Unix: QPageSetupDialog: Use print device default paper size

When invoking QPageSetupDialog from QPrintPreviewDialog, don't construct
a new QPageSetupDialog every time the pageSetup action is triggered, instead
reuse the dialog if it's already been created. This way setPrinter is called
only once. This matches how QPrintDialog invokes QPageSetupDialog.

Set the default print device paper size in initPageSizes() instead of
setPrinter().

Change-Id: Ic82e6dd47ee00ecdd942c5ba59dbf09fb18ef218
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@qt.io>
Reviewed-by: Andy Shaw <andy.shaw@qt.io>

2 files changed, 24 insertions, 14 deletions

diff --git a/src/printsupport/dialogs/qpagesetupdialog_unix.cpp b/src/printsupport/dialogs/qpagesetupdialog_unix.cpp
index d9b4a84aa9..1d8af9dbf0 100644
--- a/src/printsupport/dialogs/qpagesetupdialog_unix.cpp
+++ b/src/printsupport/dialogs/qpagesetupdialog_unix.cpp
@@ -361,13 +361,21 @@ void QPageSetupWidget::initPageSizes()
         QPlatformPrinterSupport *ps = QPlatformPrinterSupportPlugin::get();
         if (ps) {
             QPrintDevice printDevice = ps->createPrintDevice(m_printerName);
+            const QPageSize defaultSize = printDevice.defaultPageSize();
             const auto pageSizes = printDevice.supportedPageSizes();
             for (const QPageSize &pageSize : pageSizes)
                 m_ui.pageSizeCombo->addItem(pageSize.name(), QVariant::fromValue(pageSize));
-            if (m_ui.pageSizeCombo->count() > 0 && printDevice.supportsCustomPageSizes()) {
-                m_ui.pageSizeCombo->addItem(tr("Custom"));
-                m_realCustomPageSizeIndex = m_ui.pageSizeCombo->count() - 1;
+            if (m_ui.pageSizeCombo->count() > 0) {
+                if (printDevice.supportsCustomPageSizes()) {
+                    m_ui.pageSizeCombo->addItem(tr("Custom"));
+                    m_realCustomPageSizeIndex = m_ui.pageSizeCombo->count() - 1;
+                }
                 m_blockSignals = false;
+
+                // If the defaultSize is index 0, setCurrentIndex won't emit the currentIndexChanged
+                // signal; workaround the issue by initially setting the currentIndex to -1
+                m_ui.pageSizeCombo->setCurrentIndex(-1);
+                m_ui.pageSizeCombo->setCurrentIndex(m_ui.pageSizeCombo->findData(QVariant::fromValue(defaultSize)));
                 return;
             }
         }
@@ -403,12 +411,6 @@ void QPageSetupWidget::setPrinter(QPrinter *printer, QPrintDevice *printDevice,
     // Initialize the layout to the current QPrinter layout
     m_pageLayout = m_printer->pageLayout();
 
-    if (printDevice) {
-        const QPageSize pageSize = printDevice->defaultPageSize();
-        const QMarginsF printable = printDevice->printableMargins(pageSize, m_pageLayout.orientation(), m_printer->resolution());
-        m_pageLayout.setPageSize(pageSize, qt_convertMargins(printable, QPageLayout::Point, m_pageLayout.units()));
-    }
-
     // Assume if margins are Points then is by default, so set to locale default units
     if (m_pageLayout.units() == QPageLayout::Point) {
         if (QLocale().measurementSystem() == QLocale::MetricSystem)
@@ -735,8 +737,12 @@ int QPageSetupDialog::exec()
     Q_D(QPageSetupDialog);
 
     int ret = QDialog::exec();
-    if (ret == Accepted)
+    if (ret == Accepted) {
         static_cast <QUnixPageSetupDialogPrivate*>(d)->widget->setupPrinter();
+        static_cast <QUnixPageSetupDialogPrivate*>(d)->widget->updateSavedValues();
+    } else {
+        static_cast <QUnixPageSetupDialogPrivate*>(d)->widget->revertToSavedValues();
+    }
     return ret;
 }
 
diff --git a/src/printsupport/dialogs/qprintpreviewdialog.cpp b/src/printsupport/dialogs/qprintpreviewdialog.cpp
index e6b665f82c..258741c35c 100644
--- a/src/printsupport/dialogs/qprintpreviewdialog.cpp
+++ b/src/printsupport/dialogs/qprintpreviewdialog.cpp
@@ -152,8 +152,8 @@ class QPrintPreviewDialogPrivate : public QDialogPrivate
     Q_DECLARE_PUBLIC(QPrintPreviewDialog)
 public:
     QPrintPreviewDialogPrivate()
-        : printDialog(nullptr), ownPrinter(false),
-          initialized(false) {}
+        : printDialog(nullptr), pageSetupDialog(nullptr),
+          ownPrinter(false), initialized(false)  {}
 
     // private slots
     void _q_fit(QAction *action);
@@ -178,6 +178,7 @@ public:
     void updateZoomFactor();
 
     QPrintDialog *printDialog;
+    QPageSetupDialog *pageSetupDialog;
     QPrintPreviewWidget *preview;
     QPrinter *printer;
     bool ownPrinter;
@@ -602,8 +603,10 @@ void QPrintPreviewDialogPrivate::_q_pageSetup()
 {
     Q_Q(QPrintPreviewDialog);
 
-    QPageSetupDialog pageSetup(printer, q);
-    if (pageSetup.exec() == QDialog::Accepted) {
+    if (!pageSetupDialog)
+        pageSetupDialog = new QPageSetupDialog(printer, q);
+
+    if (pageSetupDialog->exec() == QDialog::Accepted) {
         // update possible orientation changes
         if (preview->orientation() == QPrinter::Portrait) {
             portraitAction->setChecked(true);
@@ -713,6 +716,7 @@ QPrintPreviewDialog::~QPrintPreviewDialog()
     if (d->ownPrinter)
         delete d->printer;
     delete d->printDialog;
+    delete d->pageSetupDialog;
 }
 
 /*!