Abstract:
An apparatus, method, and computer program for instant remote document sharing. In one embodiment, referred to as “remote document sharing,” a file on a remote server is converted to a “shared document” which is distributed to the members of a data conference for review. In another embodiment, referred to as “remote application viewing,” the “owner” of a document on a remote server shares the screens created by an application associated with the document. The other members of the data conference can view the screens, but cannot interact with the application. In another embodiment, referred to as “remote application sharing,” the “owner” of a document on a remote server shares the screens created by an application associated with the document. The other members of the data conference can view the screens and interact with the application.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to data conferencing, and more particularly to instant document sharing in a data conference. 
     2. Related Art 
     Whenever two or more people are involved in the viewing, creation or modification of a computer document, whether it be a browser web page, financial spread sheet, a CAD design, a circuit schematic layout, an organization report, a bit map image, and the like, succeeding drafts of the document are prepared, circulated, and modified in the process. Each person works on his or her portion of the document and stores it or forwards a copy to the next person. The next person will subsequently retrieve the stored copy or work on his or her copy of the document. Typically, several drafts of the document will be circulated before a final draft is produced. This is a very time-consuming process. 
     In the case where the reviewers involved in this document preparation process are at different geographical locations, getting the document from one location to another location and back becomes another tedious and time-consuming task. The document must be mailed or faxed to that person, further complicating the entire process. 
     An additional complication in many cases is that each person must have a copy of the document editing program required to view, create or modify the document. Examples of such document editing programs include Browsers, spreadsheet applications, word processing programs, image editing programs, and the like. Further, each person must have an identical copy of the document editing program. This scenario not only is expensive in many cases, but also requires additional effort to install, maintain, and update the document editing programs on the user&#39;s individual computer systems, referred to here as client computer systems. 
     One alternative method to this process is to hold meetings where the users gather and comment on the document with the hope to reduce the number of drafts needed before a final draft is produced. The shortcoming with this method is that there may be significant travel time and travel cost in getting everyone to the same location. There may be an additional restriction that the “right” location is constrained to be the location with access to the “correct” document editing program. In addition, the final draft of the document is usually circulated again for final comments. 
     One solution to this problem is to use a teleconferencing software program to share the document among the geographically dispersed reviewers. This process is often referred to as “data conferencing.” By using computer network connections, modem-connected phone lines, and the like, everyone can be connected via his or her computer. By using the teleconferencing software program, everyone&#39;s computer screen can display the same document. In addition to using the software program and network or modem connections, conference calling over the voice phone lines or through the software program creates a dynamic and live atmosphere where everyone can participate in the discussion and refer to the document displayed on the screen. 
     SUMMARY OF THE INVENTION 
     The present invention is an apparatus, method, and computer program product for instant sharing of a remote document. In one embodiment, referred to as “remote document sharing,” a file located on a remote application server is converted to a “shared document” which is distributed to the members of a data conference for review. The method of this embodiment includes printing the file, on the application server, to a virtual printer from an application associated with the file, thereby creating a shared document; and sending the shared document to a plurality of remote clients, whereby the shared document is displayed at each remote client by a viewer application. 
     In another embodiment, referred to as “remote application sharing,” the “owner” of a remote document shares the screens created by an application located on a remote application server, where the document is associated with the application. Each member of the application sharing session can view the screens and interact with the application. The method of this embodiment includes creating a shared screen at a server by sending an application screen generated by an application to a virtual device; sending the shared screen to a plurality of remote clients; presenting, on a display device attached to each of the remote clients, a display of the shared screen; collecting user input from a user at one of the remote clients; sending the user input to the remote server; causing the application at the remote server to edit the application screen based on the user input to produce an application screen update; creating a shared screen update at the remote server by sending the application screen update to the virtual device, wherein the shared screen update represents only the portion of the application screen that was edited; sending the shared screen update to the plurality of remote clients; and revising the display of the shared screen on each display device using the shared screen update. 
     In another embodiment, referred to as “remote application viewing,” the “owner” of a remote document shares the screens created by an application associated with the document. The other members of the data conference can view the screens, but cannot interact with the remote application. Only the owner can interact with the remote application. 
     In all embodiments, an annotation mode is available, where a transparent window is displayed over the shared document. Users can create objects to be displayed in the transparent window, thereby annotating the document. 
     One advantage of the present invention is that, by sharing applications in a client-server system, it provides robust, scalable, instant sharing of remote documents. 
     Another advantage of the present invention is that a document can be shared among clients without distributing the original full-featured document to those clients. Thus a client cannot present a modified copy of the document as an original. 
