ExpressionVariableOwnerFinder.h

/*
 * GDevelop Core
 * Copyright 2008-present Florian Rival ([email protected]). All rights
 * reserved. This project is released under the MIT License.
 */
#ifndef GDCORE_EXPRESSIONVARIABLEOWNERFINDER_H
#define GDCORE_EXPRESSIONVARIABLEOWNERFINDER_H
 
#include <memory>
#include <vector>
#include "GDCore/Events/Parsers/ExpressionParser2Node.h"
#include "GDCore/Events/Parsers/ExpressionParser2NodeWorker.h"
#include "GDCore/Extensions/Metadata/ExpressionMetadata.h"
#include "GDCore/Extensions/Metadata/MetadataProvider.h"
#include "GDCore/Extensions/Metadata/ObjectMetadata.h"
#include "GDCore/Extensions/Metadata/ParameterMetadata.h"
#include "GDCore/Project/Layout.h"  // For GetTypeOfObject and GetTypeOfBehavior
#include "GDCore/Project/ObjectsContainersList.h"
#include "GDCore/Tools/Localization.h"
 
namespace gd {
class Expression;
class ObjectsContainer;
class Platform;
class ParameterMetadata;
class ExpressionMetadata;
}  // namespace gd
 
namespace gd {
 
class GD_CORE_API ExpressionVariableOwnerFinder : public ExpressionParser2NodeWorker {
 public:
 
  static const gd::String GetObjectName(const gd::Platform &platform,
                      const gd::ObjectsContainersList &objectsContainersList,
                      const gd::String& rootObjectName,
                      gd::ExpressionNode& node) {
    gd::ExpressionVariableOwnerFinder typeFinder(
        platform, objectsContainersList, rootObjectName);
    node.Visit(typeFinder);
    return typeFinder.GetObjectName();
  }
 
  virtual ~ExpressionVariableOwnerFinder(){};
 
 protected:
  ExpressionVariableOwnerFinder(const gd::Platform &platform_,
                       const gd::ObjectsContainersList &objectsContainersList_,
                       const gd::String& rootObjectName_)
      : platform(platform_),
        objectsContainersList(objectsContainersList_),
        rootObjectName(rootObjectName_),
        objectName(""),
        variableNode(nullptr) {};
 
  const gd::String &GetObjectName() {
    return objectName;
  };
 
  void OnVisitSubExpressionNode(SubExpressionNode& node) override {}
  void OnVisitOperatorNode(OperatorNode& node) override {}
  void OnVisitUnaryOperatorNode(UnaryOperatorNode& node) override {}
  void OnVisitNumberNode(NumberNode& node) override {}
  void OnVisitTextNode(TextNode& node) override {}
  void OnVisitVariableNode(VariableNode& node) override {
    if (variableNode != nullptr) {
      // This is not possible
      return;
    }
    if (node.parent == nullptr) {
      objectName = rootObjectName;
      return;
    }
    variableNode = &node;
    node.parent->Visit(*this);
  }
  void OnVisitVariableAccessorNode(VariableAccessorNode& node) override {}
  void OnVisitIdentifierNode(IdentifierNode& node) override {
    if (variableNode != nullptr) {
      // This is not possible
      return;
    }
    if (node.parent == nullptr) {
      objectName = rootObjectName;
      return;
    }
    // This node is not necessarily a variable node.
    // It will be checked when visiting the FunctionCallNode.
    variableNode = &node;
    node.parent->Visit(*this);
  }
  void OnVisitEmptyNode(EmptyNode& node) override {}
  void OnVisitObjectFunctionNameNode(ObjectFunctionNameNode& node) override {}
  void OnVisitVariableBracketAccessorNode(
      VariableBracketAccessorNode& node) override {}
  void OnVisitFunctionCallNode(FunctionCallNode& functionCall) override {
    if (variableNode == nullptr) {
      return;
    }
    int parameterIndex = -1;
    for (int i = 0; i < functionCall.parameters.size(); i++) {
      if (functionCall.parameters.at(i).get() == variableNode) {
        parameterIndex = i;
        break;
      }
    }
    if (parameterIndex < 0) {
      return;
    }
    const gd::ParameterMetadata* parameterMetadata =
        MetadataProvider::GetFunctionCallParameterMetadata(
            platform,
            objectsContainersList,
            functionCall,
            parameterIndex);
    if (parameterMetadata == nullptr
     || parameterMetadata->GetType() != "objectvar") {
      return;
    }
 
    // The object on which the function is called is returned if no previous
    // parameters are objects.
    objectName = functionCall.objectName;
    for (int previousIndex = parameterIndex - 1; previousIndex >= 0; previousIndex--) {
      const gd::ParameterMetadata* previousParameterMetadata =
          MetadataProvider::GetFunctionCallParameterMetadata(
              platform,
              objectsContainersList,
              functionCall,
              previousIndex);
      if (previousParameterMetadata != nullptr
      && gd::ParameterMetadata::IsObject(previousParameterMetadata->GetType())) {
        auto previousParameterNode = functionCall.parameters[previousIndex].get();
        IdentifierNode* objectNode = dynamic_cast<IdentifierNode*>(previousParameterNode);
        objectName = objectNode->identifierName;
        return;
      }
    }
  }
 
 private:
  gd::String objectName;
  gd::ExpressionNode *variableNode;
 
  const gd::Platform &platform;
  const gd::ObjectsContainersList &objectsContainersList;
  const gd::String &rootObjectName;
};
 
}  // namespace gd
 
#endif  // GDCORE_EXPRESSIONVARIABLEOWNERFINDER_H