Extending : Perspective extension : Project Explorer tool bar
  
Project Explorer tool bar
The tool bar New entry has been replaced by a new tool bar contribution to be able to control the actions that should be enabled or disabled based on the selected resource and to also be able to replace the default wizards available for those actions. New wizards have been defined using the org.eclipse.ui.newWizards extension point and new commands have also been defined as menu contributions with filtering conditions:
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In order to remove a tool bar contribution and replace it with your own, the hideToolBarItem perspective property as part of a perspective extension (org.eclipse.ui.perspectiveExtensions extension point) is used and can be also used for any further configuration of the menu bar:
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See also
Perspective extension