Setup

Introduction

This tutorial walks you through turning an empty MonoGame project into a code-only Gum project, which acts as a starting point for the rest of the tutorials.

This tutorial covers:

• Adding Gum NuGet packages

• Modifying your Game class to support Gum and Gum Forms

• Adding your first Gum control (Button)

Adding Gum NuGet Packages

Before writing any code, we must add the Gum NuGet package. Add the Gum.MonoGame package to your game. For more information see the Setup page.

Once you are finished, your game project should reference the Gum.MonoGame project.

Adding Gum to Your Game

Gum requires a few lines of code to get started. A simplified Game class with the required calls would look like the following code:

using MonoGameGum.Forms.Controls;

public class Game1 : Game
{
    private GraphicsDeviceManager _graphics;
    
    GumService Gum => GumService.Default;
    
    public Game1()
    {
        _graphics = new GraphicsDeviceManager(this);
        Content.RootDirectory = "Content";
        IsMouseVisible = true;
    }

    protected override void Initialize()
    {
        Gum.Initialize(this);
            
        var mainPanel = new StackPanel();
        mainPanel.Visual.AddToRoot();
        
        base.Initialize();
    }

    protected override void Update(GameTime gameTime)
    {
        Gum.Update(gameTime);
        base.Update(gameTime);
    }

    protected override void Draw(GameTime gameTime)
    {
        GraphicsDevice.Clear(Color.CornflowerBlue);
        Gum.Draw();
        base.Draw(gameTime);
    }
}

+using MonoGameGum.Forms.Controls;

public class Game1 : Game
{
    private GraphicsDeviceManager _graphics;
    
+   GumService Gum => GumService.Default;
    
    public Game1()
    {
        _graphics = new GraphicsDeviceManager(this);
        Content.RootDirectory = "Content";
        IsMouseVisible = true;
    }

    protected override void Initialize()
    {
+       Gum.Initialize(this);
            
+       var mainPanel = new StackPanel();
+       mainPanel.Visual.AddToRoot();
        
        base.Initialize();
    }

    protected override void Update(GameTime gameTime)
    {
+       Gum.Update(gameTime);
        base.Update(gameTime);
    }

    protected override void Draw(GameTime gameTime)
    {
        GraphicsDevice.Clear(Color.CornflowerBlue);
+       Gum.Draw();
        base.Draw(gameTime);
    }
}

The code above includes the following sections:

• Initialize - The Initialize method prepares Gum for use. It must be called one time for every Gum project.

• Once Gum is initialized, we can create controls such as the StackPanel which contains all other controls. By calling AddToRoot, the mainPanel is drawn and receives input. All items added to the StackPanel will also be drawn and receive input, so we only need to call AddToRoot for the StackPanel.

Gum.Initialize(this);
            
var mainPanel = new StackPanel();
mainPanel.Visual.AddToRoot();

• Update - this updates the internal keyboard, mouse, and gamepad instances and applies default behavior to any forms components. For example, if a Button is added to the StackPanel, this code is responsible for checking if the cursor is overlapping the Button and adjusting the highlight/pressed state appropriately.

Gum.Update(gameTime);

• Draw - this method draws all Gum objects to the screen. This method does not yet perform any drawing since StackPanels are invisible, but we'll be adding controls later in this tutorial.

Gum.Draw();

We can run our project to see a blank (cornflower blue) screen.

Adding Controls

Now that we have Gum running, we can add controls to our StackPanel (mainPanel). The following code in Initialize adds a Button which responds to being clicked by modifying its Text property:

protected override void Initialize()
{
    Gum.Initialize(this);

    var mainPanel = new StackPanel();
    mainPanel.Visual.AddToRoot();

    // Creates a button instance
    var button = new Button();
    // Adds the button as a child so that it is drawn and has its
    // events raised
    mainPanel.AddChild(button);
    // Initial button text before being clicked
    button.Text = "Click Me";
    // Makes the button wider so the text fits
    button.Visual.Width = 350;
    // Click event can be handled with a lambda
    button.Click += (_, _) =>
        button.Text = $"Clicked at {System.DateTime.Now}";

    base.Initialize();
}

protected override void Initialize()
{
    Gum.Initialize(this);

    var mainPanel = new StackPanel();
    mainPanel.Visual.AddToRoot();

+   // Creates a button instance
+   var button = new Button();
+   // Adds the button as a child so that it is drawn and has its
+   // events raised
+   mainPanel.AddChild(button);
+   // Initial button text before being clicked
+   button.Text = "Click Me";
+   // Makes the button wider so the text fits
+   button.Visual.Width = 350;
+   // Click event can be handled with a lambda
+   button.Click += (_, _) =>
+       button.Text = $"Clicked at {System.DateTime.Now}";

    base.Initialize();
}

Conclusion

Now that we have a basic project set up with a single Button. The next tutorial covers the most common forms controls.