Merge #15768: gui: Add close window shortcut

f5a3a5b9ab gui: Add close window shortcut (Miguel Herranz)

Pull request description:

  CMD+W is the standard shortcut in macOS to close a window without
  exiting the program.

  This adds support to use the shortcut in both main and debug windows.

ACKs for top commit:
  jonasschnelli:
    Tested ACK f5a3a5b9ab
  hebasto:
    ACK f5a3a5b9ab, tested on Linux Mint 19.3 by manually opening available dialogs and sub-windows, and applying the `Ctrl+W` shortcut. Also tested with "Minimize on close" option enabled / disabled.

Tree-SHA512: 39851f6680cf97c334d5759c6f8597cb45685359417493ff8b0566672edbd32303fa15ac4260ec8ab5ea1458a600a329153014f25609e1db9cf399aa851ae2f9

src/qt/guiutil.cpp

@@ -54,6 +54,7 @@
 #include <QSettings>
 #include <QSize>
 #include <QString>
+#include <QShortcut>
 #include <QTextDocument> // for Qt::mightBeRichText
 #include <QThread>
 #include <QUrlQuery>
@@ -378,6 +379,11 @@ void bringToFront(QWidget* w)
     }
 }
 
+void handleCloseWindowShortcut(QWidget* w)
+{
+    QObject::connect(new QShortcut(QKeySequence(Qt::CTRL + Qt::Key_W), w), &QShortcut::activated, w, &QWidget::close);
+}
+
 void openDebugLogfile()
 {
     fs::path pathDebug = GetDataDir() / "debug.log";