diff --git a/NEWS.md b/NEWS.md
index 1562aed0..011136b5 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,7 +1,9 @@
 Red Panda C++ Version 1.5
 
   - fix: project files that lies in project include folder is wrongly openned in Read-only mode
-  - enhancement: add/new/remove project files won't rebuild project tree
+  - enhancement: add/new/remove/rename project files won't rebuild project tree
+  - fix: gliches in UI's left panel in some OS
+  - fix: correctly restore project layout when reopen it
 
 Red Panda C++ Version 1.4
 
diff --git a/RedPandaIDE/editor.cpp b/RedPandaIDE/editor.cpp
index 151891a2..f1137c4e 100644
--- a/RedPandaIDE/editor.cpp
+++ b/RedPandaIDE/editor.cpp
@@ -336,8 +336,8 @@ bool Editor::saveAs(const QString &name, bool fromProject){
     }
     // Update project information
     if (mInProject && pMainWindow->project() && !fromProject) {
-        int unitId = pMainWindow->project()->findUnitId(newName);
-        if (unitId<0) {
+        PProjectUnit unit = pMainWindow->project()->findUnit(newName);
+        if (!unit) {
             mInProject = false;
         }
     }
diff --git a/RedPandaIDE/editorlist.cpp b/RedPandaIDE/editorlist.cpp
index 1d7c789e..860787f5 100644
--- a/RedPandaIDE/editorlist.cpp
+++ b/RedPandaIDE/editorlist.cpp
@@ -169,10 +169,8 @@ bool EditorList::closeEditor(Editor* editor, bool transferFocus, bool force) {
 //    }
 
     if (editor->inProject() && pMainWindow->project()) {
-        int unitId = pMainWindow->project()->findUnitId(editor);
-        if (unitId>=0) {
-            pMainWindow->project()->closeUnit(unitId);
-        }
+        PProjectUnit unit = pMainWindow->project()->findUnit(editor);
+        pMainWindow->project()->closeUnit(unit);
     } else {
         if (pSettings->history().addToOpenedFiles(editor->filename())) {
             pMainWindow->rebuildOpenedFileHisotryMenu();
diff --git a/RedPandaIDE/mainwindow.cpp b/RedPandaIDE/mainwindow.cpp
index 272579d3..9caa4618 100644
--- a/RedPandaIDE/mainwindow.cpp
+++ b/RedPandaIDE/mainwindow.cpp
@@ -2224,6 +2224,10 @@ void MainWindow::loadLastOpens()
         QByteArray encoding = unit ? unit->encoding() :
                                      (pSettings->editor().autoDetectFileEncoding()? ENCODING_AUTO_DETECT : pSettings->editor().defaultEncoding());
         Editor * editor = mEditorList->newEditor(editorFilename, encoding, inProject,false,page);
+
+        if (inProject && editor) {
+            mProject->loadUnitLayout(editor);
+        }
 //        if (mProject) {
 //            mProject->associateEditorToUnit(editor,unit);
 //        }
@@ -2943,15 +2947,13 @@ void MainWindow::onProjectViewContextMenu(const QPoint &pos)
     bool onRoot = false;
     bool folderEmpty = false;
     bool multiSelection = ui->projectView->selectionModel()->selectedRows().count()>1;
-    int unitIndex = -1;
     QModelIndex current = mProjectProxyModel->mapToSource(ui->projectView->selectionModel()->currentIndex());
     if (current.isValid() && mProject) {
         ProjectModelNode * node = static_cast<ProjectModelNode*>(current.internalPointer());
         PProjectModelNode pNode = mProject->pointerToNode(node);
         if (pNode) {
-            unitIndex = pNode->unitIndex;
-            onFolder = (unitIndex<0);
-            onUnit = (unitIndex >= 0);
+            onFolder = (!pNode->isUnit);
+            onUnit = (pNode->isUnit);
             onRoot = false;
             if (onFolder && !onRoot) {
                 folderEmpty = pNode->children.isEmpty();
@@ -3022,11 +3024,11 @@ void MainWindow::onProjectViewContextMenu(const QPoint &pos)
                 }
                 QModelIndex realIndex = mProjectProxyModel->mapToSource(index);
                 ProjectModelNode * node = static_cast<ProjectModelNode*>(realIndex.internalPointer());
-                if (!node || node->unitIndex<0) {
+                if (!node || !node->isUnit) {
                     shouldAdd=false;
                     break;
                 }
-                PProjectUnit pUnit=mProject->findUnitById(node->unitIndex);
+                PProjectUnit pUnit=node->pUnit.lock();
                 if (mProject->model()->iconProvider()->VCSRepository()->isFileInRepository(
                             pUnit->fileName()
                             )
@@ -3893,7 +3895,7 @@ void MainWindow::onProjectRemoveFolder()
     PProjectModelNode folderNode =  mProject->pointerToNode(node);
     if (!folderNode)
         return;
-    if (folderNode->unitIndex>=0)
+    if (folderNode->isUnit)
         return;
     mProject->removeFolder(folderNode);
     mProject->saveOptions();
@@ -3919,7 +3921,7 @@ void MainWindow::onProjectAddFolder()
     PProjectModelNode folderNode =  mProject->pointerToNode(node);
     if (!folderNode)
         folderNode = mProject->rootNode();
-    if (folderNode->unitIndex>=0)
+    if (folderNode->isUnit)
         return;
     QString s=tr("New folder");
     int i=1;
@@ -4267,6 +4269,7 @@ void MainWindow::closeProject(bool refreshEditor)
                 auto action3 = finally([this]{
                     mEditorList->endUpdate();
                 });
+                mProject->closeAllUnits();
                 mProject.reset();
 
                 if (!mQuitting && refreshEditor) {
@@ -4294,9 +4297,8 @@ void MainWindow::updateProjectView()
         if (mProjectProxyModel->sourceModel()!=mProject->model()) {
             mProjectProxyModel->setSourceModel(mProject->model());
             mProjectProxyModel->sort(0);
-//            connect(mProject->model(), &ProjectModel::dataChanged,
-//                    this, &MainWindow::invalidateProjectProxyModel);
-//            connect(mProject->model(), &ProjectModel::rowsRemoved,
+            connect(mProject.get(), &Project::nodeRenamed,
+                    this, &MainWindow::onProjectViewNodeRenamed);
 //                    this, &MainWindow::invalidateProjectProxyModel);
 //            connect(mProject->model(), &ProjectModel::rowsInserted,
 //                    this, &MainWindow::invalidateProjectProxyModel);
@@ -5760,8 +5762,9 @@ void MainWindow::on_projectView_doubleClicked(const QModelIndex &index)
     ProjectModelNode * node = static_cast<ProjectModelNode*>(sourceIndex.internalPointer());
     if (!node)
         return;
-    if (node->unitIndex>=0) {
-        mProject->openUnit(node->unitIndex);
+    if (node->isUnit) {
+        PProjectUnit unit = node->pUnit.lock();
+        mProject->openUnit(unit);
     }
 }
 
