Preserve saved editor dock layouts

editor/src/Application.cpp

@@ -194,7 +194,7 @@ bool Application::SwitchProject(const std::string& projectPath) {
         return false;
     }
 
-    m_imguiSession.SetProjectPath(projectPath);
+    const bool hasSavedDockLayout = m_imguiSession.SetProjectPath(projectPath);
     m_editorContext->SetProjectPath(projectPath);
 
     auto& logger = Debug::Logger::Get();
@@ -208,6 +208,11 @@ bool Application::SwitchProject(const std::string& projectPath) {
 
     m_lastWindowTitle.clear();
     UpdateWindowTitle();
+
+    if (!hasSavedDockLayout) {
+        m_editorContext->GetEventBus().Publish(DockLayoutResetRequestedEvent{});
+    }
+
     return true;
 }
 

editor/src/Layout/DockLayoutController.h

@@ -6,6 +6,7 @@
 #include "UI/DockHostStyle.h"
 #include "UI/DockTabBarChrome.h"
 
+#include <fstream>
 #include <imgui.h>
 #include <imgui_internal.h>
 
@@ -24,6 +25,8 @@ public:
             [this](const DockLayoutResetRequestedEvent&) {
                 RequestReset();
             });
+        m_layoutDirty = true;
+        m_forceRebuild = false;
     }
 
     void Detach() {
@@ -34,10 +37,12 @@ public:
         m_context = nullptr;
         m_resetLayoutHandlerId = 0;
         m_layoutDirty = true;
+        m_forceRebuild = false;
     }
 
     void RequestReset() {
         m_layoutDirty = true;
+        m_forceRebuild = true;
     }
 
     void RenderDockspace() {
@@ -65,8 +70,11 @@ public:
         }
 
         if (m_layoutDirty) {
-            BuildDefaultLayout(dockspaceId, viewport->Size);
+            if (m_forceRebuild || !HasSavedDockLayout()) {
+                BuildDefaultLayout(dockspaceId, viewport->Size);
+            }
             m_layoutDirty = false;
+            m_forceRebuild = false;
         }
         UI::ConfigureDockTabBarChrome(dockspaceId);
 
@@ -74,6 +82,31 @@ public:
     }
 
 private:
+    static bool HasSavedDockLayout() {
+        if (ImGui::GetCurrentContext() == nullptr) {
+            return false;
+        }
+
+        const char* iniFilename = ImGui::GetIO().IniFilename;
+        if (iniFilename == nullptr || iniFilename[0] == '\0') {
+            return false;
+        }
+
+        std::ifstream input(iniFilename, std::ios::in);
+        if (!input.is_open()) {
+            return false;
+        }
+
+        std::string line;
+        while (std::getline(input, line)) {
+            if (line == "[Docking][Data]") {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     void BuildDefaultLayout(ImGuiID dockspaceId, const ImVec2& dockspaceSize) {
         ImGui::DockBuilderRemoveNode(dockspaceId);
         ImGui::DockBuilderAddNode(dockspaceId, m_dockspaceFlags | ImGuiDockNodeFlags_DockSpace);
@@ -97,6 +130,7 @@ private:
     IEditorContext* m_context = nullptr;
     uint64_t m_resetLayoutHandlerId = 0;
     bool m_layoutDirty = true;
+    bool m_forceRebuild = false;
     ImGuiDockNodeFlags m_dockspaceFlags = ImGuiDockNodeFlags_NoWindowMenuButton;
 };
 

editor/src/UI/ImGuiSession.h

@@ -5,6 +5,7 @@
 #include <imgui.h>
 
 #include <filesystem>
+#include <fstream>
 #include <string>
 
 namespace XCEngine {
@@ -48,15 +49,17 @@ public:
         return m_iniPath;
     }
 
-    void SetProjectPath(const std::string& projectPath) {
+    bool SetProjectPath(const std::string& projectPath) {
         if (ImGui::GetCurrentContext() == nullptr) {
-            return;
+            return false;
         }
 
         SaveSettings();
         ImGuiIO& io = ImGui::GetIO();
         ConfigureIniFile(projectPath, io);
+        const bool hasSavedLayout = HasSavedDockLayoutOnDisk(m_iniPath);
         ImGui::LoadIniSettingsFromDisk(m_iniPath.c_str());
+        return hasSavedLayout;
     }
 
 private:
@@ -64,6 +67,27 @@ private:
     static constexpr const char* kPrimaryUiFontPath = "C:/Windows/Fonts/segoeui.ttf";
     static constexpr const char* kChineseFallbackFontPath = "C:/Windows/Fonts/msyh.ttc";
 
+    static bool HasSavedDockLayoutOnDisk(const std::filesystem::path& iniPath) {
+        std::error_code ec;
+        if (!std::filesystem::is_regular_file(iniPath, ec) || ec) {
+            return false;
+        }
+
+        std::ifstream input(iniPath, std::ios::in);
+        if (!input.is_open()) {
+            return false;
+        }
+
+        std::string line;
+        while (std::getline(input, line)) {
+            if (line == "[Docking][Data]") {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     void ConfigureIniFile(const std::string& projectPath, ImGuiIO& io) {
         const std::filesystem::path configDir = std::filesystem::path(projectPath) / ".xceditor";
         std::error_code ec;