In this recipe, we'll take a look at how you can create Processing tools. These tools are small applications that can interact with the Processing editor. You can use them to insert code at the caret position, or display a message in the status bar. You can also create extra windows with Java's Swing GUI library. The Color Selector tool was made this way.
Before you can start writing code, you need to install the Processing tool template. This is explained in the previous recipe, Installing the Processing tool template.
You can start by deleting everything in the src directory. We don't need the HelloTool.java file, as we are going to write our own class. Select the src folder in the Package Explorer and go to the File | New | Class menu. The name of this file should be MyTool.
Open the file by double-clicking it. Type the following code into the file, we'll explain everything in the How it works section of the recipe.
package be.vormplus...