从0创建蓝图编辑器(源码+思维导图)

// Fill out your copyright notice in the Description page of Project Settings. #include "SMyGraphPin.h" #include "TestGraphAndBlueprintStyle.h" #include "SGraphPin.h" #include "SGraphPanel.h" #include "EdGraph/EdGraphNode.h" #include "EdGraph/EdGraphPin.h" /** * @Function OwnerNodePtr.Pin() 当前指针还在有效时分享当前指针 */ //我们将逻辑上的Pin(UEdGraphPin)简称为GraphPin，用来显示的Pin(SGraphPin)称为SlatePin.Node同理 void SMyGraphPin::Construct(const FArguments& InArgs, UEdGraphPin* InPin) { //1、初始化设置以及获取其对应的GraphPin、Shema //设置鼠标悬停时的鼠标样式 this->SetCursor(EMouseCursor::Hand); //可编辑 IsEditable = true; //获取到自己对应的GraphPin并检查 GraphPinObj = InPin; check(GraphPinObj); //获取到所属的Shema并检查 const UEdGraphSchema* OwnerSchema = GraphPinObj->GetSchema(); check(OwnerSchema); //2、创建用于显示的SlatePin SBorder::Construct(SBorder::FArguments() //背景颜色 .BorderBackgroundColor_Lambda([&]() { return FSlateColor(FLinearColor(0.f, 1.f, 1.f, 0.5f)); }) //鼠标按下事件 Geometry：几何信息 PointerEvent：按键信息 .OnMouseButtonDown_Lambda([&](const FGeometry& Geometry, const FPointerEvent& PointerEvent) { //?干啥的 bIsMovingLinks = false; //判断是否是鼠标左键&&该节点是可编辑的 if (PointerEvent.GetEffectingButton() == EKeys::LeftMouseButton&& IsEditingEnabled()) { //该GraphPin可连接 if (!GraphPinObj->bNotConnectable) { /** * OwnerNodePtr.Pin(): * Converts this weak pointer to a shared pointer that you can use to access the object (if it * hasn't expired yet.) Remember, if there are no more shared references to the object, the * returned shared pointer will not be valid. You should always check to make sure the returned * pointer is valid before trying to dereference the shared pointer! * * @return Shared pointer for this object (will only be valid if still referenced!) */ //获取到当前Pin所属的SlateNode?: Node为什么不能放在Lambda外面被赋值，会引发断点 TSharedPtr<SGraphNode> OwnerSlateNode = OwnerNodePtr.Pin(); //同时按了Alt时，断开连接的所有引脚 if (PointerEvent.IsAltDown()) { //?: 同理，为什么使用同样代码的OwnerSchema调用时会引发断点，而这里获取的不会 const UEdGraphSchema* Schema = GraphPinObj->GetSchema(); /**BreakPinLinks() * Breaks all links from/to a single pin * * @param TargetPin The pin to break links on * @param bSendsNodeNotifcation whether to send a notification to the node post pin connection change */ //断掉该GraphPin的所有连接 Schema->BreakPinLinks(*GraphPinObj, true); return FReply::Handled(); } //同时按了Ctrl/Cmd时，可将连接线拖动至别的引脚(是否按下Controller&&该引脚连接数目>0) if (PointerEvent.IsControlDown() && (GraphPinObj->LinkedTo.Num() > 0)) { //一、挑选出Panel中所有被线连接的Pin塞进AllPinsMap<FGraphPinHandle,SGraphPin> //获取当前面板中到所有的SlatePin TSet<TSharedRef<SWidget>> AllSlatePins; OwnerSlateNode->GetOwnerPanel()->GetAllPins(AllSlatePins); //有连线的Pin的Map<GraphPin,SlatePin> TMap<FGraphPinHandle, TSharedRef<SGraphPin>> AllPinsMap; //将所有Pin中有至少一个连接的塞进AllPinsMap