qt a11y: Implement QAccessibleSelectionInterface added in Qt 6.5

This adds an implementation of the
`QAccessibleSelectionInterface` that was added
in Qt 6.5 in commit [1]

commit 9d16d5e2245c26e5746fd7609300b84a2a983457
Author: Michael Weghorn <m.weghorn@posteo.de>
Date:   Tue Oct 11 15:23:54 2022 +0200

a11y: Add new QAccessibleSelectionInterface

, s.a. QTBUG-105909 [2].

The `QAccessibleSelectionInterface` is currently still marked as
preliminary in Qt, so changes to the API *might* still happen
and require an update of the implementation here as well).

Quoting from the commit message of the above commit:

> This interface is marked \preliminary until:
>
> 1. There is a working a11y bridge for macOS/VoiceOver
> 2. There is a working a11y bridge for Windows/UI Automation
> 3. There is a working a11y bridge for linux/AT-SPI
> 4. There is at least one implementation (e.g. QAccessibleTable)
>    that implements it successfully (second candidate:
>    Qt Quick TableView [...])

The AT-SPI bridge (point 3 from above) has been implemented in [3]

commit ece2feee0317b582a56a0bfc783f11fe67d3edee
Author: Michael Weghorn <m.weghorn@posteo.de>
Date:   Tue Oct 11 15:24:04 2022 +0200

a11y atspi: Bridge newly introduced QAccessibleSelectionInterface

, an implementation for `QAccessibleTable` (point 4 from above) was
added in [4]

commit 092bbc9ad30c6cd7389053dc4b332cc762693676
Author: Michael Weghorn <m.weghorn@posteo.de>
Date:   Wed Oct 12 07:07:48 2022 +0200

a11y: Implement QAccessibleSelectionInterface for item views

. The Qt Gerrit changes for the macOS implementation (point 1 from
above) and the Windows/UIA implementation (point 2 from above)
are currently still awaiting review: [5] [6]

To avoid duplication, just call the newly added methods
`QtAccessibleWidget::selectedItemCount` and
`QtAccessibleWidget::selectedItem` from the
`QAccessibleTableInterface` methods
`QtAccessibleWidget::selectedCellCount` and
and `QtAccessibleWidget::selectedCells`, and
therefore implement the former also for Qt < 6.5.

Sample use of the interface from Accerciser's IPython
console (with 18 cells selected in Calc and the spreadsheet
object selected in Accerciser's a11y object tree; screencast
attached to QTBUG-105909 [2]):

In [10]: acc.get_interfaces()
Out[10]: ['Accessible', 'Component', 'Selection', 'Table']
In [11]: sel = acc.querySelection()
In [12]: sel.nSelectedChildren
Out[12]: 18
In [13]: sel.getSelectedChild(0).name
Out[13]: 'B1'
In [14]: sel.deselectSelectedChild(1)
Out[14]: True
In [15]: sel.deselectChild(1)
Out[15]: True
In [16]: sel.selectChild(0)
Out[16]: True
In [17]: sel.clearSelection()
Out[17]: True
In [18]: sel.selectAll()
Out[18]: True

[1] https://code.qt.io/cgit/qt/qtbase.git/commit/?id=9d16d5e2245c26e5746fd7609300b84a2a983457
[2] https://bugreports.qt.io/browse/QTBUG-105909
[3] https://code.qt.io/cgit/qt/qtbase.git/commit/?id=ece2feee0317b582a56a0bfc783f11fe67d3edee
[4] https://code.qt.io/cgit/qt/qtbase.git/commit/?id=092bbc9ad30c6cd7389053dc4b332cc762693676
[5] https://codereview.qt-project.org/c/qt/qtbase/+/451353
[6] https://codereview.qt-project.org/c/qt/qtbase/+/451646

Change-Id: Iac3c050448183610af3bd3b10a56e82d7d52cb91
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/138750
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

1 files changed, 164 insertions, 48 deletions

diff --git a/vcl/qt5/QtAccessibleWidget.cxx b/vcl/qt5/QtAccessibleWidget.cxx
index 237b2db64735..84b398c006cc 100644
--- a/vcl/qt5/QtAccessibleWidget.cxx
+++ b/vcl/qt5/QtAccessibleWidget.cxx
@@ -727,6 +727,10 @@ void* QtAccessibleWidget::interface_cast(QAccessible::InterfaceType t)
     }
     if (t == QAccessible::TableInterface && accessibleProvidesInterface<XAccessibleTable>())
         return static_cast<QAccessibleTableInterface*>(this);
+#if QT_VERSION >= QT_VERSION_CHECK(6, 5, 0)
+    if (t == QAccessible::SelectionInterface && accessibleProvidesInterface<XAccessibleSelection>())
+        return static_cast<QAccessibleSelectionInterface*>(this);
+#endif
     return nullptr;
 }
 
