updated 12:55 pm EDT, Fri July 23, 2010
Implements single-window interface, new aids
Having just released Preview 2 to developers, Apple is also providing further public details on upcoming changes to Xcode 4. The programming tool is most notably switching to a single-window interface, merging several older ones together. On the left is an iTunes-style navigation bar, combining search and lists of material such as project files and debugging data. At the top is the Jump Bar, which speeds up switching between different levels of content.
The Interface Builder is no longer a separate application, and lets users drag connections from UI design to source code. A new Assistant component attempts to anticipate content a person will need, for instance by bringing up the right header when writing implementation code. The new Version Editor lets people see two iterations of source code side-by-side, going back and forth through versions using a timeline slider. Using a mix of Subversion and Git, the editor also makes it possible to manage multiple projects in one workspace.
LLVM Compiler 2.0 is now being used, which is said to compile faster and produce faster apps. The stack should moreover "completely" support C, C++ and Objective-C. Related enhancements include automatic identification and optional fixing of coding mistakes, and a new debugging engine claimed to consume less memory and run up to three times faster.
Instruments has been upgraded with elements from the Xcode interface, including the Jump Bar and stack compression. A deferred mode shifts the data collection interface off-screen while saving system power for running and metering an app. New test options include OpenGL ES performance, memory allocation, and the interaction of system processes.
A final release date for Xcode 4 remains unknown.