From 798a13f3a7a48df3bdec1b156f60b27a6536e957 Mon Sep 17 00:00:00 2001
From: LeafHacker <leafhacker@yahoo.com>
Date: Sat, 2 Jan 2021 17:46:24 +0000
Subject: [PATCH] Fix NPE while checking whether to disable button

shouldInstallButtonBeEnabled() switches on OptiFineSetting's value if OptiFineToggleSetting is enabled. However OptiFineSetting's value is null when OptiFine isn't supported by the current installation mode.

Fixes #117
---
 CHANGELOG.md                                         |  3 +++
 .../installer/gui/pages/MainPage.java                | 12 ++++++++----
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2b4b21b..08328b1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixes
+- Fix error checking whether to enable the Install button when OptiFine is enabled but not supported ([#117](https://github.com/ImpactDevelopment/Installer/issues/117))
+
 ## [0.9.3] - 2020-08-28
 
 ### Added
diff --git a/src/main/java/io/github/ImpactDevelopment/installer/gui/pages/MainPage.java b/src/main/java/io/github/ImpactDevelopment/installer/gui/pages/MainPage.java
index c4deaf7..b80a75c 100644
--- a/src/main/java/io/github/ImpactDevelopment/installer/gui/pages/MainPage.java
+++ b/src/main/java/io/github/ImpactDevelopment/installer/gui/pages/MainPage.java
@@ -139,10 +139,14 @@ public MainPage(AppWindow app) {
 
     private boolean shouldInstallButtonBeEnabled(InstallationConfig config) {
         if (config.getSettingValue(OptiFineToggleSetting.INSTANCE)) {
-            switch (config.getSettingValue(OptiFineSetting.INSTANCE)) {
-                case MISSING:
-                case CUSTOM:
-                    return Files.isRegularFile(config.getSettingValue(OptiFineFileSetting.INSTANCE));
+            // OptiFineSetting's value is null when the installation mode doesn't support optifine
+            String optifine = config.getSettingValue(OptiFineSetting.INSTANCE);
+            if (optifine != null) {
+                switch (optifine) {
+                    case MISSING:
+                    case CUSTOM:
+                        return Files.isRegularFile(config.getSettingValue(OptiFineFileSetting.INSTANCE));
+                }
             }
         }
         return true;