Code-Bin #1229 - XNA Simple Text Box

XNA Simple Text Box
Posted by: Quimby RBG | April 18, 2011 @ 12:47am

C# Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Graphics;

namespace NameSpace
{
    class TextInput
    {
        public Rectangle TextLoc;
        public string Text;
        KeyboardState OldState;
        public bool Active = false;
        private SpriteFont Font;
        private Texture2D BackImage;
        public Color[] Colour = new Color[2];
        int MaxCharacters;

public TextInput(string Default, Rectangle DrawTo, SpriteFont _Font, Texture2D BackGround, Color Active_Colour, Color Static_Colour)
        {
            Text = Default; TextLoc = DrawTo; Font = _Font; BackImage = BackGround; Colour[0] = Active_Colour; Colour[1] = Static_Colour;
            OldState = new KeyboardState(); MaxCharacters = -1;
        }

public int Max_Characters
        {set { MaxCharacters = value; }}
        public int Remaining_Characters
        {
            get
            {
                if (MaxCharacters > 0) { return MaxCharacters - Text.Length; }
                return 0;
            }
        }

public void Draw(SpriteBatch SB)
        {
            int YPos = (int)((TextLoc.Y + (TextLoc.Height / 2)) - (Font.MeasureString("|").Y / 2));
            int XPos = (int)((TextLoc.X + (TextLoc.Width / 2)) - (Font.MeasureString(Text).X / 2));
            if (Active) { SB.Draw(BackImage, TextLoc, Colour[0]); }
            else { SB.Draw(BackImage, TextLoc, Colour[1]); }
            SB.DrawString(Font, Text, new Vector2(XPos, YPos), Color.Black);
        }

public void Update()
        {
            if (Active)
            {
                KeyboardState NewState = Keyboard.GetState();
                Keys[] PressedKeys = NewState.GetPressedKeys();
                foreach (Keys key in PressedKeys)
                {
                    if (OldState.IsKeyUp(key))
                    {
                        //Backspace
                        if (key == Keys.Back) { if (Text.Length > 0) { Text = Text.Remove(Text.Length - 1, 1); } }
                        //Space
                        else if (key == Keys.Space) { if (Text.Length > 0) { Text = Text + " "; } }
                        //Confirm the textbox
                        else if (key == Keys.Enter) { Active = false; }
                        //Numbers
                        else if (key == Keys.D0 || key == Keys.D1 || key == Keys.D2 || key == Keys.D3 || key == Keys.D4 || key == Keys.D5 || key == Keys.D6 || key == Keys.D7 || key == Keys.D8 || key == Keys.D9)
                        { string DUD = key.ToString(); Text += DUD.Remove(0, 1); }
                        //Letters
                        else if (key == Keys.A || key == Keys.B || key == Keys.C || key == Keys.D || key == Keys.E || key == Keys.F || key == Keys.G || key == Keys.H || key == Keys.I || key == Keys.J || key == Keys.K || key == Keys.L || key == Keys.M || key == Keys.N || key == Keys.O || key == Keys.P || key == Keys.Q || key == Keys.R || key == Keys.S || key == Keys.T || key == Keys.U || key == Keys.V || key == Keys.W || key == Keys.X || key == Keys.Y || key == Keys.Z)
                        { try { Text += key.ToString(); } catch { } }
                        //The rest get ignored as their .ToString()s suck
                    }
                }
                OldState = NewState;
                if (MaxCharacters > -1 && Text.Length > MaxCharacters)
                { Text = Text.Remove(MaxCharacters, Text.Length - MaxCharacters); }
            }
        }

}
}

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Author Comments

~Requires Microsoft XNA 4.0~
(though probably fine with older)
This is a quick and easy text box I did up when I found out I had to ditch the GamerServices Keyboard input for getting names for my high scores table.
The max character setting is handy for high score tables as having a finite number of characters will prevent it running off the screen.
The rectangle for where it is to be drawn is exposed so you can check it against mouse clicks or, as I did, draw a "X Characters remaining" string centred below the text box.
((X+(Width/2))-font.measurestring(string).x/2)
You can update it every turn and it will only update if it is active, but I find Active useful to check against to use as a "User just confirmed text box entry" prompt by using if(Textbox.Active){Textbox.Update();}else{Do Something}

Have fun; It's pretty basic, but hopefully it might save you some time if you just want a quick alphanumeric input. :)

Quimby ~ RBG Entertainment

Rating

4.77 / 8
35 Votes