Remove unnecessary exception handling in settings

Use optionals instead where a value can be absent

Fixes #4024

common/settings/color_settings.cpp

@@ -300,20 +300,16 @@ bool COLOR_SETTINGS::MigrateFromLegacy( wxConfigBase* aCfg )
 
 COLOR4D COLOR_SETTINGS::GetColor( int aLayer ) const
 {
-    try
+    if( m_color_context == COLOR_CONTEXT::FOOTPRINT && aLayer >= PCBNEW_LAYER_ID_START
+            && aLayer <= GAL_LAYER_ID_END )
     {
-        if( m_color_context == COLOR_CONTEXT::FOOTPRINT && aLayer >= PCBNEW_LAYER_ID_START
+        aLayer += FPEDIT_LAYER_ID_START;
-                && aLayer <= GAL_LAYER_ID_END )
+    }
-        {
-            aLayer += FPEDIT_LAYER_ID_START;
-        }
 
+    if( m_colors.count( aLayer ) )
         return m_colors.at( aLayer );
-    }
+
-    catch( std::out_of_range& )
+    return COLOR4D::UNSPECIFIED;
-    {
-        return COLOR4D::UNSPECIFIED;
-    }
 }
 
 

common/settings/json_settings.cpp

@@ -237,20 +237,22 @@ void JSON_SETTINGS::SaveToFile( const std::string& aDirectory )
 }
 
 
-nlohmann::json JSON_SETTINGS::GetJson( std::string aPath ) const
+OPT<nlohmann::json> JSON_SETTINGS::GetJson( std::string aPath ) const
 {
-    nlohmann::json ret( {} );
+    nlohmann::json::json_pointer ptr = PointerFromString( std::move( aPath ) );
 
-    // Will throw an exception if the path is not found
+    if( this->contains( ptr ) )
-    try
-    {
-        ret = this->at( PointerFromString( std::move( aPath ) ) );
-    }
-    catch( ... )
     {
+        try
+        {
+            return OPT<nlohmann::json>{ this->at( ptr ) };
+        }
+        catch( ... )
+        {
+        }
     }
 
-    return ret;
+    return OPT<nlohmann::json>{};
 }
 
 
@@ -403,9 +405,12 @@ void JSON_SETTINGS::ReleaseNestedSettings( NESTED_SETTINGS* aSettings )
 
 // Specializations to allow conversion between wxString and std::string via JSON_SETTINGS API
 
-template<> wxString JSON_SETTINGS::Get( std::string aPath ) const
+template<> OPT<wxString> JSON_SETTINGS::Get( std::string aPath ) const
 {
-    return wxString( GetJson( std::move( aPath ) ).get<std::string>().c_str(), wxConvUTF8 );
+    if( OPT<nlohmann::json> opt_json = GetJson( std::move( aPath ) ) )
+        return wxString( opt_json->get<std::string>().c_str(), wxConvUTF8 );
+
+    return NULLOPT;
 }
 
 

include/settings/color_settings.h

@@ -129,12 +129,8 @@ public:
 
         COLOR4D val = m_default;
 
-        try
+        if( OPT<COLOR4D> optval = aSettings->Get<COLOR4D>( m_path ) )
-        {
+            val = *optval;
-            val = aSettings->Get<COLOR4D>( m_path );
-        }
-        catch( ... )
-        {}
 
         ( *m_map )[ m_key ] = val;
     }

include/settings/json_settings.h

@@ -25,6 +25,8 @@
 #include <utility>
 #include <wx/string.h>
 
+#include <core/optional.h>
+
 class wxConfigBase;
 class NESTED_SETTINGS;
 class PARAM_BASE;
@@ -90,19 +92,22 @@ public:
      * @param aPath is a string containing one or more keys separated by '.'
      * @return a JSON object from within this one
      */
-    nlohmann::json GetJson( std::string aPath ) const;
+    OPT<nlohmann::json> GetJson( std::string aPath ) const;
 
     /**
      * Fetches a value from within the JSON document.
-     * Will throw an exception if the value is not found or a mismatching type.
+     * Will return an empty optional if the value is not found or a mismatching type.
      * @tparam ValueType is the type to cast to
      * @param aPath is the path within the document to retrieve
      * @return a value from within this document
      */
     template<typename ValueType>
-    ValueType Get( std::string aPath ) const
+    OPT<ValueType> Get( std::string aPath ) const
     {
-        return GetJson( std::move( aPath ) ).get<ValueType>();
+        if( OPT<nlohmann::json> ret = GetJson( std::move( aPath ) ) )
+            return ret->get<ValueType>();
+
+        return NULLOPT;
     }
 
     /**
@@ -220,7 +225,7 @@ protected:
 
 // Specializations to allow conversion between wxString and std::string via JSON_SETTINGS API
 
-template<> wxString JSON_SETTINGS::Get( std::string aPath ) const;
+template<> OPT<wxString> JSON_SETTINGS::Get( std::string aPath ) const;
 
 template<> void JSON_SETTINGS::Set<wxString>( std::string aPath, wxString aVal );
 

include/settings/parameters.h

@@ -22,10 +22,11 @@
 #define _PARAMETERS_H
 
 #include <string>
-#include <boost/ptr_container/ptr_vector.hpp>
 #include <utility>
 #include <math/util.h>
-#include "json_settings.h"
+
+#include <core/optional.h>
+#include <settings/json_settings.h>
 
 
 class PARAM_BASE
@@ -81,9 +82,9 @@ public:
 
         ValueType val = m_default;
 
-        try
+        if( OPT<ValueType> optval = aSettings->Get<ValueType>( m_path ) )
         {
-            val = aSettings->Get<ValueType>( m_path );
+            val = *optval;
 
             if( m_use_minmax )
             {
@@ -91,8 +92,6 @@ public:
                     val = m_default;
             }
         }
-        catch( ... )
-        {}
 
         *m_ptr = val;
     }
@@ -141,16 +140,10 @@ public:
 
         ValueType val = m_default;
 
-        try
+        if( std::is_same<ValueType, nlohmann::json>::value )
-        {
+            val = aSettings->GetJson( m_path );
-            if( std::is_same<ValueType, nlohmann::json>::value )
+        else
-                val = aSettings->GetJson( m_path );
+            val = aSettings->Get<ValueType>( m_path );
-            else
-                val = aSettings->Get<ValueType>( m_path );
-        }
-        catch( ... )
-        {
-        }
 
         m_setter( val );
     }
@@ -274,21 +267,16 @@ public:
 
         std::vector<Type> val = m_default;
 
-        try
+        if( OPT<nlohmann::json> js = aSettings->GetJson( m_path ) )
         {
-            nlohmann::json js = aSettings->GetJson( m_path );
+            if( js->is_array() )
-
-            if( js.is_array() )
             {
                 val.clear();
 
-                for( const auto& el : js.items() )
+                for( const auto& el : js->items() )
                     val.push_back( el.value().get<Type>() );
             }
         }
-        catch( ... )
-        {
-        }
 
         *m_ptr = val;
     }
@@ -342,21 +330,16 @@ public:
 
         std::map<std::string, Value> val = m_default;
 
-        try
+        if( OPT<nlohmann::json> js = aSettings->GetJson( m_path ) )
         {
-            nlohmann::json js = aSettings->GetJson( m_path );
+            if( js->is_object() )
-
-            if( js.is_object() )
             {
                 val.clear();
 
-                for( const auto& el : js.items() )
+                for( const auto& el : js->items() )
                     val[ el.key() ] = el.value().get<Value>();
             }
         }
-        catch( ... )
-        {
-        }
 
         *m_ptr = val;
     }