Data display for concurrent task processing systems

• US 4,736,309 A
• Filed: 07/26/1985
• Issued: 04/05/1988
• Est. Priority Date: 07/31/1984
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Niblett, Peter D., Johnson, Peter W.
• Primary Examiner(s): Gruber, Felix D.
• Application Number:
  US06/759,706
• Time in Patent Office: 984 Days
• Field of Search: 364/518, 364/521, 364/522, 364/200, 364/900, 340/709, 340/721, 340/724, 340/727
• US Class Current: 715/797
• CPC Class Codes: G09G 5/14 Display of multiple viewports

Abstract

A method and apparatus for automatically changing the display in overlapping rectangular viewport areas of a display screen of a digital display apparatus and in which each viewport area is assigned a different priority level. The method includes the steps of (a) storing in a random access store indications of the position and size of each viewport area, together with an indication of the priority level of the viewport area and (b) constructing a first matrix of (2n+1)² elements, where n is equal to the number of viewport areas, by assigning a vertical component to each vertical coordinate of each viewport area and a horizontal component to each horizontal coordinate of each viewport area, and for each element so formed storing an indication of the highest priority level of the viewports falling within the boundary formed by the coordinates defining the element.

Claims

1. A method for automatically changing the display in overlapping rectangular viewport areas of a display screen of a digital display apparatus and in which each viewport area is assigned a different priority level, said method being exercisable without direct operator control and comprising the steps of:

(a) storing in a random access store indications of the position and size of each viewport area, together with an indication of the priority level of the viewport area,

(b) constructing a master matrix of (2n+1)² elements, where n is equal to the number of viewport areas, by assigning a vertical component to each vertical coordinate of each viewport area and a horizontal component to each horizontal coordinate of each viewport area, and for each of said elements so formed storing an indication of the highest priority level of the viewports covered the said elements,

(c) receiving an indication that the display of a particular viewport is to be changed,

(d) constructing a condensed matrix for the viewport area, the display of which is to be changed, by storing, for each said element, an indication of whether or not it covers the particular viewport that is to be changed, and associating the corresponding elements of identical rows and columns together,

(e) receiving indications of the coordinate values of the display to be displayed in the viewport area,

(f) using said condensed matrix to determine the coordinates of the received display information that can be displayed in the viewport area, and

(g) storing the indications of the coordinate values in the random access store.

2. Data display apparatus comprising a procedure processor, a storage unit and a display buffer operating under the control of a control system to display on a display screen multiple overlaid viewports, each assigned to a different application task,

characterized in that said control system includes:

communication means, adapted to control the apparatus to receive data display information signals from an application processor, and processor means, adapted to control the procedure processor to store in a random access store indications of the position and size of each viewport area, together with an indication of the priority level of the viewport area and to generate signals indicating the result of constructing a first matrix of (2n+1)² elements, where n is equal to the number of viewport areas, by assigning a vertical component to each vertical coordinate of each viewport area and a horizontal component to each horizontal coordinate of each viewport area, and for each of said elements so formed storing an indication of the highest priority level of the viewports covered by said elements;

to construct a second matrix for the viewport area, the display of which is to be changed, by storing, for each element, an indication whether or not it covers the particular viewport that is to be changed, and associating the corresponding elements of identical rows and columns together, and using said second matrix to determine the coordinates of the received display information that can be displayed in the viewport area and to generate and store signals indicative of the determination.