diff --git a/NEWS.md b/NEWS.md
index 7f94435a..81ff8896 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -5,6 +5,9 @@ Red Panda C++ Version 0.14.5
   - fix: can't correctly set break conditions
   - fix: crash when copy to non-c files
   - fix: fonts in cpu window is not correctly set, when dpi changed
+  - enhancement: enable group undo
+  - enhancement: add option "hide symbols start with underscore" and "hide synbols start with two underscore"
+  - fix: can't rename project files that not openned in editor
 
 
 Red Panda C++ Version 0.14.4
diff --git a/RedPandaIDE/RedPandaIDE_zh_CN.ts b/RedPandaIDE/RedPandaIDE_zh_CN.ts
index e512d01d..8d623312 100644
--- a/RedPandaIDE/RedPandaIDE_zh_CN.ts
+++ b/RedPandaIDE/RedPandaIDE_zh_CN.ts
@@ -1314,40 +1314,40 @@ Are you really want to continue?</oldsource>
         <translation>打印文档</translation>
     </message>
     <message>
-        <location filename="editor.cpp" line="3145"/>
-        <location filename="editor.cpp" line="3184"/>
-        <location filename="editor.cpp" line="3238"/>
+        <location filename="editor.cpp" line="3147"/>
+        <location filename="editor.cpp" line="3186"/>
+        <location filename="editor.cpp" line="3240"/>
         <source>Ctrl+click for more info</source>
         <translation>Ctrl+单击以获取更多信息</translation>
     </message>
     <message>
-        <location filename="editor.cpp" line="3636"/>
-        <location filename="editor.cpp" line="3666"/>
+        <location filename="editor.cpp" line="3638"/>
+        <location filename="editor.cpp" line="3668"/>
         <source>Symbol &apos;%1&apos; not found!</source>
         <translation>未找到符号&apos;%1&apos;!</translation>
     </message>
     <message>
-        <location filename="editor.cpp" line="3959"/>
+        <location filename="editor.cpp" line="3961"/>
         <source>astyle not found</source>
         <translation>找不到astyle程序</translation>
     </message>
     <message>
-        <location filename="editor.cpp" line="3960"/>
+        <location filename="editor.cpp" line="3962"/>
         <source>Can&apos;t find astyle in &quot;%1&quot;.</source>
         <translation>找不到astyle程序&quot;%1&quot;.</translation>
     </message>
     <message>
-        <location filename="editor.cpp" line="4109"/>
+        <location filename="editor.cpp" line="4111"/>
         <source>Break point condition</source>
         <translation>断点条件</translation>
     </message>
     <message>
-        <location filename="editor.cpp" line="4110"/>
+        <location filename="editor.cpp" line="4112"/>
         <source>Enter the condition of the breakpoint:</source>
         <translation>输入当前断点的生效条件:</translation>
     </message>
     <message>
-        <location filename="editor.cpp" line="4324"/>
+        <location filename="editor.cpp" line="4326"/>
         <source>Readonly</source>
         <translation>只读</translation>
     </message>
@@ -1558,22 +1558,34 @@ Are you really want to continue?</oldsource>
         <translation>优先提示局部作用域中的符号</translation>
     </message>
     <message>
-        <location filename="settingsdialog/editorcodecompletionwidget.ui" line="167"/>
+        <location filename="settingsdialog/editorcodecompletionwidget.ui" line="152"/>
+        <source>Hide symbols start with underscore</source>
+        <oldsource>Hide symbols start with underline</oldsource>
+        <translation>隐藏以下划线开头的符号</translation>
+    </message>
+    <message>
+        <location filename="settingsdialog/editorcodecompletionwidget.ui" line="159"/>
+        <source>Hide symbols start with two underscores</source>
+        <oldsource>Hide symbols start with two underline</oldsource>
+        <translation>隐藏以两个下划线开头的符号</translation>
+    </message>
+    <message>
+        <location filename="settingsdialog/editorcodecompletionwidget.ui" line="181"/>
         <source>Prefer symbols mostly used</source>
         <translation>优先提示经常使用的符号</translation>
     </message>
     <message>
-        <location filename="settingsdialog/editorcodecompletionwidget.ui" line="187"/>
+        <location filename="settingsdialog/editorcodecompletionwidget.ui" line="201"/>
         <source>Clear usage data</source>
         <translation>清除使用数据</translation>
     </message>
     <message>
-        <location filename="settingsdialog/editorcodecompletionwidget.ui" line="206"/>
+        <location filename="settingsdialog/editorcodecompletionwidget.ui" line="226"/>
         <source>Completion suggestion window width:</source>
         <translation>补全提示窗口宽度：</translation>
     </message>
     <message>
-        <location filename="settingsdialog/editorcodecompletionwidget.ui" line="236"/>
+        <location filename="settingsdialog/editorcodecompletionwidget.ui" line="256"/>
         <source>Completion suggestion window height:</source>
         <translation>补全提示窗口高度：</translation>
     </message>
@@ -3081,7 +3093,7 @@ Are you really want to continue?</oldsource>
     <message>
         <location filename="settingsdialog/formattergeneralwidget.cpp" line="224"/>
         <source>Linux braces, add braces to all conditionals.</source>
-        <translation>Linux封号花括号，所有条件语句条件花括号</translation>
+        <translation>Linux花括号，所有条件语句的分支加花括号</translation>
     </message>
     <message>
         <location filename="settingsdialog/formattergeneralwidget.cpp" line="229"/>
@@ -3762,11 +3774,11 @@ Are you really want to continue?</oldsource>
     <message>
         <location filename="mainwindow.ui" line="560"/>
         <location filename="mainwindow.ui" line="2637"/>
-        <location filename="mainwindow.cpp" line="4299"/>
         <location filename="mainwindow.cpp" line="4302"/>
-        <location filename="mainwindow.cpp" line="4306"/>
+        <location filename="mainwindow.cpp" line="4305"/>
         <location filename="mainwindow.cpp" line="4309"/>
-        <location filename="mainwindow.cpp" line="5949"/>
+        <location filename="mainwindow.cpp" line="4312"/>
+        <location filename="mainwindow.cpp" line="5954"/>
         <source>Issues</source>
         <translation>编译器</translation>
     </message>
@@ -4189,7 +4201,7 @@ Are you really want to continue?</oldsource>
     <message>
         <location filename="mainwindow.ui" line="359"/>
         <location filename="mainwindow.ui" line="362"/>
-        <location filename="mainwindow.cpp" line="6263"/>
+        <location filename="mainwindow.cpp" line="6268"/>
         <source>New Problem Set</source>
         <translation>新建试题集</translation>
     </message>
@@ -4208,14 +4220,14 @@ Are you really want to continue?</oldsource>
     <message>
         <location filename="mainwindow.ui" line="401"/>
         <location filename="mainwindow.ui" line="404"/>
-        <location filename="mainwindow.cpp" line="6306"/>
+        <location filename="mainwindow.cpp" line="6311"/>
         <source>Save Problem Set</source>
         <translation>保存试题集</translation>
     </message>
     <message>
         <location filename="mainwindow.ui" line="415"/>
         <location filename="mainwindow.ui" line="418"/>
-        <location filename="mainwindow.cpp" line="6330"/>
+        <location filename="mainwindow.cpp" line="6335"/>
         <source>Load Problem Set</source>
         <translation>载入试题集</translation>
     </message>
@@ -4554,7 +4566,7 @@ Are you really want to continue?</oldsource>
     </message>
     <message>
         <location filename="mainwindow.ui" line="2312"/>
-        <location filename="mainwindow.cpp" line="5166"/>
+        <location filename="mainwindow.cpp" line="5171"/>
         <source>Clear all breakpoints</source>
         <translation>删除所有断点</translation>
     </message>
@@ -4655,7 +4667,7 @@ Are you really want to continue?</oldsource>
     </message>
     <message>
         <location filename="mainwindow.ui" line="2466"/>
-        <location filename="mainwindow.cpp" line="5890"/>
+        <location filename="mainwindow.cpp" line="5895"/>
         <source>Rename Symbol</source>
         <translation>重命名符号</translation>
     </message>
@@ -4676,13 +4688,13 @@ Are you really want to continue?</oldsource>
     </message>
     <message>
         <location filename="mainwindow.ui" line="2486"/>
-        <location filename="mainwindow.cpp" line="6078"/>
+        <location filename="mainwindow.cpp" line="6083"/>
         <source>Export As RTF</source>
         <translation>导出为RTF</translation>
     </message>
     <message>
         <location filename="mainwindow.ui" line="2491"/>
-        <location filename="mainwindow.cpp" line="6100"/>
+        <location filename="mainwindow.cpp" line="6105"/>
         <source>Export As HTML</source>
         <translation>导出为HTML</translation>
     </message>
@@ -5162,7 +5174,7 @@ Are you really want to continue?</oldsource>
     </message>
     <message>
         <location filename="mainwindow.cpp" line="277"/>
-        <location filename="mainwindow.cpp" line="6272"/>
+        <location filename="mainwindow.cpp" line="6277"/>
         <source>Problem Set %1</source>
         <translation>试题集%1</translation>
     </message>
@@ -5236,15 +5248,15 @@ Are you really want to continue?</oldsource>
     </message>
     <message>
         <location filename="mainwindow.cpp" line="2339"/>
-        <location filename="mainwindow.cpp" line="6159"/>
-        <location filename="mainwindow.cpp" line="6199"/>
+        <location filename="mainwindow.cpp" line="6164"/>
+        <location filename="mainwindow.cpp" line="6204"/>
         <source>Bookmark Description</source>
         <translation>书签描述</translation>
     </message>
     <message>
         <location filename="mainwindow.cpp" line="2340"/>
-        <location filename="mainwindow.cpp" line="6160"/>
-        <location filename="mainwindow.cpp" line="6200"/>
+        <location filename="mainwindow.cpp" line="6165"/>
+        <location filename="mainwindow.cpp" line="6205"/>
         <source>Description:</source>
         <translation>描述：</translation>
     </message>
@@ -5365,7 +5377,7 @@ Are you really want to continue?</oldsource>
         <location filename="mainwindow.cpp" line="2737"/>
