Browser Overview Windows in NoteCards Randy Trigg Stored: {qv}1.2k>doc>browseroverview.ted Created: 3/28/86 Last updated: There is a new feature available in NoteCards Release 1.2k. It is called the browser overview and is accessible through the browser title bar middle button menu. A browser overview is a small window attached to the browser that contains a shrunken view of the entire graph (not just what appears in the browser's window). Within this overview is a wire frame representing that portion of the graph that is currently displayed in the browser window. The wire frame can be moved in the overview window to effect large scale scrolling in the browser window. Likewise, scrolling the browser window moves the wire frame in the overview window. The details of creating and manipulating overview windows follow. 1. Creating an overview window There is a new menu item "Browser Overview Win" on the browser middle button menu. Clicking on this causes an overview window to be created and attached to the upper left corner of the browser (but see 5 below). If this browser has never had an overview window, then the overview window will have the default height and width. If there previously was an overview window that has since been closed, then its height and width will be reused. 2. Reshaping the overview window If you reshape the overview window, then its contents are expanded or shrunk to "fill the container," and then the overview window is reattached to the browser. (See also 5 below.) 3. Scrolling and the wire frame There is a wire frame whose location and size in the overview match the scrolled position of the browser window relative to the entire graph. In effect, the wire frame provides a 2-dimensional scroll bar. Its position and size are dynamically updated as the browser window is scrolled and reshaped. Furthermore, the wireframe can be moved from the overview window to effect large scale scrolling of the browser window. This is done by clicking the mouse inside the overview window. The cursor is "pulled" to the nearest corner of the wire frame and as long as the button is held down, can drag the wire frame to a new position. If the button is let up with the wire frame outside the overview window, then the scrolling operation is cancelled. 4. Recomputing the overview contents For large graphs, the operation of creating the overview contents can be expensive. Thus if the browser's contents change, the overview window doesn't update automatically. In order to recompute the overview window based on current browser contents, hit Redisplay from the right button menu of the overview window. 5. The browser overview stylesheet Certain parameters governing the operation of browser overviews can be changed via the browser overview stylesheet. To bring up the browser overview stylesheet, click on "Change Overview Specs," from the browser title bar middle button menu. The stylesheet contains three submenus. The first two specify where to attach the overview window and the third specifies the mode of operation. The position at which the browser overview is attached can be selected by specifying values from two menus: the edge along which to attach (top, bottom, right, left), and the position along that edge (top/right, center, left/bottom). [Currently center position only works for top and bottom edges.] The third submenu lets you select the mode. This can have one of three values: Compress overview win: This forces the overview window to be just big enough to fit the overview contents plus the wire frame. This means that when you reshape, the window will be compressed along one dimension to fit the overview. Expand overview: This doesn't change the window size, but rather increases the size of the overview graph to fit the window shape you choose. This is done by scaling up in the dimension needed to fill the window. (Scaling is only done to node position, NOT node size. So what you're really getting is stretching out of your links.) Neither: The old style. That is, the window is whatever shape you make it and the overview contents are in the same aspect ratio as browser contents. This is the default. 6. Miscellaneous tidbits a. When the ratio between overview window size and graph size gets smaller than a threshhold value (currently .3), nodes in the overview switch from being shrunken but readable to being unreadable shaded boxes. b. Several people have complained about the annoying way that grapher doesn't let you scroll beyond the current GRAPHREGION. This is alleviated by using the wire frame in the browser overview to scroll the browser beyond its displayed region. In fact, you can even pull the wire frame partially outside the overview window and the browser will scroll appropriately. (Note that if you do such a thing, you may want to put a label in that new area or move a node over there or something to make your next Redisplay of the overview window show the increased area.) As mentioned in 3 above, if you pull the wire frame totally outside the overview window, you've done a noop. c. Thanks to Dan Russell for an influential earlier version of this idea.((( TIMESROMAN TIMESROMAN TIMESROMAN TIMESROMAN TIMESROMAN TIMESROMAN&4Ç ť"ś!-Ŕ&=$ŤĂ,BÔ@ŚÔyw˛JaFzş