From 7271c2202960fa7d344117ac9d9873c534c9b44f Mon Sep 17 00:00:00 2001
From: Robin <robinboehne@web.de>
Date: Sun, 28 Feb 2021 11:17:16 +0100
Subject: [PATCH] ControlPanel Buttons are now disabled when they have no
 function

---
 .../TypeInferenceView.java                    | 30 ++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/main/java/edu/kit/typicalc/view/content/typeinferencecontent/TypeInferenceView.java b/src/main/java/edu/kit/typicalc/view/content/typeinferencecontent/TypeInferenceView.java
index 9ac60b7..733315d 100644
--- a/src/main/java/edu/kit/typicalc/view/content/typeinferencecontent/TypeInferenceView.java
+++ b/src/main/java/edu/kit/typicalc/view/content/typeinferencecontent/TypeInferenceView.java
@@ -42,6 +42,7 @@ public class TypeInferenceView extends VerticalLayout
     private MathjaxProofTree tree;
     private final transient LatexCreator lc;
     private final Div content;
+    private ControlPanel controlPanel;
 
     /**
      * Initializes the component. When initialization is complete, the first step of the type
@@ -58,13 +59,15 @@ public class TypeInferenceView extends VerticalLayout
                 error -> getTranslation("root." + error.toString().toLowerCase(Locale.ENGLISH)));
         content = new Div();
         content.setId(CONTENT_ID);
-        ControlPanel controlPanel = new ControlPanel(this, this);
+        controlPanel = new ControlPanel(this, this);
         Scroller scroller = new Scroller(content);
         scroller.setId(SCROLLER_ID);
         scroller.setScrollDirection(Scroller.ScrollDirection.BOTH);
         add(scroller, controlPanel);
         treeNumbers = lc.getTreeNumbers();
         setContent();
+        controlPanel.setEnabledFirstStep(false);
+        controlPanel.setEnabledPreviousStep(false);
     }
 
     private void setContent() {
@@ -91,6 +94,12 @@ public class TypeInferenceView extends VerticalLayout
         int treeEnd = treeNumbers.indexOf(tree.getStepCount() - 1);
         currentStep = currentStep > treeEnd && tree.getStepCount() > 0 ? treeEnd : 0;
         refreshElements();
+        if (currentStep == 0) {
+            controlPanel.setEnabledFirstStep(false);
+            controlPanel.setEnabledPreviousStep(false);
+        }
+        controlPanel.setEnabledNextStep(true);
+        controlPanel.setEnabledLastStep(true);
     }
 
     @Override
@@ -98,18 +107,37 @@ public class TypeInferenceView extends VerticalLayout
         int treeEnd = treeNumbers.indexOf(tree.getStepCount() - 1);
         currentStep = currentStep < treeEnd ? treeEnd : unification.getStepCount() - 1;
         refreshElements();
+        if (currentStep == unification.getStepCount() - 1) {
+            controlPanel.setEnabledNextStep(false);
+            controlPanel.setEnabledLastStep(false);
+        }
+        controlPanel.setEnabledFirstStep(true);
+        controlPanel.setEnabledPreviousStep(true);
+
     }
 
     @Override
     public void nextStepButton() {
         currentStep = currentStep < unification.getStepCount() - 1 ? currentStep + 1 : currentStep;
         refreshElements();
+        if (currentStep == unification.getStepCount() - 1) {
+            controlPanel.setEnabledNextStep(false);
+            controlPanel.setEnabledLastStep(false);
+        }
+        controlPanel.setEnabledFirstStep(true);
+        controlPanel.setEnabledPreviousStep(true);
     }
 
     @Override
     public void previousStepButton() {
         currentStep = currentStep > 0 ? currentStep - 1 : currentStep;
         refreshElements();
+        if (currentStep == 0) {
+            controlPanel.setEnabledFirstStep(false);
+            controlPanel.setEnabledPreviousStep(false);
+        }
+        controlPanel.setEnabledNextStep(true);
+        controlPanel.setEnabledLastStep(true);
     }
 
     @Override