From 7cf58aa1fd4a97a231fb8423fa7ebab8a6bb2f9f Mon Sep 17 00:00:00 2001
From: LoRd_MuldeR <mulder2@gmx.de>
Date: Sun, 27 Sep 2020 22:34:42 +0200
Subject: [PATCH] Some code refactoring.

---
 README.md  |  2 +-
 src/head.c | 32 ++++++++++++++++++++++++++------
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index ee189f2..346f412 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ There currently are two different ways to use Launch5j with your application cod
 
 * ***Use the launcher executable with a separate JAR file***  
   
-  Simply put the launcher executable (`launch5j.exe`) and your JAR file into the same directory. Launch5j will automatically detect the path of the JAR file based on the location of the executable file. More specifically, Launch5j detects the full path of the executable file and then replaces the `.exe` file extension with a `.jar` file extension. You can rename the `launch5j.exe` executable to whatever you prefer.
+  Simply put the launcher executable (`launch5j.exe`) and your JAR file into the same directory. Launch5j will automatically detect the path of the JAR file based on the location of the executable file. More specifically, Launch5j detects the full path of the executable file and then replaces the `.exe` file extension with a `.jar` file extension. Of course, you can rename the `launch5j.exe` executable to whatever you prefer.
 
 * ***Combine the launcher executable and the JAR file (“wrapping”)***  
 
diff --git a/src/head.c b/src/head.c
index 538b51f..63b6638 100644
--- a/src/head.c
+++ b/src/head.c
@@ -61,6 +61,12 @@ static const ULONGLONG JAVA_MINIMUM_VERSION = 0x000B000000000000ull;
 static const ULONGLONG JAVA_MINIMUM_VERSION = 0x0008000000000000ull;
 #endif
 
+// Version
+static const DWORD REQUIRED_VERSION[] =
+{
+    (JAVA_MINIMUM_VERSION >> 48) & 0xFFFF, (JAVA_MINIMUM_VERSION >> 32) & 0xFFFF, (JAVA_MINIMUM_VERSION >> 16) & 0xFFFF, JAVA_MINIMUM_VERSION & 0xFFFF
+};
+
 /* ======================================================================== */
 /* String routines                                                          */
 /* ======================================================================== */
@@ -737,6 +743,25 @@ static int show_message_format(HWND hwnd, const DWORD flags, const wchar_t *cons
     return result;
 }
 
+static void show_jre_download_notice(const HWND hwnd)
+{
+    wchar_t *const version_str = (REQUIRED_VERSION[3U] != 0U)
+        ? awprintf(L"%u.%u.%u_%u", REQUIRED_VERSION[0U], REQUIRED_VERSION[1U], REQUIRED_VERSION[2U], REQUIRED_VERSION[3U])
+        : ((REQUIRED_VERSION[2U] != 0U) 
+            ? awprintf(L"%u.%u.%u", REQUIRED_VERSION[0U], REQUIRED_VERSION[1U], REQUIRED_VERSION[2U])
+            : awprintf(L"%u.%u", REQUIRED_VERSION[0U], REQUIRED_VERSION[1U]));
+    if(version_str)
+    {
+        if (show_message_format(hwnd, MB_ICONWARNING | MB_OKCANCEL | MB_TOPMOST, L"JRE not found",
+            L"This application requires the Java Runtime Environment, version %ls, or a compatible newer version.\n\n"
+            L"We recommend downloading the OpenJDK runtime here:\n%ls", version_str, JRE_DOWNLOAD_LINK) == IDOK)
+        {
+            ShellExecuteW(hwnd, NULL, JRE_DOWNLOAD_LINK, NULL, NULL, SW_SHOW);
+        }
+        free(version_str);
+    }
+}
+
 /* ======================================================================== */
 /* Utilities                                                                */
 /* ======================================================================== */
@@ -839,12 +864,7 @@ int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine
     if (!(java_runtime_path = detect_java_runtime()))
     {
         show_message(hwnd, MB_ICONERROR | MB_TOPMOST, L"JRE not found", L"Java Runtime Environment (JRE) could not be found!");
-        if(show_message_format(hwnd, MB_ICONWARNING | MB_OKCANCEL | MB_TOPMOST, L"JRE not found",
-            L"This application requires the Java Runtime Environment, version 8.0 (1.8.0) or a compatible newer version.\n\n"
-            L"We recommend downloading the OpenJDK runtime here:\n%ls", JRE_DOWNLOAD_LINK) == IDOK)
-        {
-            ShellExecuteW(hwnd, NULL, JRE_DOWNLOAD_LINK, NULL, NULL, SW_SHOW);
-        }
+        show_jre_download_notice(hwnd);
         goto cleanup;
     }
     show_message(hwnd, MB_ICONERROR | MB_TOPMOST, L"java_runtime_path Error", java_runtime_path);