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| Untersuchte Arbeit: Seite: 187, Zeilen: 1-31 |
Quelle: Heer et al 2005 Seite(n): 4-5 (internet version), Zeilen: p.4,32-33 and p.5,1-30 |
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| ActionLists can be configured to run once, or to run periodically for a specified duration.
The execution of ActionLists is managed by a general activity scheduler, implemented using the approach of (Hudson, S. and J.T. Stasko, 1993). The scheduler accepts Activity objects (a superclass of ActionList), parameterized by start time, duration, and step rate, and runs them accordingly. The scheduler runs in a dedicated thread and oversees all active Prefuse visualizations, ensuring atomicity and helping avoid concurrency issues. A listener interface enables other objects to monitor activity progress, and pacing functions (Hudson, S. and J.T. Stasko, 1993) can be applied to parameterize animation rates (e.g., to provide slow-in slow-out animation). 6.3.6 Rendering and Display Renderes draws VisualItems on the screen using the visual attributes of an item, for example, location, colour, to determine its actual on-screen appearance. Renderers have a simple API consisting of three methods: one to draw an item, one to return a bounding box for an item, and one to indicate if a given point is contained within an item. Prefuse includes Renderers for drawing basic shapes, straight and curved edges, text, and images, including image loading, scaling, and caching support. Implementing user can also define their own renders by extending existing Renderers, or by implementing the Renderer interface to implement custom behaviour. Mappings between items and appearances are managed by a RendererFactory: given a VisualItem, the RendererFactory returns an appropriate Renderer. This layer of indirection affords a high level of flexibility, allowing many simple Renderers to be written and then doled out as needed. It also allows visual appearances to be easily changed, either by issuing different Renderers in response [to data attributes, or by changing the RendererFactory for a given ItemRegistry.] |
[p. 4]
ActionLists can be configured to run once, or to run periodically for a specified duration. [p. 5] The execution of ActionLists is managed by a general activity scheduler, implemented using the approach of [EN 24]. The scheduler accepts Activity objects (a superclass of ActionList), parameterized by start time, duration, and step rate, and runs them accordingly. The scheduler runs in a dedicated thread and oversees all active prefuse visualizations, ensuring atomicity and helping avoid concurrency issues. A listener interface enables other objects to monitor activity progress, and pacing functions [EN 24] can be applied to parameterize animation rates (e.g., to provide slow-in slow-out animation). Rendering and Display VisualItems are drawn to the screen by Renderers, components that use the visual attributes of an item (e.g., location, color) to determine its actual on-screen appearance. Renderers have a simple API consisting of three methods: one to draw an item, one to return a bounding box for an item, and one to indicate if a given point is contained within an item. prefuse includes Renderers for drawing basic shapes, straight and curved edges, text, and images (including image loading, scaling, and caching support). Custom rendering can be achieved by extending existing Renderers, or by implementing the Renderer interface. Mappings between items and appearances are managed by a RendererFactory: given a VisualItem, the RendererFactory returns an appropriate Renderer. This layer of indirection affords a high level of flexibility, allowing many simple Renderers to be written and then doled out as needed. It also allows visual appearances to be easily changed, either by issuing different Renderers in response to data attributes, or by changing the RendererFactory for a given ItemRegistry. [En 24] Hudson, S. and J.T. Stasko. Animation Support in a User Interface Toolkit: Flexible, Robust, and Reusable Abstractions. UIST’93. pp. 57-67, 1993. |
continued from previous page; The whole page is a nearly left intact copy of material from Heer et al. (2005). The first sentence of 6.3.6 contains a typo, and that is in a part that was re-written. |
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