KDE System Administration/PlasmaDesktopScripting: Difference between revisions

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    == ECMA Script Interaction With Plasma Shells ==
    {{Moved To Userbase}}
     
    It is possible to control and interact with a Plasma user interface shell such as a plasma-desktop or (starting in KDE SC 4.5) plasma-netbook session using ECMA Script (aka JavaScript). This scripting mechanism exposes containments (Desktop Activities and Panels), widgets and various other aspects of plasma-desktop configuration using the widely known and used ECMA Script language. The QtScript engine is used for the runtime environment.
     
    This document describes the API that is provided along with how to
    run such scripts in plasma-desktop.
     
    == Examples ==
     
    A set of examples can be found [https://projects.kde.org/projects/kde/kdeexamples/repository/revisions/master/show/plasma/javascript/plasma-shell-scripting here] that demonstrate the use of various aspects of Plasma shell scripting.
     
    Contributions of additional examples are welcome and an be sent to the Plasma development mailing list (plasma-devel at kde.org) for inclusion if you do not have commit rights to the kdeexamples module.
     
    == Running Scripts ==
    There are three ways that scripts can be executed in plasma-desktop:
     
    * '''on first run''': when plasma-desktop is started without any pre-existing configuration, any scripts in $APPDATA/plasma-desktop/init/ with a ".js" suffix are run. If there is more than one script, they are run sequentially in the alphabetical order of the file names.
     
    {{note|For security reasons, scripts located in the user's home directory will '''not''' be run during this phase.}}
     
    * '''on update''': when plasma-desktop is started, it will check in
      `kde4-config --path data`/plasma-desktop/updates/
    with a ".js" suffix for scripts that have not yet been run. If there is more than one script which has not been run yet they will be executed serially in the alphabetical order of the file names.
     
    A record of which update scripts have been run is kept in the application's config file in the [Updates] group. This means that if the plasma-desktop configuraiton file is removed, all the update scripts will be run again.
     
    {{note|For security reasons, scripts located in the user's home directory will '''not''' be run during this phase.}}
     
    * '''interactively''': an interactive scripting dialog can be requested either via the KRunner window (Alt+F2, by default, or via the "Run Command" entry in various desktop menus) by entering "desktop console" as the search term. It can also be triggered directly via dbus with <code bash>qdbus org.kde.plasma-desktop /MainApplication showInteractiveConsole</code>
     
    {{note|This method is not available for plasma-netbook.}}
     
    :ECMA Script may be entered directly into this window for execution and output appears in the lower half of the window. Ctrl+E is a shortcut to run scripts, and scripts can be saved to and loaded from disk.
     
    :Scripts from files can also be loaded using KRunner with "desktop console /path/to/file" or via dbus with
    <code bash>qdbus org.kde.plasma-desktop /MainApplication loadScriptInInteractiveConsole /path/to/file</code>
     
    == Templates ==
     
    Templates are named packages that contain scripts. This provides a way for common functionality to be easily reused, helping to increase consistency and lower maintenance costs. Templates can be loaded from other scripts by name and they are also used to populate some parts of the user interface, such as the entries in the Add Panels menu.
     
    A template is a small set of files in a specified file hierarchy (or, in Plasma terms, a "Package"). In particular, a Template package contains the following files:
     
    * metadata.desktop: a .desktop file describing the template
    * contents/layout.js: a Javascript file containing the actual script
     
    Templates are stored under share/apps/plasma/layout-templates and may be installed using `plasmapkg -t layout-template -i /path/to/package`. Template packages may also be provided as a .zip file with a .plasmalayout suffix.
     
