[platform-swt-dev] Why does SelectionListener fail to fire?

["Mike Bennett" <mike@xxxxxxxxxxxxx>]

Hello

I am implementing a 4 table display and am using the example in the
snippets 
to synchronise two tables, however when I add a SelectionListener to the

ScrolledComposite, it fails to fire when I move the scroll bar.

The code is shown below, it defines 4 tables topLeft, topRight,
bottomLeft 
and bottomRight within a FormLayout.

(As a secondarty question, why does bottomLeft fail to extend to the
bottom 
of the Shell despite expandVertical being set to true ?)

Your help would be most appreciated

Thanks
Mike

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ScrolledComposite;
import org.eclipse.swt.events.ControlAdapter;
import org.eclipse.swt.events.ControlEvent;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FormAttachment;
import org.eclipse.swt.layout.FormData;
import org.eclipse.swt.layout.FormLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.ScrollBar;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.swt.widgets.TableItem;

public class TableScrollTest {
  TableViewer columnViewer;
  /**
   * @param args
   */
  public static void main(String[] args) {
    TableScrollTest tableScrollTest = new TableScrollTest();
    tableScrollTest.run();
  }

  public void run() {

    Display display = new Display ();

    Shell shell = new Shell (display);
    shell.setSize (900, 400);

    FormLayout formLayout = new FormLayout();
    shell.setLayout(formLayout);

    //  Top left

    final Table topLeft = new Table(shell,SWT.SINGLE |
SWT.FULL_SELECTION);
    topLeft.setHeaderVisible(true);
    topLeft.setLinesVisible(true);
    FormData topLeftFormData = new FormData();
    topLeftFormData.width = 244;
    topLeft.setLayoutData(topLeftFormData);
    TableColumn tlColumn1  = new TableColumn(topLeft,SWT.LEFT);
    tlColumn1.setWidth(200);
    TableColumn tlColumn2  = new TableColumn(topLeft,SWT.LEFT);
    tlColumn2.setWidth(60);
    for (int i=0; i<2; i++) {
      new TableItem (topLeft, SWT.NONE);
    }
    topLeft.pack();
    //  Top right

    final ScrolledComposite trScroller = new ScrolledComposite (shell, 
SWT.H_SCROLL );
    FormLayout trFormLayout = new FormLayout();
    trScroller.setLayout(trFormLayout);
    trScroller.setExpandHorizontal(true);
    final FormData trScrollerFormData = new FormData();
    trScrollerFormData.left = new FormAttachment(topLeft, 5);
    trScrollerFormData.top = new FormAttachment(0);
    trScrollerFormData.width = shell.getClientArea().width - 
topLeft.getSize().x - 5;
    trScroller.setLayoutData(trScrollerFormData);
    final Table topRight = new Table(trScroller,SWT.SINGLE| 
SWT.FULL_SELECTION | SWT.HIDE_SELECTION  );
    topRight.setHeaderVisible(true);
    topRight.setLinesVisible(false);
    for (int i = 0; i < 10; i++) {
      TableColumn tableColumn  = new TableColumn(topRight,SWT.CENTER);
      tableColumn.setWidth(80);
    }

    for (int i=0; i<2; i++) {
      new TableItem (topRight, SWT.NONE);
    }

    topRight.pack();
    final FormData trFormData = new FormData();
    trFormData.left = new FormAttachment(0, 0);
    trFormData.top = new FormAttachment(0);
    trFormData.width = shell.getClientArea().width - topLeft.getSize().x
- 
5;
    topRight.setLayoutData(trFormData);

    trScroller.setContent(topRight);


    //  Bottom Left

    final ScrolledComposite blScroller = new ScrolledComposite (shell, 
SWT.V_SCROLL);
    blScroller.setExpandVertical(true);
    final FormData blScrollerFormData = new FormData();
    blScrollerFormData.left = new FormAttachment(0, 5);
    blScrollerFormData.top = new FormAttachment(topLeft, 5);
    blScrollerFormData.width = 244;
    blScroller.setLayoutData(blScrollerFormData);
    final Table bottomLeft = new Table(blScroller,SWT.SINGLE | 
SWT.FULL_SELECTION);
    bottomLeft.setHeaderVisible(true);
    bottomLeft.setLinesVisible(true);
    TableColumn blColumn1  = new TableColumn(bottomLeft,SWT.LEFT);
    blColumn1.setWidth(200);
    TableColumn blColumn2  = new TableColumn(bottomLeft,SWT.LEFT);
    blColumn2.setWidth(60);
    for (int i=0; i<12; i++) {
      TableItem item = new TableItem (bottomLeft, SWT.NONE);
      item.setText(new String[] {"Row " , String.valueOf(i)});
    }
    bottomLeft.pack();
    FormData blFormData = new FormData();
    blFormData.width = 244;
    blFormData.left = new FormAttachment(0, 0);
    blFormData.top = new FormAttachment(0);
    bottomLeft.setLayoutData(blFormData);
    blScroller.setContent(bottomLeft);

    //  Bottom right

    final ScrolledComposite brScroller = new ScrolledComposite (shell, 
SWT.NONE);
    brScroller.setExpandHorizontal(true);
    brScroller.setExpandVertical(true);
    final Table bottomRight = new Table(brScroller,SWT.SINGLE| 
SWT.FULL_SELECTION | SWT.HIDE_SELECTION );
    bottomRight.setHeaderVisible(false);
    bottomRight.setLinesVisible(true);
    for (int i = 0; i < 10; i++) {
      TableColumn tableColumn  = new
TableColumn(bottomRight,SWT.CENTER);
      tableColumn.setWidth(80);
    }

    for (int i=0; i<12; i++) {
      TableItem item = new TableItem (bottomRight, SWT.NONE);
      String [] line = new String[10];
      for (int j = 0; j < line.length; j++) {
        line[j] = String.valueOf(i*10+j);
      }
      item.setText(line);
    }

    bottomRight.pack();
    final FormData brFormData = new FormData();
    brFormData.left = new FormAttachment(blScroller, 5);
    brFormData.top = new FormAttachment(trScroller,  0);
    brFormData.width = shell.getClientArea().width - topLeft.getSize().x
- 
5;
    brScroller.setLayoutData(brFormData);
    brScroller.setContent(bottomRight);


    shell.addControlListener(new ControlAdapter() {
      public void controlResized(ControlEvent event) {
        Shell shell = (Shell)event.getSource();
        Rectangle rect = shell.getClientArea();
        trFormData.width = rect.width - topLeft.getSize().x - 5;
        trScrollerFormData.width = rect.width - topLeft.getSize().x - 5;
        brFormData.width = rect.width - topLeft.getSize().x - 5;
        brFormData.height = rect.height - topRight.getSize().y - 5;
        shell.layout();
      }
    });


    final ScrollBar trScrollBar = trScroller.getHorizontalBar();
    trScrollBar.addSelectionListener( new SelectionAdapter () {
      public void widgetSelected (SelectionEvent e) {

        //  >>>>  This does not fire  <<<<
        System.out.println("trScrollBar " + trScrollBar.getSelection ()
+ " 
" + trScrollBar.getSelection ());
        brScroller.setOrigin(trScrollBar.getSelection(), 0);
      }
    });

    final ScrollBar brScrollBar = trScroller.getHorizontalBar();
    brScrollBar.addSelectionListener( new SelectionAdapter () {
      public void widgetSelected (SelectionEvent e) {

        //  >>>>  This does not fire  <<<<
        System.out.println("brScrollBar " + brScrollBar.getSelection ()
+ " 
" + brScrollBar.getSelection ());
        brScroller.setOrigin(trScrollBar.getSelection(), 0);
      }
    });

    shell.open ();

    Rectangle rect = shell.getClientArea();
    trFormData.width = rect.width - topLeft.getSize().x - 5;
    trScrollerFormData.width = rect.width - topLeft.getSize().x - 5;
    brFormData.width = rect.width - topLeft.getSize().x - 5;
    brFormData.height = rect.height - topRight.getSize().y - 5;
    shell.layout();

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