PySide6: Add QAccessible::installFactory()

Fixes: PYSIDE-1650
Change-Id: I05926888aa4de8c3a34c712ed2000ba59e524833
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

4 files changed, 270 insertions, 0 deletions

diff --git a/sources/pyside6/PySide6/QtGui/typesystem_gui_common.xml b/sources/pyside6/PySide6/QtGui/typesystem_gui_common.xml
index fa68db95b..96fc37c88 100644
--- a/sources/pyside6/PySide6/QtGui/typesystem_gui_common.xml
+++ b/sources/pyside6/PySide6/QtGui/typesystem_gui_common.xml
@@ -179,6 +179,12 @@
   </object-type>
 
   <value-type name="QAccessible">
+      <extra-includes>
+        <include file-name="QtGui/QAccessibleInterface" location="global"/>
+      </extra-includes>
+      <inject-code class="native" position="beginning"
+                   file="../glue/qtgui.cpp"
+                   snippet="qaccessible-pysidefactory"/>
       <value-type name="State"/>
       <enum-type name="Event"/>
       <enum-type name="Role"/>
@@ -186,6 +192,11 @@
       <enum-type name="RelationFlag" flags="Relation"/>
       <enum-type name="InterfaceType"/>
       <enum-type name="TextBoundaryType"/>
+      <add-function signature="installFactory(PyCallable)" static="yes">
+          <inject-code class="target" position="beginning"
+                       file="../glue/qtgui.cpp"
+                       snippet="qaccessible-installfactory"/>
+      </add-function>
   </value-type>
 
   <object-type name="QAccessibleActionInterface"/>
diff --git a/sources/pyside6/PySide6/glue/qtgui.cpp b/sources/pyside6/PySide6/glue/qtgui.cpp
index 5874dc608..81181dac4 100644
--- a/sources/pyside6/PySide6/glue/qtgui.cpp
+++ b/sources/pyside6/PySide6/glue/qtgui.cpp
@@ -41,6 +41,101 @@
  * INJECT CODE
  ********************************************************************/
 
+// @snippet qaccessible-pysidefactory
+// Helper for QAccessible::installFactory() that forwards the calls to
+// Python callables.
+class PySideAccessibleFactory
+{
+    PySideAccessibleFactory() = default;
+public:
+    ~PySideAccessibleFactory();
+
+    static PySideAccessibleFactory *instance() { return m_instance; }
+    static PySideAccessibleFactory *ensureInstance();
+
+    static void installFactory(PyObject *f);
+    static void cleanup();
+
+    static QAccessibleInterface *factory(const QString &key, QObject *o);
+
+private:
+    QAccessibleInterface *callFactories(const QString &key, QObject *o);
+
+    static PySideAccessibleFactory *m_instance;
+
+    QList<PyObject *> m_factoryFunctions;
+    QList<PyObject *> m_objects;
+};
+
+PySideAccessibleFactory *PySideAccessibleFactory::m_instance = nullptr;
+
+PySideAccessibleFactory::~PySideAccessibleFactory()
+{
+    QAccessible::removeFactory(PySideAccessibleFactory::factory);
+    if (!m_factoryFunctions.isEmpty()) {
+        Shiboken::GilState state;
+        for (auto *f : m_factoryFunctions)
+            Py_DECREF(f);
+        for (auto *o : m_objects)
+            Py_DECREF(o);
+    }
+}
+
+PySideAccessibleFactory *PySideAccessibleFactory::ensureInstance()
+{
+    if (m_instance == nullptr) {
+        m_instance = new PySideAccessibleFactory;
+        QAccessible::installFactory(PySideAccessibleFactory::factory);
+        qAddPostRoutine(PySideAccessibleFactory::cleanup);
+    }
+    return m_instance;
+}
+
+void PySideAccessibleFactory::installFactory(PyObject *f)
+{
+    if (m_instance != nullptr) {
+        Py_INCREF(f);
+        m_instance->m_factoryFunctions.append(f);
+    }
+}
+
+void PySideAccessibleFactory::cleanup()
+{
+    delete m_instance;
+    m_instance = nullptr;
+}
+
+QAccessibleInterface *PySideAccessibleFactory::factory(const QString &key, QObject *o)
+{
+    return m_instance ? m_instance->callFactories(key, o) : nullptr;
+}
+
+QAccessibleInterface *PySideAccessibleFactory::callFactories(const QString &key, QObject *o)
+{
+    Shiboken::GilState state;
+    Shiboken::AutoDecRef arglist(PyTuple_New(2));
+    PyTuple_SET_ITEM(arglist, 0, %CONVERTTOPYTHON[QString](key));
+    PyTuple_SET_ITEM(arglist, 1, %CONVERTTOPYTHON[QObject *](o));
+
+    for (auto *f : m_factoryFunctions) {
+        if (PyObject *pyResult = PyObject_CallObject(f, arglist)) {
+            if (pyResult != Py_None) {
+                m_objects.append(pyResult);
+                QAccessibleInterface* result = %CONVERTTOCPP[QAccessibleInterface *](pyResult);
+                return result;
+            }
+            Py_DECREF(pyResult);
+        }
+    }
+
+    return nullptr;
+}
+// @snippet qaccessible-pysidefactory
+
+// @snippet qaccessible-installfactory
+PySideAccessibleFactory::ensureInstance()->installFactory(%1);
+// @snippet qaccessible-installfactory
+
 // @snippet glgetshadersource
 GLsizei bufSize = 4096;
 GLsizei length = bufSize - 1;
diff --git a/sources/pyside6/tests/QtWidgets/CMakeLists.txt b/sources/pyside6/tests/QtWidgets/CMakeLists.txt
index afa5eae0a..5ec056a26 100644
--- a/sources/pyside6/tests/QtWidgets/CMakeLists.txt
+++ b/sources/pyside6/tests/QtWidgets/CMakeLists.txt
@@ -78,6 +78,7 @@ PYSIDE_TEST(parent_method_test.py)
 PYSIDE_TEST(private_mangle_test.py)
 PYSIDE_TEST(python_properties_test.py)
 PYSIDE_TEST(qabstracttextdocumentlayout_test.py)
+PYSIDE_TEST(qaccessible_test.py)
 PYSIDE_TEST(qaction_test.py)
 PYSIDE_TEST(qapp_issue_585.py)
 PYSIDE_TEST(qapp_test.py)
diff --git a/sources/pyside6/tests/QtWidgets/qaccessible_test.py b/sources/pyside6/tests/QtWidgets/qaccessible_test.py
new file mode 100644
index 000000000..fe257659b
--- /dev/null
+++ b/sources/pyside6/tests/QtWidgets/qaccessible_test.py
@@ -0,0 +1,163 @@
+#############################################################################
+##
+## Copyright (C) 2021 The Qt Company Ltd.
+## Contact: https://www.qt.io/licensing/
+##
+## This file is part of the test suite of Qt for Python.
+##
+## $QT_BEGIN_LICENSE:GPL-EXCEPT$
+## 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 General Public License Usage
+## Alternatively, this file may be used under the terms of the GNU
+## General Public License version 3 as published by the Free Software
+## Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+## 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-3.0.html.
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+'''Test cases for QAccessible::installFactory().'''
+
+import os
+import sys
+import unittest
+
+from pathlib import Path
+sys.path.append(os.fspath(Path(__file__).resolve().parents[1]))
+from init_paths import init_test_paths
+init_test_paths(False)
+
+from PySide6.QtCore import QCoreApplication, Qt
+from PySide6.QtGui import QAccessible, QAccessibleInterface, QColor
+from PySide6.QtWidgets import QWidget, QLineEdit, QVBoxLayout
+
+from helper.usesqapplication import UsesQApplication
+
+
+class LineEditAccessible(QAccessibleInterface):
+    """Mimick a QAccessibleInterface implementation for QLineEdit."""
+
+    instance_count = 0
+
+    def __init__(self, widget):
+        super().__init__()
+        LineEditAccessible.instance_count += 1
+        self._widget = widget
+        self._name = self._widget.objectName()
+        print('LineEditAccessible', self._name)
+
+    def __del__(self):
+        LineEditAccessible.instance_count -= 1
+        print('~LineEditAccessible', self._name)
+
+    def actionInterface(self):
+        return None
+
+    def backgroundColor(self):
+        return QColor(Qt.white)
+
+    def child(self, index):
+        return None
+
+    def childAt(self, x, y):
+        return None
+
+    def childCount(self):
+        return 0
+
+    def focusChild(self):
+        return None
+
+    def foregroundColor(self):
+        return QColor(Qt.black)
+
+    def indexOfChild(self, child):
+        return -1
+
+    def isValid(self):
+        return True
+
+    def object(self):
+        return self._widget
+
+    def parent(self):
+        return None
+
+    def rect(self):
+        return self._widget.geometry()
+
+    def role(self):
+        return QAccessible.EditableText
+
+    def setText(self, t, text):
+        pass
+
+    def state(self):
+        return QAccessible.State()
+
+    def tableCellInterface(self):
+        return None
+
+    def tableInterface(self):
+        return None
+
+    def text(self, t):
+        return self._widget.text() if t == QAccessible.Value else ''
+
+    def textInterface(self):
+        return None
+
+    def valueInterface(self):
+        return None
+
+    def window(self):
+        return self._widget.window().windowHandle()
+
+
+def accessible_factory(key, obj):
+    """Factory function for QAccessibleInterface for QLineEdit's."""
+    if obj.metaObject().className() == 'QLineEdit':
+        return LineEditAccessible(obj)
+    return None
+
+
+class Window(QWidget):
+    """Test window with 2 QLineEdit's."""
+    def __init__(self):
+        super().__init__()
+        self.setObjectName('top')
+        layout = QVBoxLayout(self)
+        self.m_line_edit1 = QLineEdit("bla")
+        layout.addWidget(self.m_line_edit1)
+        self.m_line_edit2 = QLineEdit("bla")
+        layout.addWidget(self.m_line_edit2)
+
+
+class QAccessibleTest(UsesQApplication):
+    """Test that LineEditAccessible instances are created for QLineEdit's."""
+
+    def setUp(self):
+        super().setUp()
+        QAccessible.installFactory(accessible_factory)
+        window = Window()
+
+    def testLineEdits(self):
+        window = Window()
+        window.show()
+        while not window.windowHandle().isExposed():
+            QCoreApplication.processEvents()
+        self.assertEqual(LineEditAccessible.instance_count, 2)
+
+
+if __name__ == "__main__":
+    unittest.main()