for (const TSharedRef<SWidget>& SlatePinRef : AllSlatePins) { UEdGraphPin* GraphPinPtr = static_cast<const SGraphPin&>(SlatePinRef.Get()).GetPinObj(); if (GraphPinPtr->LinkedTo.Num() > 0) { AllPinsMap.Add(FGraphPinHandle(GraphPinPtr), StaticCastSharedRef<SGraphPin>(SlatePinRef)); } } //二、获取到与当前Pin直接相连的Pin信息，存入LinkedPinInfoArray中 //存储Pin信息的struct(名字、所处GraphNode) struct FLinkedPinInfo { FString PinName; TWeakObjectPtr<UEdGraphNode> OwnerGraphNode; }; //通过在AllPinsMap中使用名字配对的方式找到哪些是直接连接在当前Pin上的Pin，并将其塞进LinkedPinInfoArray中 TArray<FLinkedPinInfo> LinkedPinInfoArray; for (UEdGraphPin* Pin : GetPinObj()->LinkedTo) { if (auto PinWidget = AllPinsMap.Find(Pin)) { FLinkedPinInfo PinInfo; //PinInfo.PinName = (*PinWidget)->GetPinObj()->PinName.ToString(); PinInfo.PinName = Pin->GetName(); // UE_LOG(LogTemp, Warning, TEXT("PinWidget name: %s"), *(*PinWidget)->GetPinObj()->PinName.ToString()); // UE_LOG(LogTemp, Warning, TEXT("Pin name: %s"), *(Pin->GetName())); if (StaticCastSharedRef<SMyGraphPin>(*PinWidget)->GetGraphNode()) { //PinInfo.OwnerGraphNode = StaticCastSharedRef<SMyGraphPin>(*PinWidget)->GetGraphNode()->GetNodeObj(); PinInfo.OwnerGraphNode = Pin->GetOwningNode(); if (PinInfo.OwnerGraphNode.IsValid()) { LinkedPinInfoArray.Add(MoveTemp(PinInfo)); } } } } //三、 TArray<TSharedRef<SGraphPin>> PinArray; for (FLinkedPinInfo PinInfo : LinkedPinInfoArray) { //遍历Pin所属Node的所有GraphPin for (UEdGraphPin* Pin : PinInfo.OwnerGraphNode.Get()->Pins) { //判断两者名字是否相同 if (Pin->PinName.ToString() == PinInfo.PinName) { //将对应名字的SlatePin塞入PinArray中 if (TSharedRef<SGraphPin>* pWidget = AllPinsMap.Find(FGraphPinHandle(Pin))) { PinArray.Add(*pWidget); } } } } //生成所有连线的拖拽 TSharedPtr<FDragDropOperation> DragEvent; if (PinArray.Num() > 0) { DragEvent = SpawnPinDragEvent(OwnerSlateNode->GetOwnerPanel().ToSharedRef(), PinArray); } //?: 为什么又要GetShema一次 const UEdGraphSchema* Schema = GraphPinObj->GetSchema(); //断开原有Pin Schema->BreakPinLinks(*GraphPinObj, true); //进行新的PinDrag if (DragEvent.IsValid()) { bIsMovingLinks = true; return FReply::Handled().BeginDragDrop(DragEvent.ToSharedRef()); } else { return FReply::Handled(); } } //如果是正常的鼠标拖拽 if (!ensure(OwnerSlateNode.IsValid())) { return FReply::Unhandled(); } else { TArray<TSharedRef<SGraphPin>> PinArray; PinArray.Add(SharedThis(this)); TSharedPtr<FDragDropOperation> DragEvent = SpawnPinDragEvent(OwnerSlateNode->GetOwnerPanel().ToSharedRef(), PinArray); return FReply::Handled().BeginDragDrop(DragEvent.ToSharedRef()); } } } return FReply::Handled(); })); #if 0 //背景图片 .BorderImage_Lambda([&]() { const FVector2D ICOSize(64.f, 64.f); return FTestGraphAndBlueprintStyle::GetImageBrush(TEXT("ButtonIcon_40x"), ICOSize); }) #endif }