         <location filename="mainwindow.cpp" line="3589"/>
         <location filename="mainwindow.cpp" line="3595"/>
-        <location filename="mainwindow.cpp" line="5751"/>
+        <location filename="mainwindow.cpp" line="5756"/>
         <source>Delete</source>
         <translation>删除</translation>
     </message>
@@ -5442,7 +5454,7 @@ Are you really want to continue?</oldsource>
     </message>
     <message>
         <location filename="mainwindow.cpp" line="3802"/>
-        <location filename="mainwindow.cpp" line="6266"/>
+        <location filename="mainwindow.cpp" line="6271"/>
         <source>Do you want to save it?</source>
         <translation>需要保存吗？</translation>
     </message>
@@ -5466,141 +5478,141 @@ Are you really want to continue?</oldsource>
         <location filename="mainwindow.cpp" line="4049"/>
         <location filename="mainwindow.cpp" line="4059"/>
         <location filename="mainwindow.cpp" line="4071"/>
-        <location filename="mainwindow.cpp" line="6319"/>
+        <location filename="mainwindow.cpp" line="6324"/>
         <source>Save Error</source>
         <translation>保存失败</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4227"/>
+        <location filename="mainwindow.cpp" line="4230"/>
         <source>Change Project Compiler Set</source>
         <translation>改变项目编译器配置集</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4228"/>
+        <location filename="mainwindow.cpp" line="4231"/>
         <source>Change the project&apos;s compiler set will lose all custom compiler set options.</source>
         <translation>改变项目的编译器配置集会导致所有的自定义编译器选项被重置。</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4230"/>
+        <location filename="mainwindow.cpp" line="4233"/>
         <source>Do you really want to do that?</source>
         <translation>你真的想要做那些吗？</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5167"/>
+        <location filename="mainwindow.cpp" line="5172"/>
         <source>Do you really want to clear all breakpoints in this file?</source>
         <translation>您真的要清除该文件的所有断点吗？</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5365"/>
+        <location filename="mainwindow.cpp" line="5370"/>
         <source>New project</source>
         <translation>新建项目</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5366"/>
+        <location filename="mainwindow.cpp" line="5371"/>
         <source>Close %1 and start new project?</source>
         <translation>关闭&apos;%1&apos;以打开新项目?</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5379"/>
+        <location filename="mainwindow.cpp" line="5384"/>
         <source>Folder not exist</source>
         <translation>文件夹不存在</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5380"/>
+        <location filename="mainwindow.cpp" line="5385"/>
         <source>Folder &apos;%1&apos; doesn&apos;t exist. Create it now?</source>
         <translation>文件夹&apos;%1&apos;不存在。是否创建？</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5387"/>
+        <location filename="mainwindow.cpp" line="5392"/>
         <source>Can&apos;t create folder</source>
         <translation>无法创建文件夹</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5388"/>
+        <location filename="mainwindow.cpp" line="5393"/>
         <source>Failed to create folder &apos;%1&apos;.</source>
         <translation>创建文件夹&apos;%1&apos;失败。</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5403"/>
+        <location filename="mainwindow.cpp" line="5408"/>
         <source>Save new project as</source>
         <translation></translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5752"/>
+        <location filename="mainwindow.cpp" line="5757"/>
         <source>Folder %1 is not empty.</source>
         <translation>文件夹%1不是空的。</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5753"/>
+        <location filename="mainwindow.cpp" line="5758"/>
         <source>Do you really want to delete it?</source>
         <translation>你真的要删除它吗？</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6844"/>
+        <location filename="mainwindow.cpp" line="6849"/>
         <source>Can&apos;t Commit</source>
         <translation>无法提交</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6845"/>
+        <location filename="mainwindow.cpp" line="6850"/>
         <source>Git needs user info to commit.</source>
         <translation>Git需要用信息进行提交。</translation>
     </message>
     <message>
         <location filename="mainwindow.ui" line="2556"/>
         <location filename="mainwindow.ui" line="2559"/>
-        <location filename="mainwindow.cpp" line="6242"/>
+        <location filename="mainwindow.cpp" line="6247"/>
         <source>Choose Working Folder</source>
         <translation>选择工作文件夹</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6612"/>
-        <location filename="mainwindow.cpp" line="6664"/>
+        <location filename="mainwindow.cpp" line="6617"/>
+        <location filename="mainwindow.cpp" line="6669"/>
         <source>Header Exists</source>
         <translation>头文件已存在</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6613"/>
-        <location filename="mainwindow.cpp" line="6665"/>
+        <location filename="mainwindow.cpp" line="6618"/>
+        <location filename="mainwindow.cpp" line="6670"/>
         <source>Header file &quot;%1&quot; already exists!</source>
         <translation>头文件&quot;%1&quot;已存在！</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6670"/>
+        <location filename="mainwindow.cpp" line="6675"/>
         <source>Source Exists</source>
         <translation>源文件已存在！</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6671"/>
+        <location filename="mainwindow.cpp" line="6676"/>
         <source>Source file &quot;%1&quot; already exists!</source>
         <translation>源文件&quot;%1&quot;已存在！</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6823"/>
+        <location filename="mainwindow.cpp" line="6828"/>
         <source>Can&apos;t commit!</source>
         <translation>无法提交！</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6824"/>
+        <location filename="mainwindow.cpp" line="6829"/>
         <source>The following files are in conflicting:</source>
         <translation>下列文件处于冲突状态，请解决后重新添加和提交：</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6829"/>
+        <location filename="mainwindow.cpp" line="6834"/>
         <source>Commit Message</source>
         <translation>提交信息</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6829"/>
+        <location filename="mainwindow.cpp" line="6834"/>
         <source>Commit Message:</source>
         <translation>提交信息：</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6832"/>
+        <location filename="mainwindow.cpp" line="6837"/>
         <source>Commit Failed</source>
         <translation>提交失败</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6833"/>
+        <location filename="mainwindow.cpp" line="6838"/>
         <source>Commit message shouldn&apos;t be empty!</source>
         <translation>提交信息不能为空！</translation>
     </message>
@@ -5609,125 +5621,125 @@ Are you really want to continue?</oldsource>
         <translation type="vanished">小熊猫Dev-C++项目文件 (*.dev)</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5416"/>
+        <location filename="mainwindow.cpp" line="5421"/>
         <source>New project fail</source>
         <translation>新建项目失败</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5417"/>
+        <location filename="mainwindow.cpp" line="5422"/>
         <source>Can&apos;t assign project template</source>
         <translation>无法使用模板创建项目</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5512"/>
+        <location filename="mainwindow.cpp" line="5517"/>
         <source>Remove file</source>
         <translation>删除文件</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5513"/>
+        <location filename="mainwindow.cpp" line="5518"/>
         <source>Remove the file from disk?</source>
         <translation>同时从硬盘上删除文件？</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5702"/>
+        <location filename="mainwindow.cpp" line="5707"/>
         <source>untitled</source>
         <translation>无标题</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5712"/>
+        <location filename="mainwindow.cpp" line="5717"/>
         <source>New Project File Name</source>
         <translation>新的项目文件名</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5713"/>
+        <location filename="mainwindow.cpp" line="5718"/>
         <source>File Name:</source>
         <translation>文件名：</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5719"/>
+        <location filename="mainwindow.cpp" line="5724"/>
         <source>File Already Exists!</source>
         <translation>文件已存在！</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5720"/>
+        <location filename="mainwindow.cpp" line="5725"/>
         <source>File &apos;%1&apos; already exists!</source>
         <translation>文件&apos;%1&apos;已经存在！</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5461"/>
+        <location filename="mainwindow.cpp" line="5466"/>
         <source>Add to project</source>
         <translation>添加到项目</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5405"/>
+        <location filename="mainwindow.cpp" line="5410"/>
         <source>Red Panda C++ project file (*.dev)</source>
         <translation>小熊猫C++项目文件(*.dev)</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5876"/>
+        <location filename="mainwindow.cpp" line="5881"/>
         <source>Rename Error</source>
         <translation>重命名出错</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5877"/>
+        <location filename="mainwindow.cpp" line="5882"/>
         <source>Symbol &apos;%1&apos; is defined in system header.</source>
         <translation>符号&apos;%1&apos;在系统头文件中定义，无法修改。</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="5891"/>
+        <location filename="mainwindow.cpp" line="5896"/>
         <source>New Name</source>
         <translation>新名称</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6023"/>
