Create a wrapper to make listening for configmgr changes easy.

Change-Id: Ib58d04f9e046e604b24e0e338796a7a60aa1d6fd
Reviewed-on: https://gerrit.libreoffice.org/19253
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>

1 files changed, 118 insertions, 0 deletions

diff --git a/include/comphelper/configurationlistener.hxx b/include/comphelper/configurationlistener.hxx
new file mode 100644
index 000000000000..658b84b8e80d
--- /dev/null
+++ b/include/comphelper/configurationlistener.hxx
@@ -0,0 +1,118 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#ifndef INCLUDED_COMPHELPER_CONFIGURATIONLISTENER_HXX
+#define INCLUDED_COMPHELPER_CONFIGURATIONLISTENER_HXX
+
+#include <algorithm>
+#include <vector>
+#include <iterator>
+#include <comphelper/comphelperdllapi.h>
+#include <com/sun/star/lang/XComponent.hpp>
+#include <com/sun/star/beans/XPropertySet.hpp>
+#include <com/sun/star/beans/PropertyChangeEvent.hpp>
+#include <com/sun/star/beans/XPropertyChangeListener.hpp>
+#include <rtl/ref.hxx>
+#include <cppuhelper/implbase.hxx>
+#include <comphelper/processfactory.hxx>
+#include <comphelper/configurationhelper.hxx>
+
+namespace comphelper {
+
+class ConfigurationListener;
+
+class COMPHELPER_DLLPUBLIC ConfigurationListenerPropertyBase {
+public:
+    OUString maName;
+    rtl::Reference<ConfigurationListener> mxListener;
+
+    virtual ~ConfigurationListenerPropertyBase() {}
+    virtual void setProperty(const css::uno::Any &aProperty) = 0;
+    void dispose() { mxListener.clear(); }
+};
+
+template< typename uno_type > class ConfigurationListenerProperty : public ConfigurationListenerPropertyBase
+{
+    uno_type maValue;
+protected:
+    virtual void setProperty(const css::uno::Any &aProperty) SAL_OVERRIDE
+    {
+        aProperty >>= maValue;
+    }
+public:
+    /**
+     * Provide a mirror of the configmgr's version of this property
+     * for the lifecycle of this property. The property value tracks
+     * the same value in the configuration.
+     */
+    inline ConfigurationListenerProperty(const rtl::Reference< ConfigurationListener > &xListener,
+                                             const OUString &rProp );
+
+    inline ~ConfigurationListenerProperty();
+
+    uno_type get() { return maValue; }
+};
+
+class COMPHELPER_DLLPUBLIC ConfigurationListener :
+        public cppu::WeakImplHelper< css::beans::XPropertyChangeListener >
+{
+    css::uno::Reference< css::beans::XPropertySet > mxConfig;
+    std::vector< ConfigurationListenerPropertyBase * > maListeners;
+public:
+    /// Public health warning, you -must- dispose this if you use it.
+    ConfigurationListener(const OUString &rPath,
+                          com::sun::star::uno::Reference< com::sun::star::uno::XComponentContext >
+                          const & xContext = comphelper::getProcessComponentContext())
+        : mxConfig( ConfigurationHelper::openConfig( xContext, rPath,
+                        ConfigurationHelper::EConfigurationModes::E_READONLY ),
+                  css::uno::UNO_QUERY_THROW )
+    { }
+
+    virtual ~ConfigurationListener()
+    {
+        dispose();
+    }
+
+    /// Listen for the specific property denoted by the listener
+    void addListener(ConfigurationListenerPropertyBase *pListener);
+
+    /// Stop listening.
+    void removeListener(ConfigurationListenerPropertyBase *pListener);
+
+    /// Release various circular references
+    void dispose();
+
+    // XPropertyChangeListener implementation
+    virtual void SAL_CALL disposing(css::lang::EventObject const &)
+        throw (css::uno::RuntimeException, std::exception) SAL_OVERRIDE;
+
+    /// Notify of the property change
+    virtual void SAL_CALL propertyChange(
+        css::beans::PropertyChangeEvent const &rEvt )
+        throw (css::uno::RuntimeException, std::exception) SAL_OVERRIDE;
+};
+
+template< typename uno_type > ConfigurationListenerProperty< uno_type >::ConfigurationListenerProperty(const rtl::Reference< ConfigurationListener > &xListener, const OUString &rProp )
+{
+    maName = rProp;
+    mxListener = xListener;
+    mxListener->addListener(this);
+}
+
+template< typename uno_type > ConfigurationListenerProperty< uno_type >::~ConfigurationListenerProperty()
+{
+    if (mxListener.is())
+        mxListener->removeListener(this);
+}
+
+} // namespace comphelper
+
+#endif // INCLUDED_COMPHELPER_CONFIGURATIONLISTENER_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */