I am using the P4Eclipse plugin for seamless integration with Perforce. I feel comfortable doing most of the P4 things with this plugin, except file diffing.
By Team - Diff File(s) against Depot in the right-click context menu, an internal "Depot Diff" view opens to provide a simple diff feature - I am not satisfied with this menu option, though. I prefer the P4Merge external diff tool, which is the default diff tool of the Perforce Visual Client (P4V).
In Preferences of Eclipse, I found a location to fill in the path of P4Merge. It's Team - Perforce - External Tools. But I think this setting is only for file resolving.
Is there a way to directly call P4Merge for file diffing in Eclipse?
You can set up an external tool to run P4Merge (I think).