There are a lot of viewPart in IFolderLayout,so the name of viewPart can only see the a character. How to show full name of viewPart, even though there are a lot of verwPart.
There is a preference for the minimum widths of view tabs:
IWorkbenchPreferenceConstants.VIEW_MINIMUM_CHARACTERS
You can set the value in a preference initializer or in a plugin_customization.ini file like this:
org.eclipse.ui/VIEW_MINIMUM_CHARACTERS = -1
(-1 disables any shortening of the tabs)