urho3d/Source/Urho3D/AngelScript/ScriptInstance.h

// Copyright (c) 2008-2023 the Urho3D project
// License: MIT

/// \file

#pragma once

#include "../AngelScript/ScriptEventListener.h"
#include "../Scene/Component.h"

class asIScriptFunction;
class asIScriptObject;
class asIScriptContext;
class asITypeInfo;

namespace Urho3D
{

class Script;
class ScriptFile;
enum { eAttrMapUserIdx = 0x1df4};
void CleanupTypeInfoScriptInstance(asITypeInfo *type);

/// Inbuilt scripted component methods.
enum ScriptInstanceMethod
{
    METHOD_START = 0,
    METHOD_STOP,
    METHOD_DELAYEDSTART,
    METHOD_UPDATE,
    METHOD_POSTUPDATE,
    METHOD_FIXEDUPDATE,
    METHOD_FIXEDPOSTUPDATE,
    METHOD_LOAD,
    METHOD_SAVE,
    METHOD_READNETWORKUPDATE,
    METHOD_WRITENETWORKUPDATE,
    METHOD_APPLYATTRIBUTES,
    METHOD_TRANSFORMCHANGED,
    MAX_SCRIPT_METHODS
};

/// %Script object component.
class URHO3D_API ScriptInstance : public Component, public ScriptEventListener
{
    URHO3D_OBJECT(ScriptInstance, Component);

public:
    /// Construct.
    explicit ScriptInstance(Context* context);
    /// Destruct.
    ~ScriptInstance() override;
    /// Register object factory.
    /// @nobind
    static void RegisterObject(Context* context);

    /// Handle attribute write access.
    void OnSetAttribute(const AttributeInfo& attr, const Variant& src) override;
    /// Handle attribute read access.
    void OnGetAttribute(const AttributeInfo& attr, Variant& dest) const override;

    /// Return attribute descriptions, or null if none defined.
    const Vector<AttributeInfo>* GetAttributes() const override { return &attributeInfos_; }

    /// Apply attribute changes that can not be applied immediately. Called after scene load or a network update.
    void ApplyAttributes() override;
    /// Handle enabled/disabled state change.
    void OnSetEnabled() override;

    /// Add a scripted event handler.
    void AddEventHandler(StringHash eventType, const String& handlerName) override;
    /// Add a scripted event handler for a specific sender.
    void AddEventHandler(Object* sender, StringHash eventType, const String& handlerName) override;
    /// Remove a scripted event handler.
    void RemoveEventHandler(StringHash eventType) override;
    /// Remove a scripted event handler for a specific sender.
    void RemoveEventHandler(Object* sender, StringHash eventType) override;
    /// Remove all scripted event handlers for a specific sender.
    void RemoveEventHandlers(Object* sender) override;
    /// Remove all scripted event handlers.
    void RemoveEventHandlers() override;
    /// Remove all scripted event handlers, except those listed.
    void RemoveEventHandlersExcept(const Vector<StringHash>& exceptions) override;
    /// Return whether has subscribed to an event.
    bool HasEventHandler(StringHash eventType) const override;
    /// Return whether has subscribed to a specific sender's event.
    bool HasEventHandler(Object* sender, StringHash eventType) const override;

    /// Create object of certain class from the script file. Return true if successful.
    bool CreateObject(ScriptFile* scriptFile, const String& className);
    /// Set script file only. Recreate object if necessary.
    void SetScriptFile(ScriptFile* scriptFile);
    /// Set class name only. Recreate object if necessary.
    void SetClassName(const String& className);
    /// Query for a method by declaration and execute. Log an error if not found.
    bool Execute(const String& declaration, const VariantVector& parameters = Variant::emptyVariantVector);
    /// Execute a method.
    bool Execute(asIScriptFunction* method, const VariantVector& parameters = Variant::emptyVariantVector);
    /// Add a delay-executed method call, optionally repeating.
    void DelayedExecute
        (float delay, bool repeat, const String& declaration, const VariantVector& parameters = Variant::emptyVariantVector);
    /// Clear pending delay-executed method calls. If empty declaration given, clears all.
    void ClearDelayedExecute(const String& declaration = String::EMPTY);

    /// Return script file.
    ScriptFile* GetScriptFile() const { return scriptFile_; }

    /// Return script object.
    asIScriptObject* GetScriptObject() const { return scriptObject_; }

    /// Return class name.
    const String& GetClassName() const { return className_; }

    /// Check if the object is derived from a class.
    bool IsA(const String& className) const;
    /// Check if has a method.
    bool HasMethod(const String& declaration) const;

