org.kde.koala
Class KTrader

java.lang.Object
  org.kde.qt.Qt
      org.kde.qt.QObject
          org.kde.koala.KTrader

All Implemented Interfaces:

org.kde.qt.QtSupport

public class KTrader
extends org.kde.qt.QObject

A Trader interface, similar to the CORBA Trader. Basically, it provides a way for an application to query all KDE services (that is, applications and components) that match a specific set of requirements. This allows you to find an application in real-time without you having to hard-code the name and/or path of the application. It is mostly used when you want to do complex queries that KServiceTypeProfile can't handle. \par Examples A few examples will make this a lot more clear. Say you have an application that will display HTML. In this example, you don't want to link to khtml... and furthermore, you really don't care if the HTML browser is ours or not, as long as it works. The way that you formulate your query as well as the way that you execute the browser depends on whether or not you want the browser to run stand-alone or embedded. If you want the browser to run standalone, then you will limit the query to search for all services that handle 'text/html' and, furthermore, they must be applications (Type=Application). You then will use KRun.run() to invoke the application. In "trader-speak", this looks like so:

 ArrayList offers = KTrader.self().query("text/html", "Type == 'Application'");
 KService.Ptr ptr = offers.first();
 KURL.List lst;
 lst.append("http://www.kde.org/index.html");
 KRun.run(ptr, lst);
 

It should be noted that in the above example, using KServiceTypeProfile would be the better choice since you would probably want the preferred service and the trader doesn't take this into account. The trader does allow you to do more complex things, though. Say, for instance, you want to only choose Netscape. You can do it with the constraint: "(Type == 'Application') and (Name == 'Netscape')" More the likely, though, you will only use the trader for such things as finding components. In our continuing example, we say that we want to load any KParts component that can handle HTML. We will need to use the KLibFactory and KLibLoader to actually do something with our query, then. Our code would look like so:

 ArrayList offers = KTrader.self().query("text/html", "'KParts/ReadOnlyPart' in ServiceTypes");
 KService.Ptr ptr = offers.first();
 KLibFactory factory = KLibLoader.self().factory( ptr.library() );
 if (factory)
   part = static_cast(factory.create(this, ptr.name(), "KParts.ReadOnlyPart"));
 

Please note that when including property names containing arithmetic operators like - or +, then you have to put brackets around the property name, in order to correctly separate arithmetic operations from the name. So for example a constraint expression like X-KDE-Blah < 4 needs to be written as [X-KDE-Blah] < 4 otherwise it could also be interpreted as Substract the numeric value of the property "KDE" and "Blah" from the property "X" and make sure it is less than 4. Instead of the other meaning, make sure that the numeric value of "X-KDE-Blah" is less than 4. See also the formal syntax defined in #tradersyntax .

Author:

