RedEListener.java Source code

Introduction

Here is the source code for RedEListener.java

Source

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.*;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;

/**
 * This class turns 'e' characters red using a LineStyleListener
 */
public class RedEListener {
    // Color for the StyleRanges
    private Color red;

    /**
     * Runs the application
     */
    public void run() {
        Display display = new Display();
        Shell shell = new Shell(display);

        // Get color for style ranges
        red = display.getSystemColor(SWT.COLOR_RED);

        createContents(shell);
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch()) {
                display.sleep();
            }
        }
        display.dispose();
    }

    /**
     * Creates the main window contents
     * 
     * @param shell the main window
     */
    private void createContents(Shell shell) {
        shell.setLayout(new FillLayout());

        // Create the StyledText
        final StyledText styledText = new StyledText(shell, SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL);

        // Add the syntax coloring handler
        styledText.addLineStyleListener(new LineStyleListener() {
            public void lineGetStyle(LineStyleEvent event) {
                // Create a collection to hold the StyleRanges
                java.util.List styles = new java.util.ArrayList();

                // Iterate through the text
                for (int i = 0, n = event.lineText.length(); i < n; i++) {
                    // Check for 'e'
                    if (event.lineText.charAt(i) == 'e') {
                        // Found an 'e'; combine all subsequent e's into the same StyleRange
                        int start = i;
                        for (; i < n && event.lineText.charAt(i) == 'e'; i++)
                            ;

                        // Create the StyleRange and add it to the collection
                        styles.add(new StyleRange(event.lineOffset + start, i - start, red, null));
                    }
                }
                // Set the styles for the line
                event.styles = (StyleRange[]) styles.toArray(new StyleRange[0]);
            }
        });
    }

    /**
     * The application entry point
     * 
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        new RedEListener().run();
    }
}