Feature/input-error-handling

src/main/scala/satify/model/State.scala

@@ -1,6 +1,7 @@
 package satify.model
 
 import satify.model
+import satify.model.errors.Error
 import satify.model.expression.Expression
 import satify.model.problems.Problem
 
@@ -25,13 +26,24 @@ trait State:
   type Problem = problems.Problem
   val problem: Option[Problem] = None
 
+  /** Error representation */
+  type Error = errors.Error
+  val error: Option[Error] = None
+
 /** Factory for [[State]] instances. */
 object State:
   /** Creates a new empty application state.
     * @return a new [[State]] instance.
     */
   def apply(): State = StateImpl()
 
+  /** Creates a new application state containing only the the input and the occurred error.
+    * @param input the input string
+    * @param error the [[Error]]
+    * @return a new [[State]] instance.
+    */
+  def apply(input: String, error: Error): State = StateImpl(Some(input), None, None, None, None, Some(error))
+
   /** Creates a new application state with input expression and its CNF.
     * @param exp the input [[Expression]]
     * @param cnf the [[CNF]]
@@ -68,5 +80,6 @@ object State:
       override val expression: Option[Expression] = None,
       override val cnf: Option[CNF] = None,
       override val solution: Option[Solution] = None,
-      override val problem: Option[Problem] = None
+      override val problem: Option[Problem] = None,
+      override val error: Option[Error] = None
   ) extends State

src/main/scala/satify/model/errors/Error.scala

@@ -0,0 +1,5 @@
+package satify.model.errors
+
+enum Error:
+  case InvalidInput
+  case Unknown

src/main/scala/satify/update/Update.scala

@@ -3,6 +3,8 @@ package satify.update
 import satify.dsl.Reflection.reflect
 import satify.model.*
 import satify.model.CNF.Symbol
+import satify.model.errors.Error
+import satify.model.errors.Error.InvalidInput
 import satify.model.expression.Expression
 import satify.model.problems.NQueens.*
 import satify.model.problems.ProblemChoice.{GraphColoring, NurseScheduling, NQueens as NQueensChoice}
@@ -20,9 +22,13 @@ object Update:
     message match
       case Input(char) => model
       case Solve(input) =>
-        val exp = reflect(input)
-        given CNFConverter = exp => tseitin(exp)
-        State(input, exp, Solver().solve(exp))
+        try
+          val exp = reflect(input)
+          given CNFConverter = exp => tseitin(exp)
+          State(input, exp, Solver().solve(exp))
+        catch
+          case e: Exception =>
+            State(input, InvalidInput)
       case SolveProblem(problem, parameter) =>
         val exp: Expression = problem match
           case NQueensChoice => NQueens(parameter).exp

src/main/scala/satify/view/View.scala

@@ -1,20 +1,23 @@
 package satify.view
 
+import satify.model.errors.Error
+import satify.model.errors.Error.*
 import satify.model.{CNF, Solution, State}
-import satify.view.ComponentUtils.{createInputTextArea, createNextSection, createOutputTextArea}
+import satify.view.ComponentUtils.{createErrorDialog, createInputTextArea, createNextSection, createOutputTextArea}
 import satify.view.Constants.{cnfOutputDialogName, solOutputDialogName}
 
 import scala.swing.*
 
 object View:
   def view(model: State): Set[Component] =
     import model.*
-    updateExpression(input.get) ++ updateCnf(cnf) ++ updateSolution(model, solution)
+    if error.isDefined then updateError(error.get, input.get)
+    else updateExpression(input.get) ++ updateCnf(cnf) ++ updateSolution(model, solution)
 
   /** Update the solution components
     * @param model the current state
     * @param sol the solution to show
-    * @return
+    * @return a set of components to add to the GUI
     */
   private def updateSolution(model: State, sol: Option[Solution]): Set[Component] =
     if sol.isDefined then
@@ -39,7 +42,20 @@ object View:
     else Set()
 
   /** Update the expression text area
-    * @param exp the component to show
+    * @param exp the exp to show in new component
     * @return a set of components to add to the GUI
     */
   private def updateExpression(exp: String): Set[Component] = Set(createInputTextArea(exp))
+
+  /** Update the error and show it in a dialog
+    *  @param error the error to show in a popup dialog
+    * @param input the input to show in new component
+    * @return a set of components to add to the GUI
+    */
+  private def updateError(error: Error, input: String): Set[Component] =
+    var errorDialog: Dialog = null
+    error match
+      case InvalidInput => errorDialog = createErrorDialog("Invalid input")
+      case Unknown => errorDialog = createErrorDialog("Unknown error")
+    errorDialog.open()
+    Set(createInputTextArea(input))