TextBox

The TextBox control allows users to enter a string. It supports highlighting, copy/paste, selection with mouse and keyboard, and CTRL key for performing operations on entire words.

Code Example: Creating a TextBox

The following code creates a TextBox.

var textBox = new TextBox();
this.Root.Children.Add(textBox.Visual);
textBox.X = 50;
textBox.Y = 50;
textBox.Width = 200;
textBox.Height = 34;
textBox.Placeholder = "Placeholder Text...";

var textBox2 = new TextBox();
this.Root.Children.Add(textBox2.Visual);
textBox2.X = 50;
textBox2.Y = 90;
textBox2.Width = 200;
textBox2.Height = 34;
textBox2.Placeholder = "Placeholder Text...";

Interacting with TextBoxes

Typing

TextBox supports reading characters from the keyboard. It supports:

• Regular character typing

• Backspace

• Delete

• Enter (if multi-line)

• Keyboard repeat rate

• CTRL X, C, and V for cut, copy, and paste

The TextBox respects the OS-level repat rate. For example, the following animation shows the TextBox responding to the Windows Key repeat rate.

Key repeat rate adjusted in Windows

Selection

Selection can be performed programmatically or by the user using the cursor.

The SelectionLength property can be used to determine if any text is selected. The following code shows how to output the selected characters:

if(textBox.SelectionLength > 0)
{
    var selectedText = textBox.Text.Substring(
        textBox.SelectionStart, 
        textBox.SelectionLength);
    System.Diagnostics.Debug.WriteLine("Selected text: " + selectedText");
}

The SelectionStart and SelectionLength properties can be modified to change the visual selection. For example, the following selects the first 5 letters:

textBox.SelectionStart = 0;
textBox.SelectionLength = 5;

The entire text can be selected as shown in the following code:

textBox.SelectionStart = 0;
textBox.SelectionLength = textBox.Text?.Length ?? 0; // in case text is null

Selection can also be performed by the user. Double-clicking the text box selects all text. Also, pressing CTRL+A selects all text.

Double-click selects all text

A push+drag with the mouse selects the text between the start and the current location of the drag.

Push+drag to select text

Holding down the shift key and pressing the arrow keys adjusts the selection.

Arrow keys + shift to select

TextWrapping

The TextWrapping property can be used to set whether the TextBox wraps text. By default this value is set to TextWrapping.NoWrap which means the text does not wrap, but instead extends horizontally.

TextWrapping.NoWrap causes text to scroll

If TextWrapping is set to `TextWrapping.Wrap, then text wraps to multiple lines. Note that usually this is combined with a taller text box so that multiple lines display properly.

wrappedTextBox.TextWrapping = TextWrapping.Wrap;
// If you have set up your TextBox in code, you may need to make it taller:
wrappedTextBox.Height = 140;

TextWrapping.Wrap causes text to wrap

Extended Character Sets and Keyboards

The TextBox supports entering characters respecting the current keyboard language settings. This includes typing characters with accents, pasting text, and entering alt codes (https://www.alt-codes.net/ ).

TextBox displaying the é character

Characters must be available in the current font to support being written in TextBoxes. If you would like to support more characters, you can explicitly create a font (.fnt) including the desired characters, or change the default character set in Gum.

For more information on creating fonts, see the Font and Use Custom Font pages. For more information on specifying the default character set in Gum, see the Project Property Font Ranges page.