Add PARAM_OBSOLETE to clean out old JSON structures.

While not technically necessary, the old structures can be confusing
to users looking at the files.

Fixes https://gitlab.com/kicad/code/kicad/issues/8856

3d-viewer/3d_viewer/eda_3d_viewer_settings.cpp

@@ -198,6 +198,8 @@ EDA_3D_VIEWER_SETTINGS::EDA_3D_VIEWER_SETTINGS()
                                               &m_Camera.rotation_increment, 10.0 ) );
     m_params.emplace_back( new PARAM<int>( "camera.projection_mode",
                                            &m_Camera.projection_mode, 1 ) );
+
+    m_params.emplace_back( new PARAM_OBSOLETE( "colors" ) );
 }
 
 

common/settings/json_settings.cpp

@@ -369,18 +369,6 @@ void JSON_SETTINGS::ResetToDefaults()
 }
 
 
-bool JSON_SETTINGS::IsDefault( const std::string& aParamName )
-{
-    for( const PARAM_BASE* param : m_params )
-    {
-        if( param->GetJsonPath() == aParamName )
-            return param->IsDefault();
-    }
-
-    return false;
-}
-
-
 bool JSON_SETTINGS::SaveToFile( const wxString& aDirectory, bool aForce )
 {
     if( !m_writeFile )

common/settings/parameters.cpp

@@ -25,6 +25,13 @@
 #include <gal/color4d.h>
 #include <project/project_file.h>
 #include <settings/parameters.h>
+#include <settings/json_settings_internals.h>
+
+
+void PARAM_OBSOLETE::Store( JSON_SETTINGS* aSettings ) const
+{
+    aSettings->Internals()->erase( m_path );
+}
 
 
 template <typename ValueType>

include/settings/color_settings.h

@@ -151,11 +151,6 @@ public:
         ( *m_map )[ m_key ] = m_default;
     }
 
-    bool IsDefault() const override
-    {
-        return ( *m_map )[ m_key ] == m_default;
-    }
-
     bool MatchesFile( JSON_SETTINGS* aSettings ) const override
     {
         if( OPT<COLOR4D> optval = aSettings->Get<COLOR4D>( m_path ) )

include/settings/json_settings.h

@@ -61,7 +61,8 @@ public:
     friend class NESTED_SETTINGS;
 
     JSON_SETTINGS( const wxString& aFilename, SETTINGS_LOC aLocation, int aSchemaVersion ) :
-            JSON_SETTINGS( aFilename, aLocation, aSchemaVersion, true, true, true ) {}
+            JSON_SETTINGS( aFilename, aLocation, aSchemaVersion, true, true, true )
+    {}
 
     JSON_SETTINGS( const wxString& aFilename, SETTINGS_LOC aLocation, int aSchemaVersion,
                    bool aCreateIfMissing, bool aCreateIfDefault, bool aWriteFile );
@@ -123,13 +124,6 @@ c     * @return true if the file was saved
      */
     void ResetToDefaults();
 
-    /**
-     * Checks if the current state of a parameter matches its default value
-     * @param aParamName is the JSON path to the parameter
-     * @return true if the given parameter is at its default value
-     */
-    bool IsDefault( const std::string& aParamName );
-
     /**
      * Fetches a JSON object that is a subset of this JSON_SETTINGS object, using a path of the
      * form "key1.key2.key3" to refer to nested objects.

include/settings/parameters.h

@@ -54,12 +54,6 @@ public:
 
     virtual void SetDefault() = 0;
 
-    /**
-     * Checks whether or not this param has been changed from its default value
-     * @return true if the parameter in memory matches its default value
-     */
-    virtual bool IsDefault() const = 0;
-
     /**
      * Checks whether the parameter in memory matches the one in a given JSON file
      * @param aSettings is a JSON_SETTINGS to check the JSON file contents of
@@ -144,11 +138,6 @@ public:
         *m_ptr = m_default;
     }
 
-    bool IsDefault() const override
-    {
-        return *m_ptr == m_default;
-    }
-
     bool MatchesFile( JSON_SETTINGS* aSettings ) const override
     {
         if( OPT<ValueType> optval = aSettings->Get<ValueType>( m_path ) )
@@ -167,6 +156,30 @@ protected:
     ValueType m_default;
 };
 
+/**
+ * Handles an obsolete parameter (ie: removes it on write).
+ */
+class PARAM_OBSOLETE : public PARAM_BASE
+{
+public:
+    PARAM_OBSOLETE( const std::string& aJsonPath ) :
+            PARAM_BASE( aJsonPath, false )
+    { }
+
+    void Load( JSON_SETTINGS* aSettings, bool aResetIfMissing = true ) const override
+    { }
+
+    void Store( JSON_SETTINGS* aSettings ) const override;
+
+    void SetDefault() override
+    { }
+
+    bool MatchesFile( JSON_SETTINGS* aSettings ) const override
+    {
+        return !aSettings->Contains( m_path );
+    }
+};
+
 /**
  * Stores a path as a string with directory separators normalized to unix-style
  */
@@ -268,11 +281,6 @@ public:
         *m_ptr = m_default;
     }
 
-    bool IsDefault() const override
-    {
-        return *m_ptr == m_default;
-    }
-
     bool MatchesFile( JSON_SETTINGS* aSettings ) const override
     {
         if( OPT<int> val = aSettings->Get<int>( m_path ) )
@@ -328,11 +336,6 @@ public:
         m_setter( m_default );
     }
 
-    bool IsDefault() const override
-    {
-        return m_getter() == m_default;
-    }
-
     bool MatchesFile( JSON_SETTINGS* aSettings ) const override;
 
 private:
@@ -414,11 +417,6 @@ public:
         *m_ptr = m_default;
     }
 
-    bool IsDefault() const override
-    {
-        return *m_ptr == m_default;
-    }
-
     bool MatchesFile( JSON_SETTINGS* aSettings ) const override
     {
         if( OPT<double> optval = aSettings->Get<double>( m_path ) )
@@ -463,11 +461,6 @@ public:
         *m_ptr = m_default;
     }
 
-    bool IsDefault() const override
-    {
-        return *m_ptr == m_default;
-    }
-
     bool MatchesFile( JSON_SETTINGS* aSettings ) const override;
 
 protected:
@@ -559,11 +552,6 @@ public:
         *m_ptr = m_default;
     }
 
-    bool IsDefault() const override
-    {
-        return *m_ptr == m_default;
-    }
-
     bool MatchesFile( JSON_SETTINGS* aSettings ) const override;
 
 private:
@@ -596,11 +584,6 @@ public:
         *m_ptr = m_default;
     }
 
-    bool IsDefault() const override
-    {
-        return *m_ptr == m_default;
-    }
-
     bool MatchesFile( JSON_SETTINGS* aSettings ) const override;
 
 private: