Bugzilla – Full Text Bug Listing
| Summary: | ScrolledComposite should not take focus | ||||||
|---|---|---|---|---|---|---|---|
| Product: | [RT] RAP | Reporter: | Matthias Boehm <Matthias.Boehm> | ||||
| Component: | RWT | Assignee: | Project Inbox <rap-inbox> | ||||
| Status: | RESOLVED FIXED | QA Contact: | |||||
| Severity: | normal | ||||||
| Priority: | P3 | CC: | Matthias.Boehm | ||||
| Version: | 3.0 | ||||||
| Target Milestone: | 3.2 M7 | ||||||
| Hardware: | All | ||||||
| OS: | All | ||||||
| See Also: | https://git.eclipse.org/r/#/c/94929/ | ||||||
| Whiteboard: | |||||||
| Attachments: |
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I searched for "SWT.NO_FOCUS" and found it in the following code:
package org.eclipse.rap.rwt.internal.lifecycle;
public class ControlLCAUtil {
...
// TODO [rh] Eliminate instance checks. Let the respective classes always return NO_FOCUS
private static boolean takesFocus( Control control ) {
boolean result = true;
result &= ( control.getStyle() & SWT.NO_FOCUS ) == 0;
result &= control.getClass() != Composite.class;
result &= control.getClass() != SashForm.class;
return result;
}
...
}
Perhaps this is a place where the bug could be fixed (instead of in ScrolledComposite itself)?
The original SWT ScrolledComposite has this style mask:
---
static int checkStyle (int style) {
int mask = SWT.H_SCROLL | SWT.V_SCROLL | SWT.BORDER | SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT;
return style & mask;
}
---
SWT.NO_FOCUS is not supported by ScrolledComposite implementation in both SWT and RAP.
Excuse me for reopening this bug, but in SWT the behaviour is as expected, and different to RWT, as you can see with this simple program:
package nofocusforscrolledcompositeswt;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ScrolledComposite;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class EntryPoint {
public static void main(String[] args) {
Display display = new Display ();
Shell shell = new Shell (display);
shell.setLayout(new GridLayout(2, false));
// in SWT, scrolled composite does indeed get no focus!
ScrolledComposite sc = new ScrolledComposite(shell, SWT.NO_FOCUS);
Button button = new Button(shell, SWT.NONE);
button.setText("abc");
shell.pack ();
shell.open ();
while (!shell.isDisposed ()) {
if (!display.readAndDispatch ()) display.sleep ();
}
display.dispose ();
}
}
Here the scrolled Composite does indeed not get the focus, and the focus stays on the button when pressing the TAB key.
I'll check the behaviour, but NO_FOCUS style flag is NOT documented as supported in SWT ScrolledComposite: http://help.eclipse.org/neon/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Freference%2Fapi%2Forg%2Feclipse%2Fswt%2Fcustom%2FScrolledComposite.html Only H_SCROLL, V_SCROLL are supported. By the way, in SWT the ScrolledComposite *never* gets the focus, even if the SWT.NO_FOCUS flag is *not* specified. OK... Agree. |
Created attachment 267765 [details] a simple application that demonstrates the bug I try to create a ScrolledComposite with the "NO_FOCUS" style, as in this snippet: protected void createContents(Composite parent) { ScrolledComposite sc = new ScrolledComposite(parent, SWT.NO_FOCUS); Button button = new Button(parent, SWT.NONE); button.setText("abc"); } But when pressing the TAB key, focus jumps to the button, and away from the button again, and to the button again, and so on. This does not occur if instead of the ScrolledComposite a simple Composite is used: protected void createContents(Composite parent) { Composite c = new Composite(parent, SWT.NO_FOCUS); Button button = new Button(parent, SWT.NONE); button.setText("abc"); } Here the focus stays at the button after pressing the TAB key. I found already the cause for that problem: In the constructor of the class "ScrolledComposite", the super constructor is called like this: super( parent, checkStyle( style ) ); where "checkStyle" is defined as follows: private static int checkStyle( int style ) { int mask = SWT.H_SCROLL | SWT.V_SCROLL | SWT.BORDER | SWT.LEFT_TO_RIGHT; // | SWT.RIGHT_TO_LEFT; return style & mask; } So checkStyle takes away the NO_FOCUS style. A simple complete application that demonstrates this bug is attached.