-        <location filename="mainwindow.cpp" line="6033"/>
+        <location filename="mainwindow.cpp" line="6028"/>
+        <location filename="mainwindow.cpp" line="6038"/>
         <source>Replace Error</source>
         <translation>替换出错</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6024"/>
+        <location filename="mainwindow.cpp" line="6029"/>
         <source>Can&apos;t open file &apos;%1&apos; for replace!</source>
         <translation>无法打开文件&apos;%1&apos;进行替换！</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6034"/>
+        <location filename="mainwindow.cpp" line="6039"/>
         <source>Contents has changed since last search!</source>
         <translation>内容和上次查找时不一致。</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6080"/>
+        <location filename="mainwindow.cpp" line="6085"/>
         <source>Rich Text Format Files (*.rtf)</source>
         <translation>RTF格式文件 (*.rtf)</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6102"/>
+        <location filename="mainwindow.cpp" line="6107"/>
         <source>HTML Files (*.html)</source>
         <translation>HTML文件 (*.html)</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6264"/>
+        <location filename="mainwindow.cpp" line="6269"/>
         <source>The current problem set is not empty.</source>
         <translation>当前的试题集不是空的。</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6282"/>
+        <location filename="mainwindow.cpp" line="6287"/>
         <source>Problem %1</source>
         <translation>试题%1</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6308"/>
-        <location filename="mainwindow.cpp" line="6332"/>
+        <location filename="mainwindow.cpp" line="6313"/>
+        <location filename="mainwindow.cpp" line="6337"/>
         <source>Problem Set Files (*.pbs)</source>
         <translation>试题集文件 (*.pbs)</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6338"/>
+        <location filename="mainwindow.cpp" line="6343"/>
         <source>Load Error</source>
         <translation>载入失败</translation>
     </message>
     <message>
         <location filename="mainwindow.cpp" line="3478"/>
-        <location filename="mainwindow.cpp" line="6352"/>
+        <location filename="mainwindow.cpp" line="6357"/>
         <source>Problem Case %1</source>
         <translation>试题案例%1</translation>
     </message>
@@ -5743,10 +5755,10 @@ Are you really want to continue?</oldsource>
         <location filename="mainwindow.cpp" line="2876"/>
         <location filename="mainwindow.cpp" line="3896"/>
         <location filename="mainwindow.cpp" line="4007"/>
-        <location filename="mainwindow.cpp" line="4196"/>
-        <location filename="mainwindow.cpp" line="4208"/>
-        <location filename="mainwindow.cpp" line="4614"/>
-        <location filename="mainwindow.cpp" line="4626"/>
+        <location filename="mainwindow.cpp" line="4199"/>
+        <location filename="mainwindow.cpp" line="4211"/>
+        <location filename="mainwindow.cpp" line="4619"/>
+        <location filename="mainwindow.cpp" line="4631"/>
         <source>Error</source>
         <translation>错误</translation>
     </message>
@@ -5798,50 +5810,50 @@ Are you really want to continue?</oldsource>
         <translation>打开</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4392"/>
+        <location filename="mainwindow.cpp" line="4395"/>
         <source>Compile Failed</source>
         <translation>编译失败</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4398"/>
+        <location filename="mainwindow.cpp" line="4401"/>
         <source>Run Failed</source>
         <translation>运行失败</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4643"/>
-        <location filename="mainwindow.cpp" line="4657"/>
+        <location filename="mainwindow.cpp" line="4648"/>
+        <location filename="mainwindow.cpp" line="4662"/>
         <source>Confirm Convertion</source>
         <translation>确认转换</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4644"/>
-        <location filename="mainwindow.cpp" line="4658"/>
+        <location filename="mainwindow.cpp" line="4649"/>
+        <location filename="mainwindow.cpp" line="4663"/>
         <source>The editing file will be saved using %1 encoding. &lt;br /&gt;This operation can&apos;t be reverted. &lt;br /&gt;Are you sure to continue?</source>
         <translation>当前编辑器中的文件将会使用%1编码保存。&lt;br /&gt;这项操作无法被撤回。&lt;br /&gt;你确定要继续吗？</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4808"/>
+        <location filename="mainwindow.cpp" line="4813"/>
         <source>New Watch Expression</source>
         <translation>新监视表达式</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4809"/>
+        <location filename="mainwindow.cpp" line="4814"/>
         <source>Enter Watch Expression (it is recommended to use &apos;this-&gt;&apos; for class members):</source>
         <translation>输入监视表达式</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4862"/>
+        <location filename="mainwindow.cpp" line="4867"/>
         <source>Parsing file %1 of %2: &quot;%3&quot;</source>
         <translation>（%1/%2）正在解析文件&quot;%3&quot;</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4884"/>
-        <location filename="mainwindow.cpp" line="4890"/>
+        <location filename="mainwindow.cpp" line="4889"/>
+        <location filename="mainwindow.cpp" line="4895"/>
         <source>Done parsing %1 files in %2 seconds</source>
         <translation>完成%1个文件的解析,用时%2秒</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="4887"/>
+        <location filename="mainwindow.cpp" line="4892"/>
         <source>(%1 files per second)</source>
         <translation>(每秒%1个文件）</translation>
     </message>
@@ -6582,16 +6594,24 @@ Are you really want to continue?</oldsource>
     </message>
     <message>
         <location filename="project.cpp" line="2106"/>
-        <location filename="project.cpp" line="2126"/>
         <source>Remove failed</source>
         <translation>删除失败</translation>
     </message>
     <message>
         <location filename="project.cpp" line="2107"/>
-        <location filename="project.cpp" line="2127"/>
         <source>Failed to remove file &apos;%1&apos;</source>
         <translation>无法删除文件&apos;%1&apos;</translation>
     </message>
+    <message>
+        <location filename="project.cpp" line="2124"/>
+        <source>Rename failed</source>
+        <translation>改名失败</translation>
+    </message>
+    <message>
+        <location filename="project.cpp" line="2125"/>
+        <source>Failed to rename file &apos;%1&apos; to &apos;%2&apos;</source>
+        <translation>无法将文件&apos;%1&apos;改名为&apos;%2&apos;</translation>
+    </message>
 </context>
 <context>
     <name>ProjectOutputWidget</name>
@@ -6812,7 +6832,7 @@ Are you really want to continue?</oldsource>
 <context>
     <name>QApplication</name>
     <message>
-        <location filename="main.cpp" line="380"/>
+        <location filename="main.cpp" line="392"/>
         <source>Error</source>
         <translation>错误</translation>
     </message>
@@ -6882,7 +6902,7 @@ Are you really want to continue?</oldsource>
         <translation>无法写入配置文件夹&quot;%1&quot;</translation>
     </message>
     <message>
-        <location filename="main.cpp" line="334"/>
+        <location filename="main.cpp" line="346"/>
         <source>Can&apos;t load autolink settings</source>
         <translation>无法载入自动链接设置</translation>
     </message>
@@ -7976,7 +7996,7 @@ Are you really want to continue?</oldsource>
         <translation>自动链接</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6253"/>
+        <location filename="mainwindow.cpp" line="6258"/>
         <location filename="settingsdialog/settingsdialog.cpp" line="170"/>
         <location filename="settingsdialog/settingsdialog.cpp" line="203"/>
         <location filename="settingsdialog/settingsdialog.cpp" line="209"/>
@@ -8052,15 +8072,15 @@ Are you really want to continue?</oldsource>
         <translation>杂项</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6254"/>
-        <location filename="mainwindow.cpp" line="6567"/>
+        <location filename="mainwindow.cpp" line="6259"/>
+        <location filename="mainwindow.cpp" line="6572"/>
         <location filename="settingsdialog/settingsdialog.cpp" line="203"/>
         <location filename="settingsdialog/settingsdialog.cpp" line="206"/>
         <source>Program Runner</source>
         <translation>程序运行</translation>
     </message>
     <message>
-        <location filename="mainwindow.cpp" line="6566"/>
+        <location filename="mainwindow.cpp" line="6571"/>
         <location filename="settingsdialog/settingsdialog.cpp" line="206"/>
         <source>Problem Set</source>
         <translation>试题集</translation>
diff --git a/RedPandaIDE/editor.cpp b/RedPandaIDE/editor.cpp
index cebd9edf..e94662a8 100644
--- a/RedPandaIDE/editor.cpp
+++ b/RedPandaIDE/editor.cpp
@@ -2684,6 +2684,8 @@ void Editor::showCompletion(const QString& preWord,bool autoComplete)
     mCompletionPopup->setSortByScope(pSettings->codeCompletion().sortByScope());
     mCompletionPopup->setShowKeywords(pSettings->codeCompletion().showKeywords());
     mCompletionPopup->setShowCodeSnippets(pSettings->codeCompletion().showCodeIns());
+    mCompletionPopup->setHideSymbolsStartWithUnderline(pSettings->codeCompletion().hideSymbolsStartsWithUnderLine());
+    mCompletionPopup->setHideSymbolsStartWithTwoUnderline(pSettings->codeCompletion().hideSymbolsStartsWithTwoUnderLine());
     if (pSettings->codeCompletion().showCodeIns()) {
         mCompletionPopup->setCodeSnippets(pMainWindow->codeSnippetManager()->snippets());
     }
@@ -4138,7 +4140,7 @@ void Editor::applySettings()
 {
     SynEditorOptions options = eoAltSetsColumnMode |
             eoDragDropEditing | eoDropFiles |  eoKeepCaretX | eoTabsToSpaces |
-            eoRightMouseMovesCursor | eoScrollByOneLess | eoTabIndent | eoHideShowScrollbars;
+            eoRightMouseMovesCursor | eoScrollByOneLess | eoTabIndent | eoHideShowScrollbars | eoGroupUndo;
 
