SWT(JFace)体验之ProgressBar

先看代码:
ProgressBarExamples.java
package swt_jface.demo8;
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.FontMetrics;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.ProgressBar;
import org.eclipse.swt.widgets.Shell;
public class ProgressBarExamples {

Display display = new Display();
Shell shell = new Shell(display);
public ProgressBarExamples() {
ProgressBar pb1 = new ProgressBar(shell, SWT.NULL);
final ProgressBar pb2 = new ProgressBar(shell, SWT.SMOOTH);
ProgressBar pb3 = new ProgressBar(shell, SWT.INDETERMINATE);

pb2.addPaintListener(new PaintListener() {
public void paintControl(PaintEvent e) {
Point point = pb2.getSize();

Font font = new Font(shell.getDisplay(),"Courier",10,SWT.BOLD);
e.gc.setFont(font);
e.gc.setForeground(shell.getDisplay().getSystemColor(SWT.COLOR_WHITE));

FontMetrics fontMetrics = e.gc.getFontMetrics();
int stringWidth = fontMetrics.getAverageCharWidth() * 4;
int stringHeight = fontMetrics.getHeight();

e.gc.drawString("60%", (point.x-stringWidth)/2 , (point.y-stringHeight)/2, true);
font.dispose();
}
});

pb1.setSelection(60);
pb2.setSelection(60);

pb1.setBounds(100, 10, 200, 20);
pb2.setBounds(100, 40, 200, 20);
pb3.setBounds(100, 70, 200, 20);

Label label = new Label(shell, SWT.NULL);
label.setText("(default)");
Label label2 = new Label(shell, SWT.NULL);
label2.setText("SWT.SMOOTH");

label.setAlignment(SWT.RIGHT);
label2.setAlignment(SWT.RIGHT);
label.setBounds(10, 10, 80, 20);
label2.setBounds(10, 40, 80, 20);

shell.pack();
shell.open();

while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
public static void main(String[] args) {
new ProgressBarExamples();
}
}

再来一个例子：
CountNumbers.java
package swt_jface.demo8;
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.FontMetrics;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.ProgressBar;
import org.eclipse.swt.widgets.Shell;
public class CountNumbers {

Display display = new Display();
Shell shell = new Shell(display);
Button button;
ProgressBar progressBar;

public CountNumbers() {
GridLayout gridLayout = new GridLayout(1, true);
shell.setLayout(gridLayout);

button = new Button(shell, SWT.BORDER);
button.setText("Start to count");

progressBar = new ProgressBar(shell, SWT.SMOOTH);
progressBar.setMinimum(0);
progressBar.setMaximum(10);

final Thread countThread = new Thread(){
public void run() {
for(int i=0; i<=10; i++) {
final int num = i;
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
shell.getDisplay().asyncExec(new Runnable(){
public void run() {
if(button.isDisposed() || progressBar.isDisposed()) return;
button.setText("Counting: " + num);
progressBar.setSelection(num);
//progressBar.redraw();
}
});
}
}
};

button.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
button.setEnabled(false);
countThread.start();
}
});

progressBar.addPaintListener(new PaintListener() {
public void paintControl(PaintEvent e) {
System.out.println("PAINT");
String string = (progressBar.getSelection() * 1.0 /(progressBar.getMaximum()-progressBar.getMinimum()) * 100) + "%";
Point point = progressBar.getSize();
Font font = new Font(shell.getDisplay(),"Courier",10,SWT.BOLD);
e.gc.setFont(font);
e.gc.setForeground(shell.getDisplay().getSystemColor(SWT.COLOR_WHITE));
FontMetrics fontMetrics = e.gc.getFontMetrics();
int stringWidth = fontMetrics.getAverageCharWidth() * string.length();
int stringHeight = fontMetrics.getHeight();
e.gc.drawString(string, (point.x-stringWidth)/2 , (point.y-stringHeight)/2, true);
font.dispose();
}
});

button.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
progressBar.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
shell.setSize(300, 100);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
public static void main(String[] args) {
new CountNumbers();
}
}