System for dynamic sharing of local and remote displays by maintaining a list of best-match resources

• US 5,408,600 A
• Filed: 07/06/1994
• Issued: 04/18/1995
• Est. Priority Date: 08/30/1990
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Louder, Stephen A., Wildman, Richard C., Garfinkel, Daniel
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): AMSBURY, WAYNE P
• Application Number:
  US08/271,383
• Time in Patent Office: 286 Days
• Field of Search: 395/153, 395/600, 395/700
• US Class Current: 715/759
• CPC Class Codes: G06F 2209/545 Gui
• CPC Class Codes: G06F 3/1454 involving copying of the display data of a local workstation or window to a remote workstation or window so that an actual copy of the data is displayed simultaneously on two or more displays, e.g. teledisplay
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications
• CPC Class Codes: G09G 2360/04 Display device controller operating with a plurality of display units

Abstract

A method and apparatus for sharing a local display signal from a local computer display to at least one remote computer display includes generating a connection with the display server associated with the remote computer display in response to a signal from the local workstation input device generating a remote display signal in relation to the local display signal in response to a second signal from the input device. The generation of the remote display signal involves dynamically creating a list of display resources for the remote computer display and generating the remote display signal in relation to the display resources and transmitting the remote display signal to the remote display server. Where the local display signal is shared among multiple remote computer displays, the generation of remote display signals creates a list of display resources for each of the remote computer displays, which list is updated for each rendering of the local display signal. In such a situation, the remote display signal for each remote computer display is generated in relation to the associated display resources. In one embodiment, the local display signal is a window based display signal, preferably X-windows. The generation of such a window based signal defines a window instance. Graphics contexts are dynamically allocated for each window instance and are stored remotely while identification information is stored locally.

Claims

1. Apparatus for sharing a local display signal from a local computer display to at least one remote computer display, each computer display comprising a display screen and a central processing unit, wherein each central processing unit comprises a display server for displaying a display signal on said display screen, said local computer display further comprising an input device, said apparatus comprising:

a display server extension, connected to the display server associated with said local computer display, comprising a connector for generating a connection with the display server associated with said remote computer display in response to a first command signal, a signal generator for generating a remote display signal which substantially replicates the result of said local display signal in response to said first command signal, wherein the generation of said remote display signal comprises dynamically creating a list of available remote display resources for said remote computer display that most closely resemble the local display resources used in said local display signal and generating said remote display signal by translating the local display signal using said list of available remote display resources and a transmitter for transmitting said remote display signal to the remote display server using said connection; and

a user interface, connected to the display server associated with said local computer display and connected to said input device, for generating said command signal.

2. The apparatus of claim 1, wherein the local display signal is shared among multiple remote computer displays, and wherein said display server extension dynamically creates a list of display resources for each of said remote computer displays, which list is updated for each rendering of the local display signal, and wherein a remote display signal is created for each of said remote computer displays in relation to the display resources associated with each remote computer display.

3. The apparatus of claim 1, wherein said local display signal comprises a window based display signal and wherein each of said display servers comprises a window server.

4. The apparatus of claim 3, wherein each window server is identical.

5. The apparatus of claim 4, wherein each window server comprises an X-window server.

6. The apparatus of claim 3, wherein said display server extension generates a remote display signal representative of one window displayed at said local computer display.

7. The apparatus of claim 3, wherein the display server associated with said local computer display is connected to an application, wherein said display server extension generates a remote display signal representative of all windows displayed in relation to said application.

8. The apparatus of claim 6, wherein said display server extension dynamically allocates graphics contexts for each local graphics context for each remote computer display.

9. The apparatus of claim 1, wherein said list of display resources are dynamically generated so that the image displayed at said remote computer display is substantially identical to the image displayed at said local computer display.

10. The apparatus of claim 1, wherein said remote computer display comprises a remote memory connected to each central processing unit wherein in relation to dynamically creating a list of display resources, said display server extension creates the list and causes the display resources for the remote computer display to be stored in said remote memory.

11. The apparatus of claim 10, wherein when said display server extension terminates sharing display signals with a remote computer display, the resources stored in such remote computer display are erased.

12. The apparatus of claim 1, wherein said display server extension further comprises termination means for terminating the sharing of a particular window at a particular remote computer display.

13. The apparatus of claim 1, wherein said display server extension further comprises termination means for terminating the sharing of all windows at a particular remote computer display.

14. Apparatus for sharing a local display signal from a local computer display to at least one remote computer display, each computer display comprising a display screen and a central processing unit, wherein each central processing unit comprises a display server for displaying a display signal on said display screen, said local computer display further comprising an input device, said apparatus comprising:

a display server extension, connected to the display server associated with said local computer display, comprising a connector for generating a connection with the display server associated with said remote computer display in response to a first command signal, a signal generator for generating a remote display signal which substantially replicates the result of said local display signal in response to said first command signal, wherein the generation of said remote display signal comprises dynamically creating a list of available remote display resources for said remote computer display that most closely resemble the local display resources used in said local display signal and generating said remote display signal by translating the local display signal using said list of available remote display resources and a transmitter for transmitting said remote display signal to the remote display server using said connection, wherein the display server associated with said local computer display is connected to an application, wherein said remote computer display further comprises an input device, wherein each of the input devices are capable of generating input events to be processed by said application resulting in a change to the image displayed at the local and remote computer displays, said display server extension further comprising, an input event controller for controlling which input events will be processed by the application; and

a user interface, connected to the display server associated with said local computer display and connected to said input device, for generating said command signal.