@@ -5967,7 +5970,8 @@ void MainWindow::on_actionRemove_from_project_triggered()
         PProjectModelNode folderNode =  mProject->pointerToNode(node);
         if (!folderNode)
             continue;
-        mProject->removeUnit(folderNode->unitIndex, true, removeFile);
+        PProjectUnit unit = folderNode->pUnit.lock();
+        mProject->removeUnit(unit, true, removeFile);
     };
     ui->projectView->selectionModel()->clearSelection();
     mProject->saveAll();
@@ -6159,7 +6163,7 @@ void MainWindow::newProjectUnitFile()
     }
     PProjectModelNode pNode = mProject->pointerToNode(node);
 
-    while (pNode && pNode->unitIndex>0) {
+    while (pNode && pNode->isUnit) {
         pNode = pNode->parent.lock();
     }
 
@@ -6235,13 +6239,8 @@ void MainWindow::newProjectUnitFile()
 
     setProjectViewCurrentUnit(newUnit);
 
-//    mProject->rebuildNodes();
     mProject->saveAll();
-//        updateProjectView();
-//    idx = newUnit->id;
-    Editor * editor = mProject->openUnit(newUnit->id(), false);
-    //editor->setUseCppSyntax(mProject->options().useGPP);
-    //editor->setModified(true);
+    Editor * editor = mProject->openUnit(newUnit, false);
     if (editor)
         editor->activate();
     QString branch;
@@ -6311,6 +6310,11 @@ void MainWindow::setProjectViewCurrentUnit(std::shared_ptr<ProjectUnit> unit) {
     }
 }
 
+void MainWindow::onProjectViewNodeRenamed()
+{
+    updateProjectView();
+}
+
 void MainWindow::setProjectViewCurrentNode(PProjectModelNode node)
 {
     if (node) {
@@ -7576,8 +7580,8 @@ void MainWindow::on_actionGit_Add_Files_triggered()
             PProjectModelNode folderNode =  mProject->pointerToNode(node);
             if (!folderNode)
                 continue;
-            if (folderNode->unitIndex>=0) {
-                PProjectUnit unit = mProject->findUnitById(folderNode->unitIndex);
+            if (folderNode->isUnit) {
+                PProjectUnit unit = folderNode->pUnit.lock();
                 QFileInfo info(unit->fileName());
                 QString output;
                 vcsManager.add(info.absolutePath(),info.fileName(),output);
diff --git a/RedPandaIDE/mainwindow.h b/RedPandaIDE/mainwindow.h
index a673d77a..c1bce69a 100644
--- a/RedPandaIDE/mainwindow.h
+++ b/RedPandaIDE/mainwindow.h
@@ -276,6 +276,7 @@ private:
     void setProjectViewCurrentUnit(std::shared_ptr<ProjectUnit> unit);
 
 private slots:
+    void onProjectViewNodeRenamed();
     void setDockExplorerToArea(const Qt::DockWidgetArea &area);
     void setDockMessagesToArea(const Qt::DockWidgetArea &area);
     void updateVCSActions();
diff --git a/RedPandaIDE/mainwindow.ui b/RedPandaIDE/mainwindow.ui
index 301dca55..62977126 100644
--- a/RedPandaIDE/mainwindow.ui
+++ b/RedPandaIDE/mainwindow.ui
@@ -473,12 +473,15 @@
      <enum>QTabWidget::West</enum>
     </property>
     <property name="currentIndex">
-     <number>1</number>
+     <number>4</number>
     </property>
     <property name="usesScrollButtons">
      <bool>true</bool>
     </property>
     <widget class="QWidget" name="tabFiles">
+     <property name="autoFillBackground">
+      <bool>true</bool>
+     </property>
      <attribute name="icon">
       <iconset resource="icons.qrc">
        <normaloff>:/icons/images/newlook24/018-copy.png</normaloff>:/icons/images/newlook24/018-copy.png</iconset>
@@ -561,6 +564,9 @@
      </layout>
     </widget>
     <widget class="QWidget" name="tabProject">
+     <property name="autoFillBackground">
+      <bool>true</bool>
+     </property>
      <attribute name="icon">
       <iconset resource="icons.qrc">
        <normaloff>:/icons/images/newlook24/049-newproj.png</normaloff>:/icons/images/newlook24/049-newproj.png</iconset>
@@ -612,6 +618,9 @@
      </layout>
     </widget>
     <widget class="QWidget" name="tabWatch">
+     <property name="autoFillBackground">
+      <bool>true</bool>
+     </property>
      <attribute name="icon">
       <iconset resource="icons.qrc">
        <normaloff>:/icons/images/newlook24/088-watch.png</normaloff>:/icons/images/newlook24/088-watch.png</iconset>
@@ -654,6 +663,9 @@
      </layout>
     </widget>
     <widget class="QWidget" name="tabStructure">
+     <property name="autoFillBackground">
+      <bool>true</bool>
+     </property>
      <attribute name="icon">
       <iconset resource="icons.qrc">
        <normaloff>:/icons/images/newlook24/087-update.png</normaloff>:/icons/images/newlook24/087-update.png</iconset>
@@ -693,6 +705,9 @@
      </layout>
     </widget>
     <widget class="QWidget" name="tabProblemSet">
+     <property name="autoFillBackground">
+      <bool>true</bool>
+     </property>
      <attribute name="icon">
       <iconset resource="icons.qrc">
        <normaloff>:/icons/images/newlook24/014-compopt.png</normaloff>:/icons/images/newlook24/014-compopt.png</iconset>
diff --git a/RedPandaIDE/project.cpp b/RedPandaIDE/project.cpp
index ae289e26..55c8126b 100644
--- a/RedPandaIDE/project.cpp
+++ b/RedPandaIDE/project.cpp
@@ -36,6 +36,9 @@
 #include <QDirIterator>
 #include <QMimeDatabase>
 #include <QDesktopServices>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QJsonDocument>
 #include "customfileiconprovider.h"
 #include <QMimeData>
 #include "settings.h"
@@ -193,22 +196,19 @@ void Project::open()
             newUnit->setEncoding(ENCODING_AUTO_DETECT);
         }
         newUnit->setNew(false);
-        newUnit->setParent(this);
         PProjectModelNode parentNode;
         if (mOptions.modelType==ProjectModelType::FileSystem) {
             parentNode = getParentFileSystemFolderNode(newUnit->fileName());
         } else {
             parentNode = getCustomeFolderNodeFromName(newUnit->folder());
         }
-        PProjectModelNode node = makeNewFileNode(extractFileName(newUnit->fileName()),
-                                                 newUnit->id(),
+        PProjectModelNode node = makeNewFileNode(newUnit,
                                                  newUnit->priority(),
                                                  parentNode
                                                  );
         newUnit->setNode(node);
-        mUnits.insert(newUnit->id(),newUnit);
+        mUnits.insert(newUnit->fileName(),newUnit);
     }
-    //rebuildNodes();
 }
 
 void Project::setFileName(QString value)
@@ -242,7 +242,7 @@ PProjectModelNode Project::makeNewFolderNode(
     if (newParent) {
         node->level = newParent->level+1;
     }
-    node->unitIndex = -1;
+    node->isUnit=false;
     node->priority = priority;
     node->folderNodeType = nodeType;
     QModelIndex parentIndex=mModel.getNodeIndex(newParent.get());
@@ -251,18 +251,19 @@ PProjectModelNode Project::makeNewFolderNode(
     return node;
 }
 
