Create a new SizeGrip class, so that we can force the size-grip on the main window to have the same height as toolbuttons - this makes it align to the bottom.

widgets/sizegrip.cpp

@@ -0,0 +1,52 @@
+/*
+ * Cantata
+ *
+ * Copyright (c) 2011-2013 Craig Drummond <craig.p.drummond@gmail.com>
+ *
+ * ----
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "sizegrip.h"
+#include <QToolButton>
+#include <QIcon>
+
+SizeGrip::SizeGrip(QWidget *parent)
+    : QSizeGrip(parent)
+{
+}
+
+QSize SizeGrip::sizeHint() const
+{
+    // Some styles, suach as MacOSX, do no have the size-grip
+    // However, we still want the same space taken up on the toolbar - so that 'clear playqueue'
+    // is not righ ti nth ebottom-right corner.
+    //
+    // Also, we want the size-grip to have the same height as a toolbutton - so that it is aligned
+    // to the bottom of the main window.
+    //
+    // Overriding sizeHint() as follows, fixes both these issues.
+    if (!sh.isValid()) {
+        sh=QSizeGrip::sizeHint();
+        QToolButton tb(parentWidget());
+        tb.setToolButtonStyle(Qt::ToolButtonIconOnly);
+        tb.setIcon(QIcon::fromTheme("ok"));
+        QSize tbSize=tb.sizeHint();
+        sh=QSize(sh.width()>2 ? sh.width() : tbSize.width(), tbSize.height());
+    }
+    return sh;
+}