    The metadata.desktop file contains the usual .desktop entries such as Name and Icon but must also contain Type=Service and ServiceTypes=Plasma/LayoutTemplate entries. If the layout is specific to a given Plasma application, such as plasma-desktop, this can be specific using X-Plasma-Shell. X-Plasma-ContainmentCategories defines what kind of layout it is with possible values being panel and desktop. Finally a X-KDE-PluginInfo-Name entry is required to provide a globally unique internal name for the Template. Here is an example of a Template that provides a Panel layout for Plasma Netbook:
     
    <code ini>
    [Desktop Entry]
    Encoding=UTF-8
    Name=Cool Panel
    Type=Service
    ServiceTypes=Plasma/LayoutTemplate
    X-Plasma-Shell=plasma-netbook
    X-Plasma-ContainmentCategories=panel
    X-KDE-PluginInfo-Author=Aaron Seigo
    X-KDE-PluginInfo-Name=org.kde.CoolNetbookPanel
    X-KDE-PluginInfo-Version=1.0
    X-KDE-PluginInfo-Website=http://plasma.kde.org/
    X-KDE-PluginInfo-Category=
    X-KDE-PluginInfo-Depends=
    X-KDE-PluginInfo-License=GPL
    X-KDE-PluginInfo-EnabledByDefault=true
    </code>
     
    When running a template, two global variables will be accessible in read-only mode: templateName and templateComment. They will contain the Name and Comment fields of the above desktop file, and are translated if a localization is available.
     
    === Examples of Usage ===
     
    ==== Creating panels ====
    A good example of the use of templates is the use case that triggered the creation of this feature: the desire to make it easy for users to re-create the default panel that is created on first start. There is a Template called org.kde.plasma-desktop.defaultPanel that ships with the KDE Plasma Workspace which contains the layout for the initial default panel. This is referenced by the default Plasma Desktop init script and, because it is marked as a Panel Template in the metadata.desktop file it also shows up to the user in the Add Panels menu. When selected by the user from the menu, the exact same panel that is created on desktop start up is created for them, complete with Plasma Widgets and configuration.
     
    ==== Automating tasks ====
    Another example of the usefulness of templates is the "Find Widgets" template. This template, which first shipped with Plasma Desktop v4.5, provides a function for finding widgets by name. It appears in the toolbar "Load" and "Use" menus in the Desktop Console in plasma-desktop, and makes finding widgets as simple as:
     
    <code javascript>
    var template = loadTemplate('org.kde.plasma-desktop.findWidgets')
    template.findWidgets('systemtray')
    </code>
     
    ==== Activity templates ====
    Probably the most user visible use of templates are "Activity templates", for such templates the structure is similar to the other use of templates, but we support extra features which can be triggered from the metadata.desktop. Here is an example of such an activity template:
     
    <code ini>
    [Desktop Entry]
    Encoding=UTF-8
    Name=Cool Activity Template
    Icon=user-desktop
    Type=Service
    ServiceTypes=Plasma/LayoutTemplate
    X-Plasma-Shell=plasma-desktop
    X-Plasma-ContainmentCategories=desktop
    X-Plasma-ContainmentLayout-ExecuteOnCreation=dolphin $desktop, gwenview $pictures
    X-Plasma-ContainmentLayout-ShowAsExisting=true
    X-KDE-PluginInfo-Author=John Doe
    X-KDE-PluginInfo-Name=org.kde.plasma-desktop.CoolTemplate
    X-KDE-PluginInfo-Version=1.0
    X-KDE-PluginInfo-Website=http://john.doe.org
    X-KDE-PluginInfo-Category=
    X-KDE-PluginInfo-Depends=
    X-KDE-PluginInfo-License=GPL
    X-KDE-PluginInfo-EnabledByDefault=true
    </code>
     
    The layout itself is still created from the layout.js file as usual, but this template also shows as a precreated activity to the user thanks to the X-Plasma-ContainmentLayout-ShowAsExisting key. Additionally, it startups applications in the newly created activity using the X-Plasma-ContainmentLayout-ExecuteOnCreation key.
     
    That key is a list of commands to execute, and it supports the following variables:
    * $desktop
    * $autostart
    * $documents
    * $music
    * $video
    * $downloads
    * $pictures
     
    They all expand into the path toward the user corresponding default folder.
     
    == API ==
     
    In addition to the normal ECMA Script API and the Qt-specific extensions (such as signal/slot support) provided by QtScript, the following API is provided for use by scripts.
     
    All of the API below, unless otherwise noted with a version noticed, appear as below in the KDE Software Compilation v4.4.0 and later. API that is not noted as being part of a given class or object is part of the global namespace.
     
    {{note|API compatibility is guaranteed from version to version starting with KDE Software Compilation v4.4.0.}}
     
    === Version Numbers ===
     
    Starting with KDE SC 4.5, the version number of both the scripting API and the application is available to the script via the following read-only properties:
     
    * ''String'' '''applicationVersion''': the version of the application, e.g. 0.3
    * ''String'' '''platformVersion''': the version of the KDE Platform, e.g. 0.3
    * ''number'' '''scriptingVersion''': the version of the scripting API; e.g. in KDE SC 4.5 this is 2
     
    === Activities ===
    Activities are the desktop layer in a plasma-desktop session and may contain widgts. In sightly more technical terms, they are desktop containments. Activities can be created, enumerated, modified and destroyed.
     
    New Activities can be created using the Activity constructor, like this:
     
        var activity = new Activity("folderview")
     
    The string passed into the constructor maps to the X-KDE-PluginInfo-Name= entry
    in the plugin's .desktop file). See the documentation on the Containment object class below.
     
    Read-only properties:
    * ''Array[number]'' '''activityIds''': returns a list of integer ids of all existing Plasma activities
    * ''Array[String]'' '''knownActivityTypes''':  (scripting version >= 2) a list of types of activities that can be created. This is useful to check if an Activity type is available on the system before trying to construct one.
     
    Functions:
    * ''Activity'' '''activityById(number id)''': return an object representing the activity with the given id
    * ''Activity'' '''activityForScreen(number screen[, number dekstop])''': returns an object representing the activity  currently associated with the given screen and, optionally, the given desktop.
    * ''Array[Activity]'' '''activities()''': returns an array of all activities that currently exist
     
    === Panels ===
    Panels can be created, enumerated, modified and destroyed. A panel object combines both a containment as well as the container itself, allowing for full control of things such as where it appears on screen and the hiding features associated with them.
     
    New Panels can be created using the Panel constructor, like this:
     
        var panel = new Panel("dock")
     
    The string passed into the constructor maps to the X-KDE-PluginInfo-Name= entry
    in the plugin's .desktop file).
     
    Read-only properties:
    * ''Array[number]'' '''panelIds''': returns a list of integer ids of all existing Plasma panels
    * ''Array[String]'' '''knownPanelTypes''':  (scripting version >= 2) a list of types of panels that can be created. This is useful to check if a Panel type is available on the system before trying to construct one.
     
    Functions:
    * ''Panel'' '''panelById(int id)''': returns an object representing the Panel that matches the given id
    * ''Array[Panels]'' '''panels()''': returns an array of all panels that currently exist
     
    === Activities and Panels ===
    Activity and Panel objects, once created by the script, or as returned by activityById, activityForScreen,
    or panelById) provide the following read-only properties:
     
    * ''number'' '''id: the integer id of this activity
    * ''String'' '''formFactor''': returns the form factor of the activity, e.g. "planar" for most desktop activities,"mediacenter" for media centers and either "horizontal" or "vertical" for panels.
    * ''Array[number]'' '''widgetIds''': a list of integer ids of all the widgets in this Activity
    * ''Array[String]'' '''configKeys''':  (scriptingVersion >= 2) a list of all keys that are set in the current configuration group
    * ''Array[String]'' '''configGroups''': (scriptingVersion >= 2)  a list of all the groups in the current configuration group
    * ''Array[String]'' '''globalConfigKeys''':  (scriptingVersion >= 2) a list of all keys that are set in the current global configuration group
    * ''Array[String]'' '''globalConfigGroups''': (scriptingVersion >= 2)  a list of all the groups in the current global configuration group
     
    as well as the following read/write properties:
     
    * ''number'' '''desktop''': the virtual desktop this activity is associated with, or -1 for none
    * ''number'' '''screen''': the screen this activity is associated with, or -1 for none
    * ''String'' '''name''': the name of this activity
    * ''String'' '''wallpaperPlugin''': (scriptingVersion >= 2) the wallpaper plugin to use with the Activity
    * ''String'' '''wallpaperMode''': (scriptingVersion >= 2) the wallpaper plugin mode to use with the Activity
    * ''Array[String]'' '''currentConfigGroup''': (scriptingVersion >= 2) the current configuration group path, with each entry in the array representing a sub-group. This allows one to access trees of groups with code such as: widget.currentConfigGroup = new Array('topGroup', 'subGroupOfTopGroup'). An empty Array means the default (top-level) configuration group for the widget
    * ''String'' '''version''': (scriptingVersion >= 2) the version of the Activity or Panel
     
    and the following methods:
     