-PProjectModelNode Project::makeNewFileNode(const QString &fileName, int unitId,int priority, PProjectModelNode newParent)
+PProjectModelNode Project::makeNewFileNode(PProjectUnit unit,int priority, PProjectModelNode newParent)
 {
     PProjectModelNode node = std::make_shared<ProjectModelNode>();
     if (!newParent) {
         newParent = mRootNode;
     }
     node->parent = newParent;
-    node->text = fileName;
+    node->text = extractFileName(unit->fileName());
     if (newParent) {
         node->level = newParent->level+1;
     }
-    node->unitIndex = unitId;
+    node->isUnit = true;
+    node->pUnit = unit;
     node->priority = priority;
     node->folderNodeType = ProjectModelNodeType::File;
 
@@ -277,7 +278,7 @@ PProjectModelNode Project::makeProjectNode()
     PProjectModelNode node = std::make_shared<ProjectModelNode>();
     node->text = mName;
     node->level = 0;
-    node->unitIndex = -1;
+    node->isUnit = false;
     node->folderNodeType = ProjectModelNodeType::Folder;
     return node;
 }
@@ -290,7 +291,7 @@ PProjectUnit Project::newUnit(PProjectModelNode parentNode, const QString& custo
     if (!parentNode)
         parentNode = mRootNode; // project root node
 
-    if (parentNode->unitIndex>=0) { //it's a file
+    if (parentNode->isUnit) { //it's a file
         parentNode = mRootNode;
     }
     QString s;
@@ -313,11 +314,9 @@ PProjectUnit Project::newUnit(PProjectModelNode parentNode, const QString& custo
     newUnit->setFileName(s);
     newUnit->setNew(true);
     newUnit->setFolder(getNodePath(parentNode));
-    PProjectModelNode node = makeNewFileNode(extractFileName(newUnit->fileName()),
-                                             newUnit->id(),newUnit->priority(),parentNode);
-    node->unitIndex = newUnit->id();
+    PProjectModelNode node = makeNewFileNode(newUnit,newUnit->priority(),parentNode);
     newUnit->setNode(node);
-    mUnits.insert(newUnit->id(), newUnit);
+    mUnits.insert(newUnit->fileName(), newUnit);
 
     //parentNode.Expand(True);
     switch(getFileType(customFileName)) {
@@ -349,12 +348,7 @@ PProjectUnit Project::newUnit(PProjectModelNode parentNode, const QString& custo
     return newUnit;
 }
 
-Editor *Project::openUnit(int index, bool forceOpen)
-{
-
-    PProjectUnit unit = mUnits.value(index,PProjectUnit());
-    if (!unit)
-        return nullptr;
+Editor* Project::openUnit(PProjectUnit& unit, bool forceOpen) {
 
     if (!unit->fileName().isEmpty() && fileExists(unit->fileName())) {
         if (getFileType(unit->fileName())==FileType::Other) {
@@ -375,22 +369,16 @@ Editor *Project::openUnit(int index, bool forceOpen)
         if (editor) {
             editor->setInProject(true);
             //unit->setEncoding(encoding);
-            editor->activate();
             loadUnitLayout(editor);
+            editor->activate();
             return editor;
         }
     }
     return nullptr;
 }
 
-Editor *Project::openUnit(PProjectEditorLayout editorLayout)
+Editor *Project::openUnit(PProjectUnit &unit, const PProjectEditorLayout &layout)
 {
-    if (!editorLayout)
-        return nullptr;
-    PProjectUnit unit = findUnit(editorLayout->filename);
-    if (!unit)
-        return nullptr;
-
     if (!unit->fileName().isEmpty() && fileExists(unit->fileName())) {
         if (getFileType(unit->fileName())==FileType::Other) {
             return nullptr;
@@ -407,26 +395,28 @@ Editor *Project::openUnit(PProjectEditorLayout editorLayout)
         editor = mEditorList->newEditor(unit->fileName(), encoding, true, unit->isNew());
         if (editor) {
             editor->setInProject(true);
-            //unit->setEncoding(encoding);
+            editor->setCaretY(layout->caretY);
+            editor->setCaretX(layout->caretX);
+            editor->setTopLine(layout->topLine);
+            editor->setLeftChar(layout->leftChar);
             editor->activate();
-            editor->setTopLine(editorLayout->topLine);
-            editor->setLeftChar(editorLayout->leftChar);
-            editor->setCaretX(editorLayout->caretX);
-            editor->setCaretY(editorLayout->caretY);
             return editor;
         }
     }
     return nullptr;
-
 }
 
 Editor *Project::unitEditor(const PProjectUnit &unit) const
 {
+    if (!unit)
+        return nullptr;
     return mEditorList->getOpenedEditorByFilename(unit->fileName());
 }
 
 Editor *Project::unitEditor(const ProjectUnit *unit) const
 {
+    if (!unit)
+        return nullptr;
     return mEditorList->getOpenedEditorByFilename(unit->fileName());
 }
 
@@ -456,13 +446,11 @@ void Project::rebuildNodes()
             QFileInfo fileInfo(pUnit->fileName());
             pUnit->setNode(
                         makeNewFileNode(
-                            fileInfo.fileName(),
-                            pUnit->id(),
+                            pUnit,
                             pUnit->priority(),
                             getCustomeFolderNodeFromName(pUnit->folder())
                             )
                         );
-            pUnit->node()->priority = pUnit->priority();
         }
         break;
     case ProjectModelType::FileSystem:
@@ -472,26 +460,22 @@ void Project::rebuildNodes()
             QFileInfo fileInfo(pUnit->fileName());
             pUnit->setNode(
                         makeNewFileNode(
-                            fileInfo.fileName(),
-                            pUnit->id(),
+                            pUnit,
                             pUnit->priority(),
                             getParentFileSystemFolderNode(
                                 pUnit->fileName())
                             )
                         );
-            pUnit->node()->priority = pUnit->priority();
         }
 
         break;
     }
 
     mModel.endUpdate();
-    emit nodesChanged();
 }
 
-bool Project::removeUnit(int id, bool doClose , bool removeFile)
+bool Project::removeUnit(PProjectUnit& unit, bool doClose , bool removeFile)
 {
-    PProjectUnit unit = findUnitById(id);
     if (!unit)
         return false;
 
