Base work on reimplementing editor GUI

src/Engine/Editor/EditorGUI.cpp

@@ -0,0 +1,114 @@
+#include "Editor/EditorGUI.h"
+
+void EditorGUI::Draw(World* world)
+{
+    drawMenu();
+    drawEntities(world);
+}
+
+void EditorGUI::SelectEntity(EntityWrapper entity)
+{
+    m_CurrentSelection = entity;
+    if (m_OnEntitySelected != nullptr) {
+        m_OnEntitySelected(entity);
+    }
+}
+
+void EditorGUI::drawMenu()
+{
+
+}
+
+void EditorGUI::drawEntities(World* world)
+{
+    if (!ImGui::Begin("Entities")) {
+        return;
+    }
+
+    drawEntitiesRecursive(world, EntityID_Invalid);
+
+    ImGui::End();
+}
+
+void EditorGUI::drawEntitiesRecursive(World* world, EntityID parent)
+{
+    auto entityChildren = world->GetEntityChildren();
+    auto range = entityChildren.equal_range(parent);
+    for (auto it = range.first; it != range.second; it++) {
+        if (EditorGUI::drawEntityNode(EntityWrapper(world, it->second))) {
+            drawEntitiesRecursive(world, it->second);
+            ImGui::TreePop();
+        }
+    }
+}
+
+bool EditorGUI::drawEntityNode(EntityWrapper entity)
+{
+    ImVec2 pos = ImGui::GetCursorScreenPos();
+    float width = ImGui::GetContentRegionAvailWidth();
+    ImRect bb(pos + ImVec2(20, 0), pos + ImVec2(width, 13));
+    auto window = ImGui::GetCurrentWindow();
+    if (m_CurrentSelection == entity) {
+        const ImU32 col = window->Color(ImGuiCol_HeaderActive);
+        window->DrawList->AddRectFilled(bb.Min, bb.Max, col);
+    }
+    ImGuiID id = window->GetID((std::string("#SelectButton") + std::to_string(entity)).c_str());
+    bool hovered = false;
+    bool held = false;
+    if (ImGui::ButtonBehavior(bb, id, &hovered, &held)) {
+        SelectEntity(entity);
+    }
+    //if (held) {
+    //    ImVec2 entityDragDelta = ImGui::GetMouseDragDelta(0);
+    //    if (std::abs(entityDragDelta.x) > 0 && std::abs(entityDragDelta.y) > 0) {
+    //        if (m_UIDraggingEntity == EntityID_Invalid) {
+    //            m_UIDraggingEntity = entity;
+    //            LOG_DEBUG("Started drag of entity %i", m_UIDraggingEntity);
+    //        }
+    //        ImGui::SetNextWindowPos(ImGui::GetIO().MousePos + ImVec2(20, 0));
+    //        ImGui::Begin("Change parent", nullptr, ImVec2(0, 0), 0.3f, ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoMove|ImGuiWindowFlags_NoSavedSettings);
+    //        ImGui::Text("#%i", m_UIDraggingEntity);
+    //        ImGui::End();
+    //    }
+    //}
+
+    ImGui::SetNextTreeNodeOpened(true, ImGuiSetCond_Once);
+    std::string nodeTitle;
+    const std::string& entityName = entity.World->GetName(entity);
+    if (!entityName.empty()) {
+        nodeTitle = entityName;
+    } else {
+        nodeTitle = std::string("#") + std::to_string(entity.ID);
+    }
+    if (ImGui::TreeNode(nodeTitle.c_str())) {
+        //if (m_UIDraggingEntity != EntityID_Invalid && ImGui::IsItemHoveredRect() && ImGui::IsMouseReleased(0)) {
+        //    LOG_DEBUG("Changed parent of %i to %i", m_UIDraggingEntity, entity);
+        //    changeParent(m_UIDraggingEntity, entity);
+        //    m_UIDraggingEntity = EntityID_Invalid;
+        //}
+
+        if (ImGui::BeginPopupContextItem("item context menu")) {
+            if (ImGui::Button("Add")) {
+                if (m_OnEntityCreate != nullptr) {
+                    EntityWrapper newEntity = m_OnEntityCreate(EntityWrapper(entity.World, EntityID_Invalid));
+                    ImGui::CloseCurrentPopup();
+                    SelectEntity(newEntity);
+                }
+            }
+            ImGui::SameLine();
+            if (ImGui::Button("Delete")) {
+                if (m_OnEntityDelete != nullptr) {
+                    m_OnEntityDelete(entity);
+                    ImGui::CloseCurrentPopup();
+                } 
+                if (!m_CurrentSelection.Valid()) {
+                    SelectEntity(EntityWrapper::Invalid);
+                }
+            }
+            ImGui::EndPopup();
+        }
+        return true;
+    } else {
+        return false;
+    }
+}