a11y uia: Support ISelectionProvider2

Support UIA's ISelectionProvider2 interface [1]
in addition to ISelectionProvider.

The ISelectionProvider2 interface inherits from the
ISelectionProvider interface.

A follow-up commit that will introduce bridging the
QAccessibleSelectionInterface, introduced in commit
9d16d5e2245c26e5746fd7609300b84a2a983457.

While at it, also reserve space for the amount
of children in the QList in QWindowsUiaSelectionProvider::GetSelection
before inserting them one by one, to avoid reallocations.

Sample use of the ISelectionProvider2 interface from NVDA's
Python console [2] with this commit in place:

1) start NVDA
2) run the gallery example (examples\widgets\gallery\gallery.exe)
3) click on the "Style" listbox at the top
4) press Numpad_insert+control+z to start the NVDA Python console and
   capture snapshot variables
5) query and use the interface using NVDA's Python console

    >>> import UIAHandler
    >>> iselection2 = focus.parent.UIAElement.GetCurrentPattern(10034).QueryInterface(UIAHandler.IUIAutomationSelectionPattern2)
    >>> iselection2.CurrentItemCount
    1
    >>> iselection2.CurrentFirstSelectedItem.CurrentName
    'windowsvista'
    >>> iselection2.CurrentLastSelectedItem.CurrentName
    'windowsvista'

[1] https://learn.microsoft.com/en-us/windows/win32/api/uiautomationcore/nn-uiautomationcore-iselectionprovider2
[2] https://www.nvaccess.org/files/nvda/documentation/developerGuide.html#PythonConsole

Change-Id: I43642e9e39b63c65da97af976cc322a8e5868170
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>

5 files changed, 152 insertions, 2 deletions

diff --git a/src/gui/accessible/windows/apisupport/uiapatternids_p.h b/src/gui/accessible/windows/apisupport/uiapatternids_p.h
index 0ff463cd36..676c3fe24e 100644
--- a/src/gui/accessible/windows/apisupport/uiapatternids_p.h
+++ b/src/gui/accessible/windows/apisupport/uiapatternids_p.h
@@ -49,5 +49,6 @@
 #define UIA_DropTargetPatternId         10031
 #define UIA_TextEditPatternId           10032
 #define UIA_CustomNavigationPatternId   10033
+#define UIA_SelectionPattern2Id         10034
 
 #endif
diff --git a/src/gui/accessible/windows/apisupport/uiaserverinterfaces_p.h b/src/gui/accessible/windows/apisupport/uiaserverinterfaces_p.h
index 6cf15cacb0..244176921b 100644
--- a/src/gui/accessible/windows/apisupport/uiaserverinterfaces_p.h
+++ b/src/gui/accessible/windows/apisupport/uiaserverinterfaces_p.h
@@ -236,6 +236,24 @@ __CRT_UUID_DECL(ISelectionProvider, 0xfb8b03af, 0x3bdf, 0x48d4, 0xbd,0x36, 0x1a,
 #endif
 #endif
 
+#ifndef __ISelectionProvider2_INTERFACE_DEFINED__
+#define __ISelectionProvider2_INTERFACE_DEFINED__
+DEFINE_GUID(IID_ISelectionProvider2, 0x14f68475, 0xee1c, 0x44f6, 0xa8, 0x69, 0xd2, 0x39, 0x38, 0x1f, 0x0f, 0xe7);
+MIDL_INTERFACE("14f68475-ee1c-44f6-a869-d239381f0fe7")
+ISelectionProvider2 : public ISelectionProvider
+{
+public:
+    virtual HRESULT STDMETHODCALLTYPE get_FirstSelectedItem(__RPC__deref_out_opt IRawElementProviderSimple **retVal) = 0;
+    virtual HRESULT STDMETHODCALLTYPE get_LastSelectedItem(__RPC__deref_out_opt IRawElementProviderSimple **retVal) = 0;
+    virtual HRESULT STDMETHODCALLTYPE get_CurrentSelectedItem(__RPC__deref_out_opt IRawElementProviderSimple **retVal) = 0;
+    virtual HRESULT STDMETHODCALLTYPE get_ItemCount(__RPC__out int *retVal) = 0;
+};
+
+#ifdef __CRT_UUID_DECL
+__CRT_UUID_DECL(ISelectionProvider2,  0x14f68475, 0xee1c, 0x44f6, 0xa8, 0x69, 0xd2, 0x39, 0x38, 0x1f, 0x0f, 0xe7)
+#endif
+#endif
+
 