@@ -514,20 +498,20 @@ bool Project::removeUnit(int id, bool doClose , bool removeFile)
     PProjectModelNode node = unit->node();
     PProjectModelNode parentNode = node->parent.lock();
     if (!parentNode) {
-        mUnits.remove(unit->id());
+        mUnits.remove(unit->fileName());
         return true;
     }
 
     int row = parentNode->children.indexOf(unit->node());
     if (row<0) {
-        mUnits.remove(unit->id());
+        mUnits.remove(unit->fileName());
         return true;
     }
 
     QModelIndex parentIndex = mModel.getNodeIndex(parentNode.get());
 
     mModel.removeRow(row,parentIndex);
-    mUnits.remove(unit->id());
+    mUnits.remove(unit->fileName());
 
     //remove empty parent node
     PProjectModelNode currentNode = parentNode;
@@ -558,7 +542,7 @@ bool Project::removeFolder(PProjectModelNode node)
         return false;
 
     // Check if this is actually a folder
-    if (node->unitIndex>=0 || node->level<1)
+    if (node->isUnit || node->level<1)
         return false;
 
     // Let this function call itself
@@ -594,7 +578,7 @@ void Project::saveAll()
 
 void Project::saveLayout()
 {
-    SimpleIni layIni;
+    QJsonObject jsonRoot;
     QHash<QString,int> editorOrderSet;
     // Write list of open project files
     int order=0;
@@ -611,52 +595,61 @@ void Project::saveLayout()
     // Remember what files were visible
     mEditorList->getVisibleEditors(e, e2);
     if (e)
-        layIni.SetValue("Editors","Focused", e->filename().toUtf8());
+        jsonRoot["focused"]=e->filename();
+
+    QJsonArray jsonLayouts;
     // save editor info
     foreach (const PProjectUnit& unit,mUnits) {
         Editor* editor = unitEditor(unit);
         if (editor) {
-            QByteArray groupName = QString("E_%1").arg(editor->filename()).toUtf8();
-            layIni.SetLongValue(groupName,"CursorCol", editor->caretX());
-            layIni.SetLongValue(groupName,"CursorRow", editor->caretY());
-            layIni.SetLongValue(groupName,"TopLine", editor->topLine());
-            layIni.SetLongValue(groupName,"LeftChar", editor->leftChar());
+            QJsonObject jsonLayout;
+            jsonLayout["filename"]=unit->fileName();
+            jsonLayout["caretX"]=editor->caretX();
+            jsonLayout["caretY"]=editor->caretY();
+            jsonLayout["topLine"]=editor->topLine();
+            jsonLayout["leftChar"]=editor->leftChar();
             int order=editorOrderSet.value(editor->filename(),-1);
             if (order>=0) {
-                layIni.SetLongValue(groupName,"Order",order);
+                jsonLayout["order"]=order;
             }
+            jsonLayouts.append(jsonLayout);
         }
-        // remove old data from project file
-//        SimpleIni ini;
-//        ini.LoadFile(filename().toLocal8Bit());
-//        groupName = toByteArray(QString("Unit%1").arg(i+1));
-//        ini.Delete(groupName,"Open");
-//        ini.Delete(groupName,"Top");
-//        ini.Delete(groupName,"CursorCol");
-//        ini.Delete(groupName,"CursorRow");
-//        ini.Delete(groupName,"TopLine");
-//        ini.Delete(groupName,"LeftChar");
-//        ini.SaveFile(filename().toLocal8Bit());
     }
-    layIni.SaveFile(changeFileExt(filename(), "layout").toLocal8Bit());
+    jsonRoot["editorLayouts"]=jsonLayouts;
+    QString jsonFilename=changeFileExt(filename(), "layout");
+    QFile file(jsonFilename);
+    if (file.open(QFile::WriteOnly|QFile::Truncate)) {
+        QJsonDocument doc(jsonRoot);
+        file.write(doc.toJson(QJsonDocument::Indented));
+        file.close();
+    } else {
+        throw FileError(QObject::tr("Can't open file '%1' for write.")
+                        .arg(jsonFilename));
+    }
 }
 
-void Project::renameUnit(int idx, const QString &sFileName)
+void Project::renameUnit(PProjectUnit& unit, const QString &sFileName)
 {
-    PProjectUnit unit = findUnitById(idx);
     if (!unit)
         return;
+    if (sFileName.compare(unit->fileName(),PATH_SENSITIVITY)==0)
+        return;
+
     if (fileExists(unit->fileName())) {
         unit->setNew(false);
     }
+
     Editor * editor=unitEditor(unit);
     if (editor) {
         //prevent recurse
         editor->saveAs(sFileName,true);
     }
-    unit->setNew(false);
-    unit->setFileName(sFileName);
+    removeUnit(unit,false,false);
+    PProjectModelNode parentNode = unit->node()->parent.lock();
+    unit = addUnit(sFileName,parentNode);
     setModified(true);
+
+    emit nodeRenamed();
 }
 
 bool Project::saveUnits()
@@ -725,18 +718,9 @@ bool Project::saveUnits()
     return true;
 }
 
-PProjectUnit Project::findUnitById(int id)
-{
-    return mUnits.value(id,PProjectUnit());
-}
-
 PProjectUnit Project::findUnit(const QString &filename)
 {
-    foreach(PProjectUnit unit, mUnits) {
-        if (QString::compare(unit->fileName(),filename, PATH_SENSITIVITY)==0)
-            return unit;
-    }
-    return PProjectUnit();
+    return mUnits.value(filename,PProjectUnit());
 }
 
 PProjectUnit Project::findUnit(const Editor *editor)
@@ -854,6 +838,9 @@ bool Project::assignTemplate(const std::shared_ptr<ProjectTemplate> aTemplate, b
     if (!aTemplate) {
         return true;
     }
+    mModel.beginUpdate();
+    mRootNode = makeProjectNode();
+
     mOptions = aTemplate->options();
     mOptions.compilerSet = pSettings->compilerSets().defaultIndex();
     mOptions.isCpp = useCpp;
@@ -921,7 +908,7 @@ bool Project::assignTemplate(const std::shared_ptr<ProjectTemplate> aTemplate, b
             }
         }
     }
-    rebuildNodes();
+    mModel.endUpdate();
     return true;
 }
 
