GWT Designer hangs each widget added

What steps will reproduce the problem?
1. stay WindowBuilder -> GWT -> Code generation -> code style the default one 
as "local" so all code to be generated in constructor
2.Add any widget makes designer hang
3.To unhang I have to a) force eclipse repaint by (maximize/unmaximize)eclipse 
window or manually press ctrl+S to forse frmat and reparse

What is the expected output? What do you see instead?
Palette should have widget button released; But the palette widget button is 
keep pressed (until I do step 3) so refresh doesn't work or something but I am 
not sure

What version of the product are you using? 

Eclipse Indigo 3.7 linux x64
Version: Indigo Service Release 2
Build id: 20120216-1857

  Google Plugin for Eclipse 3.7 3.6.0.v201406262229-rel-r37 com.google.gdt.eclipse.suite.e37.feature.feature.group  Google, Inc.
    Eclipse Platform    3.7.2.v20120207-1839-9gF7UHPDFxGjd-PqDr2jX_4yKaumkoHTz04_q-q    org.eclipse.platform.feature.group  Eclipse.org
      Eclipse Help System   1.3.0.v20110530-0844-7i7uFFmFFl8nvqbDpEqTvx org.eclipse.help.feature.group  Eclipse.org
      Eclipse RCP   3.7.2.v20120120-1424-9DB5FmnFq5JCf1UA38R-kz0S0272   org.eclipse.rcp.feature.group   Eclipse.org
      Equinox p2 Provisioning for IDEs. 2.1.2.R37x_v20110815-1155-6-Bk8pYWZz0qUTX5I15GZWwbXkrl  org.eclipse.equinox.p2.user.ui.feature.group    Eclipse.org - Equinox
        Add-on Function for p2  1.0.1.v20110906-1605-7A4FD4DiVOMap8cHSc6vPuny4gqO   org.eclipse.equinox.p2.extras.feature.feature.group Eclipse.org - Equinox
        Equinox p2 Core Function    1.0.1.v20110906-1605-8290FZ9FVKHVRKtmx3fpNuo02129   org.eclipse.equinox.p2.core.feature.feature.group   Eclipse.org - Equinox
        Equinox p2 RCP Management Facilities    1.0.1.v20110906-1605-782EqBqNKGVkiV-PUsgz-uny4gqO   org.eclipse.equinox.p2.rcp.feature.feature.group    Eclipse.org - Equinox
  GWT Designer  3.1.2.r37x201307151456  com.google.gdt.eclipse.designer.feature.feature.group   Google, Inc.
  GWT Designer Core 3.1.2.r37x201307151442  com.google.gdt.eclipse.designer.hosted.feature.feature.group    Google, Inc.
  GWT Designer Editor   3.1.2.r37x201307151447  com.google.gdt.eclipse.designer.editor.feature.feature.group    Google, Inc.
  WindowBuilder Core    1.6.0.r37x201305211944  org.eclipse.wb.core.feature.feature.group   Eclipse.org
  WindowBuilder Core Documentation  1.6.0.r37x201306031702  org.eclipse.wb.doc.user.feature.feature.group   Eclipse.org
  WindowBuilder Core UI 1.6.0.r37x201306031651  org.eclipse.wb.core.ui.feature.feature.group    Eclipse.org
  WindowBuilder CSS Support 1.6.0.r37x201306031647  org.eclipse.wb.css.feature.feature.group    Eclipse.org
  WindowBuilder Java Core   1.6.0.r37x201306031644  org.eclipse.wb.core.java.feature.feature.group  Eclipse.org
  WindowBuilder XML Core (requires Eclipse WTP/WST) 1.6.0.r37x201306031653  org.eclipse.wb.core.xml.feature.feature.group   Eclipse.org

GWT SDK 2.2.0

gwt projects use: JDK 1.5

eclipse vm: jdk1.7.0_71

On what operating system?
Manjaro Linux x64

Please provide any additional information below.
Including the palette I can see non-refreshing issue also with "Properties" and 
"Structure" so all gwt designer toolkit is freezing so mostly gwt designer 
cannot be used;  
I try to attach the .gwt-log file from the project where the mentioned issue 
occured
Original issue reported on code.google.com by ghtu...@gmail.com on 19 Feb 2016 at 12:13
dgallen / google-plugin-for-eclipse

GWT Designer hangs each widget added #344