    * '''remove()''': deletes this activity and all widgets inside of it
    * ''Widget'' '''widgetById(number id)''': returns an object representing the widget with the given id
    * ''Widget'' '''addWidget(String name)''': adds a new widget to the activity; the name maps to the X-KDE-PluginInfo-Name= entry
      in the widget's .desktop file
    * ''Widget'' '''addWidget(Widget widget)''': adds an existing widget to this activity; useful for moving widgets between Activities and Panels
    * '''showConfigurationInteface()''': shows the configuration user interface for this Activity or Panel on the screen
    * '''readConfig(String key, any default)''': (scriptingVersion >= 2) reads the value of key in the config with default for the default value
    * '''writeConfig(String key, any value)''': (scriptingVersion >= 2) sets key to value in the config
    * '''readGlobalConfig(String key, any default)''': (scriptingVersion >= 2) reads the value of key in the global config with default
      for the default value
    * '''writeGlobalConfig(String key, any value)''': (scriptingVersion >= 2) sets key to value in the global config
    * '''reloadConfig()''': (scriptingVersion >= 2) causes the Activity or Panel to reload its configuration; reaction to configuration changes made using readConfig are usually activated on script exit, but this can be triggered earlier on a per-widget basis using this method
    * ''Array[String]'' '''currentGlobalConfigGroup''': (scriptingVersion >= 2)  the current global configuration group path, with each entry in the array representing a sub-group, similar to currentConfigGroup. However, global configuration is shared by all instances of panels and activities of the same type.
    * ''Array[Widget]'' '''widgets([String type])''': (scriptingVersion >= 2) returns all the widgets in the Panel or Activity. If the optional type is specified, only widgets matching that type will be returned.
     
    In addition to all of the above properties and functions, Panel objects also provide the folowing read/write properties:
    * ''number'' '''length''': the number of pixels along the screen edge used
    * ''number'' '''height''': the height (or for vertical panels, the width) of the panel
    * ''String'' '''hiding''': the hiding mode of the panel, one of "none" (for no hiding), "autohide", "windowscover" or "windowsbelow"
    * ''String'' '''alignment''': right, left or center alignment of the panel (for vertical panels, right corrsponds to top and left to bottom)
    * ''String'' '''location''': returns the location of the activity (only relevant for Panels); valid values include "top", "bottom", "left", "right" and "floating"
     
    === Widgets ===
    Widgets may be enumerated by calling the widgetIds property on a Activity or Panel object. With a widget id in hand, a Widget object can be retrieved by calling widgetById(id) on an Activity or Panel object. New Widgets can be created with add addWidget(String) function provided by Activity and Panel objects.
     
    A list of all installed widget types can be retrieved the following read-only property:
     
    * ''Array[String]'' '''knownWidgetTypes''' (scripting version >= 2)
     
    A Widget object provides the following read-only properties:
     
    * ''number'' '''id''': the id of the widget
    * ''String'' '''type''': the plugin type of this widget
    * ''Array[String]'' '''configKeys''': a list of all keys that are set in the current configuration
    * ''Array[String]'' '''configGroups''': a list of all the groups in the current configuration
    * ''Array[String]'' '''globalConfigKeys''':  (scriptingVersion >= 2) a list of all keys that are set in the current global configuration group
    * ''Array[String]'' '''globalConfigGroups''': (scriptingVersion >= 2)  a list of all the groups in the current global configuration group
    * ''String'' '''version''': (scriptingVersion >= 2) the version of the Activity or Panel
     
    as well as the following read-write properties:
     