Torben Weis

Field Summary

Fields inherited from class org.kde.qt.Qt

AlignAuto, AlignBottom, AlignCenter, AlignHCenter, AlignHorizontal_Mask, AlignJustify, AlignLeft, AlignRight, AlignTop, AlignVCenter, AlignVertical_Mask, AlphaDither_Mask, ALT, AltButton, AnchorHref, AnchorName, AndNotROP, AndROP, ArrowCursor, Ascending, ASCII_ACCEL, AutoColor, AutoDither, AutoText, AvoidDither, BDiagPattern, BeginsWith, BevelJoin, BitmapCursor, BlankCursor, Bottom, BottomLeft, BottomRight, BreakAnywhere, BusyCursor, CaseSensitive, ClearROP, ColorMode_Mask, ColorOnly, Contains, ControlButton, CopyROP, CrossCursor, CrossPattern, CTRL, CustomPattern, DashDotDotLine, DashDotLine, DashLine, Dense1Pattern, Dense2Pattern, Dense3Pattern, Dense4Pattern, Dense5Pattern, Dense6Pattern, Dense7Pattern, Descending, DiagCrossPattern, DiffuseAlphaDither, DiffuseDither, Dither_Mask, DitherMode_Mask, DockBottom, DockLeft, DockMinimized, DockRight, DockTop, DockTornOff, DockUnmanaged, DontClip, DontPrint, DotLine, DownArrow, EndsWith, EraseROP, ExactMatch, ExpandTabs, FDiagPattern, FixedColor, FixedPixmap, FlatCap, ForbiddenCursor, HiEnglishUnit, HiMetricUnit, Horizontal, HorPattern, IbeamCursor, Identical, IncludeTrailingSpaces, ISODate, Key_0, Key_1, Key_2, Key_3, Key_4, Key_5, Key_6, Key_7, Key_8, Key_9, Key_A, Key_aacute, Key_Aacute, Key_acircumflex, Key_Acircumflex, Key_acute, Key_adiaeresis, Key_Adiaeresis, Key_ae, Key_AE, Key_agrave, Key_Agrave, Key_Alt, Key_Ampersand, Key_Any, Key_Apostrophe, Key_aring, Key_Aring, Key_AsciiCircum, Key_AsciiTilde, Key_Asterisk, Key_At, Key_atilde, Key_Atilde, Key_B, Key_Back, Key_Backslash, Key_Backspace, Key_BackSpace, Key_Backtab, Key_BackTab, Key_Bar, Key_BassBoost, Key_BassDown, Key_BassUp, Key_BraceLeft, Key_BraceRight, Key_BracketLeft, Key_BracketRight, Key_brokenbar, Key_C, Key_CapsLock, Key_ccedilla, Key_Ccedilla, Key_cedilla, Key_cent, Key_Clear, Key_Colon, Key_Comma, Key_Control, Key_copyright, Key_currency, Key_D, Key_degree, Key_Delete, Key_diaeresis, Key_Direction_L, Key_Direction_R, Key_division, Key_Dollar, Key_Down, Key_E, Key_eacute, Key_Eacute, Key_ecircumflex, Key_Ecircumflex, Key_ediaeresis, Key_Ediaeresis, Key_egrave, Key_Egrave, Key_End, Key_Enter, Key_Equal, Key_Escape, Key_eth, Key_ETH, Key_Exclam, Key_exclamdown, Key_F, Key_F1, Key_F10, Key_F11, Key_F12, Key_F13, Key_F14, Key_F15, Key_F16, Key_F17, Key_F18, Key_F19, Key_F2, Key_F20, Key_F21, Key_F22, Key_F23, Key_F24, Key_F25, Key_F26, Key_F27, Key_F28, Key_F29, Key_F3, Key_F30, Key_F31, Key_F32, Key_F33, Key_F34, Key_F35, Key_F4, Key_F5, Key_F6, Key_F7, Key_F8, Key_F9, Key_Favorites, Key_Forward, Key_G, Key_Greater, Key_guillemotleft, Key_guillemotright, Key_H, Key_Help, Key_Home, Key_HomePage, Key_Hyper_L, Key_Hyper_R, Key_hyphen, Key_I, Key_iacute, Key_Iacute, Key_icircumflex, Key_Icircumflex, Key_idiaeresis, Key_Idiaeresis, Key_igrave, Key_Igrave, Key_Insert, Key_J, Key_K, Key_L, Key_Launch0, Key_Launch1, Key_Launch2, Key_Launch3, Key_Launch4, Key_Launch5, Key_Launch6, Key_Launch7, Key_Launch8, Key_Launch9, Key_LaunchA, Key_LaunchB, Key_LaunchC, Key_LaunchD, Key_LaunchE, Key_LaunchF, Key_LaunchMail, Key_LaunchMedia, Key_Left, Key_Less, Key_M, Key_macron, Key_masculine, Key_MediaLast, Key_MediaNext, Key_MediaPlay, Key_MediaPrev, Key_MediaRecord, Key_MediaStop, Key_Menu, Key_Meta, Key_Minus, Key_mu, Key_multiply, Key_N, Key_Next, Key_nobreakspace, Key_notsign, Key_ntilde, Key_Ntilde, Key_NumberSign, Key_NumLock, Key_O, Key_oacute, Key_Oacute, Key_ocircumflex, Key_Ocircumflex, Key_odiaeresis, Key_Odiaeresis, Key_ograve, Key_Ograve, Key_onehalf, Key_onequarter, Key_onesuperior, Key_Ooblique, Key_OpenUrl, Key_ordfeminine, Key_oslash, Key_otilde, Key_Otilde, Key_P, Key_PageDown, Key_PageUp, Key_paragraph, Key_ParenLeft, Key_ParenRight