@@ -1631,55 +1635,9 @@ bool QtAccessibleWidget::selectRow(int row)
     return xTableSelection->selectRow(row);
 }
 
-int QtAccessibleWidget::selectedCellCount() const
-{
-    Reference<XAccessibleContext> xAcc = getAccessibleContextImpl();
-    if (!xAcc.is())
-        return 0;
-
-    Reference<XAccessibleSelection> xSelection(xAcc, UNO_QUERY);
-    if (!xSelection.is())
-        return 0;
-
-    sal_Int64 nSelected = xSelection->getSelectedAccessibleChildCount();
-    if (nSelected > std::numeric_limits<int>::max())
-    {
-        SAL_WARN("vcl.qt",
-                 "QtAccessibleWidget::selectedCellCount: Cell count exceeds maximum int value, "
-                 "using max int.");
-        nSelected = std::numeric_limits<int>::max();
-    }
-    return nSelected;
-}
-
-QList<QAccessibleInterface*> QtAccessibleWidget::selectedCells() const
-{
-    Reference<XAccessibleContext> xAcc = getAccessibleContextImpl();
-    if (!xAcc.is())
-        return QList<QAccessibleInterface*>();
-
-    Reference<XAccessibleSelection> xSelection(xAcc, UNO_QUERY);
-    if (!xSelection.is())
-        return QList<QAccessibleInterface*>();
+int QtAccessibleWidget::selectedCellCount() const { return selectedItemCount(); }
 
-    QList<QAccessibleInterface*> aSelectedCells;
-    sal_Int64 nSelected = xSelection->getSelectedAccessibleChildCount();
-    if (nSelected > std::numeric_limits<int>::max())
-    {
-        SAL_WARN("vcl.qt",
-                 "QtAccessibleWidget::selectedCells: Cell count exceeds maximum int value, "
-                 "using max int.");
-        nSelected = std::numeric_limits<int>::max();
-    }
-    for (sal_Int64 i = 0; i < nSelected; i++)
-    {
-        Reference<XAccessible> xChild = xSelection->getSelectedAccessibleChild(i);
-        QAccessibleInterface* pInterface
-            = QAccessible::queryAccessibleInterface(QtAccessibleRegistry::getQObject(xChild));
-        aSelectedCells.push_back(pInterface);
-    }
-    return aSelectedCells;
-}
+QList<QAccessibleInterface*> QtAccessibleWidget::selectedCells() const { return selectedItems(); }
 
 int QtAccessibleWidget::selectedColumnCount() const
 {
@@ -1897,4 +1855,162 @@ QAccessibleInterface* QtAccessibleWidget::table() const
     return QAccessible::queryAccessibleInterface(QtAccessibleRegistry::getQObject(xTableAcc));
 }
 
