diff --git a/.gitignore b/.gitignore
index 50258e8d..bed905dd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,7 @@
 *.pro.user.*
 .ccls
 compile_commands.json
+compile_commands.json.*
 compile_flags.txt
 .cache
 .tasks
diff --git a/src/widgets/attachmentpopup.cpp b/src/widgets/attachmentpopup.cpp
index edcc15a8..311a08b3 100644
--- a/src/widgets/attachmentpopup.cpp
+++ b/src/widgets/attachmentpopup.cpp
@@ -29,8 +29,7 @@
 using namespace vnotex;
 
 AttachmentPopup::AttachmentPopup(QToolButton *p_btn, QWidget *p_parent)
-    : QMenu(p_parent),
-      m_button(p_btn)
+    : ButtonPopup(p_btn, p_parent)
 {
     setupUI();
 
@@ -68,7 +67,7 @@ void AttachmentPopup::setupUI()
                         const auto destFolderPath = getDestFolderPath();
 
                         auto &sessionConfig = ConfigMgr::getInst().getSessionConfig();
-                        auto files = QFileDialog::getOpenFileNames(this,
+                        auto files = QFileDialog::getOpenFileNames(nullptr,
                                                                    tr("Select Files As Attachments"),
                                                                    sessionConfig.getExternalMediaDefaultPath());
                         if (files.isEmpty()) {
@@ -206,12 +205,7 @@ void AttachmentPopup::setupUI()
 
     widget->setMinimumSize(320, 384);
 
-
-    auto act = new QWidgetAction(this);
-    // @act will own @p_widget.
-    act->setDefaultWidget(widget);
-    addAction(act);
-
+    addWidget(widget);
 }
 
 QToolButton *AttachmentPopup::createButton()
diff --git a/src/widgets/attachmentpopup.h b/src/widgets/attachmentpopup.h
index 2a4d062f..e73205d2 100644
--- a/src/widgets/attachmentpopup.h
+++ b/src/widgets/attachmentpopup.h
@@ -1,16 +1,14 @@
 #ifndef ATTACHMENTPOPUP_H
 #define ATTACHMENTPOPUP_H
 
-#include <QMenu>
-
-class QToolButton;
+#include "buttonpopup.h"
 
 namespace vnotex
 {
     class FileSystemViewer;
     class Buffer;
 
-    class AttachmentPopup : public QMenu
+    class AttachmentPopup : public ButtonPopup
     {
         Q_OBJECT
     public:
@@ -43,9 +41,6 @@ namespace vnotex
         FileSystemViewer *m_viewer = nullptr;
 
         bool m_needUpdateAttachmentFolder = true;
-
-        // Button for this menu.
-        QToolButton *m_button = nullptr;
     };
 }
 
diff --git a/src/widgets/buttonpopup.cpp b/src/widgets/buttonpopup.cpp
index 44de5f3f..fba5304f 100644
--- a/src/widgets/buttonpopup.cpp
+++ b/src/widgets/buttonpopup.cpp
@@ -1,6 +1,6 @@
 #include "buttonpopup.h"
 
-#include <QVBoxLayout>
+#include <QWidgetAction>
 
 #include <utils/widgetutils.h>
 
@@ -10,8 +10,6 @@ ButtonPopup::ButtonPopup(QToolButton *p_btn, QWidget *p_parent)
     : QMenu(p_parent),
       m_button(p_btn)
 {
-    setupUI();
-
 #if defined(Q_OS_MACOS) || defined(Q_OS_MAC)
     // Qt::Popup on macOS does not work well with input method.
     setWindowFlags(Qt::Tool | Qt::NoDropShadowWindowHint);
@@ -19,16 +17,10 @@ ButtonPopup::ButtonPopup(QToolButton *p_btn, QWidget *p_parent)
 #endif
 }
 
-void ButtonPopup::setupUI()
+void ButtonPopup::addWidget(QWidget *p_widget)
 {
-    auto mainLayout = new QVBoxLayout(this);
-    WidgetUtils::setContentsMargins(mainLayout);
-}
-
-void ButtonPopup::setCentralWidget(QWidget *p_widget)
-{
-    Q_ASSERT(p_widget);
-    auto mainLayout = layout();
-    Q_ASSERT(mainLayout->count() == 0);
-    mainLayout->addWidget(p_widget);
+    auto act = new QWidgetAction(this);
+    // @act will own @p_widget.
+    act->setDefaultWidget(p_widget);
+    addAction(act);
 }
diff --git a/src/widgets/buttonpopup.h b/src/widgets/buttonpopup.h
index ce29ae96..a8d22120 100644
--- a/src/widgets/buttonpopup.h
+++ b/src/widgets/buttonpopup.h
@@ -15,10 +15,7 @@ namespace vnotex
         ButtonPopup(QToolButton *p_btn, QWidget *p_parent = nullptr);
 
     protected:
-        void setCentralWidget(QWidget *p_widget);
-
-    private:
-        void setupUI();
+        void addWidget(QWidget *p_widget);
 