, Key_Pause, Key_Percent, Key_Period, Key_periodcentered, Key_Plus, Key_plusminus, Key_Print, Key_Prior, Key_Q, Key_Question, Key_questiondown, Key_QuoteDbl, Key_QuoteLeft, Key_R, Key_Refresh, Key_registered, Key_Return, Key_Right, Key_S, Key_ScrollLock, Key_Search, Key_section, Key_Semicolon, Key_Shift, Key_Slash, Key_Space, Key_ssharp, Key_Standby, Key_sterling, Key_Stop, Key_Super_L, Key_Super_R, Key_SysReq, Key_T, Key_Tab, Key_thorn, Key_THORN, Key_threequarters, Key_threesuperior, Key_TrebleDown, Key_TrebleUp, Key_twosuperior, Key_U, Key_uacute, Key_Uacute, Key_ucircumflex, Key_Ucircumflex, Key_udiaeresis, Key_Udiaeresis, Key_ugrave, Key_Ugrave, Key_Underscore, Key_unknown, Key_Up, Key_V, Key_VolumeDown, Key_VolumeMute, Key_VolumeUp, Key_W, Key_X, Key_Y, Key_yacute, Key_Yacute, Key_ydiaeresis, Key_yen, Key_Z, KeyButtonMask, Keypad, LastCursor, LastROP, Left, LeftArrow, LeftButton, LocalDate, LocalTime, LoEnglishUnit, LogText, LoMetricUnit, MacStyle, META, MetaButton, MidButton, Minimized, MiterJoin, MODIFIER_MASK, MonoOnly, MotifStyle, MouseButtonMask, MPenCapStyle, MPenJoinStyle, MPenStyle, MV_10_DOT_0, MV_10_DOT_1, MV_10_DOT_2, MV_10_DOT_3, MV_10_DOT_4, MV_9, MV_CHEETAH, MV_JAGUAR, MV_PANTHER, MV_PUMA, MV_TIGER, MV_Unknown, NandROP, NoAccel, NoAlpha, NoBackground, NoBrush, NoButton, NoMatch, NoPen, NopROP, NorROP, NotAndROP, NotCopyROP, NotEraseROP, NotOrROP, NotROP, NotXorROP, OpaqueMode, OrderedAlphaDither, OrderedDither, OrNotROP, OrROP, Overline, PaletteBackground, PaletteBase, PaletteBrightText, PaletteButton, PaletteButtonText, PaletteDark, PaletteForeground, PaletteHighlight, PaletteHighlightedText, PaletteLight, PaletteLink, PaletteLinkVisited, PaletteMid, PaletteMidlight, PaletteShadow, PaletteText, PartialMatch, PixelUnit, PlainText, PMStyle, PointingHandCursor, PreferDither, RichText, Right, RightArrow, RightButton, RoundCap, RoundJoin, SetROP, SHIFT, ShiftButton, ShowPrefix, SingleLine, SizeAllCursor, SizeBDiagCursor, SizeFDiagCursor, SizeHorCursor, SizeVerCursor, SolidLine, SolidPattern, SplitHCursor, SplitVCursor, SquareCap, StrikeOut, TextDate, ThresholdAlphaDither, ThresholdDither, Top, TopLeft, TopRight, TornOff, TransparentMode, TwipsUnit, UI_AnimateCombo, UI_AnimateMenu, UI_AnimateToolBox, UI_AnimateTooltip, UI_FadeMenu, UI_FadeTooltip, UI_General, Underline, UNICODE_ACCEL, Unmanaged, UpArrow, UpArrowCursor, UTC, VerPattern, Vertical, WaitCursor, WDestructiveClose, WGroupLeader, WhatsThisCursor, Win3Style, WindowActive, WindowFullScreen, WindowMaximized, WindowMinimized, WindowNoState, WindowsStyle, WMacDrawer, WMacNoSheet, WMouseNoMask, WNoAutoErase, WNoMousePropagation, WNorthWestGravity, WordBreak, WPaintClever, WPaintDesktop, WPaintUnclipped, WRepaintNoErase, WResizeNoErase, WShowModal, WState_AutoMask, WState_BlockUpdates, WState_CompressKeys, WState_ConfigPending, WState_Created, WState_CreatedHidden, WState_Disabled, WState_DND, WState_Exposed, WState_ForceDisabled, WState_ForceHide, WState_FullScreen, WState_HasMouse, WState_InPaintEvent, WState_Maximized, WState_Minimized, WState_MouseTracking, WState_OwnCursor, WState_OwnSizePolicy, WState_Polished, WState_Reparented, WState_Reserved0, WState_Resized, WState_Visible, WStaticContents, WStyle_ContextHelp, WStyle_Customize, WStyle_Dialog, WStyle_DialogBorder, WStyle_Mask, WStyle_Maximize, WStyle_Minimize, WStyle_MinMax, WStyle_NoBorder, WStyle_NoBorderEx, WStyle_NormalBorder, WStyle_Reserved, WStyle_Splash, WStyle_StaysOnTop, WStyle_SysMenu, WStyle_Title, WStyle_Tool, WSubWindow, WType_Desktop, WType_Dialog, WType_Mask, WType_Modal, WType_Popup, WType_TopLevel, WV_2000, WV_2003, WV_32s, WV_95, WV_98, WV_CE, WV_CE_based, WV_CENET, WV_DOS_based, WV_Me, WV_NT, WV_NT_based, WV_XP, WWinOwnDC, WX11BypassWM, X11ParentRelative, XorROP