    /// Set script file attribute.
    void SetScriptFileAttr(const ResourceRef& value);
    /// Set delayed method calls attribute.
    void SetDelayedCallsAttr(const Vector<byte>& value);
    /// Set script file serialization attribute by calling a script function.
    void SetScriptDataAttr(const Vector<byte>& data);
    /// Set script network serialization attribute by calling a script function.
    void SetScriptNetworkDataAttr(const Vector<byte>& data);
    /// Return script file attribute.
    ResourceRef GetScriptFileAttr() const;
    /// Return delayed method calls attribute.
    Vector<byte> GetDelayedCallsAttr() const;
    /// Get script file serialization attribute by calling a script function.
    Vector<byte> GetScriptDataAttr() const;
    /// Get script network serialization attribute by calling a script function.
    Vector<byte> GetScriptNetworkDataAttr() const;

protected:
    /// Handle scene being assigned.
    void OnSceneSet(Scene* scene) override;
    /// Handle node transform being dirtied.
    void OnMarkedDirty(Node* node) override;

private:
    /// (Re)create the script object and check for supported methods if successfully created.
    void CreateObject();
    /// Release the script object.
    void ReleaseObject();
    /// Check for supported script methods.
    void GetScriptMethods();
    /// Check for script attributes.
    void GetScriptAttributes();
    /// Store values of script attributes for hot reload.
    void StoreScriptAttributes();
    /// Restore values of script attributes after hot reload is complete.
    void RestoreScriptAttributes();
    /// Clear supported script methods.
    void ClearScriptMethods();
    /// Clear attributes to C++ side attributes only.
    void ClearScriptAttributes();
    /// Subscribe/unsubscribe from scene updates as necessary.
    void UpdateEventSubscription();
    /// Handle scene update event.
    void HandleSceneUpdate(StringHash eventType, VariantMap& eventData);
    /// Handle scene post-update event.
    void HandleScenePostUpdate(StringHash eventType, VariantMap& eventData);
#if defined(URHO3D_PHYSICS) || defined(URHO3D_URHO2D)
    /// Handle physics pre-step event.
    void HandlePhysicsPreStep(StringHash eventType, VariantMap& eventData);
    /// Handle physics post-step event.
    void HandlePhysicsPostStep(StringHash eventType, VariantMap& eventData);
#endif
    /// Handle an event in script.
    void HandleScriptEvent(StringHash eventType, VariantMap& eventData);
    /// Handle script file reload start.
    void HandleScriptFileReload(StringHash eventType, VariantMap& eventData);
    /// Handle script file reload finished.
    void HandleScriptFileReloadFinished(StringHash eventType, VariantMap& eventData);

    template<typename Op>
    void executeScript(asIScriptFunction* method, Op func) const;

    /// Script file.
    WeakPtr<ScriptFile> scriptFile_;
    /// Script object.
    asIScriptObject* scriptObject_{};
    /// Class name.
    String className_;
    /// Pointers to supported inbuilt methods.
    asIScriptFunction* methods_[MAX_SCRIPT_METHODS]{};
    /// Delayed method calls.
    Vector<DelayedCall> delayedCalls_;
    /// Attributes, including script object variables.
    Vector<AttributeInfo> attributeInfos_;
    /// Storage for unapplied node and component ID attributes.
    HashMap<AttributeInfo*, unsigned> idAttributes_;
    /// Storage for attributes while script object is being hot-reloaded.
    HashMap<String, Variant> storedAttributes_;
    /// Subscribed to scene update events flag.
    bool subscribed_{};
    /// Subscribed to scene post and fixed update events flag.
    bool subscribedPostFixed_{};
};

/// Return the active AngelScript context. Provided as a wrapper to the AngelScript API function to avoid undefined symbol error in shared library Urho3D builds.
URHO3D_API asIScriptContext* GetActiveASContext();
/// Return the Urho3D context of the active AngelScript context.
URHO3D_API Context* GetScriptContext();
/// Return the ScriptInstance of the active AngelScript context.
URHO3D_API ScriptInstance* GetScriptContextInstance();
/// Return the scene node of the active AngelScript context.
URHO3D_API Node* GetScriptContextNode();
/// Return the scene of the active AngelScript context.
URHO3D_API Scene* GetScriptContextScene();
/// Return the event listener of the active AngelScript context.
URHO3D_API ScriptEventListener* GetScriptContextEventListener();
/// Return the event listener of the active AngelScript context as an Object pointer.
URHO3D_API Object* GetScriptContextEventListenerObject();

}