    * ''Array[String]'' '''currentConfigGroup''': the current configuration group path, with each entry in the array representing a sub-group. This allows one to access trees of groups with code such as: widget.currentConfigGroup = new Array('topGroup', 'subGroupOfTopGroup'). An empty Array means the default (top-level) configuration group for the widget
    * ''Array[String]'' '''currentGlobalConfigGroup''': (scriptingVersion >= 2)  the current global configuration group path, with each entry in the array representing a sub-group, similar to currentConfigGroup. However, global configuration is shared by all instances of widgets of the same type.
    * ''QRectF'' '''geometry''': the geometry of the widget (settable)
    * ''String'' '''globalShortcut''': the shortcut sequence (in the format used by QKeySequence, e.g. "Alt+F1") associated with this widget
    * ''number'' '''index''': the layout index of the widget; in a Panel this corresponds to the order the widget appears in. Changing the value of the index will change the position of the widget in Panels and may do so in some Activities as well.
     
    and the following methods:
     
    * '''remove()''': deletes this widget
    * '''readConfig(String key, any default)''': reads the value of key in the config with default
      for the default value
    * '''writeConfig(String key, any value)''': sets key to value in the config
    * '''readGlobalConfig(String key, any default)''': (scriptingVersion >= 2) reads the value of key in the global config with default
      for the default value
    * '''writeGlobalConfig(String key, any value)''': (scriptingVersion >= 2) sets key to value in the global config
    * '''reloadConfig()''': causes the widget to reload its configuration; reaction to configuration changes made using readConfig are usually activated on script exit, but this can be triggered earlier on a per-widget basis using this method
    * '''showConfigurationInteface()''': shows the configuration user interface for this widget on the screen
     
    === Screen Geometry ===
    Read-only properties:
    * ''number'' '''screenCount''': returns the number of screens connected to the computer
     
    Functions:
    * ''QRectF'' '''screenGeometry(number screen)''': returns a rect object representing the geometry of a screen
     
    === Wallpaper Plugins ===
     
    * ''Array[String => Array[String]]'' '''knownWallpaperPlugins()''': (scripting version >= 4) returns a list of all installed wallpaper plugins. They keys of the array are the wallpaper plugin names. The values are arrays containing the modes available for that wallpaper plugin. The mode array may be empty, as most wallpaper plugins only offer one mode.
     
    === Locating Applications and Paths ===
    * ''boolean'' '''applicationExists(String name)''': (scripting version >= 4) searches $PATH first, then tries in the application menu system by application storage name (aka the .desktop file name), then Name= entries for apps with installed .desktop files, then GenericName= entries for same
    * ''mixed'' '''defaultApplication(String kind [, boolean storageId = false])''': (scripting version >= 4) returns the executable (or if storageId is true, then the the app menu system id, e.g. its .desktop file name) of the default app. The "kind" parameter may be a well-known application type including "browser", "mailer", "filemanager", "terminal", "imClient" and "windowmanager" (or any other entry in share/apps/kcm_componentchooser/kcm_*.desktop); it may also be a mimetype (e.g. "application/pdf"). On failure, it returns false.
    * ''String'' '''applicationPath(String name)''':  (scripting version >= 4) returns the full local path to a given application or .desktop file if it exists.
    * ''String'' '''userDataPath([String type, String path])''':  (scripting version >= 4) returns the default path for user data. Called with no parameters, it returns the user's home directory. If only one string is passed in, the standard directory for that type of data in the user's home directory will be located; the following values are recognized:
    ** documents
    ** music
    ** video
    ** downloads
    ** pictures
    ** autostart
    ** desktop (should be considered deprecated for Plasma workspaces)
     