     Another advantage of the present invention is that it permits clients to use an application without permitting them to copy that application. Thus, clients can be billed for the use of the application on a per-use basis. 
     Further features and advantages of the present invention as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be described with reference to the accompanying drawings. 
     FIG. 1 depicts an example client-server system in which the present invention may be used. 
     FIG. 2 depicts two clients engaged in an application sharing session using a conferencing server and an application server. 
     FIG. 3 is a block diagram of a client document sharing application according to a preferred embodiment of the present invention. 
     FIG. 4 is a block diagram of a server document sharing application according to a preferred embodiment of the present invention. 
     FIG. 5 depicts the software layers in a structured system environment. 
     FIG. 6 depicts the software layers in a structured system environment as modified by a preferred embodiment of the present invention. 
     FIG. 7 is a flow diagram depicting the operation of remote document sharing mode according to a preferred embodiment of the present invention. 
     FIG. 8 is a flowchart depicting the operation of remote document sharing mode according to a preferred embodiment of the present invention. 
     FIG. 9 is a flow diagram depicting the operation of remote application viewing mode according to a preferred embodiment of the present invention. 
     FIGS. 10A and 10B constitute a flowchart depicting the operation of remote application viewing mode according to a preferred embodiment of the present invention. 
     FIG. 11 is a flow diagram depicting the operation of remote application sharing mode according to a preferred embodiment of the present invention. 
     FIGS. 12A and 12B constitute a flowchart depicting the operation of remote application sharing mode according to a preferred embodiment of the present invention. 
     FIG. 13 depicts an example computer system capable of carrying out the functionality of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is described in terms of the above example. This is for convenience only and is not intended to limit the application of the present invention. In fact, after reading the following description, it will be apparent to one skilled in the relevant art how to implement the present invention in alternative embodiments. 
     Introduction 
     The present invention is an apparatus, method, and computer program product for sharing server-hosted applications in a client-server system having multiple remote clients. FIG. 1 depicts an example client-server system  100  in which the present invention may be used. System  100  includes a conferencing server  102 , an application server  106  and a plurality of clients  104 A,  104 B,  104 N. The present invention is usually invoked after a data conference has been established among the client using the conferencing server. Methods for establishing data conferences among clients are well known in the relevant arts. 
     The present invention provides four modes to support different kinds of data sharing and collaboration: remote document sharing mode, remote application viewing mode, remote application sharing mode, and annotation mode. In each mode, a remote document is shared among the clients. 
     In each mode, a client assumes one of four roles: owner, host, editor, and spectator. The owner is the client that controls the remote document. The host is the client that has control of the data conference. An editor is a client that is allowed to edit the remote document. An annotator is a client that can edit a transparent window that overlays the remote document. A spectator is a client that can view the remote document and transparent window, but cannot edit them. 
     FIG. 2 depicts two clients  204  engaged in a data conference using conferencing server  102  and application server  106 . One key advantage of using a client-server architecture rather than a peer-to-peer architecture is that no client is burdened with communicating with all of the other clients. Clients merely communicate with the conferencing server. This advantage permits the system to be highly scalable, for example, to serve a data conference involving a large number of clients. 
     In the described implementation, a conferencing server  102  serves as the interface between the clients  204  and application server  106 . A key advantage of this implementation is the application server communicates only with the conferencing server. This provides advantages in terms of access, maintenance, security, and accounting. 
     Referring to FIG. 2, each client includes an operating system  206 , such as Windows, a memory  208 , a browser  214 , and a client document sharing application  210 . Client  204 A has assumed the role of owner. Client  204 B has assumed the role of editor. Application server  106  includes an operating system  206 , a file editing application  212 , and a server document sharing application  216 . File editing application  212  is associated with the document to be shared. For example, the file editing application can be Microsoft Word, and the document to be shared can be a Microsoft Word document. As another example, the file editing application can be a browser such as Microsoft Internet Explorer, and the document to be shared can be any web site. For example, geographically dispersed users can use this “co-browsing” feature to shop together online. 
     FIG. 3 is a block diagram of client document sharing application  210  according to a preferred embodiment of the present invention. In a preferred embodiment, client document sharing application  210  is configured as a browser plug-in that can be downloaded from the Internet and installed on a computer running a Windows-type operating system and a browser such as Windows Internet Explorer. 
     Client document sharing application  210  includes an application viewer  308 , a communication module  310 , and an editing module  312 . Editing module  312  includes a document editor  314  and an overlay editor  316 . The functions of these elements will be described in greater detail below. 
