fix: frameless window - all corners rounded + resize fixed

- CentralWidget with bottom-left/bottom-right radius 8px
- Event filter on central widget to forward mouse events for resize
- Consolidated windowFlags (Qt::Window | Frameless | MinMax | Close)
- setMouseTracking(true) for cursor updates
- Removed WA_TranslucentBackground causing black corners
- Status bar fully removed (setStatusBar(nullptr))

src/ui/mainmainwindow.cpp

@@ -24,25 +24,23 @@ MainMainWindow::MainMainWindow(QWidget *parent)
     : QMainWindow(parent), m_currentFolderId(-1), m_currentMailId(-1)
 {
     qDebug() << "[MainMainWindow] Constructor start";
+    // Enable mouse tracking for resize cursor
+    setMouseTracking(true);
     setupUI();
     qDebug() << "[MainMainWindow] setupUI done";
     connectModels();
     qDebug() << "[MainMainWindow] connectModels done";
     setWindowTitle("Wino Mail DTK");
     resize(1280, 820);
-    // Setup progress bar in status bar
-    m_progressBar = new QProgressBar(this);
-    m_progressBar->setMaximumWidth(120);
-    m_progressBar->setVisible(false);
-    statusBar()->addPermanentWidget(m_progressBar);
+    // Note: status bar is removed in createTitleBar(), no progress bar in status bar
     // Connect mail service progress/status signals
     connect(m_mailService, &MailService::progressChanged, this, &MainMainWindow::onProgressChanged);
     connect(m_mailService, &MailService::statusMessage, this, &MainMainWindow::onStatusMessage);
     connect(m_mailService, &MailService::mailSent, this, [this](const QString &) {
-        statusBar()->showMessage(tr("Message sent"), 5000);
+        // statusBar()->showMessage(tr("Message sent"), 5000); // no status bar
     });
     connect(m_mailService, &MailService::mailSendFailed, this, [this](const QString &, const QString &error) {
-        statusBar()->showMessage(tr("Send failed: %1").arg(error), 8000);
+        // statusBar()->showMessage(tr("Send failed: %1").arg(error), 8000); // no status bar
     });
     // Provide account service to settings view
     m_settingsView->setAccountService(m_accountService);
@@ -66,6 +64,16 @@ void MainMainWindow::setupUI()
 
     // === Central widget ===
     QWidget *central = new QWidget();
+    central->setObjectName("CentralWidget");
+    central->setStyleSheet(
+        "QWidget#CentralWidget {"
+        "   background-color: #f5f5f7;"
+        "   border-bottom-left-radius: 8px;"
+        "   border-bottom-right-radius: 8px;"
+        "}"
+    );
+    // Install event filter to handle resize from window edges
+    central->installEventFilter(this);
     QHBoxLayout *centralLayout = new QHBoxLayout(central);
     centralLayout->setContentsMargins(0, 0, 0, 0);
     centralLayout->setSpacing(0);
@@ -590,10 +598,9 @@ void MainMainWindow::showTemplatesManager()
 void MainMainWindow::createTitleBar()
 {
     // Enable frameless window
-    setWindowFlags(Qt::FramelessWindowHint | Qt::WindowMinMaxButtonsHint | Qt::WindowCloseButtonHint);
+    Qt::WindowFlags flags = Qt::Window | Qt::FramelessWindowHint | Qt::WindowMinMaxButtonsHint | Qt::WindowCloseButtonHint;
+    setWindowFlags(flags);
 
-    // Set Resizeable
-    setWindowFlags(windowFlags() | Qt::WindowMaximizeButtonHint);
 #ifdef Q_OS_WIN
     HWND hwnd = (HWND)this->winId();
     DWORD style = ::GetWindowLong(hwnd, GWL_STYLE);
@@ -601,10 +608,10 @@ void MainMainWindow::createTitleBar()
 #endif
 
     // Remove status bar (item 4)
-    //setStatusBar(nullptr);
+    setStatusBar(nullptr);
 
     // Apply rounded corners and border to main window (items 1, 2)
-    setAttribute(Qt::WA_TranslucentBackground);
+    // Use mask for rounded corners instead of WA_TranslucentBackground to avoid black corners
     setStyleSheet(
         "MainMainWindow {"
         "   background-color: #f5f5f7;"
@@ -896,18 +903,40 @@ void MainMainWindow::changeEvent(QEvent *event)
 
 void MainMainWindow::onProgressChanged(int percent)
 {
-    if (percent < 0 || percent > 100) {
-        m_progressBar->setVisible(false);
-        return;
+    Q_UNUSED(percent);
+    // No progress bar in status bar anymore
+}
+
+bool MainMainWindow::eventFilter(QObject *watched, QEvent *event)
+{
+    // Handle resize from central widget edges
+    if (watched == centralWidget()) {
+        if (event->type() == QEvent::MouseButtonPress) {
+            QMouseEvent *me = static_cast<QMouseEvent*>(event);
+            if (me->button() == Qt::LeftButton) {
+                // Forward to main window's mousePressEvent
+                mousePressEvent(me);
+                return true;
+            }
+        } else if (event->type() == QEvent::MouseMove) {
+            QMouseEvent *me = static_cast<QMouseEvent*>(event);
+            mouseMoveEvent(me);
+            return true;
+        } else if (event->type() == QEvent::MouseButtonRelease) {
+            QMouseEvent *me = static_cast<QMouseEvent*>(event);
+            if (me->button() == Qt::LeftButton) {
+                mouseReleaseEvent(me);
+                return true;
+            }
+        }
     }
-    m_progressBar->setValue(percent);
-    m_progressBar->setVisible(true);
+    return QMainWindow::eventFilter(watched, event);
 }
 
 void MainMainWindow::onStatusMessage(const QString &msg)
 {
-    // Show temporary message in status bar (timeout 5000 ms)
-    statusBar()->showMessage(msg, 5000);
+    Q_UNUSED(msg);
+    // No status bar anymore
 }
 
 void MainMainWindow::onAddAccountRequested()

src/ui/mainmainwindow.h

@@ -42,6 +42,7 @@ protected:
     void mouseReleaseEvent(QMouseEvent *event) override;
     bool nativeEvent(const QByteArray &eventType, void *message, qintptr *result) override;
     void changeEvent(QEvent *event) override;
+    bool eventFilter(QObject *watched, QEvent *event) override;
 
 private slots:
     void onNavChanged(int index);
@@ -144,6 +145,4 @@ private:
 
     int m_currentFolderId;
     int m_currentMailId;
-
-    QProgressBar *m_progressBar;
 };