Two Document Visualization Techniques for Zoomable Interfaces

The current page is shown with a dark border so that you can easily identify it in a zoomed out view. Clicking again on a page once it is at its preferred size advances to the next page. Pages in this structure have an absolute location in the workspace. Since zooms and pans are animated, moving from one page to the next implicitly shows the position within the document. For instance, a zoom with a pan to the left occurs near the start of the document. Towards the end of the document, Pad++ zooms out and pans to the right. In addition, hyperlinks can be annotated with arrows pointing to the destination page, giving the user a sense of where the link will take them. If the user wishes to skip a few pages, it is easy to zoom out until the required page is visible, then click on the page to view it. A zoomed out view of the entire document makes an automatic index. This type of thumbnail index can be turned on and off at a fixed position at the bottom of the screen. One difficulty with the elliptical view is that it is only practical for a relatively small numbers of pages (less than about 30). Also, for the current implementation, achieving pleasing layouts for documents of different lengths requires manual change of parameters. In this document structuring technique, each line of text is shown a little smaller than the line before (Figure 2). In our implementation, the text halves in size every twelve lines. The advantage of this layout is that you can fit any amount of text in a fixed-size frame. In addition, the first lines of the document are clearly visible within this space even when the view is zoomed out. To view text in the document, the user positions the pointer at the apex of the document and zooms in. Panning is not necessary. Another characteristic of an inverted triangle view is that there is always blank space on either side of the document apex. This space can be used for indices, annotations, and other navigational aids, or for other triangular documents to create a fractal-like view. These can be loaded by clicking on hyperlinks within the original document. We implemented a zoomable directory browser [2] that represents each file as a constant size square whose contents become visible upon zooming. The …