 #ifndef __ISelectionItemProvider_INTERFACE_DEFINED__
 #define __ISelectionItemProvider_INTERFACE_DEFINED__
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp b/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp
index 23beeae283..93b9d705c0 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp
@@ -304,6 +304,7 @@ HRESULT QWindowsUiaMainProvider::GetPatternProvider(PATTERNID idPattern, IUnknow
             *pRetVal = new QWindowsUiaToggleProvider(id());
         break;
     case UIA_SelectionPatternId:
+    case UIA_SelectionPattern2Id:
         // Lists of items.
         if (accessible->role() == QAccessible::List
                 || accessible->role() == QAccessible::PageTabList) {
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.cpp b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.cpp
index 45f3b20552..b5bf6c12e8 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.cpp
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.cpp
@@ -43,7 +43,9 @@ HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionProvider::GetSelection(SAFEARRAY *
 
     // First put selected items in a list, then build a safe array with the right size.
     QList<QAccessibleInterface *> selectedList;
-    for (int i = 0; i < accessible->childCount(); ++i) {
+    const int childCount = accessible->childCount();
+    selectedList.reserve(childCount);
+    for (int i = 0; i < childCount; ++i) {
         if (QAccessibleInterface *child = accessible->child(i)) {
             if (accessible->role() == QAccessible::PageTabList) {
                 if (child->role() == QAccessible::PageTab && child->state().focused) {
@@ -116,6 +118,116 @@ HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionProvider::get_IsSelectionRequired(
     return S_OK;
 }
 
+HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionProvider::get_FirstSelectedItem(__RPC__deref_out_opt IRawElementProviderSimple **pRetVal)
+{
+    qCDebug(lcQpaUiAutomation) << __FUNCTION__;
+
+    if (!pRetVal)
+        return E_INVALIDARG;
+    *pRetVal = nullptr;
+
+    QAccessibleInterface *accessible = accessibleInterface();
+    if (!accessible)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    QAccessibleInterface *firstSelectedChild = nullptr;
+    int i = 0;
+    while (!firstSelectedChild && i < accessible->childCount()) {
+        if (QAccessibleInterface *child = accessible->child(i)) {
+            if (accessible->role() == QAccessible::PageTabList) {
+                if (child->role() == QAccessible::PageTab && child->state().focused)
+                    firstSelectedChild = child;
+            } else if (child->state().selected) {
+                firstSelectedChild = child;
+            }
+        }
+        i++;
+    }
+
+    if (!firstSelectedChild)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    if (QWindowsUiaMainProvider *childProvider = QWindowsUiaMainProvider::providerForAccessible(firstSelectedChild))
+    {
+        *pRetVal = static_cast<IRawElementProviderSimple *>(childProvider);
+        return S_OK;
+    }
+
+    return S_FALSE;
+}
+
+HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionProvider::get_LastSelectedItem(__RPC__deref_out_opt IRawElementProviderSimple **pRetVal)
+{
+    qCDebug(lcQpaUiAutomation) << __FUNCTION__;
+
+    if (!pRetVal)
+        return E_INVALIDARG;
+    *pRetVal = nullptr;
+
+    QAccessibleInterface *accessible = accessibleInterface();
+    if (!accessible)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    QAccessibleInterface *lastSelectedChild = nullptr;
+    int i = accessible->childCount() - 1;
+    while (!lastSelectedChild && i >= 0) {
+        if (QAccessibleInterface *child = accessible->child(i)) {
+            if (accessible->role() == QAccessible::PageTabList) {
+                if (child->role() == QAccessible::PageTab && child->state().focused)
+                    lastSelectedChild = child;
+            } else if (child->state().selected) {
+                lastSelectedChild = child;
+            }
+        }
+        i--;
+    }
+
+    if (!lastSelectedChild)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    if (QWindowsUiaMainProvider *childProvider = QWindowsUiaMainProvider::providerForAccessible(lastSelectedChild))
+    {
+        *pRetVal = static_cast<IRawElementProviderSimple *>(childProvider);
+        return S_OK;
+    }
+
+    return S_FALSE;
+}
+
+HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionProvider::get_CurrentSelectedItem(__RPC__deref_out_opt IRawElementProviderSimple **pRetVal)
+{
+    qCDebug(lcQpaUiAutomation) << __FUNCTION__;
+    return get_FirstSelectedItem(pRetVal);
+}
+
+HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionProvider::get_ItemCount(__RPC__out int *pRetVal)
+{
+    qCDebug(lcQpaUiAutomation) << __FUNCTION__;
+
+    if (!pRetVal)
+        return E_INVALIDARG;
+    *pRetVal = -1;
+
+    QAccessibleInterface *accessible = accessibleInterface();
+    if (!accessible)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    int selectedCount = 0;
+    for (int i = 0; i < accessible->childCount(); i++) {
+        if (QAccessibleInterface *child = accessible->child(i)) {
+            if (accessible->role() == QAccessible::PageTabList) {
+                if (child->role() == QAccessible::PageTab && child->state().focused)
+                    selectedCount++;
+            } else if (child->state().selected) {
+                selectedCount++;
+            }
+        }
+    }
+
+    *pRetVal = selectedCount;
+    return S_OK;
+}
+
 QT_END_NAMESPACE
 
