Add support for Windows UI Automation

Replaces the Qt Accessibility Windows back end, formerly based on legacy
MSAA, with a new implementation based on UI Automation. Fixes issues with
accessibility tools like screen readers and magnifiers, and with the
automatic showing and hiding of the virtual keyboard in touchscreen-based
Windows computers.

[ChangeLog][Windows] The Windows Accessibility back end, formerly based on
Microsoft Active Accessibility, was replaced with a new implementation
based on Microsoft UI Automation.

Task-number: QTPM-487
Task-number: QTBUG-53024
Task-number: QTBUG-43190
Task-number: QTBUG-61926
Task-number: QTBUG-38499
Task-number: QTBUG-38337
Task-number: QTBUG-38501
Task-number: QTBUG-38502
Task-number: QTBUG-38504
Task-number: QTBUG-38505
Task-number: QTBUG-38507
Change-Id: I20b4f8f5e938fef791c6e9c577fcd919140999bd
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>

1 files changed, 201 insertions, 0 deletions

diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionitemprovider.cpp b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionitemprovider.cpp
new file mode 100644
index 0000000000..45216a6d1c
--- /dev/null
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionitemprovider.cpp
@@ -0,0 +1,201 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore/QtConfig>
+#ifndef QT_NO_ACCESSIBILITY
+
+#include "qwindowsuiaselectionitemprovider.h"
+#include "qwindowsuiamainprovider.h"
+#include "qwindowsuiautils.h"
+#include "qwindowscontext.h"
+
+#include <QtGui/QAccessible>
+#include <QtGui/QAccessibleInterface>
+#include <QtCore/QDebug>
+#include <QtCore/QString>
+
+QT_BEGIN_NAMESPACE
+
+using namespace QWindowsUiAutomation;
+
+
+QWindowsUiaSelectionItemProvider::QWindowsUiaSelectionItemProvider(QAccessible::Id id) :
+    QWindowsUiaBaseProvider(id)
+{
+}
+
+QWindowsUiaSelectionItemProvider::~QWindowsUiaSelectionItemProvider()
+{
+}
+
+// Selects the element (deselecting all others).
+HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionItemProvider::Select()
+{
+    qCDebug(lcQpaUiAutomation) << __FUNCTION__;
+
+    QAccessibleInterface *accessible = accessibleInterface();
+    if (!accessible)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    QAccessibleActionInterface *actionInterface = accessible->actionInterface();
+    if (!actionInterface)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    if (accessible->role() == QAccessible::RadioButton) {
+        // For radio buttons we just invoke the selection action; others are automatically deselected.
+        actionInterface->doAction(QAccessibleActionInterface::pressAction());
+    } else {
+        // Toggle list item if not already selected. It must be done first to support all selection modes.
+        if (!accessible->state().selected) {
+            actionInterface->doAction(QAccessibleActionInterface::toggleAction());
+        }
+        // Toggle selected siblings.
+        if (QAccessibleInterface *parent = accessible->parent()) {
+            for (int i = 0; i < parent->childCount(); ++i) {
+                if (QAccessibleInterface *sibling = parent->child(i)) {
+                    if ((sibling != accessible) && (sibling->state().selected)) {
+                        if (QAccessibleActionInterface *siblingAction = sibling->actionInterface()) {
+                            siblingAction->doAction(QAccessibleActionInterface::toggleAction());
+                        }
+                    }
+                }
+            }
+        }
+    }
+    return S_OK;
+}
+
+// Adds the element to the list of selected elements.
+HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionItemProvider::AddToSelection()
+{
+    qCDebug(lcQpaUiAutomation) << __FUNCTION__;
+
+    QAccessibleInterface *accessible = accessibleInterface();
+    if (!accessible)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    QAccessibleActionInterface *actionInterface = accessible->actionInterface();
+    if (!actionInterface)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    if (accessible->role() == QAccessible::RadioButton) {
+        // For radio buttons we invoke the selection action.
+        actionInterface->doAction(QAccessibleActionInterface::pressAction());
+    } else {
+        // Toggle list item if not already selected.
+        if (!accessible->state().selected) {
+            actionInterface->doAction(QAccessibleActionInterface::toggleAction());
+        }
+    }
+    return S_OK;
+}
+
+// Removes a list item from selection.
+HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionItemProvider::RemoveFromSelection()
+{
+    qCDebug(lcQpaUiAutomation) << __FUNCTION__;
+
+    QAccessibleInterface *accessible = accessibleInterface();
+    if (!accessible)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    QAccessibleActionInterface *actionInterface = accessible->actionInterface();
+    if (!actionInterface)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    if (accessible->role() != QAccessible::RadioButton) {
+        if (accessible->state().selected) {
+            actionInterface->doAction(QAccessibleActionInterface::toggleAction());
+        }
+    }
+
+    return S_OK;
+}
+
+// Returns true if element is currently selected.
+HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionItemProvider::get_IsSelected(BOOL *pRetVal)
+{
+    qCDebug(lcQpaUiAutomation) << __FUNCTION__;
+
+    if (!pRetVal)
+        return E_INVALIDARG;
+    *pRetVal = FALSE;
+
+    QAccessibleInterface *accessible = accessibleInterface();
+    if (!accessible)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    if (accessible->role() == QAccessible::RadioButton)
+        *pRetVal = accessible->state().checked;
+    else
+        *pRetVal = accessible->state().selected;
+    return S_OK;
+}
+
+// Returns the provider for the container element (e.g., the list for the list item).
+HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionItemProvider::get_SelectionContainer(IRawElementProviderSimple **pRetVal)
+{
+    qCDebug(lcQpaUiAutomation) << __FUNCTION__;
+
+    if (!pRetVal)
+        return E_INVALIDARG;
+    *pRetVal = nullptr;
+
+    QAccessibleInterface *accessible = accessibleInterface();
+    if (!accessible)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    QAccessibleActionInterface *actionInterface = accessible->actionInterface();
+    if (!actionInterface)
+        return UIA_E_ELEMENTNOTAVAILABLE;
+
+    // Radio buttons do not require a container.
+    if (accessible->role() == QAccessible::ListItem) {
+        if (QAccessibleInterface *parent = accessible->parent()) {
+            if (parent->role() == QAccessible::List) {
+                *pRetVal = QWindowsUiaMainProvider::providerForAccessible(parent);
+            }
+        }
+    }
+    return S_OK;
+}
+
+QT_END_NAMESPACE
+
+#endif // QT_NO_ACCESSIBILITY