Continuing with the API redesign, we have some changes planned for the Position utility.

API Redesign

Merge offset option into the my and at options
The offset option will be removed in favor of including the offset as part of the my or at options.
For example, while you would currently do:

$( "#elem" ).position({
    my: "left top",
    at: "left top",
    of: "#otherElem",
    offset: "50 20"
});

You would now do:

$( "#elem" ).position({
    my: "left+50 top+20",
    at: "left top",
    of: "#otherElem"
});

Regardless of whether you include the offset in the my or at option, the offset will always adjust based on the final position, just like the offset option currently does. We also plan on supporting percentages, so you can offset the element based on a percent of its width or height. If you specify a percentage in the my option, then the percentage will be based on the size of the element being positioned. If you specify a percentage in the at option, then the percentage will be based on the size of the element being positioned against.
For example, to place an element 1/4 of the way down the screen and horizontally centered, you could do:

$( "#elem" ).position({
    my: "center top",
    at: "center top+25%",
    of: window
});

And to position an element so that only the left 10% of it is visible, you could do:

$( "#elem" ).position({
    my: "left-10% center",
    at: "right center",
    of: window
});

Better collision handling
Currently the collision handling is fairly simple. If you enable collision (by specifying fit or flip) then the plugin will detect if there is a collision and if there is, it will move the element accordingly. However, depending on the size of the element, this adjustment may actually cause even less of the element to be visible. We plan on making the collision handling smarter so that it will never make the positioning worse. There will be no change in the API, just better handling for collisions.

Feedback

We’d love to hear your feedback on these changes. We want to make sure we address any issues the community may have before we finalize and implement these changes. If you have any feedback, please post it on the related forum post. Thanks.

As previously stated, jQuery UI is undergoing an API redesign which will slim down the size of the API in order to provide a more stable codebase that is easier to learn and use. This post lists out the details of the proposed changes for the Progressbar widget along with the reasoning behind each change.

API Redesign

Add support for indeterminate progress bars.
We had previously said that indeterminate progress bars should be a separate widget. However, there is a common enough use case where you may want to start providing feedback about that a task has started before you know the actual progress. In this case you may want to start with an indeterminate progress bar and switch to a determinate progress bar as soon as you have enough information to provide details. In order to support this, we will allow the value option to be set to false to indicate that the progress bar should be indeterminate.

Switching from an indeterminate state to a determinate state would look like this:

$( "#progressbar" ).progressbar({
    value: false
});

// later when you find out more information
$( "#progressbar" ).progressbar( "option", {
    value: 15,
    max: 250
});

Feedback

We’d love to hear your feedback on these changes. We want to make sure we address any issues the community may have before we finalize and implement these changes. If you have any feedback, please post it on the related forum post. Thanks.