15. The apparatus of claim 14, wherein said input event controller determines which of the input devices will generate input events to be processed by the application, by defining one of the input devices as a current input instance.

16. The apparatus of claim 15, wherein said input event controller defines as the current input instance that input device which is generating input events.

17. The apparatus of claim 16, wherein said input event controller comprises a timer for measuring the time elapsed between generation of input events by the current input instance, and wherein said input event controller will not redefine the current input instance until a preselected time period has elapsed from the generation of the last input event by the current input instance.

18. The apparatus of claim 15, wherein said input event controller defines the current input instance in response to a second command signal.

19. A method for sharing a local display signal from a local computer display to at least one remote computer display, each computer display comprising a display screen and a central processing unit, wherein each central processing unit comprises a display server for displaying a display signal on said display screen, said local computer display further comprising an input device, said method comprising the steps of:

generating a connection with the display server associated with said remote computer display in response to a first signal from said input device;

generating a remote display signal which substantially replicates the result of said local display signal in response to a second signal from said input device, wherein the generation of said remote display signal comprises dynamically creating a list of available remote display resources for said remote computer display that most closely resemble the local display resources used in said local display signal, and generating said remote display signal by translating the local display signal using said list of available remote display resources; and

transmitting said remote display signal to the remote display server using said connection, whereby said remote display server is enabled to receive said remote display signal and update said remote display screen with said remote display signal.

20. The method of claim 19, wherein the local display signal is shared among multiple remote computer displays, and wherein said step of generating a remote display signal comprises the steps of creating a list of display resources for each of said remote computer displays, updating said list for each rendering of the local display signal and creating a remote display signal for each of said remote computer displays in relation to the display resources associated with each remote computer display.

21. The method of claim 19, wherein said local display signal comprises a window based display signal and wherein each of said display servers comprises a window server.

22. The method of claim 21, wherein each window server is identical.

23. The method of claim 22, wherein each window server comprises an X-window server.

24. The method of claim 21, wherein said step of generating a remote display signal comprises the step of generating a remote display signal representative of one window displayed at said local computer display.

25. The method of claim 24, further comprising the step of dynamically allocating graphics contexts for each remote computer display.

26. The method of claim 21, wherein the display server associated with said local computer display is connected to an application, wherein said step of generating a remote display signal comprises the step of generating a remote display signal representative of all windows displayed in relation to said application.

27. The method of claim 19, wherein the step of creating a list of display resources for each of said remote computer displays comprises the step of dynamically generating a list of display resources so that the image displayed at said remote computer display is substantially identical to the image displayed at said local computer display.

28. The method of claim 19, wherein said local computer display comprises a local memory connected to the central processing unit and wherein said remote computer display comprises a remote memory connected to each central processing unit wherein in relation to the step of dynamically creating a list of display resources said method further comprises the step of storing the display resources for the remote computer display in said remote memory and storing the location of said display resources in said local memory.

29. A method for sharing a local display signal from a local computer display to at least one remote computer display, each computer display comprising a display screen and a central processing unit, wherein each central processing unit comprises a display server for displaying a display signal on said display screen, said local computer display further comprising an input device, said method comprising the steps of:

generating a connection with the display server associated with said remote computer display in response to a first signal from said input device;

generating a remote display signal which substantially replicates the result of said local display signal in response to a second signal from said input device, wherein the generation of said remote display signal comprises dynamically creating a list of available remote display resources for said remote computer display that most closely resemble the local display resources used in said local display signal and generating said remote display signal by translating the local display signal using said list of available remote display resources; and

transmitting said remote display signal to the remote display server using said connection, whereby said remote display server is enabled to receive said remote display signal and update said remote display screen with said remote display signal, the display server associated with said local computer display is connected to an application, wherein said remote computer display further comprises an input device, wherein each of the input devices are capable of generating input events to be processed by said application resulting in a change to the image displayed at the local and remote computer displays, said method further comprising the step of controlling which input events will be processed by the application.

30. The method of claim 29, wherein said step of controlling input events comprises the step of defining one of the input devices as a current input instance whereby only one of the input devices will generate input events to be processed by the application.

31. The method of claim 30, wherein said step of defining one of the input devices as a current input instance comprises the step of defining that input device which is generating input events as the current input instance.

32. The method of claim 31, wherein said step of defining one of the input devices as a current input instance comprises the steps of measuring the time elapsed between generation of input events by the current input instance and redefine the current input instance only after a preselected time period has elapsed from the generation of the last input event by the current input instance.