Fix Qt deprecation warn for getContentsMargins()

Fixes the following warning:

  error: ‘void QWidget::getContentsMargins(int*, int*, int*, int*) const’ is deprecated: use contentsMargins() [-Werror=deprecated-declarations]

The new code also has advantages in that 'l' can be set to const and
it is more readable because it is clear that only 'l' is used.

QWidget::getContentsMargins() was deprecated in 5.14.0 [1]. and
QWidget::contentsMargins() is available since 4.6 [2].

[1] https://code.qt.io/cgit/qt/qtbase.git/tree/dist/changes-5.14.0/?h=v5.14.0
[2] https://doc.qt.io/archives/qt-4.8/qlayout.html#contentsMargins

diff --git a/src/frontends/qt/GuiView.cpp b/src/frontends/qt/GuiView.cpp
index 6890c16ad4559eb9183f158a84b16b3e00d5b890..c7a1bd94581ae211e3187b3d240f1cc722291b8e 100644 (file)
--- a/src/frontends/qt/GuiView.cpp
+++ b/src/frontends/qt/GuiView.cpp
@@ -4604,8 +4604,8 @@ bool GuiView::lfunUiToggle(string const & ui_component)
                menuBar()->setVisible(!menuBar()->isVisible());
        } else
        if (ui_component == "frame") {
-               int l, t, r, b;
-               getContentsMargins(&l, &t, &r, &b);
+               int const l = contentsMargins().left();
+
                //are the frames in default state?
                d.current_work_area_->setFrameStyle(QFrame::NoFrame);
                if (l == 0) {