_property
.
fn has_method(&self, method: StringName) -> bool
fn has_method(&self, method: StringName) -> bool
Validation function for the engine to verify if the script exposes a certain method.
fn get_script(&self) -> &Gd<Script>
fn get_script(&self) -> &Gd<Script>
Lets the engine get a reference to the script this instance was created for.
This function has to return a reference, because scripts are reference-counted in Godot, and it must be guaranteed that the object is
not freed before the engine increased the reference count. (Every time a ref-counted Gd<T>
is dropped, the reference count is
decremented.)
fn get_property_type(&self, name: StringName) -> VariantType
fn get_property_type(&self, name: StringName) -> VariantType
Lets the engine fetch the type of a particular property.
fn get_property_state(&self) -> Vec<(StringName, Variant)>
fn get_property_state(&self) -> Vec<(StringName, Variant)>
A dump of all property names and values that are exposed to the engine.
fn get_language(&self) -> Gd<ScriptLanguage>
fn get_language(&self) -> Gd<ScriptLanguage>
Lets the engine get a reference to the ScriptLanguage
this instance belongs to.
fn on_refcount_decremented(&self) -> bool
fn on_refcount_decremented(&self) -> bool
Callback from the engine when the reference count of the base object has been decreased. When this method returns true
the engine will
not free the object the script is attached to.
fn on_refcount_incremented(&self)
fn on_refcount_incremented(&self)
Callback from the engine when the reference count of the base object has been increased.
fn property_get_fallback(&self, name: StringName) -> Option<Variant>
fn property_get_fallback(&self, name: StringName) -> Option<Variant>
The engine may call this function if it failed to get a property value via ScriptInstance::get_property
or the native type’s getter.
fn property_set_fallback(
this: SiMut<'_, Self>,
name: StringName,
value: &Variant,
) -> bool
fn property_set_fallback( this: SiMut<'_, Self>, name: StringName, value: &Variant, ) -> bool
The engine may call this function if
IScriptExtension::is_placeholder_fallback_enabled
is enabled.
fn get_method_argument_count(&self, _method: StringName) -> Option<u32>
Available on since_api="4.3"
only.
fn get_method_argument_count(&self, _method: StringName) -> Option<u32>
since_api="4.3"
only.This function will be called to handle calls to Object::get_method_argument_count
and Callable::get_argument_count
.
If None
is returned the public methods will return 0
.
Dyn Compatibility§
This trait is not dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.