The application, published this week by the U.S. Patent and Trademark Office, is entitled "User-Interface Design." Apple re-filed the continuation with the USPTO this January, along with previous related filings that date back to 2004.
The proposed invention relates to specifying user interface objects in "a procedural and largely display resolution independent manner," the filing states. Graphical user interface elements are typically designed for use in a specified resolution, but as a user changes the resolution of their display, the originally designed object can become distorted or, in the case of a very high resolution display, unusably small.
Operating systems have previously used standard techniques to address this problem, such as taking a low-resolution object, like an icon, and up-sampling it to create a larger image. The problem with this method is it creates blurry edges, much like with iOS icons designed for the iPad 2 when they are displayed on the Retina display of the new third-generation iPad.
Another way of accommodating multiple resolutions is to take an object designed for a high-resolution screen and then downsampling it to an unknown target resolution. But Apple's filing states the problem with this method is it's impossible to know what width to give an object's edge to ensure it is crisp when down-sampled for a lower resolution.
"Line width is a critical factor in GUI design as the width of lines define the edge of graphical objects," Apple explains in the filing. "If edges appear blurry or ill-defined, the entire GUI design may be compromised."
Apple's solution as described in the filing is to create a plurality of attributes for a graphical user interface object, such as an icon or cursor, and store those multiple attributes and their associated values in a file. These attributes can be associated with distinct display resolutions, ensuring that the operating system will appear appropriately on any screen.
Apple's system could even accommodate resolutions for which graphical elements have not been specifically created. For example, if a user's machine is operating at a screen resolution between two of the resolutions specified by the designer, the rendering engine could interpolate between the two values and provide a better display than up-sampling or down-sampling of GUI elements would provide.
Operating system files that contain multiple attributes for various resolutions are referred to by Apple in the filing as "recipe" files. These types of files can already be found in the OS X operating system.
Last week, AppleInsider was first to reveal that Apple has continued to make behind-the-scenes improvements to OS X that will allow Macs with high-resolution Retina displays to show higher quality images. Evidence of this came in a new, larger TextEdit icon file, which contains new Retina display-caliber 1,204-by-1,024-pixel icons.
In a manner similar to what is described in Apple's patent application published by the USPTO this week, the icon files contain a number of images designed to be displayed by the operating system at various screen resolutions. The new higher-resolution icons could be utilized by a Retina display Mac with an ultra-high resolution screen.
OS X 10.7.4 TextEdit icons from left to right: 1024x1024, 512x512, 256x256, 128x128 (click to enlarge).
Rumors have indicated that Apple plans to upgrade its Mac lineup to new high-resolution Retina displays this year. Double-resolution Retina displays were previously introduced with Apple's iOS products starting with the iPhone 4 and iPod touch, and brought this year to the third-generation iPad.
Apple is expected to unveil new, thinner MacBook Pro models with Retina displays at its annual Worldwide Developers Conference, which begins on June 11 in San Francisco, Calif. It has also been suggested that Apple's next-generation iMacs will also receive a Retina upgrade at WWDC.