added possibility to specify modules dependencies

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@39677 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/module.cpp

@@ -36,6 +36,7 @@ wxModuleList wxModule::m_modules;
 
 void wxModule::RegisterModule(wxModule* module)
 {
+    module->m_state = State_Registered;
     m_modules.Append(module);
 }
 
@@ -69,42 +70,133 @@ void wxModule::RegisterModules()
     }
 }
 
-bool wxModule::InitializeModules()
+bool wxModule::DoInitializeModule(wxModule *module,
+                                  wxModuleList &initializedModules)
 {
-    // Initialize user-defined modules
-    wxModuleList::compatibility_iterator node;
-    for ( node = m_modules.GetFirst(); node; node = node->GetNext() )
+    if ( module->m_state == State_Initializing )
     {
-        wxModule *module = node->GetData();
-        if ( !module->Init() )
+        wxLogError(_("Circular dependency involving module \"%s\" detected."),
+                   module->GetClassInfo()->GetClassName());
+        return false;
+    }
+
+    module->m_state = State_Initializing;
+
+    const wxArrayClassInfo& dependencies = module->m_dependencies;
+
+    // satisfy module dependencies by loading them before the current module
+    for ( unsigned int i = 0; i < dependencies.size(); ++i )
+    {
+        wxClassInfo * cinfo = dependencies[i];
+
+        // Check if the module is already initialized
+        wxModuleList::compatibility_iterator node;
+        for ( node = initializedModules.GetFirst(); node; node = node->GetNext() )
         {
-            wxLogError(_("Module \"%s\" initialization failed"),
-                       module->GetClassInfo()->GetClassName());
+            if ( node->GetData()->GetClassInfo() == cinfo )
+                break;
+        }
 
-            // clean up already initialized modules - process in reverse order
-            wxModuleList::compatibility_iterator n;
-            for ( n = node->GetPrevious(); n; n = n->GetPrevious() )
+        if ( node )
+        {
+            // this dependency is already initialized, nothing to do
+            continue;
+        }
+
+        // find the module in the registered modules list
+        for ( node = m_modules.GetFirst(); node; node = node->GetNext() )
+        {
+            wxModule *moduleDep = node->GetData();
+            if ( moduleDep->GetClassInfo() == cinfo )
             {
-                n->GetData()->OnExit();
-            }
+                if ( !DoInitializeModule(moduleDep, initializedModules ) )
+                {
+                    // failed to initialize a dependency, so fail this one too
+                    return false;
+                }
 
+                break;
+            }
+        }
+
+        if ( !node )
+        {
+            wxLogError(_("Dependency \"%s\" of module \"%s\" doesn't exist."),
+                       cinfo->GetClassName(),
+                       module->GetClassInfo()->GetClassName());
             return false;
         }
     }
 
+    if ( !module->Init() )
+    {
+        wxLogError(_("Module \"%s\" initialization failed"),
+                   module->GetClassInfo()->GetClassName());
+        return false;
+    }
+
+    wxLogTrace(TRACE_MODULE, wxT("Module \"%s\" initialized"),
+               module->GetClassInfo()->GetClassName());
+
+    module->m_state = State_Initialized;
+    initializedModules.Append(module);
+
     return true;
 }
 
-void wxModule::CleanUpModules()
+// Initialize user-defined modules
+bool wxModule::InitializeModules()
 {
-    // Cleanup user-defined modules
-    wxModuleList::compatibility_iterator node;
-    for ( node = m_modules.GetFirst(); node; node = node->GetNext() )
+    wxModuleList initializedModules;
+
+    for ( wxModuleList::compatibility_iterator node = m_modules.GetFirst();
+          node;
+          node = node->GetNext() )
+    {
+        wxModule *module = node->GetData();
+
+        // the module could have been already initialized as dependency of
+        // another one
+        if ( module->m_state == State_Registered )
+        {
+            if ( !DoInitializeModule( module, initializedModules ) )
+            {
+                // failed to initialize all modules, so clean up the already
+                // initialized ones
+                DoCleanUpModules(initializedModules);
+
+                return false;
+            }
+        }
+    }
+
+    // remember the real initialisation order
+    m_modules = initializedModules;
+
+    return true;
+}
+
+// Clean up all currently initialized modules
+void wxModule::DoCleanUpModules(const wxModuleList& modules)
+{
+    // cleanup user-defined modules in the reverse order compared to their
+    // initialization -- this ensures that dependencies are respected
+    for ( wxModuleList::compatibility_iterator node = modules.GetLast();
+          node;
+          node = node->GetPrevious() )
     {
         wxLogTrace(TRACE_MODULE, wxT("Cleanup module %s"),
                    node->GetData()->GetClassInfo()->GetClassName());
-        node->GetData()->Exit();
+
+        wxModule * module = node->GetData();
+
+        wxASSERT_MSG( module->m_state == State_Initialized,
+                        _T("not initialized module being cleaned up") );
+
+        module->Exit();
+        module->m_state = State_Registered;
     }
 
+    // clear all modules, even the non-initialized ones
     WX_CLEAR_LIST(wxModuleList, m_modules);
 }