Settings window: Add mechanism for conditionally hidden settings

src/settings_gui.cpp

@@ -801,7 +801,7 @@ private:
 	bool IsVisibleByRestrictionMode(RestrictionMode mode) const;
 };
 
-/** Standard setting */
+/** Cargodist per-cargo setting */
 struct CargoDestPerCargoSettingEntry : SettingEntry {
 	CargoID cargo;
 
@@ -813,6 +813,16 @@ protected:
 	virtual void DrawSettingString(uint left, uint right, int y, bool highlight, int32 value) const;
 };
 
+/** Conditionally hidden standard setting */
+struct ConditionallyHiddenSettingEntry : SettingEntry {
+	std::function<bool()> hide_callback;
+
+	ConditionallyHiddenSettingEntry(const char *name, std::function<bool()> hide_callback)
+		: SettingEntry(name), hide_callback(hide_callback) {}
+
+	virtual bool UpdateFilterState(SettingFilter &filter, bool force_visible);
+};
+
 /** Containers for BaseSettingEntry */
 struct SettingsContainer {
 	typedef std::vector<BaseSettingEntry*> EntryVector;
@@ -1238,6 +1248,16 @@ bool CargoDestPerCargoSettingEntry::UpdateFilterState(SettingFilter &filter, boo
 	}
 }
 
+bool ConditionallyHiddenSettingEntry::UpdateFilterState(SettingFilter &filter, bool force_visible)
+{
+	if (this->hide_callback && this->hide_callback()) {
+		SETBITS(this->flags, SEF_FILTERED);
+		return false;
+	} else {
+		return SettingEntry::UpdateFilterState(filter, force_visible);
+	}
+}
+
 /* == SettingsContainer methods == */
 
 /**