[news.eclipse.platform.swt] Re: Transparent Shell question

["Steve Northover" <steve_northover@xxxxxxxxxx>]

One thing that seems funny in your code is that you hammer GWL_EXSTYLE
instead of just adding WS_EX_LAYERED to it.  Do you have a functioning C
example?  If so, it's easy to rewrite it to use the internal Windows
implementation classes to experiment and see what is wrong.  I wouldn't
suggest shipping a final product that uses the implementation classes but
they are handy to see what is going on.  This is exactly the process I use
when presented with a mystery.

Another possiblilty is to temporarily hack Control.createHandle() to create
the window with the appropriate style bits?  Might make a difference?
(probably not).

"Ross Yakulis" <yakulis@xxxxxxxxx> wrote in message
news:bemopq$2a7$1@xxxxxxxxxxxxxx
> I have that already.
>
>
> public static void main(String[] args) {
>     Shell shell = new Shell(SWT.NO_TRIM);
>
>     shell.setLayout(new FillLayout());
>     shell.setBackground(new Color(null, 255, 255, 255));
>     Background b = new Background(shell, 0); // draws an irregular image
>     int alpha = 128; //0=transparent, 255=opaque only matters if using
> LWA_ALPHA
>     OS.SetWindowLong(shell.handle, OS.GWL_EXSTYLE, OSEx.WS_EX_LAYERED);
>     OSEx.SetLayeredWindowAttributes(shell.handle, null, alpha,
> OSEx.LWA_COLORKEY);
>     shell.open();
>     Display display = shell.getDisplay();
>     while (!shell.isDisposed()) {
>         if (!display.readAndDispatch()) {
>             display.sleep();
>         }
>     }
> }
>
> Where OSEX is a native that calls :
>
> public class OSEx {
>     static {
>         System.loadLibrary("osex");
>     }
>     public static final native boolean SetLayeredWindowAttributes(int
hwnd,
> RGB crKey,
>             int bAlpha, int     dwFlags);
>     public static final int LWA_COLORKEY = 1;
>     public static final int LWA_ALPHA = 2;
>     public static final int WS_EX_LAYERED = 0x80000;
> }
>
> // CPP implementation of SetLayeredWindowAttributes
> JNIEXPORT jboolean JNICALL
> Java_com_avaya_osex_OSEx_SetLayeredWindowAttributes
> (JNIEnv *env, jclass theClass, jint windowHandle, jobject crKey, jint
alpha,
> jint flags) {
>  SetLayeredWindowAttributes((HWND)windowHandle,
(COLORREF)RGB(255,255,255),
> (BYTE)alpha, (DWORD)flags );
>  return( 0 );
> }
>
> "Steve Northover" <steve_northover@xxxxxxxxxx> wrote in message
> news:bemnki$1ae$1@xxxxxxxxxxxxxx
> > Use SWT.NO_TRIM.
> >
> > "Ross Yakulis" <yakulis@xxxxxxxxx> wrote in message
> > news:bekc50$p3s$1@xxxxxxxxxxxxxx
> > > I read the post on Nov 2002 "shell alpha channel transparency" and
> > > implemented that solution.  (setting the EX_STYLE to layered window
> > > and then setting the layered window attributes).  So now my shell
> > > rectangular area is transparent and I can place my iregular image in
it
> > and
> > > have the
> > > shell appear as a non-rectangular window (almost).
> > >
> > > My problem is that no matter what combination of styles I use,
> > > I always get a thin rectangular border, even though the inside
> > > area of the shell is transparent.   How do I get rid of that border?
> The
> > > application I an creating is windows only.
> > >
> > > Ross
> > >
> > >
> >
> >
> >
>
>