     FIG. 4 is a block diagram of a server document sharing application  216  according to a preferred embodiment of the present invention. In a preferred embodiment, server document sharing application  216  is a software program executing on a computer running a Windows-type operating system. 
     In order to share a remote document, document sharing application  216  first converts the document to another form by “loading” the document, as will be discussed in detail below. Therefore, the document sharing application  216  includes document loader  402 . Depending on the sharing mode, document loading may involve invoking an application associated with the document. Accordingly, document loader  402  includes an application invoker  404 . The present invention also uses virtual devices and drivers in document loading. Accordingly, document loader  402  includes virtual devices and drivers  406 . Application server  106  shares a loaded document by transmitting data to other clients, and receiving such data, using communication module  410 . 
     Referring to FIG. 3, when a loaded document is received by a client  204 ; a viewer a application  308  allows a user to view the document. Methods for exchanging such data are discussed extensively in U.S. Pat. No. 5,623,603, assigned to the assignee of the present application, and the disclosure thereof incorporated herein by reference in its entirety. 
     Editing module  312  enables users to perform editing functions. Document editor  314  allows users to edit a shared document. Overlay editor  316  allows users to edit the transparent overlay screen. Annotating the transparent window and sending data representing the annotations to a remote computer, where the annotations are drawn on the display, is discussed extensively in U.S. Pat. No. 5,577,188, assigned to the assignee of the present application, and the disclosure thereof incorporated herein by reference in its entirety. 
     Structured System Programming Environment 
     Before proceeding to the discussion of the methods of document sharing, the software layers in a structured system programming environment such as Microsoft Windows are explained. Referring to FIGS. 5 and 6, in starting the server document sharing application  216 , the software layers in a structured system programming environment are modified. 
     FIG. 5 depicts the software layers in a conventional structured system environment. In this environment, a running application program  502  interfaces with input and output devices strictly through the operating system&#39;s Window system environment, represented by OS Window system  504 . When the application program requests the OS Window system to write a character to the screen, the OS Window system in turn directs a display driver  506  to write the character to the monitor  508 . A driver such as a display driver is a software program written specifically to handle a specific device or device type, such as monitor  508 . For example, there are several standards of display resolution with computer monitors. A display driver is needed for each standard in order to control and interface with each type of monitor. 
     Display driver  506  tells the monitor  508  specifically how to write a character on the screen. For example, in an application program such as a word processor running on top of OS Window system  504 , when the user inputs a character “a” from the keyboard and when the word processor receives the character “a” as input, the word processor will display the character “a” on the screen at the right place to reassure the user that he or she has input a character “a”. To write the character “a” to the screen, the word processor calls a OS Window system  504  write-to-screen routine, specifying the character “a” and the location on the screen to place the character. The OS Window system  504  routine in turn calls the display driver with the given information, and the display driver specifically tells the computer screen the placement of dots on the screen to compose the visual image resembling the character “a”. 
     In activating server document sharing application  216 , referring to FIG. 6, the software layer structure is modified. The application call to OS Window system  504  is redirected to a virtual display device  604 . Virtual display device  604  is one of the virtual devices and drivers  406  within document loader  402 . 
     In a preferred embodiment, redirection of the application calls to OS Window system is accomplished by renaming the appropriate OS Window System calls with predefined alternate calls and naming the virtual display device to the OS Window system&#39;s original calls. When the application calls the OS Window System via its name, it is calling the virtual display device rather than the OS Window System. The virtual display device calls the OS Window system through its predefined names. The virtual display device calls the OS Window system with the information to place on the screen as requested by a file editing application  212 , which can be any application such as a word processor. 
     In one embodiment, virtual display driver  604  reports the screen updates to server document sharing application  216  via dynamic link library  606 . When the screen updates are finished, server document sharing application  216  reads the screen updates stored in dynamic link library  606 . In annotation mode, client document sharing application  210  checks for overlapping screen objects and re-draws the annotation objects if necessary. This process is fully explained in U.S. Pat. No. 5,577,188. 
     In another embodiment, server document sharing application  216  creates a shared screen  608 , or a shared screen update  610 , which is passed directly (via conferencing server  102 ) to document sharing application  210  for display, and for transmission to other clients in the data conference for display to other users. This embodiment is used in the application viewing and application sharing modes, as described in detail below. 
     In document sharing mode, a representation of the entire document is sent to each client&#39;s viewer application  308 . In one embodiment, this is accomplished by using a virtual printer driver  612 . The document to be shared is printed from its associated file editing application  212  to virtual printer driver  612 , creating a shared document  614  in a predefined format. Shared document  614  is passed directly to client document sharing application  210  for display, and for transmission to other clients in the data conference for display to other users. 
