Navigator: consider how to approach path resolution

obviously, we get a trivial case, when the path is explicit,
and we need a tricky full blown resolution with backtracking
when forced to interpolate wildcards to cover a given UICoord
spec against the actual UI topology.

Do we need it?
 * actually not right now
 * but already a complete implementation of the ViewSpec concept
   requires such a resolution

src/gui/interact/ui-coord-resolver.cpp

@@ -0,0 +1,53 @@
+/*
+  UICoordResolver  -  resolve UI coordinate spec against actual window topology
+
+  Copyright (C)         Lumiera.org
+    2017,               Hermann Vosseler <Ichthyostega@web.de>
+
+  This program is free software; you can redistribute it and/or
+  modify it under the terms of the GNU General Public License as
+  published by the Free Software Foundation; either version 2 of
+  the License, or (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+* *****************************************************/
+
+
+/** @file ui-coord-resolver.cpp
+ ** Implementation details of resolving a UICoord path against the actual UI topology.
+ ** 
+ ** @todo WIP 10/2017 initial draft       ////////////////////////////////////////////////////////////TICKET #1107
+ */
+
+
+#include "gui/interact/ui-coord-resolver.hpp"
+//#include "gui/ctrl/global-ctx.hpp"
+//#include "lib/symbol.hpp"
+//#include "lib/util.hpp"
+
+//using util::cStr;
+//using util::isnil;
+using lib::Symbol;
+
+
+namespace gui {
+namespace interact {
+  
+  /** */
+  bool
+  UICoordResolver::pathResolution()
+  {
+    UNIMPLEMENTED ("backtracking reolution of path wildcards");
+  }
+  
+  
+  
+}}// namespace gui::interact

src/gui/interact/ui-coord-resolver.hpp

@@ -48,13 +48,15 @@
 #include "lib/error.hpp"
 #include "lib/symbol.hpp"
 #include "gui/interact/ui-coord.hpp"
+#include "lib/iter-source.hpp"
+#include "lib/iter-stack.hpp"
 //#include "lib/util.hpp"
 
 //#include <boost/noncopyable.hpp>
 //#include <string>
 //#include <vector>
 #include <utility>
-//#include <memory>
+#include <memory>
 
 
 namespace gui {
@@ -64,8 +66,8 @@ namespace interact {
   
 //  using std::unique_ptr;
 //  using std::string;
-//  using lib::Literal;
-  using lib::Symbol;
+  using lib::Literal;
+//  using lib::Symbol;
 //  using util::unConst;
 //  using util::isnil;
 //  using util::min;
@@ -82,12 +84,36 @@ namespace interact {
     public:
       virtual ~LocationQuery() { }  ///< this is an interface
       
+      using ChildIter = lib::IterSource<Literal>;
+
       /** */
     };
   
   
   
   
+  namespace path { ///< @internal implementation details of UICoord resolution against actual UI
+
+    struct Resolution
+      {
+        const char* anchor = nullptr;
+        size_t depth       = 0;
+        std::unique_ptr<UICoord> covfefe;
+        bool isComplete    = false;
+      };
+
+    struct ResolutionState
+      {
+        using ChildIter = LocationQuery::ChildIter;
+
+        lib::IterStack<ChildIter> backlog;
+        lib::IterQueue<Resolution> solutions;
+      };
+
+  }//(End) implementation details
+
+
+
   /**
    * Query and mutate UICoord specifications in relation to actual UI topology.
    * 
@@ -96,11 +122,17 @@ namespace interact {
   class UICoordResolver
     : public UICoord::Builder
     {
+      LocationQuery& query_;
+      path::Resolution res_;
       
     public:
       UICoordResolver (UICoord const& uic, LocationQuery& queryAPI)
         : Builder{uic}
-      { }
+        , query_{queryAPI}
+        , res_{}
+        {
+          attempt_trivialResolution();
+        }
       
       
       /* === query functions === */
@@ -158,6 +190,14 @@ namespace interact {
       
       
     private:
+      void
+      attempt_trivialResolution()
+        {
+          UNIMPLEMENTED ("if possible, establish a trivial anchorage and coverage right away");
+        }
+
+      /** @internal algorithm to resolve this UICoord path against the actual UI topology */
+      bool pathResolution();
     };
   
   

tests/gui/interact/ui-coord-resolver-test.cpp

@@ -114,7 +114,7 @@ namespace test {
           UICoordResolver resolver{uic, locationQuery};
 
           CHECK (not resolver.isCovered());
-          CHECK (not resolver.canCover());
+          CHECK (    resolver.canCover());
 
           UICoord uic2 = resolver.cover()
                                  .extend("otherView");