Fix sizeHint of QProgressDialog to have enough space for window margins

Some styles, notably QMacStyle, use different margins for widgets and
for windows. For these margins to be returned correctly, we have to
tell the style that we want them for a toplevel widget. This was
done correctly when laying out the dialog, but not when calculating the
sizeHint, leading to a default size of the dialog that was too small
to fit the text.

As a drive-by, change variable names in the sizeHint method to be a
bit more readable.

Change-Id: Ib4168c7be176fa816241ebcc5f9235db4a7f982f
Fixes: QTBUG-80272
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit 13bbb1d9b9411e6eb65848efa8c0d481109b8868)
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 10 insertions, 7 deletions

diff --git a/src/widgets/dialogs/qprogressdialog.cpp b/src/widgets/dialogs/qprogressdialog.cpp
index e1a6bce5b1..9507053ffe 100644
--- a/src/widgets/dialogs/qprogressdialog.cpp
+++ b/src/widgets/dialogs/qprogressdialog.cpp
@@ -708,14 +708,17 @@ void QProgressDialog::setValue(int progress)
 QSize QProgressDialog::sizeHint() const
 {
     Q_D(const QProgressDialog);
-    QSize sh = d->label ? d->label->sizeHint() : QSize(0, 0);
-    QSize bh = d->bar->sizeHint();
-    int margin = style()->pixelMetric(QStyle::PM_DefaultTopLevelMargin);
-    int spacing = style()->pixelMetric(QStyle::PM_DefaultLayoutSpacing);
-    int h = margin * 2 + bh.height() + sh.height() + spacing;
+    QSize labelSize = d->label ? d->label->sizeHint() : QSize(0, 0);
+    QSize barSize = d->bar->sizeHint();
+    int marginBottom = style()->pixelMetric(QStyle::PM_LayoutBottomMargin, 0, this);
+    int spacing = style()->pixelMetric(QStyle::PM_LayoutVerticalSpacing, 0, this);
+    int marginLeft = style()->pixelMetric(QStyle::PM_LayoutLeftMargin, 0, this);
+    int marginRight = style()->pixelMetric(QStyle::PM_LayoutRightMargin, 0, this);
+
+    int height = marginBottom * 2 + barSize.height() + labelSize.height() + spacing;
     if (d->cancel)
-        h += d->cancel->sizeHint().height() + spacing;
-    return QSize(qMax(200, sh.width() + 2 * margin), h);
+        height += d->cancel->sizeHint().height() + spacing;
+    return QSize(qMax(200, labelSize.width() + marginLeft + marginRight), height);
 }
 
 /*!\reimp