tdf#161501 vcl: Make TabitemValue position-aware

Add a new `TabBarPosition` enum that describes whether
a tab bar is at the top, left, right, or bottom
(relative to the tab page content) and make use of
that for the new `meTabBarPosition` member for
`TabitemValue` that gets used for drawing tab items
via the native rendering API.

Set the position accordingly for both the vertical
tab control (`TabControl`) and `SvxIconChoiceCtrl_Impl`,
which implements the tab bar for `VerticalTabControl`.

For Qt-based VCL plugins, implement mapping to
the corresponding `QTabBar::Shape`. [1]

At least the Breeze Qt style uses that shape to decide
whether on what side of the tab item to draw the
selection/focus indicator.

This change by itself doesn't yet make any visual
difference for the Breeze style, as the "Top" value/
`QTabBar::RoundedNorth` is the default anyway, and
`SvxIconChoiceCtrl_Impl` doesn't yet use the
native drawing API for drawing focus/selection, but
only for mousehover feedback.
The plan is to implement that in a follow-up change.

[1] https://doc.qt.io/qt-6/qtabbar.html#Shape-enum

Change-Id: Idf1e41d3bc309d152a4a36d14e8617bd6429940c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/170841
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

1 files changed, 20 insertions, 0 deletions

diff --git a/vcl/qt5/QtGraphics_Controls.cxx b/vcl/qt5/QtGraphics_Controls.cxx
index b24b46b28a8d..9dd0b3a4f61e 100644
--- a/vcl/qt5/QtGraphics_Controls.cxx
+++ b/vcl/qt5/QtGraphics_Controls.cxx
@@ -223,6 +223,24 @@ void QtGraphics_Controls::drawFrame(QStyle::PrimitiveElement element, QImage* im
     QApplication::style()->drawPrimitive(element, &option, &painter);
 }
 
+static QTabBar::Shape lcl_mapTabBarPosition(TabBarPosition eTabPos)
+{
+    switch (eTabPos)
+    {
+        case TabBarPosition::Bottom:
+            return QTabBar::RoundedSouth;
+        case TabBarPosition::Left:
+            return QTabBar::RoundedWest;
+        case TabBarPosition::Right:
+            return QTabBar::RoundedEast;
+        case TabBarPosition::Top:
+            return QTabBar::RoundedNorth;
+        default:
+            assert(false && "Unhandled tab bar position");
+            return QTabBar::RoundedNorth;
+    }
+}
+
 void QtGraphics_Controls::fillQStyleOptionTab(const ImplControlValue& value, QStyleOptionTab& sot)
 {
     const TabitemValue& rValue = static_cast<const TabitemValue&>(value);
@@ -232,6 +250,8 @@ void QtGraphics_Controls::fillQStyleOptionTab(const ImplControlValue& value, QSt
         sot.position = rValue.isFirst() ? QStyleOptionTab::OnlyOneTab : QStyleOptionTab::End;
     else
         sot.position = QStyleOptionTab::Middle;
+
+    sot.shape = lcl_mapTabBarPosition(rValue.meTabBarPosition);
 }
 
 void QtGraphics_Controls::fullQStyleOptionTabWidgetFrame(QStyleOptionTabWidgetFrame& option,