Development/Tutorials/Plasma4/JavaScript/CheatSheet: Difference between revisions

    From KDE TechBase
    m (fix mistype)
    m (Fix syntax highlighting.)
    (4 intermediate revisions by 3 users not shown)
    Line 21: Line 21:
    * To connect to a signal use <tt>object.signalName.connect(function() {});</tt>
    * To connect to a signal use <tt>object.signalName.connect(function() {});</tt>
    * Enumeration values can be used like
    * Enumeration values can be used like
    <code>
    <syntaxhighlight lang="javascript">
    if (plasmoid.formFactor() == Vertical) {
    if (plasmoid.formFactor() == Vertical) {
         layout.setOrientation(QtVertical);
         layout.setOrientation(QtVertical);
    Line 27: Line 27:
         layout.setOrientation(QtHorizontal);
         layout.setOrientation(QtHorizontal);
    }
    }
    </code>
    </syntaxhighlight>


    == Global variables and functions ==
    == Global variables and functions ==
    Line 52: Line 52:


    * The Name and Comment fields in the <tt>metadata.desktop</tt> file can be translated like <tt>Name[nl]=Hallo JavaScript</tt>
    * The Name and Comment fields in the <tt>metadata.desktop</tt> file can be translated like <tt>Name[nl]=Hallo JavaScript</tt>
    * <tt>plasmoid.i18n()</tt> takes a string (in English) as the first argument, and substitutes in the following arguments to replace %1, %2, %3 etc.  Eg: <tt>plasmoid.i18n("The file is called %1", fileName);</tt>
    * <tt>i18n()</tt> takes a string (in English) as the first argument, and substitutes in the following arguments to replace %1, %2, %3 etc.  Eg: <tt>i18n("The file is called %1", fileName);</tt>
    * <tt>plasmoid.i18nc()</tt> works just the same, but has an extra argument at the start that provides some context for translators.  Eg: <tt>plasmoid.i18nc("Player name - score", "%1 - %2", playerName, score);</tt>
    * <tt>i18nc()</tt> works just the same, but has an extra argument at the start that provides some context for translators.  Eg: <tt>i18nc("Player name - score", "%1 - %2", playerName, score);</tt>
    * <tt>plasmoid.i18np()</tt> is for cases where plural forms might be important.  Eg: <tt>plasmoid.i18np("One image in album %2", "%1 images in album %2", imageCount, albumName);</tt>
    * <tt>i18np()</tt> is for cases where plural forms might be important.  Eg: <tt>i18np("One image in album %2", "%1 images in album %2", imageCount, albumName);</tt>
    * <tt>plasmoid.i18ncp()</tt> is a combination of the previous two.  Eg: <tt>plasmoid.i18ncp("Personal file", "One file", "%1 files", numFiles);</tt>
    * <tt>i18ncp()</tt> is a combination of the previous two.  Eg: <tt>i18ncp("Personal file", "One file", "%1 files", numFiles);</tt>


    == DataEngines ==
    == DataEngines ==
    Line 67: Line 67:


    * Prior to KDE 4.4, DO NOT use <tt>plasmoid.dataEngine("engine name").serviceForSource("source name")</tt> - you will get a dummy service back. Instead, use <tt>plasmoid.service("engine name", "source name")</tt>
    * Prior to KDE 4.4, DO NOT use <tt>plasmoid.dataEngine("engine name").serviceForSource("source name")</tt> - you will get a dummy service back. Instead, use <tt>plasmoid.service("engine name", "source name")</tt>
    === Notifications ===
    If you want to use the standard notifications in KDE, you can using Services, with the following code:
    <syntaxhighlight lang="javascript">
    engine = dataEngine("notifications");
    service = engine.serviceForSource("notification");
    op = service.operationDescription("createNotification");
    op["appName"] = "foo";
    op["appIcon"] = "konqueror";
    op["summary"] = "this is a summary";
    op["body"] = "body of notification";
    op["timeout"] = 2000;
    service.startOperationCall(op);
    </syntaxhighlight>

    Revision as of 11:18, 30 June 2011

    JavaScript Plasmoid Cheat Sheet
    Tutorial Series   JavaScript Plasmoids
    Previous   Now Playing: Advanced DataEngine Usage Example
    What's Next   n/a
    Further Reading   JavaScript Plasmoid API reference


    Basics

    • Everything but the metadata.desktop file goes in a directory named contents
    • X-Plasma-MainScript in the metadata.desktop file should point to the main script, relative to the contents directory
    • X-Plasma-DefaultSize in the metadata.desktop file specifies the default widget size in width,height format (eg: 200,100)
    • plasmoidviewer is an immensely useful tool
    • To connect to a signal use object.signalName.connect(function() {});
    • Enumeration values can be used like
    if (plasmoid.formFactor() == Vertical) {
        layout.setOrientation(QtVertical);
    } else {
        layout.setOrientation(QtHorizontal);
    }
    

    Global variables and functions

    • The plasmoid variable contains all the main plasmoid functionality and represents the main plasmoid widget, and corresponds to the Applet class in C++
    • The startupArguments variable contains any arguments that were passed to the plasmoid when it was started (such as when the plasmoid is registered as a handler for a mimetype)
    • The loadui function can be used to load a Qt UI file. Beware that a relative path is relative to plasma's working directory (in 4.2 at least), and so may not do what you want.
    • The print function prints debug output
    • There are several constructor methods:
      • PlasmaSvg(file, parent) constructs a Plasma::Svg. The second argument is optional.
      • PlasmaFrameSvg(file, parent) constructs a Plasma:FrameSvg. The second argument is optional.
      • QPainter()
      • QGraphicsItem()
      • QTimer()
      • QFont()
      • QRectF()
      • QSizeF()
      • QPoint()
      • LinearLayout() constructs a QGraphicsLinearLayout
      • Url() constructs a KUrl
    • Plus constructors for all the Plasma widgets (eg: IconWidget()).

    Languages

    • The Name and Comment fields in the metadata.desktop file can be translated like Name[nl]=Hallo JavaScript
    • i18n() takes a string (in English) as the first argument, and substitutes in the following arguments to replace %1, %2, %3 etc. Eg: i18n("The file is called %1", fileName);
    • i18nc() works just the same, but has an extra argument at the start that provides some context for translators. Eg: i18nc("Player name - score", "%1 - %2", playerName, score);
    • i18np() is for cases where plural forms might be important. Eg: i18np("One image in album %2", "%1 images in album %2", imageCount, albumName);
    • i18ncp() is a combination of the previous two. Eg: i18ncp("Personal file", "One file", "%1 files", numFiles);

    DataEngines

    • Add a dataUpdate method to plasmoid to receive updates: plasmoid.dataUpdate = function(name, data) { /* ... */ } - data contains an object mapping keys to values
    • plasmoid.dataEngine("engine name").connectSource("source name", plasmoid, 500); updates every half second
    • plasmoid.dataEngine("engine name").connectSource("source name", plasmoid); updates when new data is available
    • plasmaengineexplorer is your friend

    Services

    • Prior to KDE 4.4, DO NOT use plasmoid.dataEngine("engine name").serviceForSource("source name") - you will get a dummy service back. Instead, use plasmoid.service("engine name", "source name")

    Notifications

    If you want to use the standard notifications in KDE, you can using Services, with the following code:

    engine = dataEngine("notifications");
    service = engine.serviceForSource("notification");
    op = service.operationDescription("createNotification");
    op["appName"] = "foo";
    op["appIcon"] = "konqueror";
    op["summary"] = "this is a summary";
    op["body"] = "body of notification";
    op["timeout"] = 2000;
    
    service.startOperationCall(op);