Vcl: Disable buttons if the associated UNO slot is disabled

The goal of this is to have buttons in the Sidebar and NotebookBar automatically disabled
without an additional wrapper.

Change-Id: I8d25cdc6b87323e02daf6969c68582354f301375

include/vcl/buttonstatuslistener.hxx

+/* -*- 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_VCL_BUTTONSTATUSLISTENER_HXX
+#define INCLUDED_VCL_BUTTONSTATUSLISTENER_HXX
+
+#include <cppuhelper/implbase.hxx>
+#include <vcl/button.hxx>
+
+#include <com/sun/star/util/URL.hpp>
+#include <com/sun/star/frame/XStatusListener.hpp>
+#include <com/sun/star/frame/XDispatch.hpp>
+
+
+class VCL_DLLPUBLIC ButtonStatusListener : public cppu::WeakImplHelper < css::frame::XStatusListener>
+{
+public:
+    ButtonStatusListener(Button* button, const rtl::OUString& aCommand);
+
+private:
+    VclPtr<Button> mButton; /** The button on which actions are performed */
+
+    /** Dispatcher. Need to keep a reference to it as long as this StatusListener exists. */
+    css::uno::Reference<css::frame::XDispatch> mxDispatch;
+    css::util::URL maCommandURL;
+
+public:
+    virtual void SAL_CALL statusChanged(const css::frame::FeatureStateEvent& rEvent)
+            throw(css::uno::RuntimeException, std::exception) override;
+
+    virtual void SAL_CALL disposing(const css::lang::EventObject& /*Source*/)
+            throw( css::uno::RuntimeException, std::exception ) override;
+
+    void dispose();
+};
+
+#endif // INCLUDED_VCL_BUTTONSTATUSLISTENER_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
\ No newline at end of file

vcl/Library_vcl.mk

@@ -205,6 +205,7 @@ $(eval $(call gb_Library_add_exception_objects,vcl,\
     vcl/source/window/winproc \
     vcl/source/window/wrkwin \
     vcl/source/control/button \
+    vcl/source/control/buttonstatuslistener \
     vcl/source/control/combobox \
     vcl/source/control/ctrl \
     vcl/source/control/edit \

vcl/source/control/button.cxx

@@ -32,6 +32,7 @@
 #include <vcl/dialog.hxx>
 #include <vcl/fixed.hxx>
 #include <vcl/button.hxx>
+#include <vcl/buttonstatuslistener.hxx>
 #include <vcl/salnativewidgets.hxx>
 #include <vcl/edit.hxx>
 #include <vcl/layout.hxx>
@@ -43,6 +44,7 @@
 
 #include <comphelper/dispatchcommand.hxx>
 
+
 using namespace css;
 
 #define PUSHBUTTON_VIEW_STYLE       (WB_3DLOOK |                        \
@@ -67,6 +69,9 @@ using namespace css;
 class ImplCommonButtonData
 {
 public:
+    ImplCommonButtonData();
+    ~ImplCommonButtonData();
+
     Rectangle       maFocusRect;
     long            mnSeparatorX;
     DrawButtonFlags mnButtonState;
@@ -76,9 +81,8 @@ public:
     ImageAlign      meImageAlign;
     SymbolAlign     meSymbolAlign;
 
-public:
-                    ImplCommonButtonData();
-                   ~ImplCommonButtonData();
+    /** StatusListener. Updates the button as the slot state changes */
+    rtl::Reference<ButtonStatusListener> mpStatusListener;
 };
 
 ImplCommonButtonData::ImplCommonButtonData() : maFocusRect(), mnSeparatorX(0), mnButtonState(DrawButtonFlags::NONE),
@@ -104,12 +108,16 @@ Button::~Button()
 void Button::dispose()
 {
     Control::dispose();
+    if (mpButtonData->mpStatusListener.is())
+        mpButtonData->mpStatusListener->dispose();
 }
 
 void Button::SetCommandHandler(const OUString& aCommand)
 {
     maCommand = aCommand;
     SetClickHdl( LINK( this, Button, dispatchCommandHandler) );
+
+    mpButtonData->mpStatusListener = new ButtonStatusListener(this, aCommand);
 }
 
 void Button::Click()

vcl/source/control/buttonstatuslistener.cxx

+/* -*- 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/.
+ */
+
+#include <vcl/buttonstatuslistener.hxx>
+#include <comphelper/processfactory.hxx>
+
+#include <com/sun/star/frame/Desktop.hpp>
+#include <com/sun/star/frame/XDispatch.hpp>
+#include <com/sun/star/frame/XDispatchProvider.hpp>
+#include <com/sun/star/frame/XStatusListener.hpp>
+#include <com/sun/star/util/URL.hpp>
+#include <com/sun/star/util/URLTransformer.hpp>
+
+ButtonStatusListener::ButtonStatusListener(Button* button, const rtl::OUString& aCommand) {
+    mButton = button;
+
+    css::uno::Reference<css::uno::XComponentContext> xContext = ::comphelper::getProcessComponentContext();
+    css::uno::Reference<css::frame::XDesktop2> xDesktop = css::frame::Desktop::create(xContext);
+
+    css::uno::Reference<css::frame::XFrame> xFrame(xDesktop->getActiveFrame());
+    if (!xFrame.is())
+        xFrame = css::uno::Reference<css::frame::XFrame>(xDesktop, css::uno::UNO_QUERY);
+
+    css::uno::Reference<css::frame::XDispatchProvider> xDispatchProvider(xFrame, css::uno::UNO_QUERY);
+    if (!xDispatchProvider.is())
+        return;
+
+    maCommandURL.Complete = aCommand;
+    css::uno::Reference<css::util::XURLTransformer> xParser = css::util::URLTransformer::create(xContext);
+    xParser->parseStrict(maCommandURL);
+
+    mxDispatch = xDispatchProvider->queryDispatch(maCommandURL, "", 0);
+    if (!mxDispatch.is())
+        return;
+
+    mxDispatch->addStatusListener(this, maCommandURL);
+}
+
+void ButtonStatusListener::statusChanged(const css::frame::FeatureStateEvent& rEvent)
+            throw(css::uno::RuntimeException, std::exception)
+{
+    mButton->Enable(rEvent.IsEnabled);
+}
+
+void ButtonStatusListener::disposing(const css::lang::EventObject& /*Source*/)
+            throw( css::uno::RuntimeException, std::exception )
+{
+    mxDispatch.clear();
+}
+
+void ButtonStatusListener::dispose()
+{
+    if (mxDispatch.is()) {
+        mxDispatch->removeStatusListener(this, maCommandURL);
+        mxDispatch.clear();
+    }
+    mButton.clear();
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
\ No newline at end of file