print: Clamp margins entered by the user in the page setup dialog

The current functionality discards all margins if any values fall
outside the minimum or maximum limits. This can confuse and
frustrate users since the Windows native page setup dialog doesn't
enforce minimum values.

Introduce a new parameter outOfBoundsPolicy for the set margins
functions in the QPageLayout:
- OutOfBoundsPolicy::Reject The old behavior rejecting out of
  bounds values.
- OutOfBoundsPolicy::Clamp The new behavior for clamping the values.

The OutOfBoundsPolicy is applied only in StandardMode to maintain
backwards compatibility in FullPageMode, where all margins are
accepted.

Use the new Clamp policy in the printsupport where the clamping is
necessary.

Maintain binary compatibility by putting the declaration of the old
symbols without policy parameter behind QT_GUI_REMOVED_SINCE, and
implement them in removed_api.cpp to call the new versions.

Task-number: QTBUG-122410
Change-Id: I06aee292c1daff2863502f471b03798dafbcd81b
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 124 insertions, 3 deletions

diff --git a/tests/auto/gui/painting/qpagelayout/tst_qpagelayout.cpp b/tests/auto/gui/painting/qpagelayout/tst_qpagelayout.cpp
index cbbf857357..4490877e87 100644
--- a/tests/auto/gui/painting/qpagelayout/tst_qpagelayout.cpp
+++ b/tests/auto/gui/painting/qpagelayout/tst_qpagelayout.cpp
@@ -12,6 +12,7 @@ private slots:
     void invalid();
     void basics();
     void setGetMargins();
+    void setGetClampedMargins();
     void setUnits_data();
     void setUnits();
 };
@@ -216,7 +217,7 @@ void tst_QPageLayout::basics()
 
 void tst_QPageLayout::setGetMargins()
 {
-    // A4, 20pt margins
+    // A4, 10pt margins
     QMarginsF margins = QMarginsF(10, 10, 10, 10);
     QMarginsF min = QMarginsF(10, 10, 10, 10);
     QMarginsF max = QMarginsF(585, 832, 585, 832);
@@ -229,7 +230,7 @@ void tst_QPageLayout::setGetMargins()
     QCOMPARE(change.minimumMargins(), min);
     QCOMPARE(change.maximumMargins(), max);
 
-    // Set magins within min/max ok
+    // Set margins within min/max ok
     margins = QMarginsF(20, 20, 20, 20);
     change.setMargins(margins);
     QCOMPARE(change.margins(QPageLayout::Millimeter), QMarginsF(7.06, 7.06, 7.06, 7.06));
@@ -289,7 +290,7 @@ void tst_QPageLayout::setGetMargins()
     fullPage.setMargins(margins);
     QCOMPARE(fullPage.margins(), margins);
 
-    // Set margins all above max is rejected
+    // Set margins all above max is accepted
     margins = QMarginsF(1000, 1000, 1000, 1000);
     fullPage.setMargins(margins);
     QCOMPARE(fullPage.margins(), margins);
@@ -312,6 +313,126 @@ void tst_QPageLayout::setGetMargins()
     QCOMPARE(fullPage.maximumMargins(), max);
 }
 
+void tst_QPageLayout::setGetClampedMargins()
+{
+    // A4, 10pt margins
+    QMarginsF margins = QMarginsF(10, 10, 10, 10);
+    QMarginsF min = QMarginsF(10, 10, 10, 10);
+    QMarginsF max = QMarginsF(585, 832, 585, 832);
+    QPageLayout change = QPageLayout(QPageSize(QPageSize::A4), QPageLayout::Portrait, margins, QPageLayout::Point, min);
+    QCOMPARE(change.isValid(), true);
+
+    // Clamp margins within min/max ok
+    margins = QMarginsF(20, 20, 20, 20);
+    change.setMargins(margins, QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins(QPageLayout::Millimeter), QMarginsF(7.06, 7.06, 7.06, 7.06));
+    QCOMPARE(change.marginsPoints(), QMargins(20, 20, 20, 20));
+    QCOMPARE(change.marginsPixels(72), QMargins(20, 20, 20, 20));
+    QCOMPARE(change.margins(), margins);
+
+    // Clamp margins all below min
+    change.setMargins(QMarginsF(0, 0, 0, 0), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins(), change.minimumMargins());
+
+    // Clamp margins all above max
+    change.setMargins(QMarginsF(1000, 1000, 1000, 1000), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins(), change.maximumMargins());
+
+    // Only 1 wrong, clamp still works
+    change.setMargins(QMarginsF(50, 50, 50, 0), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins(), QMarginsF(50, 50, 50, change.minimumMargins().bottom()));
+
+    // A4, 20pt margins
+    margins = QMarginsF(20, 20, 20, 20);
+    min = QMarginsF(10, 10, 10, 10);
+    max = QMarginsF(585, 832, 585, 832);
+    QPageLayout fullPage = QPageLayout(QPageSize(QPageSize::A4), QPageLayout::Portrait, margins, QPageLayout::Point, min);
+    fullPage.setMode(QPageLayout::FullPageMode);
+    QCOMPARE(fullPage.isValid(), true);
+    QCOMPARE(fullPage.margins(), margins);
+    QCOMPARE(fullPage.minimumMargins(), min);
+    QCOMPARE(fullPage.maximumMargins(), max);
+
+    // Clamp margins within min/max ok
+    margins = QMarginsF(50, 50, 50, 50);
+    fullPage.setMargins(margins, QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(fullPage.margins(), margins);
+
+    // Clamp margins all below min, no clamping
+    margins = QMarginsF(0, 0, 0, 0);
+    fullPage.setMargins(margins, QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(fullPage.margins(), margins);
+
+    // Clamp margins all above max, no clamping
+    margins = QMarginsF(1000, 1000, 1000, 1000);
+    fullPage.setMargins(margins, QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(fullPage.margins(), margins);
+
+    // Only 1 wrong, no clamping
+    margins = QMarginsF(50, 50, 50, 0);
+    fullPage.setMargins(margins, QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(fullPage.margins(), margins);
+
+    // Set page size, sets min/max, clamps existing margins
+    margins = QMarginsF(20, 500, 20, 500);
+    fullPage.setMargins(margins, QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(fullPage.margins(), margins);
+    min = QMarginsF(30, 30, 30, 30);
+    max = QMarginsF(267, 390, 267, 390);
+    fullPage.setPageSize(QPageSize(QPageSize::A6));
+    fullPage.setMinimumMargins(min);
+    QCOMPARE(fullPage.margins(), margins);
+    QCOMPARE(fullPage.minimumMargins(), min);
+    QCOMPARE(fullPage.maximumMargins(), max);
+
+    // Test set* API calls
+    min = QMarginsF(1, 2, 3, 4);
+    max = QMarginsF(595 - min.right(), 842 - min.bottom(), 595 - min.left(), 842 - min.top());
+    change = QPageLayout(QPageSize(QPageSize::A4), QPageLayout::Portrait, margins, QPageLayout::Point, min);
+    QCOMPARE(change.minimumMargins(), min);
+    QCOMPARE(change.maximumMargins(), max);
+
+    // Test setLeftMargin
+    change.setLeftMargin(0, QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().left(), min.left());
+    change.setLeftMargin(change.fullRectPoints().width(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().left(), max.left());
+    change.setLeftMargin(min.left(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().left(), min.left());
+    change.setLeftMargin(max.left(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().left(), max.left());
+
+    // Test setTopMargin
+    change.setTopMargin(0, QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().top(), min.top());
+    change.setTopMargin(change.fullRectPoints().height(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().top(), max.top());
+    change.setTopMargin(min.top(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().top(), min.top());
+    change.setTopMargin(max.top(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().top(), max.top());
+
+    // Test setRightMargin
+    change.setRightMargin(0, QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().right(), min.right());
+    change.setRightMargin(change.fullRectPoints().width(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().right(), max.right());
+    change.setRightMargin(min.right(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().right(), min.right());
+    change.setRightMargin(max.right(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().right(), max.right());
+
+    // Test setBottomMargin
+    change.setBottomMargin(0, QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().bottom(), min.bottom());
+    change.setBottomMargin(change.fullRectPoints().height(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().bottom(), max.bottom());
+    change.setBottomMargin(min.bottom(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().bottom(), min.bottom());
+    change.setBottomMargin(max.bottom(), QPageLayout::OutOfBoundsPolicy::Clamp);
+    QCOMPARE(change.margins().bottom(), max.bottom());
+}
+
 void tst_QPageLayout::setUnits_data()
 {
     QTest::addColumn<QPageLayout::Unit>("units");