@@ -1188,17 +1175,16 @@ PProjectUnit Project::addUnit(const QString &inFileName, PProjectModelNode paren
         newUnit->setCompileCpp(false);
         newUnit->setLink(false);
     }
-    newUnit->setFolder(getNodePath(parentNode));
+    if (mOptions.modelType == ProjectModelType::FileSystem)
+        newUnit->setFolder(getNodePath(parentNode));
     newUnit->setPriority(1000);
     newUnit->setOverrideBuildCmd(false);
     newUnit->setBuildCmd("");
 
-    PProjectModelNode node = makeNewFileNode(extractFileName(newUnit->fileName()),
-                                             newUnit->id(),
+    PProjectModelNode node = makeNewFileNode(newUnit,
                                              newUnit->priority(), parentNode);
-    node->unitIndex = newUnit->id();
     newUnit->setNode(node);
-    mUnits.insert(newUnit->id(),newUnit);
+    mUnits.insert(newUnit->fileName(),newUnit);
 
     setModified(true);
     return newUnit;
@@ -1487,6 +1473,17 @@ void Project::buildPrivateResource(bool forceSave)
     stringsToFile(contents,hFile);
 }
 
+void Project::closeAllUnits()
+{
+    foreach (PProjectUnit unit, mUnits) {
+        Editor * editor = unitEditor(unit);
+        if (editor) {
+            editor->setInProject(false);
+            mEditorList->forceCloseEditor(editor);
+        }
+    }
+}
+
 void Project::checkProjectFileForUpdate(SimpleIni &ini)
 {
     bool cnvt = false;
@@ -1537,10 +1534,10 @@ void Project::checkProjectFileForUpdate(SimpleIni &ini)
                     QMessageBox::Ok);
 }
 
-void Project::closeUnit(int id)
+void Project::closeUnit(PProjectUnit& unit)
 {
-    PProjectUnit unit = findUnitById(id);
-    Editor * editor =unitEditor(unit);
+    saveLayout();
+    Editor * editor = unitEditor(unit);
     if (editor) {
         editor->setInProject(false);
         mEditorList->forceCloseEditor(editor);
@@ -1563,12 +1560,14 @@ void Project::createFolderNodes()
                 node = makeNewFolderNode(s.mid(0,i),node);
             else
                 node = findnode;
-            node->unitIndex = -1;
+            if (!node->isUnit) {
+                qDebug()<<"node "<<node->text<<"is not a folder:"<<s;
+                node = mRootNode;
+            }
             s.remove(0,i+1);
             i = s.indexOf('/');
         }
         node = makeNewFolderNode(s, node);
-        node->unitIndex = -1;
         mCustomFolderNodes.append(node);
     }
 }
@@ -1715,11 +1714,11 @@ QString Project::getNodePath(PProjectModelNode node)
     if (!node)
         return result;
 
-    if (node->unitIndex>=0) // not a folder
+    if (node->isUnit) // not a folder
         return result;
 
     PProjectModelNode p = node;
-    while (p && p->unitIndex==-1 && p!=mRootNode) {
+    while (p && !p->isUnit && p!=mRootNode) {
         if (!result.isEmpty())
             result = p->text + "/" + result;
         else
@@ -1729,11 +1728,6 @@ QString Project::getNodePath(PProjectModelNode node)
     return result;
 }
 
-int Project::getUnitFromString(const QString &s)
-{
-    return findUnitId(s);
-}
-
 PProjectModelNode Project::getParentFileSystemFolderNode(const QString &filename)
 {
     QFileInfo fileInfo(filename);
@@ -1763,47 +1757,59 @@ void Project::incrementBuildNumber()
 
 PProjectUnit Project::loadLayout()
 {
-    SimpleIni layIni;
-    SI_Error error = layIni.LoadFile(changeFileExt(filename(), "layout").toLocal8Bit());
-    if (error!=SI_OK)
+    QString jsonFilename = changeFileExt(filename(), "layout");
+    qDebug()<<"read file"<<jsonFilename;
+    QFile file(jsonFilename);
+    if (!file.open(QIODevice::ReadOnly))
         return PProjectUnit();
-    QString focusedFilename = fromByteArray(layIni.GetValue("Editors","Focused"));
-    //TopRight := layIni.ReadInteger('Editors', 'FocusedRight', -1);
+    QByteArray content = file.readAll();
+    QJsonParseError parseError;
+    QJsonDocument doc(QJsonDocument::fromJson(content,&parseError));
+    file.close();
+    if (parseError.error!=QJsonParseError::NoError)
+        return PProjectUnit();
+
+    QJsonObject jsonRoot=doc.object();
+
+    QJsonArray jsonLayouts=jsonRoot["editorLayouts"].toArray();
+
     QHash<int,PProjectEditorLayout> opennedMap;
-    SimpleIni::TNamesDepend sections;
-    layIni.GetAllSections(sections);
-    QSet<QString> sectionNames;
-    for(const SimpleIni::Entry& entry:sections) {
-        QString key(entry.pItem);
-        sectionNames.insert(key);
-    }
-    foreach (PProjectUnit unit,mUnits) {
-        QByteArray groupName = QString("E_%1").arg(unit->fileName()).toUtf8();
-        if (sectionNames.contains(groupName)) {
+    for (int i=0;i<jsonLayouts.size();i++) {
+        QJsonObject jsonLayout = jsonLayouts[i].toObject();
+        QString unitFilename = jsonLayout["filename"].toString();
+        if (mUnits.contains(unitFilename)) {
             PProjectEditorLayout editorLayout = std::make_shared<ProjectEditorLayout>();
-            editorLayout->filename=unit->fileName();
-            editorLayout->topLine=layIni.GetLongValue(groupName,"TopLine");
-            editorLayout->leftChar=layIni.GetLongValue(groupName,"LeftChar");
-            editorLayout->caretX=layIni.GetLongValue(groupName,"CursorCol");
-            editorLayout->caretY=layIni.GetLongValue(groupName,"CursorRow");
-            int order = layIni.GetLongValue(groupName,"Order",-1);
+            editorLayout->filename=unitFilename;
+            editorLayout->topLine=jsonLayout["topLine"].toInt();
+            editorLayout->leftChar=jsonLayout["leftChar"].toInt();
+            editorLayout->caretX=jsonLayout["caretX"].toInt();
+            editorLayout->caretY=jsonLayout["caretY"].toInt();
+            int order = jsonLayout["order"].toInt(-1);
             if (order>=0)
                 opennedMap.insert(order,editorLayout);
         }
     }
+
     for (int i=0;i<mUnits.count();i++) {
         PProjectEditorLayout editorLayout = opennedMap.value(i,PProjectEditorLayout());
         if (editorLayout) {
-            openUnit(editorLayout);
+            PProjectUnit unit = findUnit(editorLayout->filename);
+            openUnit(unit,editorLayout);
         }
     }
-    PProjectUnit unit = findUnit(focusedFilename);
-    if (unit) {
-        Editor * editor = unitEditor(unit);
-        if (editor)
-            editor->activate();
+
+    QString focusedFilename = jsonRoot["focused"].toString();
+
+    if (!focusedFilename.isEmpty()) {
+        PProjectUnit unit = findUnit(focusedFilename);
+        if (unit) {
+            Editor * editor = unitEditor(unit);
+            if (editor)
+                editor->activate();
+        }
+        return unit;
     }
-    return unit;
+    return PProjectUnit();
 }
 
