Add form validation

Launcher/Forms/FormTemplates/TextBox.axaml.cs

@@ -15,6 +15,8 @@ public TextBox()
 
     public TextBox(FormEntry entry) : this()
     {
+        TextBlock.IsVisible = !string.IsNullOrEmpty(entry.Name);
+
         TextBlock.Text = entry.Name;
         TextBlock.HorizontalAlignment = entry.Alignment.ToAvaloniaAlignment();
         if (!string.IsNullOrWhiteSpace(entry.Value))

LauncherGamePlugin/Forms/Form.cs

@@ -9,6 +9,27 @@ public class Form
 
     public Func<Task<byte[]?>>? Background { get; set; } = null;
     public IGame? Game { get; set; } = null;
+
+    public TextBoxElement? ValidationFailureField { get; set; }
+
+    public bool Validate(IApp app)
+    {
+        try
+        {
+            FormEntries.ForEach(x => x.Validate());
+        }
+        catch (Exception ex)
+        {
+            if (ValidationFailureField != null)
+            {
+                ValidationFailureField.Name = ex.Message;
+            }
+            app.ShowForm(this);
+            return false;
+        }
+
+        return true;
+    }
 
     public Form(List<FormEntry> entries)
     {
@@ -48,9 +69,9 @@ public static Form CreateDismissibleTextPrompt(string text, IApp app)
     public static FormEntry TextInput(string label, string value = "") 
         => new TextInputElement(label, value);
 
-    public static FormEntry TextBox(string text, FormAlignment alignment = FormAlignment.Default,
+    public static TextBoxElement TextBox(string text, FormAlignment alignment = FormAlignment.Default,
         string fontWeight = "")
-        => new TextBoxElement(text, fontWeight, alignment: alignment);
+        => new(text, fontWeight, alignment: alignment);
 
     public static FormEntry ClickableLinkBox(string text, Action<Form> action,
         FormAlignment alignment = FormAlignment.Default, string fontWeight = "")

LauncherGamePlugin/Forms/FormEntry.cs

@@ -160,6 +160,7 @@ public abstract class FormEntry
     public string Value { get; set; }
     public bool Enabled { get; set; }
     public Form ContainingForm { get; set; }
+    public List<IFormValidator> Validators { get; } = new();
     public FormAlignment Alignment;
     public event Action<FormEntry>? OnChange;
     public void InvokeOnChange() => OnChange?.Invoke(this);
@@ -171,4 +172,7 @@ public FormEntry(string name = "", string value = "", FormAlignment alignment =
         Enabled = enabled;
         Alignment = alignment;
     }
+
+    public void Validate()
+        => Validators.ForEach(x => x.Validate(this));
 }

LauncherGamePlugin/Forms/FormValidator.cs

@@ -0,0 +1,71 @@
+namespace LauncherGamePlugin.Forms;
+
+public interface IFormValidator
+{
+    // Throws on failed validation
+    public void Validate(FormEntry entry);
+}
+
+public class NotEmptyValidation : IFormValidator
+{
+    public void Validate(FormEntry entry)
+    {
+        if (string.IsNullOrWhiteSpace(entry.Value))
+            throw new Exception($"{Utils.OnlyLetters(entry.Name)} is empty");
+    }
+}
+
+public class ExistsValidation : IFormValidator
+{
+    public void Validate(FormEntry entry)
+    {
+        if (entry is FilePickerElement filePickerElement)
+        {
+            if (!File.Exists(entry.Value))
+                throw new Exception($"{Utils.OnlyLetters(filePickerElement.Name)} file does not exist on disk");
+        }
+
+        if (entry is FolderPickerElement folderPickerElement)
+        {
+            if (!Directory.Exists(entry.Value))
+                throw new Exception($"{Utils.OnlyLetters(folderPickerElement.Name)} folder does not exist on disk");
+        }
+    }
+}
+
+public class ContainsValidation : IFormValidator
+{
+    private string _contians;
+
+    public ContainsValidation(string contains)
+    {
+        _contians = contains;
+    }
+
+    public void Validate(FormEntry entry)
+    {
+        if (!entry.Value.Contains(_contians))
+            throw new Exception($"{Utils.OnlyLetters(entry.Name)} does not contain {_contians}");
+    }
+}
+
+public static class FormEntryExtensions
+{
+    public static FormEntry NotEmpty(this FormEntry formEntry)
+    {
+        formEntry.Validators.Add(new NotEmptyValidation());
+        return formEntry;
+    }
+
+    public static FormEntry Exists(this FormEntry formEntry)
+    {
+        formEntry.Validators.Add(new ExistsValidation());
+        return formEntry;
+    }
+
+    public static FormEntry Contains(this FormEntry formEntry, string contains)
+    {
+        formEntry.Validators.Add(new ContainsValidation(contains));
+        return formEntry;
+    }
+}

