Linux - Show visible error, if xdelta3/ java doesn't exist, Fixes #18

AM2RLauncher/AM2RLauncher/CrossPlatformOperations.cs

@@ -215,10 +215,20 @@ namespace AM2RLauncher
         /// <returns><see langword="true"/> if it is installed, <see langword="false"/> if not.</returns>
         public static bool IsJavaInstalled()
         {
+            string process = null;
+            string arguments = null;
+
             if (currentPlatform.IsWinForms)
             {
-                string process = "cmd.exe",
+                process = "cmd.exe";
                 arguments = "/C java -version";
+            }
+            else if (currentPlatform.IsGtk)
+            {
+                process = "java";
+                arguments = "-version";
+            }
+
             ProcessStartInfo javaStart = new ProcessStartInfo();
             javaStart.FileName = process;
             javaStart.Arguments = arguments;
@@ -243,14 +253,43 @@ namespace AM2RLauncher
             }
 
             return java.ExitCode == 0;
+            
         }
-            else if (currentPlatform.IsGtk)
+
+        /// <summary>
+        /// Checks if command-line xdelta is installed on non-Windows systems.
+        /// </summary>
+        /// <returns><see langword="true"/> if it is installed, <see langword="false"/> if not.</returns>
+        public static bool CheckIfXdeltaIsInstalled()
         {
-                return true;            // sorry linux users, either Eto, .net or GTK is dumb.
+            string process = "xdelta3";
+            string arguments = "-V";      
+
+            ProcessStartInfo xdeltaStart = new ProcessStartInfo();
+            xdeltaStart.FileName = process;
+            xdeltaStart.Arguments = arguments;
+            xdeltaStart.UseShellExecute = false;
+            xdeltaStart.CreateNoWindow = true;
+
+
+            Process xdelta = new Process();
+
+            xdelta.StartInfo = xdeltaStart;
+
+            try
+            {
+                xdelta.Start();
+
+                xdelta.WaitForExit();
             }
+            catch (System.ComponentModel.Win32Exception)
+            {
                 return false;
             }
 
+            return xdelta.ExitCode == 0;
+        }
+
         /// <summary>
         /// This applies an Xdelta Patch cross-platform.
         /// </summary>

AM2RLauncher/AM2RLauncher/MainForm/MainForm.Methods.cs

@@ -251,6 +251,19 @@ namespace AM2RLauncher
         {
             log.Info("Installing profile " + profile.Name + "...");
 
+            // check if xdelta is installed on linux, by searching all folders in PATH
+            if (Platform.IsGtk && !CrossPlatformOperations.CheckIfXdeltaIsInstalled())
+            {
+                Application.Instance.Invoke(new Action(() =>
+                {
+                    MessageBox.Show(Language.Text.XdeltaNotFound, Language.Text.WarningWindowTitle, MessageBoxButtons.OK);
+                }));
+                SetPlayButtonState(UpdateState.Install);
+                UpdateStateMachine();
+                log.Error("Xdelta not found. Aborting installing a profile...");
+                return;
+            }
+
             string profilesHomePath = CrossPlatformOperations.CURRENTPATH + "/Profiles";
             string profilePath = profilesHomePath + "/" + profile.Name;
 
@@ -419,14 +432,33 @@ namespace AM2RLauncher
 
                 // Check for java, exit safely with a warning if not found!
                 if (!CrossPlatformOperations.IsJavaInstalled())
+                {
+                    //message box show needs to be done on main thread
+                    Application.Instance.Invoke(new Action(() =>
                     {
                         MessageBox.Show(Language.Text.JavaNotFound, Language.Text.WarningWindowTitle, MessageBoxButtons.OK);
+                    }));
                     SetApkButtonState(ApkButtonState.Create);
                     UpdateStateMachine();
                     log.Error("Java not found! Aborting Android APK creation.");
                     return;
                 }
 
+                // check if xdelta is installed on linux, by searching all folders in PATH
+                if (Platform.IsGtk && !CrossPlatformOperations.CheckIfXdeltaIsInstalled())
+                {   
+                    //message box show needs to be done on main thread
+                    Application.Instance.Invoke(new Action(() =>
+                    {
+                        MessageBox.Show(Language.Text.XdeltaNotFound, Language.Text.WarningWindowTitle, MessageBoxButtons.OK);
+                    }));
+                    SetApkButtonState(ApkButtonState.Create);
+                    UpdateStateMachine();
+                    log.Error("Xdelta not found. Aborting Android APK creation...");
+                    return;
+
+                }
+
                 log.Debug("java installed!");
 
                 string proc = "",