1. A method, comprising: at an electronic device with a display: displaying, on the display, a first user interface of an application, the first user interface including a plurality of content items; detecting an input dragging a first content item, in the plurality of content items, across the first user interface; and, in response to detecting the input dragging the first content item across the first user interface, displaying a sidebar that contains objects in which the first content item is configured to be placed.