Fix ScrenPanel first repainting if server blocks.

screenpanel-sf/src/main/java/ScreenPanelSF.java

@@ -7,7 +7,6 @@ import ch.psi.pshell.epics.ChannelInteger;
 import ch.psi.pshell.epics.Epics;
 import ch.psi.pshell.imaging.Overlay;
 import ch.psi.pshell.imaging.Overlays;
-import ch.psi.pshell.imaging.Source;
 import ch.psi.pshell.workbench.App;
 import ch.psi.pshell.framework.Context;
 import ch.psi.pshell.framework.Panel;
@@ -72,7 +71,8 @@ public class ScreenPanelSF extends Panel implements CamServerViewer.CamServerVie
 
     @Override
     public void onStart() {
-        super.onStart();        
+        super.onStart();   
+        repaint(); //Even if invoked, amServerViewer.initialize can block first painting if server is not reachable.
         try {                    
             SwingUtilities.invokeLater(()->{
                 try {            

screenpanel-sls/src/main/java/ScreenPanelSLS.java

@@ -100,8 +100,9 @@ public class ScreenPanelSLS extends Panel implements CamServerViewer.CamServerVi
     }
 
     @Override
-    public void onStart() {
+    public void onStart() {        
         super.onStart(); 
+        repaint(); //Even if invoked, ServerViewer.initialize can block first painting if server is not reachable.
         try {            
             SwingUtilities.invokeLater(()->{
                 try {