 void Project::loadOptions(SimpleIni& ini)
@@ -2050,16 +2056,37 @@ void Project::loadUnitLayout(Editor *e)
 {
     if (!e)
         return;
-    SimpleIni layIni;
-    SI_Error error;
-    error = layIni.LoadFile(changeFileExt(filename(), "layout").toLocal8Bit());
-    if (error != SI_Error::SI_OK)
+
+    QString jsonFilename = changeFileExt(filename(), "layout");
+    QFile file(jsonFilename);
+    if (!file.open(QIODevice::ReadOnly))
         return;
-    QByteArray groupName = (QString("E_%1").arg(e->filename())).toUtf8();
-    e->setCaretY(layIni.GetLongValue(groupName,"CursorRow",1));
-    e->setCaretX(layIni.GetLongValue(groupName,"CursorCol",1));
-    e->setTopLine(layIni.GetLongValue(groupName,"TopLine",1));
-    e->setLeftChar(layIni.GetLongValue(groupName,"LeftChar",1));
+    QByteArray content = file.readAll();
+    QJsonParseError parseError;
+    QJsonDocument doc{QJsonDocument::fromJson(content,&parseError)};
+    file.close();
+    if (parseError.error!=QJsonParseError::NoError)
+        return;
+
+    QJsonObject jsonRoot=doc.object();
+
+    QJsonArray jsonLayouts=jsonRoot["editorLayouts"].toArray();
+
+    QHash<int,PProjectEditorLayout> opennedMap;
+    for (int i=0;i<jsonLayouts.size();i++) {
+        QJsonObject jsonLayout = jsonLayouts[i].toObject();
+        QString unitFilename = jsonLayout["filename"].toString();
+        if (unitFilename.compare(e->filename(),PATH_SENSITIVITY)==0) {
+            qDebug()<<i<<unitFilename<<e->filename();
+            e->setCaretY(jsonLayout["caretY"].toInt());
+            e->setCaretX(jsonLayout["caretX"].toInt());
+            e->setTopLine(jsonLayout["topLine"].toInt());
+            e->setLeftChar(jsonLayout["leftChar"].toInt());
+            return;
+        }
+    }
+
+
 }
 
 PCppParser Project::cppParser()
@@ -2067,23 +2094,6 @@ PCppParser Project::cppParser()
     return mParser;
 }
 
-int Project::findUnitId(const QString &fileName) const
-{
-    QDir dir(directory());
-    foreach (const PProjectUnit& unit, mUnits) {
-        if (dir.absoluteFilePath(fileName) == dir.absoluteFilePath(unit->fileName()))
-            return unit->id();
-    }
-    return -1;
-}
-
-int Project::findUnitId(const Editor *editor) const
-{
-    if (!editor)
-        return -1;
-    return findUnitId(editor->filename());
-}
-
 void Project::removeFolderRecurse(PProjectModelNode node)
 {
     if (!node)
@@ -2092,13 +2102,13 @@ void Project::removeFolderRecurse(PProjectModelNode node)
     for (int i=node->children.count()-1;i>=0;i++) {
         PProjectModelNode childNode = node->children[i];
         // Remove folder inside folder
-        if (childNode->unitIndex<0 && childNode->level>0) {
+        if (!childNode->isUnit && childNode->level>0) {
             removeFolderRecurse(childNode);
         // Or remove editors at this level
-        } else if (childNode->unitIndex >= 0 && childNode->level > 0) {
+        } else if (childNode->isUnit && childNode->level > 0) {
             // Remove editor in folder from project
-            int editorIndex = childNode->unitIndex;
-            if (!removeUnit(editorIndex,true))
+            PProjectUnit unit = childNode->pUnit.lock();
+            if (!removeUnit(unit,true))
                 return;
         }
     }
@@ -2113,7 +2123,7 @@ void Project::updateFolderNode(PProjectModelNode node)
 {
     for (int i=0;i<node->children.count();i++){
         PProjectModelNode child = node->children[i];
-        if (child->unitIndex<0) {
+        if (!child->isUnit) {
             mFolders.append(getNodePath(child));
             updateFolderNode(child);
         }
@@ -2162,6 +2172,18 @@ QStringList Project::binDirs()
     return lst;
 }
 
+void Project::renameFolderNode(PProjectModelNode node, const QString newName)
+{
+    if (!node)
+        return;
+    if (node->isUnit)
+        return;
+    node->text = newName;
+    updateFolders();
+    setModified(true);
+    emit nodeRenamed();
+}
+
 EditorList *Project::editorList() const
 {
     return mEditorList;
@@ -2214,14 +2236,11 @@ const QString &Project::filename() const
     return mFilename;
 }
 
-int ProjectUnit::mIdGenerator=0;
-
 ProjectUnit::ProjectUnit(Project* parent)
 {
     mNode = nullptr;
     mParent = parent;
     mFileMissing = false;
-    mId=mIdGenerator++;
     mPriority=0;
 }
 
@@ -2230,11 +2249,6 @@ Project *ProjectUnit::parent() const
     return mParent;
 }
 
-void ProjectUnit::setParent(Project* newParent)
-{
-    mParent = newParent;
-}
-
 const QString &ProjectUnit::fileName() const
 {
     return mFileName;
@@ -2416,16 +2430,6 @@ void ProjectUnit::setFileMissing(bool newDontSave)
     mFileMissing = newDontSave;
 }
 