Constructor Summary

	KTrader()
protected	KTrader(java.lang.Class dummy)

Method Summary

java.lang.String	className()
void	dispose() Delete the wrapped C++ instance ahead of finalize()
protected void	finalize() Deletes the wrapped C++ instance
boolean	isDisposed() Has the wrapped C++ instance been deleted?
org.kde.qt.QMetaObject	metaObject()
java.util.ArrayList	query(java.lang.String servicetype)
java.util.ArrayList	query(java.lang.String servicetype, java.lang.String constraint)
java.util.ArrayList	query(java.lang.String servicetype, java.lang.String constraint, java.lang.String preferences) The main function in the KTrader class.
java.util.ArrayList	query(java.lang.String servicetype, java.lang.String genericServiceType, java.lang.String constraint, java.lang.String preferences) A variant of query(), that takes two service types as an input.
static KTrader	self() This is a static pointer to a KTrader instance.

Methods inherited from class org.kde.qt.QObject

activate_filters, activate_signal_bool, activate_signal, activate_signal, activate_signal, activate_signal, blockSignals, checkConnectArgs, child, child, child, childEvent, children, connect, connect, connectInternal, connectNotify, customEvent, deleteLater, disconnect, disconnect, disconnect, disconnect, disconnect, disconnect, disconnect, disconnectInternal, disconnectNotify, dumpObjectInfo, dumpObjectTree, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, emit, event, eventFilter, highPriority, i18n, inherits, insertChild, installEventFilter, isA, isWidgetType, killTimer, killTimers, name, name, normalizeSignalSlot, objectTrees, parent, property, queryList, queryList, queryList, queryList, queryList, registerUserData, removeChild, removeEventFilter, sender, setName, setProperty, signalsBlocked, startTimer, timerEvent, tr, tr

Methods inherited from class org.kde.qt.Qt

arrowCursor, bin, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, bitBlt, black, blankCursor, blue, color0, color1, copyBlt, copyBlt, copyBlt, copyBlt, copyBlt, crossCursor, cyan, darkBlue, darkCyan, darkGray, darkGreen, darkMagenta, darkRed, darkYellow, dec, dynamicCast, endl, flush, forbiddenCursor, fromUtf8, gray, green, hex, ibeamCursor, lightGray, magenta, oct, op_div, op_div, op_div, op_div, op_equals, op_equals, op_equals, op_equals, op_minus, op_minus, op_minus, op_mult, op_mult, op_mult, op_mult, op_mult, op_mult, op_mult, op_mult, op_mult, op_not_equals, op_not_equals, op_not_equals, op_not_equals, op_plus, op_plus, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_read, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, op_write, pointingHandCursor, qAlpha, qApp, qAppName, qBlue, qCompress, qCompress, qDebug, qDebug, qDrawArrow, qDrawItem, qDrawItem, qDrawItem, qDrawPlainRect, qDrawPlainRect, qDrawPlainRect, qDrawPlainRect, qDrawPlainRect, qDrawPlainRect, qDrawShadeLine, qDrawShadeLine, qDrawShadeLine, qDrawShadeLine, qDrawShadeLine, qDrawShadeLine, qDrawShadeLine, qDrawShadeLine, qDrawShadePanel, qDrawShadePanel, qDrawShadePanel, qDrawShadePanel, qDrawShadePanel, qDrawShadePanel, qDrawShadePanel, qDrawShadePanel, qDrawShadeRect, qDrawShadeRect, qDrawShadeRect, qDrawShadeRect, qDrawShadeRect, qDrawShadeRect, qDrawShadeRect, qDrawShadeRect, qDrawShadeRect, qDrawShadeRect, qDrawWinButton, qDrawWinButton, qDrawWinButton, qDrawWinButton, qDrawWinButton, qDrawWinButton, qDrawWinPanel, qDrawWinPanel, qDrawWinPanel, qDrawWinPanel, qDrawWinPanel, qDrawWinPanel, qFatal, qFatal, qGLVersion, qGray, qGray, qGreen, qInitNetworkProtocols, qInstallPath, qInstallPathBins, qInstallPathData, qInstallPathDocs, qInstallPathHeaders, qInstallPathLibs, qInstallPathPlugins, qInstallPathSysconf, qInstallPathTranslations, qItemRect, qItemRect, qObsolete, qObsolete, qObsolete, qRed, qRgb, qRgba, qRound, qSharedBuild, qSuppressObsoleteWarnings, qSuppressObsoleteWarnings, qSysInfo, qSystemWarning, qSystemWarning, qUncompress, qUncompress, qVersion, qWarning, qWarning, red, reset, SIGNAL, sizeAllCursor, sizeBDiagCursor, sizeFDiagCursor, sizeHorCursor, sizeVerCursor, SLOT, splitHCursor, splitVCursor, upArrowCursor, waitCursor, whatsThisCursor, white, ws, yellow

