Presenting Visible Tasks

Most operating systems present you a desktop or a work space to organize your tasks. Programs appear in windows or boxes in your desktop, and you can resize or move them as you like. Each program window has a common interface that surrounds the actual content. This area is called the window chrome and it gets assigned by the operating system.

(Chrome in Windows XP on the top, Mac OS X on the bottom)

Functionality
The functionality of this chrome pretty much defines how much you can interact with the visible tasks. The buttons on the chrome let you terminate the task, hide it or maximize it for full attention. Operating systems add more functionality by even more buttons, for instance some Windows tasks have a question mark button for context-sensitive help, or Mac OS X windows’ left hand button lets you hide the contents of the task but keep the title bar visible.
The chrome mostly reacts in a usual drag ‘n drop way. You can move or resize a window buy dragging its chrome from various places.

Visual Separation
The more important role of the chrome is to separate each task visually. In a crowded multi-tasking environment each task should stand out for itself, especially the active task. Windows relies on its colored and relatively thick window borders, while on OS X there is no unity about borders. (Some applications have it and some don’t) But OS X applies drop-shadows to tasks which work well in lightly colored environments.

(Windows XP on top, OS X on the bottom)

Multi-Tasking Interfaces Introduction

Computers of today grow more and more powerful everyday, and the first thing we experience is better multi-tasking capabilities. In the most fundamental levels the computer can do only one operation at a time, however thanks to clever software management, computer resources are shared between applications. In terms of technology each modern operating system today is capable of multi-tasking; the only question is how these systems present this technology to the end-user. Can the user take full advantage of multi-tasking in his speedy workflow? Humans are also multi-tasking, but in their interaction with computers, the performance is determined by the lowest common denominator which is usually the computer. A good user interface is more than necessary in a multi-tasking environment.

Different Kind of Tasks
A multi-tasking environment manages tasks at different states. If we follow the Windows environment:


Notepad is the active task that receives input from the keyboard. Paint is inactive but visible on the environment. There is also another task, Calculator which is hidden from the environment.


What does a multi-tasking user interface needs?
- Presenting visible tasks
- Managing invisible tasks
- Switching between tasks
- Distinguishing different kinds of tasks

(Each will be discussed in its own section)