basic theme changing

ui/widgets/settings/pageappearance.cpp

@@ -1,13 +1,42 @@
 #include "pageappearance.h"
 #include "ui_pageappearance.h"
 
+#include <QDebug>
+
 PageAppearance::PageAppearance(QWidget* parent):
     QWidget(parent),
-    m_ui(new Ui::PageAppearance())
+    m_ui(new Ui::PageAppearance()),
+    styles()
 {
     m_ui->setupUi(this);
+
+    m_ui->themeInput->addItem(tr("System"));
+    styles.push_back("system");
+    QStringList themes = QStyleFactory::keys();
+    for (const QString& key : themes) {
+        m_ui->themeInput->addItem(key);
+        styles.push_back(key);
+    }
+
+    QSettings settings;
+    QVariant vtheme = settings.value("theme");
+    if (vtheme.isValid()) {
+        QString theme = vtheme.toString();
+        m_ui->themeInput->setCurrentText(theme);
+    } else {
+        m_ui->themeInput->setCurrentText("System");
+    }
+
+    connect(m_ui->themeInput, qOverload<int>(&QComboBox::currentIndexChanged), this, &PageAppearance::onThemeChanged);
 }
 
 PageAppearance::~PageAppearance()
 {
 }
+
+void PageAppearance::onThemeChanged(int index)
+{
+    if (index >= 0) {
+        emit variableModified("theme", styles[index]);
+    }
+}

ui/widgets/settings/pageappearance.h

@@ -3,6 +3,10 @@
 
 #include <QWidget>
 #include <QScopedPointer>
+#include <QStyleFactory>
+#include <QVariant>
+#include <QSettings>
+#include <vector>
 
 namespace Ui
 {
@@ -19,8 +23,15 @@ public:
     PageAppearance(QWidget* parent = nullptr);
     ~PageAppearance();
 
+signals:
+    void variableModified(const QString& key, const QVariant& value);
+
+protected slots:
+    void onThemeChanged(int index);
+
 private:
     QScopedPointer<Ui::PageAppearance> m_ui;
+    std::vector<QString> styles;
 };
 
 #endif // PAGEAPPEARANCE_H

ui/widgets/settings/pagegeneral.h

@@ -3,6 +3,7 @@
 
 #include <QWidget>
 #include <QScopedPointer>
+#include <QVariant>
 
 namespace Ui
 {
@@ -19,6 +20,9 @@ public:
     PageGeneral(QWidget* parent = nullptr);
     ~PageGeneral();
 
+signals:
+    void variableModified(const QString& key, const QVariant& value);
+
 private:
     QScopedPointer<Ui::PageGeneral> m_ui;
 };

ui/widgets/settings/settings.cpp

@@ -3,11 +3,19 @@
 
 Settings::Settings(QWidget* parent):
     QWidget(parent),
-    m_ui(new Ui::Settings())
+    m_ui(new Ui::Settings()),
+    modifiedSettings()
 {
     m_ui->setupUi(this);
 
     connect(m_ui->list, &QListWidget::currentItemChanged, this, &Settings::onCurrentPageChanged);
+
+    connect(m_ui->General, &PageGeneral::variableModified, this, &Settings::onVariableModified);
+    connect(m_ui->Appearance, &PageAppearance::variableModified, this, &Settings::onVariableModified);
+
+    connect(m_ui->applyButton, &QPushButton::clicked, this, &Settings::apply);
+    connect(m_ui->okButton, &QPushButton::clicked, this, &Settings::confirm);
+    connect(m_ui->cancelButton, &QPushButton::clicked, this, &Settings::close);
 }
 
 Settings::~Settings()
@@ -22,3 +30,33 @@ void Settings::onCurrentPageChanged(QListWidgetItem* current)
         m_ui->content->setCurrentIndex(m_ui->list->currentRow());
     }
 }
+
+void Settings::onVariableModified(const QString& key, const QVariant& value)
+{
+    modifiedSettings[key] = value;
+}
+
+void Settings::apply()
+{
+    QSettings settings;
+    for (const std::pair<const QString, QVariant>& pair: modifiedSettings) {
+        if (pair.first == "theme") {
+            QString theme = pair.second.toString();
+            if (theme.toLower() == "system") {
+                QApplication::setStyle(Shared::Global::getInstance()->defaultSystemStyle);
+            } else {
+                QApplication::setStyle(theme);
+            }
+        }
+
+        settings.setValue(pair.first, pair.second);
+    }
+
+    modifiedSettings.clear();
+}
+
+void Settings::confirm()
+{
+    apply();
+    close();
+}

ui/widgets/settings/settings.h

@@ -4,6 +4,9 @@
 #include <QWidget>
 #include <QListWidgetItem>
 #include <QScopedPointer>
+#include <QSettings>
+
+#include "shared/global.h"
 
 namespace Ui
 {
@@ -20,11 +23,17 @@ public:
     Settings(QWidget* parent = nullptr);
     ~Settings();
 
+public slots:
+    void apply();
+    void confirm();
+
 protected slots:
     void onCurrentPageChanged(QListWidgetItem* current);
+    void onVariableModified(const QString& key, const QVariant& value);
 
 private:
     QScopedPointer<Ui::Settings> m_ui;
+    std::map<QString, QVariant> modifiedSettings;
 };
 
 #endif // SETTINGS_H