Example usage for org.eclipse.swt.widgets Canvas update

Introduction

In this page you can find the example usage for org.eclipse.swt.widgets Canvas update.

Prototype

public void update() 

Source Link

Document

Forces all outstanding paint requests for the widget to be processed before this method returns.

Usage

From source file:Snippet21.java

public static void main(String[] args) {
    Display display = new Display();
    final Color red = display.getSystemColor(SWT.COLOR_RED);
    final Color blue = display.getSystemColor(SWT.COLOR_BLUE);
    Shell shell = new Shell(display);
    Button b = new Button(shell, SWT.PUSH);
    b.setBounds(10, 10, 100, 32);/*from ww  w  . j av  a 2  s.  c  o  m*/
    b.setText("Button");
    shell.setDefaultButton(b);
    final Canvas c = new Canvas(shell, SWT.BORDER);
    c.setBounds(10, 50, 100, 32);
    c.addListener(SWT.Traverse, new Listener() {
        public void handleEvent(Event e) {
            switch (e.detail) {
            /* Do tab group traversal */
            case SWT.TRAVERSE_ESCAPE:
            case SWT.TRAVERSE_RETURN:
            case SWT.TRAVERSE_TAB_NEXT:
            case SWT.TRAVERSE_TAB_PREVIOUS:
            case SWT.TRAVERSE_PAGE_NEXT:
            case SWT.TRAVERSE_PAGE_PREVIOUS:
                e.doit = true;
                break;
            }
        }
    });
    c.addListener(SWT.FocusIn, new Listener() {
        public void handleEvent(Event e) {
            c.setBackground(red);
        }
    });
    c.addListener(SWT.FocusOut, new Listener() {
        public void handleEvent(Event e) {
            c.setBackground(blue);
        }
    });
    c.addListener(SWT.KeyDown, new Listener() {
        public void handleEvent(Event e) {
            System.out.println("KEY");
            for (int i = 0; i < 64; i++) {
                Color c1 = red, c2 = blue;
                if (c.isFocusControl()) {
                    c1 = blue;
                    c2 = red;
                }
                c.setBackground(c1);
                c.update();
                c.setBackground(c2);
            }
        }
    });
    Text t = new Text(shell, SWT.SINGLE | SWT.BORDER);
    t.setBounds(10, 85, 100, 32);

    Text r = new Text(shell, SWT.MULTI | SWT.BORDER);
    r.setBounds(10, 120, 100, 32);

    c.setFocus();
    shell.setSize(200, 200);
    shell.open();
    while (!shell.isDisposed()) {
        if (!display.readAndDispatch())
            display.sleep();
    }
    display.dispose();
}

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