Multiple Windows Strategies

1. Multiple Windows Strategies CIS 577 Bruce R. Maxim UM-Dearborn

2. Windows • User dialogs are not displayed on paper any more (all terminals are CRT’s) • Users are shown a large screen covered with smaller windows containing information or supporting user interaction • Designers need to develop a set of strategies to reduce the time the user spends dealing with distracting clutter and extra hand-eye movements

3. Windows Systems • It was apparent that early designers were happy to let users open as many windows as they wished on the desktop • The notion of allowing windows to be assembled into rooms was a first step • Both HP-Vue and Sun Solaris offered virtual workspaces with strategies to navigate among clusters of windows several years ago

4. Window Components • Rectangular screen areas that contain software application output or document files • Titles (various poistions) • Borders or frames (needed to locate) • Scroll bars (various styles) • Buttons or icons (need at least one to close)

5. Window Actions • Open (type command or click on icon) • Open, place, and size (use mouse) • Close (icon or function key) • Resizing • Move (mouse or cursor keys) • Bring forward or activate (mouse click)

6. Challenges Multiple Windows Designs • Multiple monitors • Users don’t like gaps • Rapid display flipping • Burden on user to remember information location • Split screens • Reduced screen real estate for each application • Fixed size, space filling, tiled • Reduced screen space for each application • Variable size, space filling, tiled • Requires overlapping and surprising auto resize

7. Challenges Multiple Windows Designs • Variable size, non-space filling, tiled • Blank screen space allowed • Piles of tiles • Mouse selection of exposed corners • Automatic panning • Some windows forced off top of screen • Window zooming • Temporarily enlarging selected window

8. Challenges Multiple Windows Designs • Arbitrary overlaps • 2.5D display to allow mouse selction • Cascades • Microsoft windows

9. Coordination of Multiple Windows Tasks • Synchronized scrolling • Hierarchical browsing • Direct selection • Two dimensional browsing • Dependent windows opening • Dependent windows closing • Save or open windows state

10. Image Browsing in Tightly Coupled Windows • Vertical and horizontal scroll bars only work for images 3 to 5 times screen size • Zoom-in and Zoom-out techniques work better on larger images • Keep overview on screen with enlarged subsection • Zoom and replace (easy to implement, sometimes users find it disorienting) • Fisheye view nice alternative to zoom and replace

11. Next 10 slides from Sneiderman and Plaisant

12. Windows Design • Users need to consult multiple sources rapidly • Must minimally disrupt user's task • With large displays, eye-head movement and visibility are problems • With small displays, windows too small to be effective • Need to offer users sufficient information and flexibility to accomplish task, while reducing window housekeeping actions

13. Windows Design • Windows housekeeping • Distracting clutter, eye-head movement • opening, closing, moving, changing size • time spent manipulating windows instead of on task • Can apply direct-manipulation strategy to windows • Rooms - a form of window macro that enables users to specify actions on several windows at once

14. Coordinating Multiple Windows • Designers may break through to the next generation of window managers by developing coordinate windows, in which windows appear, change contents, and close as a direct result of user actions in the task domain • Such sequences of actions can be established by designers, or by users with end-user programming tools

15. Coordinating Multiple Windows • A careful study of user tasks can lead to task-specific coordinations based on sequences of actions • Important coordinations: • Synchronized scrolling • Hierarchical browsing • Opening/closing of dependent windows • Saving/opening of window state

16. Image Browsing • A two-dimensional cousin of hierarchical browsing • Works with large images • Overview in one window (context), detail in another (focus) • Field of view box in the overview • Panning in the detail view, changes the field of view box • Matched aspect ratios between field of view box and the detail view

17. Image Browser Design • The design of image browsers should be governed by the users’ tasks, which can be classified as follows: • Image generation • Open-ended exploration • Diagnostics • Navigation • Monitoring

18. Zoom factors: 5-30 • Larger suggests an intermediate view is needed • Semantic zooming • Side by side placement, versus fisheye view

19. Personal Role Manager (PRM) • Role-centered design - emphasizes user's tasks rather than documents • Docucentric design - focus on user's document

20. Personal Role Management • A role centered design emphasizes the user tasks rather than the applications and documents • Vision statement • Set of people • Task hierarchy • Schedule • Set of documents

21. Personal Role Management • Allows for fast switching and resumption of roles • Frees user cognitive resources to work on task domain actions rather than interface domain actions • Uses screen space efficiently and productively for tasks

22. PRM Requirements • Support for unified framework • Provide visual, spatial layout that matches task • Support multiple information access for fast rearrangement of information • Allow fast switching and resumption among roles • Free user's cognitive resources to work on task-domain actions • Use screen space efficiently and productively for tasks

23. Slides from Dix

24. Elements of windowing systems • Device independence • programming the abstract terminal device drivers image models for output and (partially) input • pixels • PostScript (MacOS X, NextStep) • Graphical Kernel System (GKS) • Programmers' Hierarchical Interface to Graphics (PHIGS) • Resource sharing • achieving simultaneity of user tasks • window system supports independent processes • isolation of individual applications

25. Roles of a Windowing System

26. Windowing System Architectures • Three possible software architectures • all assume device driver is separate • differ in how multiple application management is implemented • Each application manages all processes • everyone worries about synchronization • reduces portability of applications • Management role within kernel of operating system • applications tied to operating system • Management role as separate application maximum portability

27. Client-Server Architecture

28. X Windows Architecture - 1

29. X Windows Architecture - 2 • Pixel imaging model with some pointing mechanism • X protocol defines server-client communication • separate window manager client enforces policies for input/output: • how to change input focus • tiled vs. overlapping windows • inter-client data transfer