     //options
     options.setFlag(eoAutoIndent,pSettings->editor().autoIndent());
diff --git a/RedPandaIDE/main.cpp b/RedPandaIDE/main.cpp
index 8def0b91..e6e1870a 100644
--- a/RedPandaIDE/main.cpp
+++ b/RedPandaIDE/main.cpp
@@ -37,12 +37,16 @@
 #include "editorlist.h"
 #include "widgets/choosethemedialog.h"
 #include "thememanager.h"
+
 #ifdef Q_OS_WIN
 #include <QTemporaryFile>
 #include <windows.h>
 #include <psapi.h>
 #include <QSharedMemory>
 #include <QBuffer>
+#include <winuser.h>
+
+#include "widgets/cpudialog.h"
 #endif
 
 QString getSettingFilename(const QString& filepath, bool& firstRun);
@@ -124,12 +128,18 @@ bool WindowLogoutEventFilter::nativeEventFilter(const QByteArray & /*eventType*/
         }
         break;
     case WM_DPICHANGED:{
-        int oldDPI = screenDPI();
-        QEvent * dpiEvent = new QEvent(DPI_CHANGED_EVENT);
-        qApp->postEvent(pMainWindow,dpiEvent);
-        setScreenDPI(HIWORD(pMsg->wParam));
-        int newDPI = screenDPI();
-        pMainWindow->updateDPI(oldDPI,newDPI);
+        if (pMsg->hwnd == (HWND)pMainWindow->winId()) {
+            int oldDPI = screenDPI();
+            QEvent * dpiEvent = new QEvent(DPI_CHANGED_EVENT);
+            qApp->postEvent(pMainWindow,dpiEvent);
+            setScreenDPI(HIWORD(pMsg->wParam));
+            int newDPI = screenDPI();
+            pMainWindow->updateDPI(oldDPI,newDPI);
+        } else if (pMainWindow->cpuDialog() &&
+                   (HWND)pMainWindow->cpuDialog()->winId() == pMsg->hwnd) {
+            int newDPI = HIWORD(pMsg->wParam);
+            pMainWindow->cpuDialog()->updateDPI(newDPI);
+        }
         break;
         }
     case WM_USER_OPEN_FILE: {
@@ -243,13 +253,17 @@ int main(int argc, char *argv[])
         } else if (!settingFilename.isEmpty() && firstRun)
             openInSingleInstance = false;
         if (openInSingleInstance) {
+            int openCount = 0;
             while (true) {
                 if (tempFile.open(QFile::NewOnly))
                     break;
                 QThread::msleep(100);
+                openCount++;
+                if (openCount>100)
+                    break;
             }
 
