Support multiple page ranges in QPrinter

Add a new QRangeCollection type to store and manage
multiple page ranges. This moves out the parser and validator
logic from the platform dependent (UNIX) dialog and makes it
publicly available from QPrinter.

This improves the usability of QPrinter in those applications
which doesn't use print dialog to configure printer.
(e.g.: QTextDocument, QWebEnginePage)

Change-Id: I0be5a8a64781c411f83b96a24f216605a84958e5
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

3 files changed, 28 insertions, 96 deletions

diff --git a/src/printsupport/dialogs/qprintdialog_unix.cpp b/src/printsupport/dialogs/qprintdialog_unix.cpp
index a59d8bbb4a..cc6694d471 100644
--- a/src/printsupport/dialogs/qprintdialog_unix.cpp
+++ b/src/printsupport/dialogs/qprintdialog_unix.cpp
@@ -59,6 +59,7 @@
 #include <QtWidgets/qstyleditemdelegate.h>
 #include <QtWidgets/qformlayout.h>
 #include <QtPrintSupport/qprinter.h>
+#include <QtGui/qrangecollection.h>
 
 #include <qpa/qplatformprintplugin.h>
 #include <qpa/qplatformprintersupport.h>
@@ -745,85 +746,6 @@ void QPrintDialogPrivate::selectPrinter(const QPrinter::OutputFormat outputForma
 }
 
 #if QT_CONFIG(cups)
-static std::vector<std::pair<int, int>> pageRangesFromString(const QString &pagesString) noexcept
-{
-    std::vector<std::pair<int, int>> result;
-    const QStringList items = pagesString.split(',');
-    for (const QString &item : items) {
-        if (item.isEmpty())
-            return {};
-
-        if (item.contains(QLatin1Char('-'))) {
-            const QStringList rangeItems = item.split('-');
-            if (rangeItems.count() != 2)
-                return {};
-
-            bool ok;
-            const int number1 = rangeItems[0].toInt(&ok);
-            if (!ok)
-                return {};
-
-            const int number2 = rangeItems[1].toInt(&ok);
-            if (!ok)
-                return {};
-
-            if (number1 < 1 || number2 < 1 || number2 < number1)
-                return {};
-
-            result.push_back(std::make_pair(number1, number2));
-
-        } else {
-            bool ok;
-            const int number = item.toInt(&ok);
-            if (!ok)
-                return {};
-
-            if (number < 1)
-                return {};
-
-            result.push_back(std::make_pair(number, number));
-        }
-    }
-
-    // check no range intersects with the next
-    std::sort(result.begin(), result.end(),
-              [](const std::pair<int, int> &it1, const std::pair<int, int> &it2) { return it1.first < it2.first; });
-    int previousSecond = -1;
-    for (auto pair : result) {
-        if (pair.first <= previousSecond)
-            return {};
-
-        previousSecond = pair.second;
-    }
-
-    return result;
-}
-
-static QString stringFromPageRanges(const std::vector<std::pair<int, int>> &pageRanges) noexcept
-{
-    QString result;
-
-    for (auto pair : pageRanges) {
-        if (!result.isEmpty())
-            result += QLatin1Char(',');
-
-        if (pair.first == pair.second)
-            result += QString::number(pair.first);
-        else
-            result += QStringLiteral("%1-%2").arg(pair.first).arg(pair.second);
-    }
-
-    return result;
-}
-
-static bool isValidPagesString(const QString &pagesString) noexcept
-{
-    if (pagesString.isEmpty())
-        return false;
-
-    auto pagesRanges = pageRangesFromString(pagesString);
-    return !pagesRanges.empty();
-}
 
 void QPrintDialogPrivate::updatePpdDuplexOption(QRadioButton *radio)
 {
@@ -894,13 +816,11 @@ void QPrintDialogPrivate::setupPrinter()
 
 #if QT_CONFIG(cups)
     if (options.pagesRadioButton->isChecked()) {
-        auto pageRanges = pageRangesFromString(options.pagesLineEdit->text());
-
-        p->setPrintRange(QPrinter::AllPages);
-        p->setFromTo(0, 0);
+        p->setPrintRange(QPrinter::PageRange);
+        p->rangeCollection()->parse(options.pagesLineEdit->text());
 