     Remote Document Sharing Mode 
     FIG. 7 is a flow diagram depicting the operation of document sharing mode according to a preferred embodiment of the present invention. FIG. 7 depicts the data flows between file editing application  212 , server document sharing application  216  running on application server  106  and client document sharing application  210  running on client  204 . FIG. 8 is a flowchart depicting this operation. 
     Referring to FIG. 8, the user of owner client  204 A selects a remote file to share in step  802 . In response, the application invoker of server document sharing application  216  invokes the file editing application  212  associated with the selected file in step  804 . In a preferred embodiment, the application invoker employs automatic application association to select the associated file editing application based on associations established by the operating system according to methods well-known in the relevant arts. If the file editing application is already running, step  804  merely involves opening the selected file using the associated file editing application. However, if the file editing application is not open when the file is selected, the file editing application is launched first. 
     The default printer associated with file editing application  212  or Windows is checked in step  806 . If the default printer is not set to be the virtual printer associated with virtual printer driver  612 , then the default printer is saved in step  810  and the virtual printer is selected as the default printer in step  812 . Otherwise, steps  810  and  812  are skipped. 
     The selected file is then printed to the virtual printer in step  814 . Referring to FIG. 6, this operation entails redirecting the print call from file editing application  212  at the OS Window System  504  to virtual printer driver  612 , thereby creating shared document  614 . Shared document  614  is then passed to client document sharing application  210  for viewing and distribution. If necessary, the default printer is restored in step  816 . If file editing application  212  was launched in step  804 , then it is closed in step  818 . 
     Client document sharing application  210 , on receipt of shared document  614 , sends the shared document to server  102  for distribution to all clients in the data conference. All of the clients in the data conference then display the shared document using a viewer application  308 , as shown in step  822 . 
     In FIG. 7, time flows from top to bottom. Referring to that figure, virtual printer driver  612  generates printer file  702  which is modified by server document sharing application  216  to create a shared document  614 . Server document sharing application  216  forwards it to conferencing server  102  for distribution to client document sharing applications  210  for display. Using annotation mode, the client document sharing applications  210  can exchange user input  704  through conferencing server  102  to draw various objects upon a transparent window overlaying the shared document  614 . 
     Remote Application Viewing Mode 
     FIG. 9 is a flow diagram depicting the operation of remote application viewing mode according to a preferred embodiment of the present invention. FIGS. 10A and 10B constitute a flowchart depicting that operation. 
     A user of a client document sharing application  210  selects a file editing application to view in step  1002 . In response, the file editing application is invoked, generating an application screen  902 , as shown in step  1004 . Server document sharing application  216  causes application screen  902  to be sent to virtual display driver  604 , thereby generating a shared screen  608  as shown in step  1006 . Server  102  distributes the shared screen to the clients in the data conference in step  1010 . In step  1012 , the clients in the data conference, running client document sharing application  210 , display the shared screen using viewer application  308 . 
     Referring to FIG. 9, the users in the data conference that have been granted the role of editor can exchange user input in the form of annotations  904 . However, in application viewing mode, the remote application is controlled only by the owner&#39;s user input  906 . in one implementation, conferencing server  102  authenticates the owner using well-known conventional methods. 
     The other clients in the data conference are not permitted to control the application directly. When client document sharing application  210  receives input from the owner in step  1014 , it forwards this user input  906  to file editing application  602  via conferencing server  102  and server document sharing application  216  to drive the application to edit the application screen based on that input, as shown in step  1016 . In response, the application provides an application screen update  908 . Server document sharing application  216  sends application screen update  908  to virtual display driver  604 , thereby creating a shared screen update  610 , as shown in step  1020 . 
     Server document sharing application  216  forwards the shared screen update to conferencing server  102 . The server distributes the shared screen update to the clients in the data conference, as shown in step  1024 . In response, the clients revise the shared screen currently being displayed using the shared screen update, and display the revised shared screen in step  1026 . 
     Remote Application Sharing Mode 
     FIG. 11 is a flow diagram depicting the operation of application sharing mode according to a preferred embodiment of the present invention. FIGS. 12A and 12B constitute a flowchart depicting that operation. 