-            if (app.arguments().length()>=2) {
+            if (app.arguments().length()>=2 && openCount<100) {
 #ifdef Q_OS_WIN
                 if (sendFilesToInstance()) {
                     tempFile.remove();
diff --git a/RedPandaIDE/mainwindow.cpp b/RedPandaIDE/mainwindow.cpp
index d96d359e..39a72a4c 100644
--- a/RedPandaIDE/mainwindow.cpp
+++ b/RedPandaIDE/mainwindow.cpp
@@ -625,9 +625,6 @@ void MainWindow::applySettings()
     for (QWidget* p:findChildren<QWidget*>()) {
         p->setFont(font);
     }
-    if (mCPUDialog!=nullptr) {
-        mCPUDialog->resetEditorFont();
-    }
     if (pSettings->environment().useCustomIconSet()) {
         QString customIconSetFolder = pSettings->dirs().config(Settings::Dirs::DataType::IconSet);
         pIconsManager->prepareCustomIconSet(customIconSetFolder);
@@ -1844,7 +1841,7 @@ void MainWindow::showSearchPanel(bool showReplace)
 void MainWindow::showCPUInfoDialog()
 {
     if (mCPUDialog==nullptr) {
-        mCPUDialog = new CPUDialog(this);
+        mCPUDialog = new CPUDialog();
         connect(mCPUDialog, &CPUDialog::closed, this, &MainWindow::cleanUpCPUDialog);
         updateCompileActions();
     }
@@ -4107,6 +4104,9 @@ void MainWindow::closeEvent(QCloseEvent *event) {
     mCompilerManager->stopRun();
     if (!mShouldRemoveAllSettings)
         mSymbolUsageManager->save();
+
+    if (mCPUDialog!=nullptr)
+        cleanUpCPUDialog();
     event->accept();
     return;
 }
@@ -4465,6 +4465,8 @@ void MainWindow::onOJProblemCaseNewOutputGetted(const QString &/* id */, const Q
 
 void MainWindow::cleanUpCPUDialog()
 {
+    disconnect(mCPUDialog,&CPUDialog::closed,
+               this,&MainWindow::cleanUpCPUDialog);
     CPUDialog* ptr=mCPUDialog;
     mCPUDialog=nullptr;
     ptr->deleteLater();
diff --git a/RedPandaIDE/project.cpp b/RedPandaIDE/project.cpp
index c8f07497..9344203b 100644
--- a/RedPandaIDE/project.cpp
+++ b/RedPandaIDE/project.cpp
@@ -2115,24 +2115,23 @@ bool ProjectModel::setData(const QModelIndex &index, const QVariant &value, int
             }
             // Target filename does not exist anymore. Do a rename
             // change name in project file first (no actual file renaming on disk)
-            mProject->saveUnitAs(idx,newName);
-
+            //save old file, if it is openned;
             // remove old file from monitor list
             pMainWindow->fileSystemWatcher()->removePath(oldName);
 
-            // Finally, we can rename without issues
-            if (!QFile::remove(oldName)){
+            if (!QFile::rename(oldName,newName)) {
                 QMessageBox::critical(pMainWindow,
-                                      tr("Remove failed"),
-                                      tr("Failed to remove file '%1'")
-                                      .arg(oldName),
+                                      tr("Rename failed"),
+                                      tr("Failed to rename file '%1' to '%2'")
+                                      .arg(oldName,newName),
                                       QMessageBox::Ok);
-                mProject->saveUnitAs(idx,oldName);
                 return false;
             }
+            mProject->saveUnitAs(idx,newName);
 
             // Add new filename to file minitor
             pMainWindow->fileSystemWatcher()->addPath(newName);
+
             //suffix changed
             if (mProject && mProject->modelType() == ProjectModelType::FileSystem
                     && QFileInfo(oldName).suffix()!=QFileInfo(newName).suffix()) {
diff --git a/RedPandaIDE/qsynedit/SynEdit.cpp b/RedPandaIDE/qsynedit/SynEdit.cpp
index 22540f55..f80d9b2f 100644
--- a/RedPandaIDE/qsynedit/SynEdit.cpp
+++ b/RedPandaIDE/qsynedit/SynEdit.cpp
@@ -2681,78 +2681,81 @@ void SynEdit::doAddChar(QChar AChar)
         setSelLength(1);
     }
 
-    mUndoList->BeginBlock();
-    doSetSelText(AChar);
-    int oldCaretX=mCaretX-1;
-    int oldCaretY=mCaretY;
-    // auto
-    if (mOptions.testFlag(eoAutoIndent)
-            && mHighlighter
-            && mHighlighter->getClass()==SynHighlighterClass::CppHighlighter
-            && (oldCaretY<=mLines->count()) ) {
+    if (isIdentChar(AChar)) {
+        doSetSelText(AChar);
+    } else {
+        mUndoList->BeginBlock();
+        doSetSelText(AChar);
+        int oldCaretX=mCaretX-1;
+        int oldCaretY=mCaretY;
+        // auto
+        if (mOptions.testFlag(eoAutoIndent)
+                && mHighlighter
+                && mHighlighter->getClass()==SynHighlighterClass::CppHighlighter
+                && (oldCaretY<=mLines->count()) ) {
 