+// QAccessibleSelectionInterface
+int QtAccessibleWidget::selectedItemCount() const
+{
+    Reference<XAccessibleContext> xAcc = getAccessibleContextImpl();
+    if (!xAcc.is())
+        return 0;
+
+    Reference<XAccessibleSelection> xSelection(xAcc, UNO_QUERY);
+    if (!xSelection.is())
+        return 0;
+
+    sal_Int64 nSelected = xSelection->getSelectedAccessibleChildCount();
+    if (nSelected > std::numeric_limits<int>::max())
+    {
+        SAL_WARN("vcl.qt",
+                 "QtAccessibleWidget::selectedItemCount: Cell count exceeds maximum int value, "
+                 "using max int.");
+        nSelected = std::numeric_limits<int>::max();
+    }
+    return nSelected;
+}
+
+QList<QAccessibleInterface*> QtAccessibleWidget::selectedItems() const
+{
+    Reference<XAccessibleContext> xAcc = getAccessibleContextImpl();
+    if (!xAcc.is())
+        return QList<QAccessibleInterface*>();
+
+    Reference<XAccessibleSelection> xSelection(xAcc, UNO_QUERY);
+    if (!xSelection.is())
+        return QList<QAccessibleInterface*>();
+
+    QList<QAccessibleInterface*> aSelectedItems;
+    sal_Int64 nSelected = xSelection->getSelectedAccessibleChildCount();
+    if (nSelected > std::numeric_limits<int>::max())
+    {
+        SAL_WARN("vcl.qt",
+                 "QtAccessibleWidget::selectedItems: Cell count exceeds maximum int value, "
+                 "using max int.");
+        nSelected = std::numeric_limits<int>::max();
+    }
+    for (sal_Int64 i = 0; i < nSelected; i++)
+    {
+        Reference<XAccessible> xChild = xSelection->getSelectedAccessibleChild(i);
+        QAccessibleInterface* pInterface
+            = QAccessible::queryAccessibleInterface(QtAccessibleRegistry::getQObject(xChild));
+        aSelectedItems.push_back(pInterface);
+    }
+    return aSelectedItems;
+}
+
+#if QT_VERSION >= QT_VERSION_CHECK(6, 5, 0)
+QAccessibleInterface* QtAccessibleWidget::selectedItem(int nSelectionIndex) const
+{
+    Reference<XAccessibleContext> xAcc = getAccessibleContextImpl();
+    if (!xAcc.is())
+        return nullptr;
+
+    Reference<XAccessibleSelection> xSelection(xAcc, UNO_QUERY);
+    if (!xSelection.is())
+        return nullptr;
+
+    if (nSelectionIndex < 0 || nSelectionIndex >= xSelection->getSelectedAccessibleChildCount())
+    {
+        SAL_WARN("vcl.qt",
+                 "QtAccessibleWidget::selectedItem called with invalid index: " << nSelectionIndex);
+        return nullptr;
+    }
+
+    Reference<XAccessible> xChild = xSelection->getSelectedAccessibleChild(nSelectionIndex);
+    if (!xChild)
+        return nullptr;
+
+    return QAccessible::queryAccessibleInterface(QtAccessibleRegistry::getQObject(xChild));
+}
+
+bool QtAccessibleWidget::isSelected(QAccessibleInterface* pItem) const
+{
+    Reference<XAccessibleContext> xAcc = getAccessibleContextImpl();
+    if (!xAcc.is())
+        return false;
+
+    Reference<XAccessibleSelection> xSelection(xAcc, UNO_QUERY);
+    if (!xSelection.is())
+        return false;
+
+    int nChildIndex = indexOfChild(pItem);
+    if (nChildIndex < 0)
+        return false;
+
+    return xSelection->isAccessibleChildSelected(nChildIndex);
+}
+
+bool QtAccessibleWidget::select(QAccessibleInterface* pItem)
+{
+    Reference<XAccessibleContext> xAcc = getAccessibleContextImpl();
+    if (!xAcc.is())
+        return false;
+
+    Reference<XAccessibleSelection> xSelection(xAcc, UNO_QUERY);
+    if (!xSelection.is())
+        return false;
+
+    int nChildIndex = indexOfChild(pItem);
+    if (nChildIndex < 0)
+        return false;
+
+    xSelection->selectAccessibleChild(nChildIndex);
+    return true;
+}
+
+bool QtAccessibleWidget::unselect(QAccessibleInterface* pItem)
+{
+    Reference<XAccessibleContext> xAcc = getAccessibleContextImpl();
+    if (!xAcc.is())
+        return false;
+
+    Reference<XAccessibleSelection> xSelection(xAcc, UNO_QUERY);
+    if (!xSelection.is())
+        return false;
+
+    int nChildIndex = indexOfChild(pItem);
+    if (nChildIndex < 0)
+        return false;
+
+    xSelection->deselectAccessibleChild(nChildIndex);
+    return true;
+}
+
+bool QtAccessibleWidget::selectAll()
+{
+    Reference<XAccessibleContext> xAcc = getAccessibleContextImpl();
+    if (!xAcc.is())
+        return false;
+
+    Reference<XAccessibleSelection> xSelection(xAcc, UNO_QUERY);
+    if (!xSelection.is())
+        return false;
+
+    xSelection->selectAllAccessibleChildren();
+    return true;
+}
+
+bool QtAccessibleWidget::clear()
+{
+    Reference<XAccessibleContext> xAcc = getAccessibleContextImpl();
+    if (!xAcc.is())
+        return false;
+
+    Reference<XAccessibleSelection> xSelection(xAcc, UNO_QUERY);
+    if (!xSelection.is())
+        return false;
+
+    xSelection->clearAccessibleSelection();
+    return true;
+}
+#endif
+
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