From 4d15a2fa4833201a8c33c995f05113ed64f5c795 Mon Sep 17 00:00:00 2001
From: wh201906 <wh201906@yandex.com>
Date: Sun, 21 May 2023 13:48:48 +0800
Subject: [PATCH] Change theme without restarting app

For issue #29
---
 src/main.cpp          | 25 -------------------------
 src/mainwindow.cpp    | 27 +++++++++++++++++++++++++++
 src/mainwindow.h      |  3 +++
 src/settingstab.cpp   |  5 ++++-
 src/settingstab.h     |  1 +
 src/ui/settingstab.ui |  2 +-
 6 files changed, 36 insertions(+), 27 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index 824f704..df80108 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -97,31 +97,6 @@ int main(int argc, char *argv[])
     QString theme = m_settings->value("Theme_Name").toString();
     m_settings->endGroup();
 
-    QFile* themeFile = new QFile();
-    QTextStream* themeStream = new QTextStream();
-    QString qssString = a.styleSheet(); // default behavior
-    if(theme == "(none)")
-        ;
-    else if(theme == "qdss_dark")
-    {
-        themeFile->setFileName(":/qdarkstyle/dark/darkstyle.qss");
-        themeFile->open(QFile::ReadOnly | QFile::Text);
-        themeStream->setDevice(themeFile);
-        qssString = themeStream->readAll();
-    }
-    else if(theme == "qdss_light")
-    {
-        themeFile->setFileName(":/qdarkstyle/light/lightstyle.qss");
-        themeFile->open(QFile::ReadOnly | QFile::Text);
-        themeStream->setDevice(themeFile);
-        qssString = themeStream->readAll();
-    }
-    a.setStyleSheet(qssString);
-    delete themeFile;
-    delete themeStream;
-    themeFile = nullptr;
-    themeStream = nullptr;
-
     m_settings = nullptr;
 
     MainWindow w;
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 7c6b0f2..26b15bb 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -14,6 +14,8 @@ MainWindow::MainWindow(QWidget *parent)
     , ui(new Ui::MainWindow)
 {
     ui->setupUi(this);
+    // might not be empty(specified by -stylesheet option)
+    m_appDefaultQss = qApp->styleSheet();
     contextMenu = new QMenu();
 
     IOConnection = new Connection();
@@ -77,6 +79,7 @@ MainWindow::MainWindow(QWidget *parent)
     ui->funcTab->insertTab(4, fileTab, tr("File"));
 
     settingsTab = new SettingsTab();
+    connect(settingsTab, &SettingsTab::themeChanged, this, &MainWindow::onThemeChanged);
     connect(settingsTab, &SettingsTab::opacityChanged, this, &MainWindow::onOpacityChanged); // not a slot function, but works fine.
     connect(settingsTab, &SettingsTab::fullScreenStateChanged, this, &MainWindow::setFullScreen);
     connect(settingsTab, &SettingsTab::updateAvailableDeviceTypes, deviceTab, &DeviceTab::getAvailableTypes);
@@ -532,6 +535,30 @@ void MainWindow::onOpacityChanged(qreal value)
     }
 }
 
+void MainWindow::onThemeChanged(const QString& themeName)
+{
+    QFile themeFile;
+    QTextStream themeStream;
+    QString qssString = qApp->styleSheet(); // default behavior
+    if(themeName == "(none)")
+        qssString = m_appDefaultQss;
+    else if(themeName == "qdss_dark")
+    {
+        themeFile.setFileName(":/qdarkstyle/dark/darkstyle.qss");
+        themeFile.open(QFile::ReadOnly | QFile::Text);
+        themeStream.setDevice(&themeFile);
+        qssString = themeStream.readAll();
+    }
+    else if(themeName == "qdss_light")
+    {
+        themeFile.setFileName(":/qdarkstyle/light/lightstyle.qss");
+        themeFile.open(QFile::ReadOnly | QFile::Text);
+        themeStream.setDevice(&themeFile);
+        qssString = themeStream.readAll();
+    }
+    qApp->setStyleSheet(qssString);
+}
+
 void MainWindow::dockInit()
 {
     setDockNestingEnabled(true);
diff --git a/src/mainwindow.h b/src/mainwindow.h
index 1c0a0d0..1480084 100644
--- a/src/mainwindow.h
+++ b/src/mainwindow.h
@@ -56,6 +56,7 @@ public slots:
     void showUpTab(int tabID);
     void setFullScreen(bool isFullScreen);
     void onOpacityChanged(qreal value);
+    void onThemeChanged(const QString& themeName);
     void onDockTopLevelChanged(bool topLevel); // for opacity
 
 protected:
@@ -113,6 +114,8 @@ private slots:
     SettingsTab* settingsTab;
     QList<QDockWidget*> dockList;
 
+    QString m_appDefaultQss;
+
 #ifndef Q_OS_ANDROID
     QCheckBox* onTopBox;
 
diff --git a/src/settingstab.cpp b/src/settingstab.cpp
index ecbf3cb..8e7fadb 100644
--- a/src/settingstab.cpp
+++ b/src/settingstab.cpp
@@ -231,6 +231,7 @@ void SettingsTab::loadPreference()
     on_Android_forceLandscapeBox_clicked();
     // Android_dockBox only affect the config file
 #else
+    on_Theme_setButton_clicked();
     on_Opacity_Box_valueChanged(ui->Opacity_Box->value());
 #endif
     if(fontValid)
@@ -338,8 +339,10 @@ void SettingsTab::on_Conf_exportButton_clicked()
 
 void SettingsTab::on_Theme_setButton_clicked()
 {
+    QString themeName = ui->Theme_nameBox->currentData().toString();
     m_settings->beginGroup("SerialTest");
-    m_settings->setValue("Theme_Name", ui->Theme_nameBox->currentData().toString());
+    m_settings->setValue("Theme_Name", themeName);
     m_settings->endGroup();
+    emit themeChanged(themeName);
 }
 
diff --git a/src/settingstab.h b/src/settingstab.h
index f002e6c..1e161e7 100644
--- a/src/settingstab.h
+++ b/src/settingstab.h
@@ -59,6 +59,7 @@ private slots:
     MySettings* m_settings;
     void createConfFile(const QString &path, bool overwrite = false);
 signals:
+    void themeChanged(const QString& themeName);
     void opacityChanged(qreal value);
     void fontChanged(QFont font);
     void fullScreenStateChanged(bool isFullScreen);
diff --git a/src/ui/settingstab.ui b/src/ui/settingstab.ui
index 2d27d40..b0898e5 100644
--- a/src/ui/settingstab.ui
+++ b/src/ui/settingstab.ui
@@ -322,7 +322,7 @@ If no config file is detected, This app will create one in the current working d
             <item>
              <widget class="QLabel" name="label_9">
               <property name="text">
-               <string>Theme *:</string>
+               <string>Theme:</string>
               </property>
              </widget>
             </item>