 #endif // QT_CONFIG(accessibility)
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.h
index 9a187c9413..8717e54ee7 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.h
@@ -13,17 +13,35 @@ QT_BEGIN_NAMESPACE
 
 // Implements the Selection control pattern provider. Used for Lists.
 class QWindowsUiaSelectionProvider : public QWindowsUiaBaseProvider,
-                                     public QWindowsComBase<ISelectionProvider>
+                                     public QWindowsComBase<ISelectionProvider2>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaSelectionProvider)
 public:
     explicit QWindowsUiaSelectionProvider(QAccessible::Id id);
     virtual ~QWindowsUiaSelectionProvider();
 
+    // override to support ISelectionProvider and ISelectionProvider2 at the same time
+    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID id, LPVOID *iface) override
+    {
+        HRESULT res = QWindowsComBase<ISelectionProvider2>::QueryInterface(id, iface);
+        // QWindowsComBase<ISelectionProvider2>::QueryInterface doesn't handle ISelectionProvider,
+        // from which ISelectionProvider2 inherits
+        if (res == E_NOINTERFACE)
+            res = qWindowsComQueryInterface<ISelectionProvider>(this, id, iface) ? S_OK : E_NOINTERFACE;
+
+        return res;
+    };
+
     // ISelectionProvider
     HRESULT STDMETHODCALLTYPE GetSelection(SAFEARRAY **pRetVal) override;
     HRESULT STDMETHODCALLTYPE get_CanSelectMultiple(BOOL *pRetVal) override;
     HRESULT STDMETHODCALLTYPE get_IsSelectionRequired(BOOL *pRetVal) override;
+
+    // ISelectionProvider2
+    HRESULT STDMETHODCALLTYPE get_FirstSelectedItem(__RPC__deref_out_opt IRawElementProviderSimple **pRetVal) override;
+    HRESULT STDMETHODCALLTYPE get_LastSelectedItem(__RPC__deref_out_opt IRawElementProviderSimple **pRetVal) override;
+    HRESULT STDMETHODCALLTYPE get_CurrentSelectedItem(__RPC__deref_out_opt IRawElementProviderSimple **pRetVal) override;
+    HRESULT STDMETHODCALLTYPE get_ItemCount(__RPC__out int *pRetVal) override;
 };
 
 QT_END_NAMESPACE