         // Button for this menu.
         QToolButton *m_button = nullptr;
diff --git a/src/widgets/outlinepopup.cpp b/src/widgets/outlinepopup.cpp
index 31fedbf0..d4c1cdd7 100644
--- a/src/widgets/outlinepopup.cpp
+++ b/src/widgets/outlinepopup.cpp
@@ -1,8 +1,6 @@
 #include "outlinepopup.h"
 
-#include <QVBoxLayout>
 #include <QToolButton>
-#include <QWidgetAction>
 
 #include <core/global.h>
 #include <utils/widgetutils.h>
@@ -11,8 +9,7 @@
 using namespace vnotex;
 
 OutlinePopup::OutlinePopup(QToolButton *p_btn, QWidget *p_parent)
-    : QMenu(p_parent),
-      m_button(p_btn)
+    : ButtonPopup(p_btn, p_parent)
 {
     setupUI();
 
@@ -26,13 +23,7 @@ void OutlinePopup::setupUI()
 {
     m_viewer = new OutlineViewer(tr("Outline"), this);
     m_viewer->setMinimumSize(320, 384);
-
-    auto act = new QWidgetAction(this);
-    // @act will own @p_widget.
-    act->setDefaultWidget(m_viewer);
-    addAction(act);
-
-
+    addWidget(m_viewer);
 }
 
 void OutlinePopup::setOutlineProvider(const QSharedPointer<OutlineProvider> &p_provider)
@@ -42,7 +33,7 @@ void OutlinePopup::setOutlineProvider(const QSharedPointer<OutlineProvider> &p_p
 
 void OutlinePopup::showEvent(QShowEvent* p_event)
 {
-    QMenu::showEvent(p_event);
+    ButtonPopup::showEvent(p_event);
 
     // Move it to be right-aligned.
     if (m_button->isVisible()) {
diff --git a/src/widgets/outlinepopup.h b/src/widgets/outlinepopup.h
index 437e803d..1b519239 100644
--- a/src/widgets/outlinepopup.h
+++ b/src/widgets/outlinepopup.h
@@ -1,7 +1,8 @@
 #ifndef OUTLINEPOPUP_H
 #define OUTLINEPOPUP_H
 
-#include <QMenu>
+#include "buttonpopup.h"
+
 #include <QSharedPointer>
 
 class QToolButton;
@@ -11,7 +12,7 @@ namespace vnotex
     class OutlineProvider;
     class OutlineViewer;
 
-    class OutlinePopup : public QMenu
+    class OutlinePopup : public ButtonPopup
     {
         Q_OBJECT
     public:
@@ -27,9 +28,6 @@ namespace vnotex
 
         // Managed by QObject.
         OutlineViewer *m_viewer = nullptr;
-
-        // Button with this menu.
-        QToolButton *m_button = nullptr;
     };
 }
 
diff --git a/src/widgets/tagpopup.cpp b/src/widgets/tagpopup.cpp
index 89d25817..9f9b03fb 100644
--- a/src/widgets/tagpopup.cpp
+++ b/src/widgets/tagpopup.cpp
@@ -1,9 +1,5 @@
 #include "tagpopup.h"
 
-#include <QHBoxLayout>
-#include <QVBoxLayout>
-#include <QWidgetAction>
-
 #include <utils/widgetutils.h>
 #include <buffer/buffer.h>
 
@@ -31,14 +27,8 @@ TagPopup::TagPopup(QToolButton *p_btn, QWidget *p_parent)
 void TagPopup::setupUI()
 {
     m_tagViewer = new TagViewer(true, this);
-    //setCentralWidget(m_tagViewer);
-
     m_tagViewer->setMinimumSize(256, 320);
-
-    auto act = new QWidgetAction(this);
-    // @act will own @p_widget.
-    act->setDefaultWidget(m_tagViewer);
-    addAction(act);
+    addWidget(m_tagViewer);
 }
 
 void TagPopup::setBuffer(Buffer *p_buffer)
diff --git a/src/widgets/wordcountpopup.cpp b/src/widgets/wordcountpopup.cpp
index e9d0b7b5..0d6e3a67 100644
--- a/src/widgets/wordcountpopup.cpp
+++ b/src/widgets/wordcountpopup.cpp
@@ -4,7 +4,6 @@
 #include <QLabel>
 #include <QGroupBox>
 #include <QPointer>
-#include <QWidgetAction>
 
 #include <utils/widgetutils.h>
 
@@ -72,10 +71,5 @@ void WordCountPopup::updateCount(const ViewWindow::WordCountInfo &p_info)
 void WordCountPopup::setupUI()
 {
     m_panel = new WordCountPanel(this);
-
-
-    auto act = new QWidgetAction(this);
-    // @act will own @p_widget.
-    act->setDefaultWidget(m_panel);
-    addAction(act);
+    addWidget(m_panel);
 }