-int ProjectUnit::id() const
-{
-    return mId;
-}
-
-void ProjectUnit::setId(int newId)
-{
-    mId = newId;
-}
-
 ProjectModel::ProjectModel(Project *project, QObject *parent):
     QAbstractItemModel(parent),
     mProject(project)
@@ -2547,8 +2551,10 @@ QVariant ProjectModel::data(const QModelIndex &index, int role) const
         return p->text;
     } else if (role == Qt::DecorationRole) {
         QIcon icon;
-        if (p->unitIndex>=0) {
-            icon = mIconProvider->icon(mProject->findUnitById(p->unitIndex)->fileName());
+        if (p->isUnit) {
+            PProjectUnit unit = p->pUnit.lock();
+            if (unit)
+                icon = mIconProvider->icon(unit->fileName());
         } else {
             if (p == mProject->rootNode().get()) {
                 QString branch;
@@ -2585,12 +2591,12 @@ Qt::ItemFlags ProjectModel::flags(const QModelIndex &index) const
         return Qt::ItemIsEnabled | Qt::ItemIsDropEnabled | Qt::ItemIsEditable;
     if (mProject && mProject->modelType() == ProjectModelType::FileSystem) {
         Qt::ItemFlags flags = Qt::ItemIsEnabled | Qt::ItemIsSelectable;
-        if (p->unitIndex>=0)
+        if (p->isUnit)
             flags.setFlag(Qt::ItemIsEditable);
         return flags;
     } else {
         Qt::ItemFlags flags = Qt::ItemIsEnabled | Qt::ItemIsEditable | Qt::ItemIsSelectable | Qt::ItemIsDragEnabled;
-        if (p->unitIndex<0) {
+        if (!p->isUnit) {
             flags.setFlag(Qt::ItemIsDropEnabled);
             flags.setFlag(Qt::ItemIsDragEnabled,false);
         }
@@ -2615,10 +2621,10 @@ bool ProjectModel::setData(const QModelIndex &index, const QVariant &value, int
             emit dataChanged(index,index);
             return true;
         }
-        int idx = node->unitIndex;
-        if (idx >= 0) {
+        PProjectUnit unit = node->pUnit.lock();
+        if (unit) {
             //change unit name
-            PProjectUnit unit = mProject->findUnitById(idx);
+
             QString newName = value.toString().trimmed();
             if (newName.isEmpty())
                 return false;
@@ -2642,9 +2648,9 @@ bool ProjectModel::setData(const QModelIndex &index, const QVariant &value, int
                         mProject->editorList()->closeEditor(e);
 
                     // Remove it from the current project...
-                    int projindex = mProject->findUnitId(newName);
-                    if (projindex>=0) {
-                        mProject->removeUnit(projindex,false);
+                    PProjectUnit unit = mProject->findUnit(newName);
+                    if (unit) {
+                        mProject->removeUnit(unit,false);
                     }
 
                     // All references to the file are removed. Delete the file from disk
@@ -2674,17 +2680,13 @@ bool ProjectModel::setData(const QModelIndex &index, const QVariant &value, int
                                       QMessageBox::Ok);
                 return false;
             }
-            mProject->renameUnit(idx,newName);
+            mProject->renameUnit(unit,newName);
 
             // Add new filename to file minitor
             mProject->fileSystemWatcher()->addPath(newName);
 
-            //suffix changed
-            if (mProject && mProject->modelType() == ProjectModelType::FileSystem
-                    && QFileInfo(oldName).suffix()!=QFileInfo(newName).suffix()) {
-                mProject->rebuildNodes();
-            } else
-                emit dataChanged(index,index);
+            mProject->saveAll();
+
             return true;
         } else {
             //change folder name
@@ -2693,10 +2695,11 @@ bool ProjectModel::setData(const QModelIndex &index, const QVariant &value, int
                 return false;
             if (newName ==  node->text)
                 return false;
-            node->text = newName;
-            mProject->updateFolders();
-            mProject->saveAll();
+            mProject->renameFolderNode(node,newName);
+
             emit dataChanged(index,index);
+
+            mProject->saveAll();
             return true;
         }
 
@@ -2767,7 +2770,7 @@ bool ProjectModel::canDropMimeData(const QMimeData * data, Qt::DropAction action
 //    }
     ProjectModelNode* p= static_cast<ProjectModelNode*>(idx.internalPointer());
     PProjectModelNode node = mProject->pointerToNode(p);
-    if (node->unitIndex>=0)
+    if (node->isUnit)
         return false;
     QByteArray encoded = data->data(format);
     QDataStream stream(&encoded, QIODevice::ReadOnly);
@@ -2835,8 +2838,8 @@ bool ProjectModel::dropMimeData(const QMimeData *data, Qt::DropAction action, in
         beginInsertRows(newParentIndex,node->children.count(),node->children.count());
         droppedNode->parent = node;
         node->children.append(droppedNode);
-        if (droppedNode->unitIndex>=0) {
-            PProjectUnit unit = mProject->findUnitById(droppedNode->unitIndex);
+        if (droppedNode->isUnit) {
+            PProjectUnit unit = droppedNode->pUnit.lock();
             unit->setFolder(mProject->getNodePath(node));
         }
         endInsertRows();
@@ -2863,8 +2866,10 @@ QMimeData *ProjectModel::mimeData(const QModelIndexList &indexes) const
     for (; it != indexes.end(); ++it) {
         stream << (qint32)((*it).row()) << (qint32)((*it).column()) << (quintptr)((*it).internalPointer());
         ProjectModelNode* p = static_cast<ProjectModelNode*>((*it).internalPointer());
-        if (p && p->unitIndex>=0) {
-            urls.append(QUrl::fromLocalFile(mProject->findUnitById(p->unitIndex)->fileName()));
+        if (p && p->isUnit) {
+            PProjectUnit unit = p->pUnit.lock();
+            if (unit)
+                urls.append(QUrl::fromLocalFile(unit->fileName()));
         }
     }
     if (!urls.isEmpty())
@@ -2893,9 +2898,9 @@ bool ProjectModelSortFilterProxy::lessThan(const QModelIndex &source_left, const
         return true;
     if (!pRight)
         return false;
-    if (pLeft->unitIndex<0 && pRight->unitIndex>=0)
+    if (!pLeft->isUnit && pRight->isUnit)
         return true;
-    if (pLeft->unitIndex>=0 && pRight->unitIndex<0)
+    if (pLeft->isUnit && !pRight->isUnit)
         return false;
     if (pLeft->priority!=pRight->priority)
         return pLeft->priority>pRight->priority;
diff --git a/RedPandaIDE/project.h b/RedPandaIDE/project.h
index c6fe7f4a..cacbd7e0 100644
--- a/RedPandaIDE/project.h
+++ b/RedPandaIDE/project.h
@@ -44,12 +44,15 @@ struct ProjectModelItemRecord {
     QString fullPath;
 };
 
+class ProjectUnit;
+
 struct ProjectModelNode;
 using PProjectModelNode = std::shared_ptr<ProjectModelNode>;
 struct ProjectModelNode {
     QString text;
     std::weak_ptr<ProjectModelNode> parent;
-    int unitIndex;
+    bool isUnit;
+    std::weak_ptr<ProjectUnit> pUnit;
     int priority;
     QList<PProjectModelNode>  children;
     ProjectModelNodeType folderNodeType;
@@ -71,7 +74,6 @@ class ProjectUnit {
 public:
     explicit ProjectUnit(Project* parent);
     Project* parent() const;
-    void setParent(Project* newParent);
     const QString &fileName() const;
     void setFileName(QString newFileName);
     bool isNew() const;
@@ -102,10 +104,6 @@ public:
     bool FileMissing() const;
     void setFileMissing(bool newDontSave);
 