    If a second string is passed in, it is considered a request for a specific path and the following types are recognized:
    ** apps - Applications menu (.desktop files).
    ** autostart - Autostart directories (both XDG and kde-specific)
    ** cache - Cached information (e.g. favicons, web-pages)
    ** cgi - CGIs to run from kdehelp.
    ** config - Configuration files.
    ** data - Where applications store data.
    ** emoticons - Emoticons themes
    ** exe - Executables in $prefix/bin. findExe() for a function that takes $PATH into account.
    ** html - HTML documentation.
    ** icon - Icons, see KIconLoader.
    ** kcfg - KConfigXT config files.
    ** lib - Libraries.
    ** locale - Translation files for KLocale.
    ** mime - Mime types defined by KDE-specific .desktop files.
    ** module - Module (dynamically loaded library).
    ** qtplugins - Qt plugins (dynamically loaded objects for Qt)
    ** services - Services.
    ** servicetypes - Service types.
    ** sound - Application sounds.
    ** templates - Templates for the "Create new file" functionality.
    ** wallpaper - Wallpapers.
    ** tmp - Temporary files (specific for both current host and current user)
    ** socket - UNIX Sockets (specific for both current host and current user)
    ** xdgconf-menu - Freedesktop.org standard location for menu layout (.menu) files.
    ** xdgdata-apps - Freedesktop.org standard location for application desktop files.
    ** xdgdata-dirs - Freedesktop.org standard location for menu descriptions (.directory files).
    ** xdgdata-mime - Freedesktop.org standard location for MIME type definitions.
    ** xdgdata-icon - Freedesktop.org standard location for icons.
    ** xdgdata-pixmap - Gnome-compatibility location for pixmaps.
     
    The second parameter should be a specific resource to find the path to. An example might be userDataPath("data", "plasma-desktop").
     
    === Misc. Global Properties and Functions ===
    Read-write properties:
    * ''boolean'' '''locked''': whether the desktop shell and widgets are locked or not (settable)
    * ''string'' '''theme''': (scripting version >= 3) the name of the desktop theme to use for the interface, e.g. default, Air, Oxygen, etc.
     
    Read-only properties:
    * ''boolean'' '''hasBattery''': whether or not the system has the ability to run on battery power, e.g. a laptop or mobile device
    * ''boolean'' '''multihead''': (scripting version >= 3) true if the system is running with multiple screens in a "Xaphod" multiple display server configuration
    * ''int'' '''multiheadScreen''': (scripting version >= 3) if multihead is true, contains the (real) screen id of the current screen
     
    Functions:
    * '''sleep(number ms)''': sleeps the script for the specified number of millseconds
     
    === QRectF ===
    A rectangle class is also provided for use with Widget, Panel and screen geometry properties and functions.
     
    Read-only properites:
    * ''boolean'' '''empty''': true if the rectangle's width or height is less than, or equal to, 0; an empty rectangle is also invalid
    * ''boolean'' '''null''': true if the rectangle has both the width and the height set to 0; a null rectangle is also empty and not valid
    * ''boolean'' '''valid''':  true if the rectangle has a width > 0 and height 0.
     
    Read-write properties:
    * ''number'' '''left'''
    * ''number'' '''top'''
    * ''number'' '''bottom'''
    * ''number'' '''right'''
    * ''number'' '''height'''
    * ''number'' '''width'''
    * ''number'' '''x'''
    * ''number'' '''y'''
     
    Constructors:
    * '''QRectF'''
    * '''QRectF(number x, number y, number width, number height)''': Sets the coordinates of the rectangle's top-left corner to (x, y), and its size to the given width and height.
     
    Functions:
    * '''adjust(number dx1, number dy1, number dx2, number dy2)''': adds dx1, dy1, dx2 and dy2 respectively to the existing coordinates of the rectangle
    * ''QRectF'' '''adjusted(number dx1, number dy1, number dx2, number dy2)''': returns a new QRectF with dx1, dy1, dx2 and dy2 added respectively to the existing coordinates of the rectangle
    * '''translate(number dx, number dy)''': translates the rect by dx, dy
    * '''setCoords(number x1, number y1, number x2, number y2)''': sets the coordinates of the rectangle's top-left corner to (x1, y1), and the coordinates of its bottom-right corner to (x2, y2).
    * '''setRect(number x, number y, number width, number height)''': sets the coordinates of the rectangle's top-left corner to (x, y), and its size to the given width and height.
    * ''boolean'' '''contains(number x, number y)''': returns true if the rect contains the point (x, y)
    * '''moveBottom(number delta)'': moves the bottom by delta pixels
    * '''moveLeft(number delta)''': moves the left by delta pixels
    * '''moveRight(number delta)''': moves the right by delta pixels
    * '''moveTo(number x, number y)''': moves the top left of the rect to point (x, y)
    * '''moveTop(number delta)''': moves the top by delta pixels

    Latest revision as of 13:24, 11 March 2016

    This page is now on the Userbase wiki.