Mega Code Archive
Detect when the user scrolls a text control
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import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.ScrollBar;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
/*
* Detect when the user scrolls a text control
*
* For a list of all SWT example snippets see
* http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#snippets
*/
public class Snippet191 {
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
final Text text = new Text(shell, SWT.BORDER | SWT.H_SCROLL
| SWT.V_SCROLL);
for (int i = 0; i < 32; i++) {
text.append(i + "-This is a line of text in a widget-" + i + "\n");
}
text.setSelection(0);
Listener listener = new Listener() {
int lastIndex = text.getTopIndex();
public void handleEvent(Event e) {
int index = text.getTopIndex();
if (index != lastIndex) {
lastIndex = index;
System.out.println("Scrolled, topIndex=" + index);
}
}
};
/* NOTE: Only detects scrolling by the user */
text.addListener(SWT.MouseDown, listener);
text.addListener(SWT.MouseMove, listener);
text.addListener(SWT.MouseUp, listener);
text.addListener(SWT.KeyDown, listener);
text.addListener(SWT.KeyUp, listener);
text.addListener(SWT.Resize, listener);
ScrollBar hBar = text.getHorizontalBar();
if (hBar != null) {
hBar.addListener(SWT.Selection, listener);
}
ScrollBar vBar = text.getVerticalBar();
if (vBar != null) {
vBar.addListener(SWT.Selection, listener);
}
shell.pack();
Point size = shell.computeSize(SWT.DEFAULT, SWT.DEFAULT);
shell.setSize(size.x - 32, size.y / 2);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
display.dispose();
}
}
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