         // server-side page filtering
-        QCUPSSupport::setPageRange(p, stringFromPageRanges(pageRanges));
+        QCUPSSupport::setPageRange(p, p->rangeCollection()->toString());
     }
 
     // page set
@@ -1100,7 +1020,7 @@ void QPrintDialog::accept()
 {
     Q_D(QPrintDialog);
 #if QT_CONFIG(cups)
-    if (d->options.pagesRadioButton->isChecked() && !isValidPagesString(d->options.pagesLineEdit->text())) {
+    if (d->options.pagesRadioButton->isChecked() && printer()->rangeCollection()->isEmpty()) {
         QMessageBox::critical(this, tr("Invalid Pages Definition"),
                               tr("%1 does not follow the correct syntax. Please use ',' to separate "
                               "ranges and pages, '-' to define ranges and make sure ranges do "
diff --git a/src/printsupport/kernel/qprinter.cpp b/src/printsupport/kernel/qprinter.cpp
index fbf5e5c2ba..25855d6da7 100644
--- a/src/printsupport/kernel/qprinter.cpp
+++ b/src/printsupport/kernel/qprinter.cpp
@@ -49,6 +49,7 @@
 #include "qlist.h"
 #include <qcoreapplication.h>
 #include <qfileinfo.h>
+#include <QtGui/qrangecollection.h>
 
 #include <private/qpagedpaintdevice_p.h>
 
@@ -1981,12 +1982,12 @@ void QPrinter::setPrinterSelectionOption(const QString &option)
     \note If fromPage() and toPage() both return 0, this indicates that
     \e{the whole document will be printed}.
 
-    \sa setFromTo(), toPage()
+    \sa setFromTo(), toPage(), rangeCollection()
 */
 
 int QPrinter::fromPage() const
 {
-    return d->fromPage;
+    return d->rangeCollection->firstPage();
 }
 
 /*!
@@ -2005,12 +2006,12 @@ int QPrinter::fromPage() const
     The programmer is responsible for reading this setting and
     printing accordingly.
 
-    \sa setFromTo(), fromPage()
+    \sa setFromTo(), fromPage(), rangeCollection()
 */
 
 int QPrinter::toPage() const
 {
-    return d->toPage;
+    return d->rangeCollection->lastPage();
 }
 
 /*!
@@ -2027,17 +2028,25 @@ int QPrinter::toPage() const
     This function is mostly used to set a default value that the user can
     override in the print dialog when you call setup().
 
-    \sa fromPage(), toPage()
+    \sa fromPage(), toPage(), rangeCollection()
 */
 
 void QPrinter::setFromTo(int from, int to)
 {
-    if (from > to) {
-        qWarning("QPrinter::setFromTo: 'from' must be less than or equal to 'to'");
-        from = to;
-    }
-    d->fromPage = from;
-    d->toPage = to;
+    d->rangeCollection->clear();
+    d->rangeCollection->addRange(from, to);
+}
+
+/*!
+    \since 6.0
+
+    Returns the range collection associated with this device.
+
+    \sa QRangeCollection, fromPage(), toPage()
+*/
+QRangeCollection *QPrinter::rangeCollection()
+{
+    return d->rangeCollection;
 }
 
 /*!
diff --git a/src/printsupport/kernel/qprinter.h b/src/printsupport/kernel/qprinter.h
index 28dca78a63..e606ceba47 100644
--- a/src/printsupport/kernel/qprinter.h
+++ b/src/printsupport/kernel/qprinter.h
@@ -56,6 +56,7 @@ QT_BEGIN_NAMESPACE
 #endif
 
 class QPrinterPrivate;
+class QRangeCollection;
 class QPaintEngine;
 class QPrintEngine;
 class QPrinterInfo;
@@ -249,6 +250,8 @@ public:
     int fromPage() const;
     int toPage() const;
 
+    QRangeCollection *rangeCollection();
+
     void setPrintRange(PrintRange range);
     PrintRange printRange() const;