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

KTrader

protected KTrader(java.lang.Class dummy)

KTrader

public KTrader()

Method Detail

metaObject

public org.kde.qt.QMetaObject metaObject()

Overrides:

metaObject in class org.kde.qt.QObject

className

public java.lang.String className()

Overrides:

className in class org.kde.qt.QObject

query

public java.util.ArrayList query(java.lang.String servicetype,
                                 java.lang.String constraint,
                                 java.lang.String preferences)

The main function in the KTrader class. It will return a list of services that match your specifications. The only required parameter is the service type. This is something like 'text/plain' or 'text/html'. The constraint parameter is used to limit the possible choices returned based on the constraints you give it. The constraint language is rather full. The most common keywords are AND, OR, NOT, IN, and EXIST, all used in an almost spoken-word form. An example is:

                 (Type == 'Service') and (('KParts/ReadOnlyPart' in ServiceTypes) or (exist Exec))
                 

The keys used in the query (Type, ServiceType, Exec) are all fields found in the .desktop files.

Parameters:

servicetype - A service type like 'text/plain', 'text/html', or 'KOfficePlugin'.

constraint - A constraint to limit the choices returned, null to get all services of the given servicetype

preferences - Indicates a particular preference to return, null to ignore. Uses an expression in the constraint language that must return a number

Returns:

A list of services that satisfy the query

See Also:

#http://developer#kde#org/documentation/library/kdeqt/tradersyntax#html

query

public java.util.ArrayList query(java.lang.String servicetype,
                                 java.lang.String constraint)

query

public java.util.ArrayList query(java.lang.String servicetype)

query

public java.util.ArrayList query(java.lang.String servicetype,
                                 java.lang.String genericServiceType,
                                 java.lang.String constraint,
                                 java.lang.String preferences)

A variant of query(), that takes two service types as an input. It is not exactly the same as adding the second service type in the constraints of the other query call, because this one takes into account user preferences for this combination of service types. Example usage: To get list of applications that can handle a given mimetype, set servicetype to the mimetype and genericServiceType is "Application". To get list of embeddable components that can handle a given mimetype, set servicetype to the mimetype and genericServiceType is "KParts/ReadOnlyPart".

Parameters:

servicetype - A service type like 'text/plain', 'text/html', or 'KOfficePlugin'.

genericServiceType - a basic service type, like 'KParts/ReadOnlyPart' or 'Application'

constraint - A constraint to limit the choices returned, null to get all services of the given servicetype

preferences - Indicates a particular preference to return, null to ignore. Uses an expression in the constraint language that must return a number

Returns:

A list of services that satisfy the query

See Also:

#http://developer#kde#org/documentation/library/kdeqt/tradersyntax#html

self

public static KTrader self()

This is a static pointer to a KTrader instance. You will need to use this to access the KTrader functionality since the constuctors are protected.

Returns:

Static KTrader instance

finalize

protected void finalize()
                 throws java.lang.InternalError

Deletes the wrapped C++ instance

Overrides:

finalize in class org.kde.qt.QObject

Throws:

java.lang.InternalError

dispose

public void dispose()

Delete the wrapped C++ instance ahead of finalize()

Overrides:

dispose in class org.kde.qt.QObject

isDisposed

public boolean isDisposed()

Has the wrapped C++ instance been deleted?

Overrides:

isDisposed in class org.kde.qt.QObject