Thread: Point of Sale
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Remote User is offline Remote User
2006-03-15 , 00:14
Posts: 192 | Thanked: 5 times | Joined on Nov 2005 @ Eugene, Oregon
#48
Originally Posted by djs_tx
My company builds some linux based telemetry and data acquisition systems. We do all our GUI's in java because that lets us have a single GUI that looks the same on a local display as it does on a web browser.

You have just shown me a third way to get there, X forwarding so let me ask... What are the pros / cons of X forwarding versus something like VNC?
Sorry for the late reply. I was ignoring my own thread here because the move from X core fonts to Xft fonts was frustrating me and I am embarrased about that. I'm glad to say that we've finally made the transition and things will change around here soon because of that.

Both accomplish very similar things. If you wanted to make a fairly feature rich GUI but not necessarily graphically intensive, what techniques / platforms would you employ to get the most out of a mobile terminal like the 770?
VNC gives you a static image - the whole thing has to be sent over the network. X gives you a dynamic GUI that is 100% data-driven and, in our case, network-driven. If you manipulate the GUI (something you can't do withVNC because it's just a picture) then you can directly manipulate the data behind the GUI, even if it's on the other side of the planet, and even if other people are viewing the same GUI you are viewing. All that's sent over the network is the information about the GUI that the remote display and graphics processor needs to construct the remote user's GUI.

The extra element in this is the GUI toolkit - that's what we had to add to the mix. We built our GUI out of 'X Primitives'. Most people think of X as a windowing system, which it is, but it's also a transparent network protocol. It allows users, their displays and their input devices to be physically separate from where the programs are running and the data storage. It also allows GUIs to represent virtually any kind of resource on any kind of network. That's a long way from what a Desktop GUI is all about.

GUI, by the way, doesn't always mean pictures. It can mean, as it does in our case, use of 'textures' (aka background tiles) and special use of fonts. We add 'frosting' and 'shadowing' to our text to make it easier to read - we increase the contrast. The bottom line of all this is that much in the same way someone can watch TV without needing a PC, someone can be a user of software without needing a PC. In both cases all they need is a display terminal that attaches to a network with rich content. In the case of software the user also needs a rich array of input devices to be available. When the IPTV experience arrives it will also require a rich array of user input devices.

To all, then, we have finally put the X core font limitation (aka the roadblock) behind us and will soon have the POS demo running. Thanks for being patient.