-        //unindent if ':' at end of the line
-        if (AChar == ':') {
-            QString line = mLines->getString(oldCaretY-1);
-            if (line.length() <= oldCaretX) {
-                int indentSpaces = calcIndentSpaces(oldCaretY,line+":", true);
-                if (indentSpaces != leftSpaces(line)) {
-                    QString newLine = GetLeftSpacing(indentSpaces,true) + trimLeft(line);
-                    mLines->putString(oldCaretY-1,newLine);
-                    internalSetCaretXY(BufferCoord{newLine.length()+2,oldCaretY});
-                    setBlockBegin(caretXY());
-                    setBlockEnd(caretXY());
-                    mUndoList->AddChange(
-                                SynChangeReason::crDelete,
-                                BufferCoord{1, oldCaretY},
-                                BufferCoord{line.length()+1, oldCaretY},
-                                line,
-                                SynSelectionMode::smNormal
-                                );
-                    mUndoList->AddChange(
-                                SynChangeReason::crInsert,
-                                BufferCoord{1, oldCaretY},
-                                BufferCoord{newLine.length()+1, oldCaretY},
-                                "",
-                                SynSelectionMode::smNormal
-                                );
+            //unindent if ':' at end of the line
+            if (AChar == ':') {
+                QString line = mLines->getString(oldCaretY-1);
+                if (line.length() <= oldCaretX) {
+                    int indentSpaces = calcIndentSpaces(oldCaretY,line+":", true);
+                    if (indentSpaces != leftSpaces(line)) {
+                        QString newLine = GetLeftSpacing(indentSpaces,true) + trimLeft(line);
+                        mLines->putString(oldCaretY-1,newLine);
+                        internalSetCaretXY(BufferCoord{newLine.length()+2,oldCaretY});
+                        setBlockBegin(caretXY());
+                        setBlockEnd(caretXY());
+                        mUndoList->AddChange(
+                                    SynChangeReason::crDelete,
+                                    BufferCoord{1, oldCaretY},
+                                    BufferCoord{line.length()+1, oldCaretY},
+                                    line,
+                                    SynSelectionMode::smNormal
+                                    );
+                        mUndoList->AddChange(
+                                    SynChangeReason::crInsert,
+                                    BufferCoord{1, oldCaretY},
+                                    BufferCoord{newLine.length()+1, oldCaretY},
+                                    "",
+                                    SynSelectionMode::smNormal
+                                    );
+                    }
                 }
-            }
-        } else if (AChar == '{' || AChar == '}' || AChar == '#') {
-            //Reindent line when add '{' '}' and '#' at the beginning
-            QString left = mLines->getString(oldCaretY-1).mid(0,oldCaretX-1);
-            // and the first nonblank char is this new {
-            if (left.trimmed().isEmpty()) {
-                int indentSpaces = calcIndentSpaces(oldCaretY,AChar, true);
-                if (indentSpaces != leftSpaces(left)) {
-                    QString right = mLines->getString(oldCaretY-1).mid(oldCaretX-1);
-                    QString newLeft = GetLeftSpacing(indentSpaces,true);
-                    mLines->putString(oldCaretY-1,newLeft+right);
-                    BufferCoord newCaretPos =  BufferCoord{newLeft.length()+2,oldCaretY};
-                    internalSetCaretXY(newCaretPos);
-                    setBlockBegin(caretXY());
-                    setBlockEnd(caretXY());
-                    mUndoList->AddChange(
-                                SynChangeReason::crDelete,
-                                BufferCoord{1, oldCaretY},
-                                BufferCoord{left.length()+1, oldCaretY},
-                                left,
-                                SynSelectionMode::smNormal
-                                );
-                    mUndoList->AddChange(
-                                SynChangeReason::crInsert,
-                                BufferCoord{1, oldCaretY},
-                                BufferCoord{newLeft.length()+1, oldCaretY},
-                                "",
-                                SynSelectionMode::smNormal
-                                );
+            } else if (AChar == '{' || AChar == '}' || AChar == '#') {
+                //Reindent line when add '{' '}' and '#' at the beginning
+                QString left = mLines->getString(oldCaretY-1).mid(0,oldCaretX-1);
+                // and the first nonblank char is this new {
+                if (left.trimmed().isEmpty()) {
+                    int indentSpaces = calcIndentSpaces(oldCaretY,AChar, true);
+                    if (indentSpaces != leftSpaces(left)) {
+                        QString right = mLines->getString(oldCaretY-1).mid(oldCaretX-1);
+                        QString newLeft = GetLeftSpacing(indentSpaces,true);
+                        mLines->putString(oldCaretY-1,newLeft+right);
+                        BufferCoord newCaretPos =  BufferCoord{newLeft.length()+2,oldCaretY};
+                        internalSetCaretXY(newCaretPos);
+                        setBlockBegin(caretXY());
+                        setBlockEnd(caretXY());
+                        mUndoList->AddChange(
+                                    SynChangeReason::crDelete,
+                                    BufferCoord{1, oldCaretY},
+                                    BufferCoord{left.length()+1, oldCaretY},
+                                    left,
+                                    SynSelectionMode::smNormal
+                                    );
+                        mUndoList->AddChange(
+                                    SynChangeReason::crInsert,
+                                    BufferCoord{1, oldCaretY},
+                                    BufferCoord{newLeft.length()+1, oldCaretY},
+                                    "",
+                                    SynSelectionMode::smNormal
+                                    );
 
+                    }
                 }
             }
         }
+        mUndoList->EndBlock();
     }
-    mUndoList->EndBlock();
-
     //DoOnPaintTransient(ttAfter);
 }
 
@@ -4779,11 +4782,13 @@ void SynEdit::setSelTextPrimitiveEx(SynSelectionMode PasteMode, const QString &V
 
 void SynEdit::doSetSelText(const QString &Value)
 {
-    mUndoList->BeginBlock();
-    auto action = finally([this]{
-        mUndoList->EndBlock();
+    bool blockBeginned = false;
+    auto action = finally([this, &blockBeginned]{
+        if (blockBeginned)
+            mUndoList->EndBlock();
     });
     if (selAvail()) {
+      mUndoList->BeginBlock();
       mUndoList->AddChange(
                   SynChangeReason::crDelete, mBlockBegin, mBlockEnd,
                   selText(), mActiveSelectionMode);
diff --git a/RedPandaIDE/settings.cpp b/RedPandaIDE/settings.cpp
index 4c6364e3..4eb0a4c0 100644
--- a/RedPandaIDE/settings.cpp
+++ b/RedPandaIDE/settings.cpp
@@ -3606,6 +3606,26 @@ void Settings::CodeCompletion::setMinCharRequired(int newMinCharRequired)
     mMinCharRequired = newMinCharRequired;
 }
 
+bool Settings::CodeCompletion::hideSymbolsStartsWithTwoUnderLine() const
+{
+    return mHideSymbolsStartsWithTwoUnderLine;
+}
+
+void Settings::CodeCompletion::setHideSymbolsStartsWithTwoUnderLine(bool newHideSymbolsStartsWithTwoUnderLine)
+{
+    mHideSymbolsStartsWithTwoUnderLine = newHideSymbolsStartsWithTwoUnderLine;
+}
+
+bool Settings::CodeCompletion::hideSymbolsStartsWithUnderLine() const
+{
+    return mHideSymbolsStartsWithUnderLine;
+}
+
+void Settings::CodeCompletion::setHideSymbolsStartsWithUnderLine(bool newHideSymbolsStartsWithOneUnderLine)
+{
+    mHideSymbolsStartsWithUnderLine = newHideSymbolsStartsWithOneUnderLine;
+}
+
 bool Settings::CodeCompletion::appendFunc() const
 {
     return mAppendFunc;
@@ -3732,6 +3752,8 @@ void Settings::CodeCompletion::doSave()
     saveValue("show_code_ins",mShowCodeIns);
     saveValue("clear_when_editor_hidden",mClearWhenEditorHidden);
     saveValue("min_char_required",mMinCharRequired);
+    saveValue("hide_symbols_start_with_two_underline", mHideSymbolsStartsWithTwoUnderLine);
+    saveValue("hide_symbols_start_with_underline", mHideSymbolsStartsWithUnderLine);
 }
 
 
@@ -3751,6 +3773,8 @@ void Settings::CodeCompletion::doLoad()
     mAppendFunc = boolValue("append_func",true);
     mShowCodeIns = boolValue("show_code_ins",true);
     mMinCharRequired = intValue("min_char_required",1);
+    mHideSymbolsStartsWithTwoUnderLine = boolValue("hide_symbols_start_with_two_underline", true);
+    mHideSymbolsStartsWithUnderLine = boolValue("hide_symbols_start_with_underline", false);
 
     bool doClear = true;
 
diff --git a/RedPandaIDE/settings.h b/RedPandaIDE/settings.h
index 11a4ad1a..6f0f4059 100644
--- a/RedPandaIDE/settings.h
+++ b/RedPandaIDE/settings.h
@@ -602,6 +602,12 @@ public:
         int minCharRequired() const;
         void setMinCharRequired(int newMinCharRequired);
 
