GSoC notebookbar: better default page handling

+ selected default tab page in the Impress
+ the default tab page is set when context isn't supported
+ switching between unsupported contexts is not causing
  switch to default tab to avoid closing of tab which was
  recently used by user

Change-Id: Ieeda8a79e6c67708551351f9bb49d8b006c0e74f
Reviewed-on: https://gerrit.libreoffice.org/27432
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Samuel Mehrbrodt <Samuel.Mehrbrodt@cib.de>

include/vcl/tabctrl.hxx

@@ -213,6 +213,7 @@ protected:
     virtual void ImplPaint(vcl::RenderContext& rRenderContext, const Rectangle& rRect) override;
 
 private:
+    bool bLastContextWasSupported;
     vcl::EnumContext::Context eLastContext;
     Link<NotebookBar*,void> m_aIconClickHdl;
 };

sd/uiconfig/simpress/ui/notebookbar.ui

@@ -1476,6 +1476,10 @@
                 <property name="can_focus">False</property>
                 <property name="label" translatable="yes">Home</property>
                 <property name="use_underline">True</property>
+                <style>
+                  <class name="context-default"/>
+                  <class name="context-any"/>
+                </style>
               </object>
               <packing>
                 <property name="position">1</property>

vcl/source/control/tabctrl.cxx

@@ -2205,7 +2205,8 @@ VCL_BUILDER_FACTORY(NotebookbarTabControl);
 
 NotebookbarTabControl::NotebookbarTabControl(vcl::Window* pParent, WinBits nStyle)
     : TabControl(pParent, nStyle)
-    , eLastContext( vcl::EnumContext::Context::Context_Any )
+    , bLastContextWasSupported(true)
+    , eLastContext(vcl::EnumContext::Context::Context_Any)
 {
     LanguageTag aLocale( Application::GetSettings().GetUILanguageTag());
     ResMgr* pResMgr = ResMgr::SearchCreateResMgr( "vcl", aLocale );
@@ -2222,6 +2223,8 @@ void NotebookbarTabControl::SetContext( vcl::EnumContext::Context eContext )
 {
     if (eLastContext != eContext)
     {
+        bool bHandled = false;
+
         for (int nChild = 0; nChild < GetChildCount(); ++nChild)
         {
             TabPage* pPage = static_cast<TabPage*>(GetChild(nChild));
@@ -2231,10 +2234,22 @@ void NotebookbarTabControl::SetContext( vcl::EnumContext::Context eContext )
             else
                 EnablePage(nChild + 2, false);
 
-            if (pPage->HasContext(eContext) && eContext != vcl::EnumContext::Context::Context_Any)
+            if (!bHandled && bLastContextWasSupported
+                && pPage->HasContext(vcl::EnumContext::Context::Context_Default))
+            {
                 SetCurPageId(nChild + 2);
+            }
+
+            if (pPage->HasContext(eContext) && eContext != vcl::EnumContext::Context::Context_Any)
+            {
+                SetCurPageId(nChild + 2);
+                bHandled = true;
+                bLastContextWasSupported = true;
+            }
         }
 
+        if (!bHandled)
+            bLastContextWasSupported = false;
         eLastContext = eContext;
     }
 }