How to minimize a view programmatically in Eclipse e4 versions/ Adding a view to the trimbar

Below snippet can be used to minimize a view.

IViewPart part = page.showView("com.kk.views.showtasks");
if (part != null) {
 IWorkbenchPartReference myView = page.findViewReference(viewid);
MUIElement element = ((WorkbenchPage) page).getActiveElement(myView);
WorkbenchWindow activeWorkbenchWindow = (WorkbenchWindow) PlatformUI.getWorkbench().getActiveWorkbenchWindow();
if (activeWorkbenchWindow != null) {
MWindow window = activeWorkbenchWindow.getModel();
if (window != null) {
            EModelService service = window.getContext().get(EModelService.class);
if (service != null) {
element.getTags().add(IPresentationEngine.MINIMIZED);

}
}
}
}

More important thing here is,
element.getTags().add(IPresentationEngine.MINIMIZED);

When above code gets invoked, MinMaxAddon.minimize(..) will be invoked internally to minimize a view. Minimized view will be added as a toolbar item to the trimbar.

MUIElement element = ((WorkbenchPage) page).getActiveElement(myView);
Here element is PartStack element, that means all the elements(Parts) which are there in the partstack will be minimized.

How to add right trimbar/side bar in eclipse

This can be achieved through "org.eclipse.ui.menus" extension point with the locationURI as "toolbar:org.eclipse.ui.trim.vertical2"

<extension
       point="org.eclipse.ui.menus">
    <menuContribution
          allPopups="false"
          locationURI="toolbar:org.eclipse.ui.trim.vertical2">
       <toolbar
             id="myrightsidetrimbar"
             label="Eclispe rightside trimbar">
          <command
                commandId="com.kk.command.showHelp"
                icon="icons/help.gif"
                label="Help"
                style="push">
          </command>
            </toolbar>
    </menuContribution>
 </extension>


toolbar:org.eclipse.ui.trim.vertical2 -> will be for used for Right trimbar

We can find all these uri identifiers in MenuUtil.java in eclipse org.eclispe.ui.workbench plugin

 /** Top Left Trim Area */
public final static String TRIM_COMMAND1 = "toolbar:org.eclipse.ui.trim.command1"; //$NON-NLS-1$
/** Top Right Trim Area */
public final static String TRIM_COMMAND2 = "toolbar:org.eclipse.ui.trim.command2"; //$NON-NLS-1$
/** Left Vertical Trim Area */
public final static String TRIM_VERTICAL1 = "toolbar:org.eclipse.ui.trim.vertical1"; //$NON-NLS-1$
/** Right Vertical Trim Area */
public final static String TRIM_VERTICAL2 = "toolbar:org.eclipse.ui.trim.vertical2"; //$NON-NLS-1$
/** Bottom (Status) Trim Area */
public final static String TRIM_STATUS = "toolbar:org.eclipse.ui.trim.status"; //$NON-NLS-1$

How to get Eclipse EModelService from workbench ?

WorkbenchWindow activeWorkbenchWindow = (WorkbenchWindow) PlatformUI.getWorkbench().getActiveWorkbenchWindow();
if (activeWorkbenchWindow != null) {
MWindow window = activeWorkbenchWindow.getModel();
if (window != null) {
EModelService modelService = window.getContext().get(EModelService.class);

//your calls
}
}

eclipse -clean option in mac os x

1. Go to eclipse directory
2. Find Eclipse Application
3. Right click on  Eclipse Application
4. It will show "Show Package Contents" menu option
4. Click on Show Package Contents
5. Go to Contents folder
6. Go to MacOS folder
7. Open the terminal
8. Drag the MacOS directory to terminal for change directory(ex: cd <macos directory>)
8. execute this " ./eclipse -clean"

eclipse.ini file in Mac os x

1. Go to eclipse directory
2. Find Eclipse Application
3. Right click on  Eclipse Application
4. It will show "Show Package Contents" menu option
4. Click on Show Package Contents
5. Go to Contents
6. Go to MacOS
7. Look for eclipse.ini file

Unsupported major.minor version 51.0

java.lang.UnsupportedClassVersionError happens because of a higher JDK during compile time and lower JDK during runtime.

51.0 in "Unsupported major.minor version 51.0" represents that, .class file generated with JDK 1.7 and but you are trying with run with(runtime) with lower version of it.

Below are the version numbers and compatible JDK's.

J2SE 8 = 52,
J2SE 7 = 51,
J2SE 6.0 = 50,
J2SE 5.0 = 49,
JDK 1.4 = 48,
JDK 1.3 = 47,
JDK 1.2 = 46,
JDK 1.1 = 45


To resolve this issue, make use of same version during the compile time and run-time.

Example: You would have generatd jar file with jdk 1.7 and but you are trying to run that jar using JDK 1.6 eclipse, this leads to above error.

org.eclipse.swt.SWTError: No more handles

Resources:
http://www.eclipse.org/articles/swt-design-2/swt-design-2.html
http://stackoverflow.com/questions/2018553/swt-no-more-handles
http://i-proving.com/2006/06/05/diagnosing-handle-leaks-in-swtrcp-windows-applications/
http://www.sybase.com/detail?id=1019174
http://www.eclipse.org/articles/swt-design-2/sleak.htm

What is User handle ?
http://msdn.microsoft.com/en-us/library/windows/desktop/ms725486(v=vs.85).aspx

Tools for identifying handles:
Process explorer to check the handles:
http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx

http://ltearno.free.fr/dpus/

Using Sleak identify memory leaks
http://eclipsesource.com/blogs/2009/04/17/finding-swt-leaks-with-sleak/