“Closed" windows in Figure 4.6, are windows that have been "set aside" and appear in a list in the upper right of the desktop. Could read on multiple workspaces.

This timeline lists all of the graphical user interface environments that I have been able to find information about through my own research and on the Internet.

A key constraint on the effectiveness of window-based human-computer interfaces is that the display screen is too small for many applications. This results in “window thrashing,” in which the user must expend considerable effort to keep desired windows visible. Rooms is a window manager that overcomes small screen size by exploiting the statistics of window access, dividing the user's workspace into a suite of virtual workspaces with transitions among them. Mechanisms are described for solving the problems of navigation and simultaneous access to separated information that arise from multiple workspaces.

A graphic terminal is disclosed using bitmaps to represent plural overlapping displays. Graphics software is also disclosed in which the overlapping asynchronous windows or layers are manipulated by manipulating the bitmaps. With this software, the physical screen becomes several logical screens (layers) all running simultaneously, any one of which may be interacted with at any time.

A multiple window display system is provided for displaying data from different applications in a multi-tasking environment. The display system includes plural screen buffers (12.sub.l to 12.sub.n) for storing character codes and attribute codes of data which may be displayed on the display screen. Task selection means (26) selectively couples the output of a single selected one of the plural screen buffers to the character generator (16) and attribute logic (18) at any given time. Address modification means (20.sub.l to 20.sub.n, 22.sub.l to 22.sub.n) permits changes to be made in the display windows. The software driver includes screen control blocks (32), window control blocks (34), presentation space control blocks (36), presentation spaces (38), and a screen matrix (40) in system memory. The presentation spaces (38) receive application data for plural windows of the displayable area. Each window defines the whole or a subset of a corresponding presentation space. The screen matrix (40) is mapped to the display screen and filters data from the windows of the presentation spaces to the screen buffer to designate which of the data will be shown in corresponding positions on the display screen.

In a multi-window system for setting a plurality of windows on the screen for independent display in each window, a novel display control method is disclosed in which a visible region of a given window is determined from the positions and overlapped relations between the windows on the display screen, and display data is selectively applied to the visible region. The visible region is checked for crossing between an object window and another window making up a reference window on the screen, and if they cross each other, the object window is divided into subregions, while the subregion not overlapped with the reference window is regarded as a new object region, which is collated with another reference window and subdivided. This process of collation and division is repeated. A display output is thus applied sequentially to the subregions which are found to be a visible region.

In a multiwindow system in which a plurality of windows are set on a display screen at positions such that these windows partially overlap and the display priority and position of each window can be arbitrarily changed, when the operator instructs to change the display priority of the window, a check is automatically made to see if there exists the window which will be completely covered by the other windows having priorities higher than that of this window and will fully disappear from the screen if the display priority is changed or not. If such a window is found out, the display priority of this window is changed in the state in which this window is automatically shifted to the position where a part of this window can be seen on the screen, thereafter the window is displayed on the screen. The changing process of the display priority of the window and the automatic shifting process of the position of the window are controlled by referring to and correcting the contents of the window management tables in which the data indicative of the sizes, positions, display priorities, and the like of the respective windows is stored.

An interactive display terminal of the multiple overlapping window type is provided. Each of the windows is smaller in dimension than the overall display screen. One or more of the windows have an associated virtual distributed menu which is made up of a plurality of menu items respectively distributed about the periphery of the associated window but not displayed during normal operations. Cursor means and means for moving the cursor are also provided. The display terminal further includes apparatus which in response to the movement of the cursor across a selected region in a window periphery will effect the display of a selected menu item associated with the particular selected region. The overlapping windows are preferably rectangular in shape and the selected regions are adjacent to corners of the periphery. The menu items are distributed so as to be positioned adjacent to the respective region across which the cursor movement will result in the item display.