Plasma/Vocabulary: Difference between revisions
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==Plasma== | |||
Plasma refers to the framework upon which | Plasma refers to the framework upon which | ||
the various Plasma workspaces, | the various Plasma workspaces, | ||
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scriptable and highly portable, and componentized interface to the user. | scriptable and highly portable, and componentized interface to the user. | ||
==Widget== | |||
A widget is a single component on the canvas. | A widget is a single component on the canvas. | ||
Other common names that are analogous are "applet" or "gadget". | Other common names that are analogous are "applet" or "gadget". | ||
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(some of which are supported by Plasma via ScriptEngines as well). | (some of which are supported by Plasma via ScriptEngines as well). | ||
==Plasmoid== | |||
A Plasmoid is the combination of files that go into creating a native Plasma widget. | A Plasmoid is the combination of files that go into creating a native Plasma widget. | ||
This includes: | This includes: | ||
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* ... | * ... | ||
==Applet== | |||
An applet is the code part of a Plasmoid, | An applet is the code part of a Plasmoid, | ||
technically because it provides a Plasma::Applet object. | technically because it provides a Plasma::Applet object. | ||
To users, this will be an implementation detail they are unlikely to see. | To users, this will be an implementation detail they are unlikely to see. | ||
==Corona== | |||
The Corona, a QGraphicsScene subclass, is the Plasma canvas. | The Corona, a QGraphicsScene subclass, is the Plasma canvas. | ||
It contains all of the Containments that exist for the application, | It contains all of the Containments that exist for the application, | ||
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and other such canvas-global tasks. | and other such canvas-global tasks. | ||
==Containment== | |||
A Containment is a top level grouping of widgets. | A Containment is a top level grouping of widgets. | ||
Each Containment manages the layout and configuration data | Each Containment manages the layout and configuration data | ||
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(usually one per screen). | (usually one per screen). | ||
==Data Engine== | |||
A DataEngine is a plugin that provides a ''visualization'' | A DataEngine is a plugin that provides a ''visualization'' | ||
with a standard way to access a body of information. | with a standard way to access a body of information. | ||
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that all visualizations must implement to receive updates. | that all visualizations must implement to receive updates. | ||
==Runner== | |||
A Runner is a plugin that provides possible matches to search queries. | A Runner is a plugin that provides possible matches to search queries. | ||
Runners are generally used and coordinated via Plasma::RunnerManager, | Runners are generally used and coordinated via Plasma::RunnerManager, | ||
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This sytem is used in KRunner, Kickoff | This sytem is used in KRunner, Kickoff | ||
and other places that need this kind of functionality. | and other places that need this kind of functionality. | ||
== More terminology == | |||
Revision as of 14:27, 12 February 2023
Plasma
Plasma refers to the framework upon which the various Plasma workspaces, Plasma and KRunner plugins, etc. are built upon.
The Plasma library provides a scene/view (much like model/view) approach to presenting a user interface. Widgets sit on a canvas (the "Corona", a QGraphicsScene subclass), grouped into Containments. Data is obtained via DataEngines and Runners. The entire scene is designed to be viewed in a flexible manner, including zooming and resolution independence.
Plasma also provides many standardized services such as artwork, presentation and script management, and creating add-ons for a Plasma application quite easy.
The goal of Plasma is to provide a flexible, re-targetable, scriptable and highly portable, and componentized interface to the user.
Widget
A widget is a single component on the canvas. Other common names that are analogous are "applet" or "gadget". Superkaramba Themes, Apple's Dashboard, Google Gadgets, Yahoo Widgets, Vista Sidebar Widgets, Opera Widgets are all examples of other widget systems (some of which are supported by Plasma via ScriptEngines as well).
Plasmoid
A Plasmoid is the combination of files that go into creating a native Plasma widget. This includes:
- metadata (e.g. .desktop files)
- images (svg, png, etc)
- configuration definitions (KConfigXT)
- code (C++, ECMA Script, HTML+JavaScript, Python, ..)
- ...
Applet
An applet is the code part of a Plasmoid, technically because it provides a Plasma::Applet object. To users, this will be an implementation detail they are unlikely to see.
Corona
The Corona, a QGraphicsScene subclass, is the Plasma canvas. It contains all of the Containments that exist for the application, providing the "model" for the Views to use.
It handles initiating loading and saving of Containments and Applets and other such canvas-global tasks.
Containment
A Containment is a top level grouping of widgets. Each Containment manages the layout and configuration data of its set of widgets independently from other Containments.
In the Plasma Desktop, for instance, each panel on screen is viewing a (panel) Containment, and each activity is a collection of one or more Containments as well (usually one per screen).
Data Engine
A DataEngine is a plugin that provides a visualization with a standard way to access a body of information. Each unit of data is called a "source", and source may be created on demand. Sources are updated either when the data changes (such as in response to a hotplug event for the devices DataEngine) or in a timed interval as requested by the visualization.
The timings and memory management of the sources are handled by DataEngine, making implementation of DataEngines trivial.
The sources themselves are organized into a list, and each source can have zero or more key/value pairs. The values are QVariants and therefore quite flexible.
DataEngines send information to visualizations via the dataUpdated(QString source, Plasma::Data data) slot that all visualizations must implement to receive updates.
Runner
A Runner is a plugin that provides possible matches to search queries. Runners are generally used and coordinated via Plasma::RunnerManager, which provides a multi-threaded runtime for collections of Runners. This sytem is used in KRunner, Kickoff and other places that need this kind of functionality.