FontMetricsPaintSWT.java Source code

Introduction

Here is the source code for FontMetricsPaintSWT.java

Source

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.FontMetrics;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class FontMetricsPaintSWT {
    public static void main(String[] args) {
        final Display display = new Display();
        final Shell shell = new Shell(display);
        shell.setText("Canvas Example");
        shell.setLayout(new FillLayout());

        Canvas canvas = new Canvas(shell, SWT.NONE);

        canvas.addPaintListener(new PaintListener() {
            public void paintControl(PaintEvent e) {

                Font font = new Font(shell.getDisplay(), new FontData("Helvetica", 18, SWT.NORMAL));
                e.gc.setFont(font);
                e.gc.drawText("My Text", 0, 0);

                FontMetrics fm = e.gc.getFontMetrics();
                int bHeight = fm.getLeading() + fm.getAscent();
                int oHeight = fm.getAscent();
                int yHeight = fm.getAscent() + fm.getDescent();
                int totalHeight = fm.getHeight(); // Equals fm.getLeading() + fm.getAscent()
                                                  // + fm.getDescent();

                e.gc.drawLine(10, bHeight, 100, bHeight);
                e.gc.drawLine(10, oHeight, 100, oHeight);
                e.gc.drawLine(10, yHeight, 100, yHeight);
                e.gc.drawLine(10, totalHeight, 100, totalHeight);

                font.dispose();

            }
        });

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