LauncherGamePlugin/Utils.cs

@@ -1,5 +1,6 @@
 using System.Diagnostics;
 using System.Runtime.InteropServices;
+using System.Text;
 using LauncherGamePlugin.Enums;
 
 namespace LauncherGamePlugin;
@@ -220,4 +221,7 @@ public static string TimeSpanAsTimeEstimate(TimeSpan estimatedTime)
 
         return estimatedDisplay;
     }
+
+    public static string OnlyLetters(string input)
+        => new(input.Where(char.IsLetter).ToArray());
 }

RemoteDownloaderPlugin/Gui/AddOrEditEmuProfileGui.cs

@@ -12,7 +12,6 @@ public class AddOrEditEmuProfileGui
     private string _args;
     private string _workDir;
     private readonly bool _addOrUpdate;
-    private string _error;
 
     public AddOrEditEmuProfileGui(IApp app, Plugin instance)
     {
@@ -24,7 +23,6 @@ public AddOrEditEmuProfileGui(IApp app, Plugin instance)
         _args = "";
         _workDir = "";
         _addOrUpdate = false;
-        _error = "";
     }
 
     public AddOrEditEmuProfileGui(IApp app, Plugin instance, EmuProfile profile)
@@ -42,11 +40,10 @@ public void ShowGui()
         List<FormEntry> formEntries = new()
         {
             Form.TextBox(_addOrUpdate ? "Add new emulation platform" : "Edit emulation platform", FormAlignment.Left, "Bold"),
-            Form.TextInput("Platform:", _platform),
-            Form.FilePicker("Executable Path:", _path),
-            Form.TextInput("CLI Args:", _args),
-            Form.FolderPicker("Working Directory:", _workDir),
-
+            Form.TextInput("Platform:", _platform).NotEmpty(),
+            Form.FilePicker("Executable Path:", _path).NotEmpty().Exists(),
+            Form.TextInput("CLI Args:", _args).NotEmpty().Contains("{EXEC}"),
+            Form.FolderPicker("Working Directory:", _workDir).NotEmpty().Exists(),
         };
 
         if (_addOrUpdate)
@@ -75,51 +72,29 @@ public void ShowGui()
         {
             formEntries.Add(Form.Button("Cancel", _ => _app.HideForm(), "Save", Process));
         }
-
-        if (!string.IsNullOrWhiteSpace(_error))
-            formEntries.Add(Form.TextBox(_error, fontWeight: "Bold"));
-
-        _app.ShowForm(formEntries);
+
+        var errorEntry = Form.TextBox("", FormAlignment.Center);
+        formEntries.Add(errorEntry);
+        var form = new Form(formEntries)
+        {
+            ValidationFailureField = errorEntry
+        };
+
+        _app.ShowForm(form);
     }
 
     public void Process(Form form)
     {
+        if (!form.Validate(_app))
+        {
+            return;
+        }
+
         _platform = form.GetValue("Platform:");
         _path = form.GetValue("Executable Path:");
         _args = form.GetValue("CLI Args:");
         _workDir = form.GetValue("Working Directory:");
-
-        if (string.IsNullOrWhiteSpace(_platform) || 
-            string.IsNullOrWhiteSpace(_path) ||
-            string.IsNullOrWhiteSpace(_args) ||
-            string.IsNullOrWhiteSpace(_workDir))
-        {
-            _error = "Not all fields are filled";
-            ShowGui();
-            return;
-        }
-
-        if (!File.Exists(_path))
-        {
-            _error = "Executable path does not exist";
-            ShowGui();
-            return;
-        }
-
-        if (!Directory.Exists(_workDir))
-        {
-            _error = "Working directory does not exist";
-            ShowGui();
-            return;
-        }
-
-        if (!_args.Contains("{EXEC}"))
-        {
-            _error = "Args does not specify an {EXEC} param";
-            ShowGui();
-            return;
-        }
-
+
         EmuProfile? existingProfile = _instance.Storage.Data.EmuProfiles.FirstOrDefault(x => x.Platform == _platform);
         if (existingProfile == null)
         {