After looking into the problem and the issues around it, this probably won't be fixed in the 3.2 timeframe.  It would require changes in both kdelibs and kdebase.  I'll try to come up with a patch before then, but I don't expect that it would be accepted any sooner than 3.3.

why do you need patches to kdelibs and kdebase to make a systray icon transparent? It works for anything else - including the mega complex kmoon :)

JuK currently does a blend of the current status and a semi-transparent application icon to indicate the status.  However to generate this properly the KSystemTray needs to have an accurate way to get the background of the widget.  There's actually some X magic in the system tray applet to set the background of the QXEmbed widget used there to the background of the Kicker.  To get a background pixmap into KSystemTray it would probably need to be passed over DCOP between the applet and the kdelibs class and then the blend could be done in JuK.  

Subject: Re:  The playing icon in systray isn't transparent

On Friday 14 November 2003 11:52, Scott Wheeler wrote:
> To get a background pixmap into KSystemTray it would probably 
> need to be passed over DCOP between the applet and the kdelibs 
> class and then the blend could be done in JuK.  
> 
You just need to set a correct alpha mask on your widget.

Greetings, Stephan

Nope -- tried that last night before my reply.  That works for part of the background, but the semi-transparency of the icon still looks really bad.

On this note, I have often been a little annoyed as to the fact that the taskbar icon isn't themed (I know, I've made this point in other applications too, but I find it important ;) ). Maybe the simplest fix would be simply to use the JuK application icon, as opposed to one found in the program folder? I am not, however, certain how you would actually do it practically, as my only experience with C++ as of yet is KStyle programming ;).

Uhm, there is only on JuK application icon -- there's not a separate one for the system tray icon.

For 3.2 would it be possible to just have the current status icon by itself (ie not blended) and have the JuK icon when it is stopped?

Created attachment 3769 [details]
JuK Paused systray icon

Sample icon for JuK while paused.

Created attachment 3770 [details]
JuK Playing systray icon

Sample icon for JuK while it is playing.

Created attachment 3771 [details]
Patch to load icons for the system tray instead of creating them.

This patch changes systemtray.cpp to load PNGs for the Playing and Paused
systray icons, rather than dynamically creating them.  Although creating them
dynamically would be better in case more states are created in the future,
current kdelibs makes that infeasible.	I will also attach the GIMP template I
used to create the icons.  Although I have attempted to make the icons resemble
the current generated ones when possible, it is still possible to detect a
difference.

Forgot to comment on my last patch, it depends on adding the two .png's that I've created to the list of icons to install.  I'm still working on the changes to make that happen.

Created attachment 3772 [details]
Template for JuK systray icons (GIMP 1.3)

I used this template to create the two PNGs I've attached.  I simply resized
the playing and paused icons to 16x16, and cut-and-pasted them into the Overlay
layer.	GIMP automatically centered on the paste operation, so no further
tweaking was needed.

Created attachment 3791 [details]
Better patch to implement transparent system tray icons

This patch is much improved from the one I submitted yesterday.  It apparently
*IS* possible to overlay the icons and still maintain transparency, but it
involves an intermediate step using QImages instead of QPixmaps.

I also had to create a function to copy one QImage into another, as I couldn't
find an existing one.  I would imagine that the function is slow, but since
it's only called twice, I think it's OK.

This patch also allows a change in the icon theme for people who don't like
Crystal for whatever reason.  This also makes all of my GIMPery completely
unnecessary. :)

I think that this patch fixes this bug.

Created attachment 3792 [details]
JuK's system tray with my transparent systray patch

I've taken a screenshot of the results of my patch to systemtray.cpp.  Now it's
time to change that damn kicker background back! ;-)

Subject: kdemultimedia/juk

CVS commit by wheeler: 

Patch from Michal Pyne to fix system tray icon transparency when blending
a status icon with the JuK icon.

CCMAIL:67713-done@bugs.kde.org
CCMAIL:pynm0001@comcast.net


  M +62 -14    systemtray.cpp   1.28


--- kdemultimedia/juk/systemtray.cpp  #1.27:1.28
@@ -31,4 +31,6 @@
 #include "jukIface.h"
 
+static bool copyImage(QImage &dest, QImage &src, int x, int y);
+
 ////////////////////////////////////////////////////////////////////////////////
 // public methods
@@ -130,5 +132,7 @@ void SystemTray::createPopup(const QStri
         m_popup->setView(box);
 
-        // We don't want an autodelete popup.  There are times when it will need to be hidden before the timeout.
+        // We don't want an autodelete popup.  There are times when it will need
+        // to be hidden before the timeout.
+
         m_popup->setAutoDelete(false);
         m_popup->show();
@@ -144,21 +148,19 @@ QPixmap SystemTray::createPixmap(const Q
     QPixmap fgPix = SmallIcon(pixName);
 
-    // Make this pretty close to invisible.  I'm certain there's a cleaner way to
-    // do this, but I am exceedingly lazy.
-    KIconEffect::semiTransparent(bgPix);
-    KIconEffect::semiTransparent(bgPix);
-
-    QPainter p(&buffer);
-    p.drawPixmap(0, 0, bgPix);
+    QImage bgImage = bgPix.convertToImage(); // Probably 22x22
+    QImage fgImage = fgPix.convertToImage(); // Should be 16x16
 
-    p.drawPixmap((buffer.width() - fgPix.width()) / 2,
-        (buffer.height() - fgPix.height()) / 2, fgPix);
+    KIconEffect::semiTransparent (bgImage);
+    KIconEffect::semiTransparent (bgImage);
+    copyImage(bgImage, fgImage, (bgImage.width() - fgImage.width()) / 2,
+              (bgImage.height() - fgImage.height()) / 2);
 
-    return buffer;
+    bgImage.setAlphaBuffer (true);
+    bgPix.convertFromImage (bgImage);
+    return bgPix;
 }
 
 void SystemTray::setToolTip(const QString &tip)
 {
-    // if(!QToolTip::textFor(this).isNull())
     QToolTip::remove(this);
 
@@ -200,4 +202,50 @@ void SystemTray::wheelEvent(QWheelEvent 
 }
 
+/*
+ * This function copies the entirety of src into dest, starting in
+ * dest at x and y.  This function exists because I was unable to find
+ * a function like it in either QImage or kdefx
+ */
+
+static bool copyImage(QImage &dest, QImage &src, int x, int y)
+{
+    if(dest.depth() != src.depth())
+        return false;   
+    if((x + src.width()) >= dest.width())
+        return false;
+    if((y + src.height()) >= dest.height())
+        return false;
+    
+    // We want to use KIconEffect::overlay to do this, since it handles
+    // alpha, but the images need to be the same size.  We can handle that.
+
+    QImage large_src(dest);
+
+    // It would perhaps be better to create large_src based on a size, but
+    // this is the easiest way to make a new image with the same depth, size,
+    // etc.
+
+    large_src.detach();
+        
+    // However, we do have to specifically ensure that setAlphaBuffer is set
+    // to false
+
+    large_src.setAlphaBuffer (false);
+    large_src.fill(0); // All transparent pixels
+    large_src.setAlphaBuffer (true);
+    
+    int w = src.width();
+    int h = src.height();
+    for(int dx = 0; dx < w; dx++)
+        for(int dy = 0; dy < h; dy++)
+            large_src.setPixel(dx + x, dy + y, src.pixel(dx, dy));
+    
+    // Apply effect to image
+
+    KIconEffect::overlay (dest, large_src);
+    
+    return true;
+}
+
 #include "systemtray.moc"
 

It still do not work for my KDE 3.2.0 (kdf 0.5).