+        bool hideSymbolsStartsWithUnderLine() const;
+        void setHideSymbolsStartsWithUnderLine(bool newHideSymbolsStartsWithOneUnderLine);
+
+        bool hideSymbolsStartsWithTwoUnderLine() const;
+        void setHideSymbolsStartsWithTwoUnderLine(bool newHideSymbolsStartsWithTwoUnderLine);
+
     private:
         int mWidth;
         int mHeight;
@@ -617,6 +623,8 @@ public:
         bool mShowCodeIns;
         bool mClearWhenEditorHidden;
         int mMinCharRequired;
+        bool mHideSymbolsStartsWithTwoUnderLine;
+        bool mHideSymbolsStartsWithUnderLine;
 
         // _Base interface
     protected:
diff --git a/RedPandaIDE/settingsdialog/editorcodecompletionwidget.cpp b/RedPandaIDE/settingsdialog/editorcodecompletionwidget.cpp
index 9e35d2a6..51ca2221 100644
--- a/RedPandaIDE/settingsdialog/editorcodecompletionwidget.cpp
+++ b/RedPandaIDE/settingsdialog/editorcodecompletionwidget.cpp
@@ -51,6 +51,8 @@ void EditorCodeCompletionWidget::doLoad()
     ui->chkAppendFunc->setChecked(pSettings->codeCompletion().appendFunc());
     ui->chkShowCodeIns->setChecked(pSettings->codeCompletion().showCodeIns());
     ui->chkClearWhenEditorHidden->setChecked(pSettings->codeCompletion().clearWhenEditorHidden());
+    ui->chkHideSymbolsStartWithTwoUnderline->setChecked(pSettings->codeCompletion().hideSymbolsStartsWithTwoUnderLine());
+    ui->chkHideSymbolsStartWithUnderline->setChecked(pSettings->codeCompletion().hideSymbolsStartsWithUnderLine());
 
     ui->spinMinCharRequired->setValue(pSettings->codeCompletion().minCharRequired());
 }
@@ -77,6 +79,9 @@ void EditorCodeCompletionWidget::doSave()
 
     pSettings->codeCompletion().setClearWhenEditorHidden(ui->chkClearWhenEditorHidden->isChecked());
 
+    pSettings->codeCompletion().setHideSymbolsStartsWithTwoUnderLine(ui->chkHideSymbolsStartWithTwoUnderline->isChecked());
+    pSettings->codeCompletion().setHideSymbolsStartsWithUnderLine(ui->chkHideSymbolsStartWithUnderline->isChecked());
+
     pSettings->codeCompletion().save();
 }
 
diff --git a/RedPandaIDE/settingsdialog/editorcodecompletionwidget.ui b/RedPandaIDE/settingsdialog/editorcodecompletionwidget.ui
index 95e02252..dcec458a 100644
--- a/RedPandaIDE/settingsdialog/editorcodecompletionwidget.ui
+++ b/RedPandaIDE/settingsdialog/editorcodecompletionwidget.ui
@@ -146,6 +146,20 @@
         </property>
        </widget>
       </item>
+      <item>
+       <widget class="QCheckBox" name="chkHideSymbolsStartWithUnderline">
+        <property name="text">
+         <string>Hide symbols start with underscore</string>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QCheckBox" name="chkHideSymbolsStartWithTwoUnderline">
+        <property name="text">
+         <string>Hide symbols start with two underscores</string>
+        </property>
+       </widget>
+      </item>
       <item>
        <widget class="QWidget" name="widget" native="true">
         <layout class="QHBoxLayout" name="horizontalLayout">
@@ -195,10 +209,16 @@
        <widget class="QWidget" name="widget_2" native="true">
         <layout class="QGridLayout" name="gridLayout">
          <property name="leftMargin">
-          <number>11</number>
+          <number>0</number>
          </property>
          <property name="topMargin">
-          <number>11</number>
+          <number>0</number>
+         </property>
+         <property name="rightMargin">
+          <number>0</number>
+         </property>
+         <property name="bottomMargin">
+          <number>0</number>
          </property>
          <item row="0" column="0">
           <widget class="QLabel" name="label">
diff --git a/RedPandaIDE/utils.cpp b/RedPandaIDE/utils.cpp
index 4b0bd02e..19291498 100644
--- a/RedPandaIDE/utils.cpp
+++ b/RedPandaIDE/utils.cpp
@@ -1142,3 +1142,8 @@ void copyFolder(const QString &fromDir, const QString &toDir)
 }
 
 
+
+float pointToPixel(float point, float dpi)
+{
+     return point * dpi / 72;
+}
diff --git a/RedPandaIDE/utils.h b/RedPandaIDE/utils.h
index eec0816d..3de98a93 100644
--- a/RedPandaIDE/utils.h
+++ b/RedPandaIDE/utils.h
@@ -234,6 +234,7 @@ void resetCppParser(std::shared_ptr<CppParser> parser, int compilerSetIndex=-1);
 int screenDPI();
 void setScreenDPI(int dpi);
 float pointToPixel(float point);
+float pointToPixel(float point, float dpi);
 float pixelToPoint(float pixel);
 
 void copyFolder(const QString &fromDir, const QString& toDir);
diff --git a/RedPandaIDE/widgets/codecompletionpopup.cpp b/RedPandaIDE/widgets/codecompletionpopup.cpp
index 1e679cee..ef440f38 100644
--- a/RedPandaIDE/widgets/codecompletionpopup.cpp
+++ b/RedPandaIDE/widgets/codecompletionpopup.cpp
@@ -53,6 +53,9 @@ CodeCompletionPopup::CodeCompletionPopup(QWidget *parent) :
     mShowCodeSnippets = true;
 
     mIgnoreCase = false;
+
+    mHideSymbolsStartWithTwoUnderline = false;
+    mHideSymbolsStartWithUnderline = false;
 }
 
 CodeCompletionPopup::~CodeCompletionPopup()
@@ -382,6 +385,9 @@ void CodeCompletionPopup::filterList(const QString &member)
 
     mCompletionStatementList.clear();
     mCompletionStatementList.reserve(mFullCompletionStatementList.size());
+    bool hideSymbolsTwoUnderline = mHideSymbolsStartWithTwoUnderline && !member.startsWith("__") ;
+    bool hideSymbolsUnderline = mHideSymbolsStartWithUnderline && !member.startsWith("_") ;
+    int len = member.length();
     foreach (const PStatement& statement, mFullCompletionStatementList) {
 
         int matched = 0;
@@ -391,31 +397,37 @@ void CodeCompletionPopup::filterList(const QString &member)
         int lastPos = -10;
         int totalPos = 0;
         statement->matchPositions.clear();
-        foreach (const QChar& ch, member) {
-            if (mIgnoreCase)
-                pos = command.indexOf(ch,pos,Qt::CaseInsensitive);
-            else
-                pos = command.indexOf(ch,pos,Qt::CaseSensitive);
-            if (pos<0) {
-                break;
+        if (hideSymbolsTwoUnderline && statement->command.startsWith("__")) {
+
+        } else if (hideSymbolsUnderline && statement->command.startsWith("_")) {
+
+        } else {
+            foreach (const QChar& ch, member) {
+                if (mIgnoreCase)
+                    pos = command.indexOf(ch,pos,Qt::CaseInsensitive);
+                else
+                    pos = command.indexOf(ch,pos,Qt::CaseSensitive);
+                if (pos<0) {
+                    break;
+                }
+                if (pos == lastPos+1) {
+                    statement->matchPositions.last()->end++;
+                } else {
+                    PStatementMathPosition matchPosition=std::make_shared<StatementMatchPosition>();
+                    matchPosition->start = pos;
+                    matchPosition->end = pos+1;
+                    statement->matchPositions.append(matchPosition);
+                }
+                if (ch==command[pos])
+                    caseMatched++;
+                matched++;
+                totalPos += pos;
+                lastPos = pos;
+                pos+=1;
             }
-            if (pos == lastPos+1) {
-                statement->matchPositions.last()->end++;
-            } else {
-                PStatementMathPosition matchPosition=std::make_shared<StatementMatchPosition>();
-                matchPosition->start = pos;
-                matchPosition->end = pos+1;
-                statement->matchPositions.append(matchPosition);
-            }
-            if (ch==command[pos])
-                caseMatched++;
-            matched++;
-            totalPos += pos;
-            lastPos = pos;
-            pos+=1;
         }
 