     The owner of client document sharing application  210  selects a remote application to view in step  1202 . In response, the file editing application is invoked, generating an application screen  1102 , as shown in step  1204 . Server document sharing application  216  causes application screen  1102  to be sent to virtual display driver  604 , thereby generating a shared screen  608  as shown in step  1206 . Server  102  distributes the shared screen to the clients in the data conference in step  1210 . In step  1212 , the clients in the data conference display the shared screen using viewer application  308 . 
     In application sharing mode, both the owner and editors are permitted to control the file editing application directly. Steps  1214  through  1226  illustrate this process. Referring to FIG. 11, a user of client document sharing application  210  generates editor user input  1104 , which is sent to server document sharing application  216  through conferencing server  102 . Server document sharing application  216  receives the editor user input in step  1214 , and forwards this input to file editing application  212 , thereby driving that application to edit the current application screen based on editor user input  1104  as shown in step  1216 . Server document sharing application  216  sends the application screen update to virtual display driver  604 , thereby creating a shared screen update  610 , as shown in step  1220 . 
     Server distributes the shared screen update to all the clients in the data conference using conferencing server  102 , as shown in step  1224 . Each client revises the current shared screen using the shared screen update, and displays the revised shared screen using its viewer application  308 , as shown in step  1226 . The process of steps  1214  through  1226  is repeated as needed. 
     Exemplary Computer System 
     The present invention may be implemented using hardware, software or a combination thereof and may be implemented in a computer system or other processing system. In fact, in one implementation, the invention is directed toward one or more computer systems capable of carrying out the functionality described herein. An exemplary computer system  1300  is shown in FIG.  13 . The computer system  1300  includes one or more processors, such as processor  1304 . The processor  1304  is connected to a communication bus  1306 . Various software implementations are described in terms of this exemplary computer system. After reading this description, it will become apparent to a person skilled in the relevant art how to implement the invention using other computer systems and/or computer architectures. 
     Computer system  1300  also includes a main memory  1308 , preferably random access memory (RAM), and can also include a secondary memory  1310 . The secondary memory  1310  can include, for example, a hard disk drive  1312  and/or a removable storage drive  1314 , representing a floppy disk drive, a magnetic tape drive, an optical disk drive, etc. The removable storage drive  1314  reads from and/or writes to a removable storage unit  1318  in a well known manner. Removable storage unit  1318 , represents a floppy disk, magnetic tape, optical disk, etc. which is read by and written to by removable storage drive  1314 . As will be appreciated, the removable storage unit  1318  includes a computer usable storage medium having stored therein computer software and/or data. 
     In alternative implementations, secondary memory  1310  may include other similar means for allowing computer programs or other instructions to be loaded into computer system  1300 . Such means can include, for example, a removable storage unit  1322  and an interface  1320 . Examples of such include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, or PROM) and associated socket, and other removable storage units  1322  and interfaces  1320  which allow software and data to be transferred from the removable storage unit  1318  to computer system  1300 . 
     Computer system  1300  can also include a communications interface  1324 . Communications interface  1324  allows software and data to be transferred between computer system  1300  and external devices. Examples of communications interface  1324  can include a modem, a network interface (such as an Ethernet card), a communications port, a PCMCIA slot and card, etc. Software and data transferred via communications interface  1324  are in the form of signals which can be electronic, electromagnetic, optical or other signals capable of being received by communications interface  1324 . These signals  1326  are provided to communications interface  1324  via a channel  1328 . This channel  1328  carries signals  1326  and can be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link and other communications channels. 
     In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage device  1318 , a hard disk installed in hard disk drive  1312 , and signals  1326 . These computer program products are means for providing software to computer system  1300 . 
     Computer programs (also called computer control logic) are stored in main memory  1308  and/or secondary memory  1310 . Computer programs can also be received via communications interface  1324 . Such computer programs, when executed, enable the computer system  1300  to perform the features of the present invention as discussed herein. In particular, the computer programs, when executed, enable the processor  1304  to perform the features of the present invention. Accordingly, such computer programs represent controllers of the computer system  1300 . 
     In an implementation where the invention is implemented using software, the software may be stored in a computer program product and loaded into computer system  1300  using removable storage drive  1314 , hard drive  1312  or communications interface  1324 . The control logic (software), when executed by the processor  1304 , causes the processor  1304  to perform the functions of the invention as described herein. 
     In another implementation, the invention is implemented primarily in hardware using, for example, hardware components such as application specific integrated circuits (ASICs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art(s). In yet another implementation, the invention is implemented using a combination of both hardware and software. 
     While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be placed therein without departing from the spirit and scope of the invention. Thus the present invention should not be limited by any of the above-described example embodiments, but should be defined only in accordance with the following claims and their equivalents.