I am trying to make an Eclipse plug-in where the text in code-editor should get updated from a file. In most examples, I see people using IDE.openEditor(page, inputFile); However, I cannot find the org.eclipse.ui.ide.IDE extension point. Downloading the jar and putting it in build path causes an error. I think it should be available in the list of possible extensions or dependencies. Any help on where to find it is highly appreciated. Thank you.
This is not an extension point, it is a Java API that you call.
It is in the org.eclipse.ui.ide plug-in so you need to add that to your plug-in's dependencies. You can do that in the MANIFEST.MF/plugin.xml editor on the 'Dependencies' tab in the 'Required Plug-ins' section. This will add the dependency to the Require-Bundle section in the MANIFEST.MF
Note: You should not need to download anything for Eclipse dependencies, the plugin should already be in your 'target platform'. It is also not correct to just put plug-in dependencies just on the build path - you must put them in the MANIFEST.MF