-        if (mIgnoreCase && matched==member.length()) {
+        if (mIgnoreCase && matched== len) {
             statement->caseMatched = caseMatched;
             statement->matchPosTotal = totalPos;
             if (member.length()>0) {
@@ -424,7 +436,7 @@ void CodeCompletionPopup::filterList(const QString &member)
             } else
                 statement->firstMatchLength = 0;
             mCompletionStatementList.append(statement);
-        } else if (caseMatched == member.length()) {
+        } else if (caseMatched == len) {
             statement->caseMatched = caseMatched;
             statement->matchPosTotal = totalPos;
             if (member.length()>0) {
@@ -799,6 +811,26 @@ bool CodeCompletionPopup::isIncluded(const QString &fileName)
     return mIncludedFiles.contains(fileName);
 }
 
+void CodeCompletionPopup::setHideSymbolsStartWithTwoUnderline(bool newHideSymbolsStartWithTwoUnderline)
+{
+    mHideSymbolsStartWithTwoUnderline = newHideSymbolsStartWithTwoUnderline;
+}
+
+bool CodeCompletionPopup::hideSymbolsStartWithTwoUnderline() const
+{
+    return mHideSymbolsStartWithTwoUnderline;
+}
+
+bool CodeCompletionPopup::hideSymbolsStartWithUnderline() const
+{
+    return mHideSymbolsStartWithUnderline;
+}
+
+void CodeCompletionPopup::setHideSymbolsStartWithUnderline(bool newHideSymbolsStartWithUnderline)
+{
+    mHideSymbolsStartWithUnderline = newHideSymbolsStartWithUnderline;
+}
+
 const QString &CodeCompletionPopup::memberOperator() const
 {
     return mMemberOperator;
diff --git a/RedPandaIDE/widgets/codecompletionpopup.h b/RedPandaIDE/widgets/codecompletionpopup.h
index 6212159b..e05e879b 100644
--- a/RedPandaIDE/widgets/codecompletionpopup.h
+++ b/RedPandaIDE/widgets/codecompletionpopup.h
@@ -112,6 +112,11 @@ public:
     bool useCppKeyword() const;
     void setUseCppKeyword(bool newUseCppKeyword);
 
+    bool hideSymbolsStartWithUnderline() const;
+    void setHideSymbolsStartWithUnderline(bool newHideSymbolsStartWithUnderline);
+    bool hideSymbolsStartWithTwoUnderline() const;
+    void setHideSymbolsStartWithTwoUnderline(bool newHideSymbolsStartWithTwoUnderline);
+
     const PStatement &currentStatement() const;
     void setCurrentStatement(const PStatement &newCurrentStatement);
     const std::shared_ptr<QHash<StatementKind, std::shared_ptr<ColorSchemeItem> > >& colors() const;
@@ -160,6 +165,8 @@ private:
     bool mIgnoreCase;
     bool mSortByScope;
     bool mUseCppKeyword;
+    bool mHideSymbolsStartWithUnderline;
+    bool mHideSymbolsStartWithTwoUnderline;
 
     // QWidget interface
 protected:
@@ -170,6 +177,7 @@ protected:
 public:
     bool event(QEvent *event) override;
     const QString &memberOperator() const;
+
 };
 
 #endif // CODECOMPLETIONPOPUP_H
diff --git a/RedPandaIDE/widgets/cpudialog.cpp b/RedPandaIDE/widgets/cpudialog.cpp
index 46bd199f..b564b7c7 100644
--- a/RedPandaIDE/widgets/cpudialog.cpp
+++ b/RedPandaIDE/widgets/cpudialog.cpp
@@ -54,8 +54,7 @@ CPUDialog::CPUDialog(QWidget *parent) :
         ui->txtCode->setForegroundColor(palette().color(QPalette::Text));
         ui->txtCode->setBackgroundColor(palette().color(QPalette::Base));
     }
-
-    resetEditorFont();
+    resetEditorFont(screenDPI());
     ui->lstRegister->setModel(pMainWindow->debugger()->registerModel());
 
     ui->rdIntel->setChecked(pSettings->debugger().useIntelStyle());
@@ -98,6 +97,19 @@ void CPUDialog::updateButtonStates(bool enable)
     ui->btnStepOverInstruction->setEnabled(enable);
 }
 
+void CPUDialog::updateDPI(float dpi)
+{
+    QFont font(pSettings->environment().interfaceFont());
+    font.setPixelSize(pointToPixel(pSettings->environment().interfaceFontSize(),dpi));
+    font.setStyleStrategy(QFont::PreferAntialias);
+    setFont(font);
+    for (QWidget* p:findChildren<QWidget*>()) {
+        if (p!=ui->txtCode)
+            p->setFont(font);
+    }
+    resetEditorFont(dpi);
+}
+
 void CPUDialog::setDisassembly(const QString& file, const QString& funcName,const QStringList& lines)
 {
     ui->txtFunctionName->setText(QString("%1:%2").arg(file, funcName));
@@ -114,14 +126,14 @@ void CPUDialog::setDisassembly(const QString& file, const QString& funcName,cons
         ui->txtCode->setCaretXYEx(true,BufferCoord{1,activeLine+1});
 }
 
-void CPUDialog::resetEditorFont()
+void CPUDialog::resetEditorFont(float dpi)
 {
     QFont f=QFont(pSettings->editor().fontName());
-    f.setPixelSize(pointToPixel(pSettings->editor().fontSize()));
+    f.setPixelSize(pointToPixel(pSettings->editor().fontSize(),dpi));
     f.setStyleStrategy(QFont::PreferAntialias);
     ui->txtCode->setFont(f);
     QFont f2=QFont(pSettings->editor().nonAsciiFontName());
-    f2.setPixelSize(pointToPixel(pSettings->editor().fontSize()));
+    f2.setPixelSize(pointToPixel(pSettings->editor().fontSize(),dpi));
     f2.setStyleStrategy(QFont::PreferAntialias);
     ui->txtCode->setFontForNonAscii(f2);
 }
diff --git a/RedPandaIDE/widgets/cpudialog.h b/RedPandaIDE/widgets/cpudialog.h
index e66c2502..f5dc5018 100644
--- a/RedPandaIDE/widgets/cpudialog.h
+++ b/RedPandaIDE/widgets/cpudialog.h
@@ -33,8 +33,9 @@ public:
     void updateInfo();
     void updateButtonStates(bool enable);
 public slots:
+    void updateDPI(float dpi);
     void setDisassembly(const QString& file, const QString& funcName,const QStringList& lines);
-    void resetEditorFont();
+    void resetEditorFont(float dpi);
 signals:
     void closed();
 private: