1 files changed, 77 insertions, 0 deletions
diff --git a/src/gui/accessible/qaccessiblebridgeutils.cpp b/src/gui/accessible/qaccessiblebridgeutils.cpp
new file mode 100644
index 0000000000..994f95fee9
--- /dev/null
+++ b/src/gui/accessible/qaccessiblebridgeutils.cpp
@@ -0,0 +1,77 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+#include "qaccessiblebridgeutils_p.h"
+#include <QtCore/qmath.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace QAccessibleBridgeUtils {
+
+static bool performAction(QAccessibleInterface *iface, const QString &actionName)
+{
+    if (QAccessibleActionInterface *actionIface = iface->actionInterface()) {
+        if (actionIface->actionNames().contains(actionName)) {
+            actionIface->doAction(actionName);
+            return true;
+        }
+    }
+    return false;
+}
+
+QStringList effectiveActionNames(QAccessibleInterface *iface)
+{
+    QStringList actions;
+    if (QAccessibleActionInterface *actionIface = iface->actionInterface())
+        actions = actionIface->actionNames();
+
+    if (iface->valueInterface()) {
+        if (!actions.contains(QAccessibleActionInterface::increaseAction()))
+            actions << QAccessibleActionInterface::increaseAction();
+        if (!actions.contains(QAccessibleActionInterface::decreaseAction()))
+            actions << QAccessibleActionInterface::decreaseAction();
+    }
+    return actions;
+}
+
+bool performEffectiveAction(QAccessibleInterface *iface, const QString &actionName)
+{
+    if (!iface)
+        return false;
+    if (performAction(iface, actionName))
+        return true;
+    if (actionName != QAccessibleActionInterface::increaseAction()
+        && actionName != QAccessibleActionInterface::decreaseAction())
+        return false;
+
+    QAccessibleValueInterface *valueIface = iface->valueInterface();
+    if (!valueIface)
+        return false;
+    bool success;
+    const QVariant currentVariant = valueIface->currentValue();
+    double stepSize = valueIface->minimumStepSize().toDouble(&success);
+    if (!success || qFuzzyIsNull(stepSize)) {
+        const double min = valueIface->minimumValue().toDouble(&success);
+        if (!success)
+            return false;
+        const double max = valueIface->maximumValue().toDouble(&success);
+        if (!success)
+            return false;
+        stepSize = (max - min) / 10;  // this is pretty arbitrary, we just need to provide something
+        const int typ = currentVariant.userType();
+        if (typ != QMetaType::Float && typ != QMetaType::Double) {
+            // currentValue is an integer. Round it up to ensure stepping in case it was below 1
+            stepSize = qCeil(stepSize);
+        }
+    }
+    const double current = currentVariant.toDouble(&success);
+    if (!success)
+        return false;
+    if (actionName == QAccessibleActionInterface::decreaseAction())
+        stepSize = -stepSize;
+    valueIface->setCurrentValue(current + stepSize);
+    return true;
+}
+
+}   //namespace
+
+QT_END_NAMESPACE