-    int id() const;
-
-    void setId(int newId);
-
 private:
     Project* mParent;
     QString mFileName;
@@ -120,8 +118,6 @@ private:
     QByteArray mEncoding;
     PProjectModelNode mNode;
     bool mFileMissing;
-    int mId;
-    static int mIdGenerator;
 };
 
 using PProjectUnit = std::shared_ptr<ProjectUnit>;
@@ -206,46 +202,37 @@ public:
                 PProjectModelNode parentNode);
     QString folder();
     void buildPrivateResource(bool forceSave=false);
-    void closeUnit(int id);
+    void closeAllUnits();
+    void closeUnit(PProjectUnit& unit);
     PProjectUnit doAutoOpen();
     bool fileAlreadyExists(const QString& s);
 
     QString getNodePath(PProjectModelNode node);
-    int getUnitFromString(const QString& s);
     void incrementBuildNumber();
 
     PProjectUnit  newUnit(PProjectModelNode parentNode,
                  const QString& customFileName="");
-    Editor* openUnit(int index, bool forceOpen=true);
-    Editor* openUnit(PProjectEditorLayout editorLayout);
+    Editor* openUnit(PProjectUnit& unit, bool forceOpen=true);
+    Editor* openUnit(PProjectUnit& unit, const PProjectEditorLayout& layout);
     Editor* unitEditor(const PProjectUnit& unit) const;
     Editor* unitEditor(const ProjectUnit* unit) const;
-    Editor* unitEditor(int id) const {
-        PProjectUnit unit=mUnits.value(id,PProjectUnit());
-        if (!unit)
-            return nullptr;
-        return unitEditor(unit);
-    }
 
     QList<PProjectUnit> unitList();
 
     PProjectModelNode pointerToNode(ProjectModelNode * p, PProjectModelNode parent=PProjectModelNode());
     void rebuildNodes();
-    bool removeUnit(int id, bool doClose, bool removeFile = false);
+    bool removeUnit(PProjectUnit& unit, bool doClose, bool removeFile = false);
     bool removeFolder(PProjectModelNode node);
     void resetParserProjectFiles();
     void saveAll(); // save [Project] and  all [UnitX]
     void saveLayout(); // save all [UnitX]
     void saveOptions();
-    void renameUnit(int idx, const QString& sFileName);
+    void renameUnit(PProjectUnit& unit, const QString& sFileName);
     bool saveUnits();
 
-    PProjectUnit findUnitById(int id);
     PProjectUnit findUnit(const QString& filename);
     PProjectUnit findUnit(const Editor* editor);
 
-    int findUnitId(const QString& fileName) const;
-    int findUnitId(const Editor* editor) const;
     void associateEditor(Editor* editor);
     void associateEditorToUnit(Editor* editor, PProjectUnit unit);
     bool setCompileOption(const QString &key, const QString &value);
@@ -283,9 +270,12 @@ public:
 
     QStringList binDirs();
 
+    void renameFolderNode(PProjectModelNode node, const QString newName);
+    void loadUnitLayout(Editor *e);
 signals:
-    void nodesChanged();
+    void nodeRenamed();
     void modifyChanged(bool value);
+
 private:
     void checkProjectFileForUpdate(SimpleIni& ini);
     void createFolderNodes();
@@ -296,7 +286,6 @@ private:
     PProjectModelNode getCustomeFolderNodeFromName(const QString& name);
     void loadOptions(SimpleIni& ini);
     PProjectUnit loadLayout();
-    void loadUnitLayout(Editor *e);
 
     PProjectModelNode makeNewFolderNode(
             const QString& folderName,
@@ -304,8 +293,8 @@ private:
             ProjectModelNodeType nodeType=ProjectModelNodeType::Folder,
             int priority=0);
     PProjectModelNode makeNewFileNode(
-            const QString& fileName,
-            int unitId,
+            //const QString& fileName,
+            PProjectUnit unit,
             int priority,
             PProjectModelNode newParent);
     PProjectModelNode makeProjectNode();
@@ -315,7 +304,7 @@ private:
     void updateCompilerSetType();
 
 private:
-    QHash<int,PProjectUnit> mUnits;
+    QHash<QString,PProjectUnit> mUnits;
     ProjectOptions mOptions;
     QString mFilename;
     QString mName;
diff --git a/RedPandaIDE/settingsdialog/projectfileswidget.cpp b/RedPandaIDE/settingsdialog/projectfileswidget.cpp
index 494b2db1..cd96a9eb 100644
--- a/RedPandaIDE/settingsdialog/projectfileswidget.cpp
+++ b/RedPandaIDE/settingsdialog/projectfileswidget.cpp
@@ -47,7 +47,7 @@ void ProjectFilesWidget::doSave()
 {
     for (int i=0;i<mUnits.count();i++) {
         PProjectUnit unitCopy = mUnits[i];
-        PProjectUnit unit = pMainWindow->project()->findUnitById(unitCopy->id());
+        PProjectUnit unit = pMainWindow->project()->findUnit(unitCopy->fileName());
         unit->setPriority(unitCopy->priority());
         unit->setCompile(unitCopy->compile());
         unit->setLink(unitCopy->link());
@@ -70,11 +70,13 @@ PProjectUnit ProjectFilesWidget::currentUnit()
     ProjectModelNode* node = static_cast<ProjectModelNode*>(index.internalPointer());
     if (!node)
         return PProjectUnit();
-    int idx = node->unitIndex;
-    if (idx>=0) {
-        foreach (PProjectUnit unit, mUnits) {
-            if (unit->id() == idx)
-                return unit;
+    if (!node->isUnit)
+        return PProjectUnit();
+    PProjectUnit unit=node->pUnit.lock();
+    if (unit) {
+        foreach (PProjectUnit tmpUnit, mUnits) {
+            if (tmpUnit->fileName() == unit->fileName())
+                return tmpUnit;
         }
     }
     return PProjectUnit();
@@ -88,7 +90,6 @@ void ProjectFilesWidget::copyUnits()
     mUnits.clear();
     foreach (const PProjectUnit& unit, project->unitList()) {
         PProjectUnit unitCopy = std::make_shared<ProjectUnit>(project.get());
-        unitCopy->setId(unit->id());
         unitCopy->setPriority(unit->priority());
         unitCopy->setCompile(unit->compile());
         unitCopy->setLink(unit->link());
@@ -145,9 +146,8 @@ void ProjectFilesWidget::on_treeProject_doubleClicked(const QModelIndex &index)
         disableFileOptions();
         return;
     }
-    int i = node->unitIndex;
-    if (i>=0) {
-        PProjectUnit unit = mUnits[i];
+    PProjectUnit unit = node->pUnit.lock();
+    if (unit) {
         ui->grpFileOptions->setEnabled(true);
         ui->spinPriority->setValue(unit->priority());
         ui->chkCompile->setChecked(unit->compile());