Icons have been a part of modern computing since- well, I'm sure we've all used a Windows computer with too many icons littered over the desktop at some point.
Icons can of course be a short-cut to opening an application or document.
They can also show a running program or open documents, be a short-cut to system controls, show system alerts or information from the outside world- the weather, email messages etc.
They are found in menus, on the desktop, in taskbars, in the notification area, as discussed in my previous post.
In fact, they are found in many different places.
Let's have a look at an example in Ubuntu Linux: Opera web browser. Its icon can be found in the Applications>Internet menu
in the panel, if you chose to put it there
on the desktop, if you chose to put it there
in the notification area, if the program is running
and in the bottom panel, if the program is running.
That's five instances of an icon for one program. Of course it's possible to have fewer- at a bare minimum, two, as the panel, desktop and notification area icons are optional. But a quick-start icon is useful- one click to start a frequently-used program is a lot more convenient than three clicks through a menu, even if it does leave a panel littered with program start-up icons.
For other programs, being able to send the program to the notification area is useful- an icon there doesn't take up space or crowd and confuse the bottom panel where open files and documents sit. So for an application like Rhythmbox or Transmission, an icon might appear twice on the screen- a quick start icon and a notification icon.
Document applications like Open Office might also have two icons visible on the screen- a quick start icon and individual document icons.
Wouldn't it be far less cluttered just to have one icon? One icon to start an application, to give information about what an application is doing, to show open documents and to give information about the system or the world outside. Is that possible? Well, yes.
Here's a screen shot of Opera in an application launcher, in this case Docky.
(The icons do a Mexican wave as the mouse pointed moves over them. Individual icons hop to attract attention. The launcher panel hides itself as the mouse pointer moves away. Is Linux meant to be this sexy?)
I can pin the Opera icon to the launcher if I want, but in this case I opened Opera from the Applications>Internet menu. The icon is illuminated to show the program is open, so let's have a look at what's open with a right-click:
The menu tells me I have one page open in Opera. I can switch to that page from the menu, or just left-click to bring Opera into focus. If I select 'Pin to Dock', the Opera menu will appear on the launcher at start-up, and with one icon I'll be able to start the program and view open documents- no need for five icons!
Let's have a look at what else is running! The Gimp is on the launcher- a right-click shows me my open documents:
I can select an open document from the menu and bring it into focus.
I can also switch easily to a text file or a card game I have open- as well as check the time, see if I have email, browse a disk or switch off the computer. (I can't open an application which isn't pinned to the launcher- yet- but that is coming.)
If I open Rhythmbox and play an album, Docky shows me the track information and album cover. A left click brings Rhythmbox into focus and a right-click gives me menu options- pause, next etc. Pretty much ideal behaviour, if you ask me.
There's also an icon for Pidgin on the panel- so will the little bird hop up and tell me I have a new chat message? I'm not sure how well Docky integrates notifications like this. Docky clearly originated as an application launcher, but it's now moving towards being a panel replacement for Linux.
Another application launcher which already has the features to make it a complete panel replacement application is Avant Window Navigator. It has a notification area which can replace the panel notification area, and already has a Main Menu applet for launching applications. In terms of features, it is probably slightly ahead of Docky, if not quite as funky visually.
Both Docky and Avant are very nearly at the point where they can replace the conventional taskbar/panel. One big drawback is that they are one dimensional and can become very clutered and disorganised if too many applications are pinned to the dock. I'd like to see them become two-dimensional, with icons grouped an appearing in vertical columns above a group icon, perhaps. Although the forthcoming Docky Application Menu pretty much pre-empts my thinking.