Positioning and realizing of virtualized visible content within a viewport

摘要

A method and medium are provided for presenting virtualized visible content within a viewport in a user interface. An anchor is received that represents a point on a line of virtualized visible content and a target value is received that represents a location in a viewport of a user interface. The anchor and target values can be received from user input devices or by analyzing the position of a scroll thumb relative to a scroll trough in the user interface. A first line of virtualized visible content that corresponds to the anchor value is realized by loading the line into memory from another source. The line is then positioned in the viewport based on the target value. Additional lines surrounding the first line are realized until the viewport is full. Lines that are not visible in the viewport can be unrealized, thus conserving computing resources.