Pointer (user interface)

Common pointer types (enlarged)

In computing, a pointer or mouse cursor (as part of a personal computer WIMP style of interaction)[1][2][3] is a symbol or graphical image on the computer monitor or other display device that echoes movements of the pointing device, commonly a mouse, touchpad, or stylus pen. It signals the point where actions of the user take place. It can be used in text-based or graphical user interfaces to select and move other elements. It is distinct from the cursor, which responds to keyboard input. The cursor may also be repositioned using the pointer.

The pointer commonly appears as an angled arrow, (angled because historically that improved appearance on low resolution screens[4] ) but it can vary within different programs or operating systems. The use of a pointer is employed when the input method, or pointing device, is a device that can move fluidly across a screen and select or highlight objects on the screen. In GUIs where the input method relies on hard keys, such as the five-way key on many mobile phones, there is no pointer employed, and instead the GUI relies on a clear focus state.

Appearance

The pointer "hotspot" is the active pixel of the pointer, used to target a click or drag. The hotspot is normally along the pointer edges or in its center, though it may reside at any location in the pointer.[5][6]

In many GUIs, moving the pointer around the screen may reveal other screen hotspots as the pointer changes shape depending on the circumstances. For example:

The default wait cursor for Windows XP replaces the pointer with an hourglass.

Pointer trails and animation

An example of mouse pointer trails.

Pointer trails can be used to enhance its visibility during movement. Pointer trails are a feature of GUI operating systems to enhance the visibility of the pointer. Although disabled by default, pointer trails have been an option in every version of Microsoft Windows since Windows 3.1x.

When pointer trails are active and the mouse or stylus is moved, the system waits a moment before removing the pointer image from the old location on the screen. A copy of the pointer persists at every point that the pointer has visited in that moment, resulting in a snake-like trail of pointer icons that follow the actual pointer. When the user stops moving the mouse or removes the stylus from the screen, the trails disappear and the pointer returns to normal.

Pointer trails have been provided as a feature mainly for users with poor vision and for screens where low visibility may become an issue, such as LCD screens in bright sunlight.

In Windows, pointer trails may be enabled in the Control Panel, usually under the Mouse applet.

Introduced with Windows NT, an animated pointer was a small looping animation that was played at the location of the pointer.[9] This is used, for example, to provide a visual cue that the computer is busy with a task.[10] After their introduction, many animated pointers became available for download from third party suppliers. Unfortunately, animated pointers are not without their problems. In addition to imposing a small additional load on the CPU, the animated pointer routines did introduce a security vulnerability. A client-side exploit known as the Windows Animated Cursor Remote Code Execution Vulnerability used a buffer overflow vulnerability to load malicious code via the animated cursor load routine of Windows.[11]

Editor

A pointer editor is software for creating and editing static or animated mouse pointers. Pointer editors usually support both static and animated mouse cursors, but there are exceptions. An animated cursor is a sequence of static cursors representing individual frames of an animation. A pointer editor should be able to:

Pointer editors are occasionally combined with icon editors, because computer icons and cursors share similar properties. Both contain small raster images and the file format used to store icons and static cursors in Microsoft Windows is similar.

Despite the similarities, pointer editors differ from icon editors in a number of ways. While icons contain multiple images with different sizes and color depths, static cursors (for Windows) only contain a single image. Pointer editors must provide means to set the hot spot. Animated pointer editors additionally must be able to handle animations.

See also

Wikimedia Commons has media related to Cursor.

References

  1. ↑ Markoff, John (February 16, 2009). "The Cellphone, Navigating Our Lives". The New York Times. New York. Retrieved December 14, 2011. [...] so-called WIMP interface — for windows, icons, menus, pointer [...]
  2. ↑ Hinckley, Ken (December 1996). "Haptic Issues for Virtual Manipulation". Microsoft. Retrieved December 14, 2011. The Windows-Icons-Menus-Pointer (WIMP) interface paradigm dominates modern computing systems.
  3. ↑ Hinckley, Ken. "Input Technologies and Techniques" (PDF). Microsoft. Retrieved December 14, 2011. Researchers are looking to move beyond the current "WIMP" (Windows, Icons, Menus, and Pointer) interface [...]
  4. ↑ "Document from 1981 reveals why mouse cursor is tilted and not straight". Retrieved 18 February 2014.
  5. ↑ Mouse
  6. ↑ Setting a Cursor's Hot Spot
  7. ↑ Hale, Kevin (3 October 2007). "Visualizing Fitts' Law". Particle Tree.
  8. ↑ Atwood, Jeff (9 August 2006). "Fitts' Law and Infinite Width". Coding Horror.
  9. ↑ Staff (2007). Encyclopedia Of Information Technology. Atlantic Publishers & Distributors. p. 24. ISBN 81-269-0752-5.
  10. ↑ Lock & Philander (2009). Michael Sangster, ed. FCS Systems Analysis & Design L4. Pearson Education South Africa. p. 149. ISBN 1-77025-428-5.
  11. ↑ McClure, Stuart; Scambray, Joel; Kurtz, George (2009). Hacking exposed: network security secrets & solutions (6th ed.). McGraw Hill Professional. p. 177. ISBN 0-07-161374-9.
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