UH2@PSUVM.BITNET (Lee Sailer) (10/13/89)
In a demo of OS/2 a couple of days ago, I saw what looked like the next generation of clipboard capabilities, at least in one dimension. Forgive me, but I am rather fuzzy on the details. They called it Dynamic Data Exchange. In the demo, a block of numbers in a spreadsheet was marked, and then the DDE menu option allowed that block to be given a name, say 'SALES'. Then, a bar chart drawing utility from another vendor was run, and the DDE menu option allowed the user to select from a number of currently open DDE objects, including SALES. A bar chart of the numbers in SALES appeared. So far, this seems pretty clipboard like (and I don't know how many of the capabilities of IFF are there). The difference was that when the user goes backt to the spreadsheet, and changes some of the numbers, the bar chart changes, too, without even a 'redraw' command from the user. I suppose this can be hacked using REXX and IFF, and so on, but it looked pretty elegant to me. Did Microsoft sream this up, or is it something they borrowed from somewhere else? lee
bradch@microsoft.UUCP (Bradford Christian ms1) (10/22/89)
In article <89286.094909UH2@PSUVM.BITNET> UH2@PSUVM.BITNET (Lee Sailer) writes: >In a demo of OS/2 a couple of days ago, I saw what looked like the next >generation of clipboard capabilities, at least in one dimension. Forgive >me, but I am rather fuzzy on the details. > >They called it Dynamic Data Exchange. In the demo, a block of numbers >in a spreadsheet was marked, and then the DDE menu option allowed that >block to be given a name, say 'SALES'. Then, a bar chart drawing utility >from another vendor was run, and the DDE menu option allowed the user >to select from a number of currently open DDE objects, including SALES. >A bar chart of the numbers in SALES appeared. > >So far, this seems pretty clipboard like (and I don't know how many >of the capabilities of IFF are there). The difference was that when >the user goes backt to the spreadsheet, and changes some of the numbers, >the bar chart changes, too, without even a 'redraw' command from the >user. > >I suppose this can be hacked using REXX and IFF, and so on, but it >looked pretty elegant to me. Did Microsoft sream this up, or is it >something they borrowed from somewhere else? > > lee I think "hot-links" have been around for a few years on "larger" computers, but I'm not sure. It's really very simple to do, and in fact I don't think Microsoft had to change any code in Windows to get DDE to work. It is simply a small set of messages that applications can use to comunicate changes to other apps. The user sees the link creation as just a special form of Paste. Basicaly, the user copies something from one app to the clipboard and then issues a Paste Link command in the other app. The second app informs the first that it wants to link to the source of the data in the clipboard. The first app remembers what apps have linked to it's data and sends messages whenever relevent things change. The interesting messages are: Initiate(application, topic) Terminate() Request(format, item) Data(pointer, item) Advise(options, item) Unadvide(item) Poke(pointer, item) Initiate starts a conversation between two applications and Terminate stops it. Request is sent by a client to ask the server to provide an item. Data is the server's response (pointer points to the actual object being sent). Advise sets up a connection to a particular object (Initiate just connects the apps) and Unadvise breaks the connection. Poke is use be servers to send data to a client without a link being set up. Anyway, DDE can be fun (and useful :-) and would be realy easy to get going on the Amiga. All it would take would be for Commodore to spec it. So, is it "in there?" BradCh