Package com.sun.jna.platform.dnd
Klasse DragHandler
java.lang.Object
com.sun.jna.platform.dnd.DragHandler
- Alle implementierten Schnittstellen:
DragGestureListener,DragSourceListener,DragSourceMotionListener,EventListener
public abstract class DragHandler
extends Object
implements DragSourceListener, DragSourceMotionListener, DragGestureListener
Provides simplified drag handling for a component.
Usage:
int actions = DnDConstants.MOVE_OR_COPY;
Component component = ...;
DragHandler handler = new DragHandler(component, actions);
- Supports painting an arbitrary
Iconwith transparency to represent the item being dragged (restricted to theWindowof the drag source if the platform doesn't support drag images). - Disallow starting a drag if the user requests an unsupported action.
- Adjusts the cursor on drags with no modifier for which the default action is disallowed but where one or more non-default actions are allowed, e.g. a drag (with no modifiers) to a target which supports "link" should change the cursor to "link" (prior to 1.6, the JRE behavior is to display a "not allowed" cursor, even though the action actually depends on how the drop target responds). The bug is fixed in java 1.6.
- Disallow drops to targets if the non-default (user-requested) action is not supported by the target, e.g. the user requests a "copy" when the target only supports "move". This is generally the responsibility of the drop handler, which decides whether or not to accept a drag. The DragHandler provides static modifier state information since the drop handler doesn't have access to it.
DropTargetDragEvent.acceptDrag(int), but often client code
simply relies on DropTargetDragEvent.getDropAction().-
Feldübersicht
FelderModifizierer und TypFeldBeschreibungprotected static final intConvenience to referenceDnDConstants.ACTION_COPY.(Package privat) static final intModifier mask for a user-requested copy.static final floatDefault transparency for ghosting.(Package privat) static final intModifier mask for any user-requested action.protected static final intConvenience to referenceDnDConstants.ACTION_LINK.(Package privat) static final intModifier mask for a user-requested link.static final DimensionDefault maximum size for ghosted images.protected static final intConvenience to referenceDnDConstants.ACTION_MOVE.(Package privat) static final intModifier mask for a user-requested move.protected static final intConvenience to referenceDnDConstants.ACTION_NONE.(Package privat) static final booleanstatic final intgetModifiers()returns this value when the current modifiers state is unknown.static final TransferablegetTransferable(java.awt.dnd.DropTargetEvent)returns this value when the currentTransferableis unknown. -
Konstruktorübersicht
KonstruktorenModifiziererKonstruktorBeschreibungprotectedDragHandler(Component dragSource, int actions) Enable drags from the given component, supporting the actions in the given action mask. -
Methodenübersicht
Modifizierer und TypMethodeBeschreibung(Package privat) static StringactionString(int action) protected intPick a different drop action if the target doesn't support the current one and there are no modifiers.protected booleanOverride to control whether a drag is started.protected ImagecreateDragImage(GraphicsConfiguration gc, Icon icon) Create an image from the given icon.voidvoidvoidvoidCalled when a user drag gesture is recognized.voidvoidprotected voidOverride to perform any decoration of the target at the start of a drag, if desired.voidprotected intgetAcceptableDropAction(int targetActions) Returns the first available action supported by source and target.protected CursorgetCursorForAction(int actualAction) protected IcongetDragIcon(DragGestureEvent e, Point srcOffset) Override this to provide a custom image.protected intGet the currently requested drop action.(Package privat) static intUsed to communicate modifier state toDropHandler.protected abstract TransferableOverride to provide an appropriateTransferablerepresenting the data being dragged.static TransferableUsed to communicate the currentTransferableduring a drag, if available.protected IconscaleDragIcon(Icon icon, Point imageOffset) Change the size of the given drag icon, if appropriate.protected voidsetModifiers(int mods) Update the modifiers hint.protected voidHook to update the cursor on variousDragSourceEventupdates.
-
Felddetails
-
MAX_GHOST_SIZE
Default maximum size for ghosted images. -
DEFAULT_GHOST_ALPHA
public static final float DEFAULT_GHOST_ALPHADefault transparency for ghosting.- Siehe auch:
-
UNKNOWN_MODIFIERS
public static final int UNKNOWN_MODIFIERSgetModifiers()returns this value when the current modifiers state is unknown.- Siehe auch:
-
UNKNOWN_TRANSFERABLE
getTransferable(java.awt.dnd.DropTargetEvent)returns this value when the currentTransferableis unknown. -
MOVE
protected static final int MOVEConvenience to referenceDnDConstants.ACTION_MOVE.- Siehe auch:
-
COPY
protected static final int COPYConvenience to referenceDnDConstants.ACTION_COPY.- Siehe auch:
-
LINK
protected static final int LINKConvenience to referenceDnDConstants.ACTION_LINK.- Siehe auch:
-
NONE
protected static final int NONEConvenience to referenceDnDConstants.ACTION_NONE.- Siehe auch:
-
MOVE_MASK
static final int MOVE_MASKModifier mask for a user-requested move.- Siehe auch:
-
OSX
static final boolean OSX -
COPY_MASK
static final int COPY_MASKModifier mask for a user-requested copy. -
LINK_MASK
static final int LINK_MASKModifier mask for a user-requested link. -
KEY_MASK
static final int KEY_MASKModifier mask for any user-requested action.- Siehe auch:
-
-
Konstruktordetails
-
DragHandler
Enable drags from the given component, supporting the actions in the given action mask.- Parameter:
dragSource- source of the drag.actions- actions which should be supported.
-
-
Methodendetails
-
getModifiers
static int getModifiers()Used to communicate modifier state toDropHandler. Note that this field will only be accurate when aDragHandlerin the same VM started the drag. Otherwise,UNKNOWN_MODIFIERSwill be returned.- Gibt zurück:
- Current drag modifiers.
-
getTransferable
Used to communicate the currentTransferableduring a drag, if available. Work around absence of access to the data when dragging pre-1.5.- Parameter:
e- event- Gibt zurück:
Transferablerepresentation of the item being dragged.
-
canDrag
Override to control whether a drag is started. The default implementation disallows the drag if the user is applying modifiers and the user-requested action is not supported.- Parameter:
e- event- Gibt zurück:
- Whether to allow a drag
-
setModifiers
protected void setModifiers(int mods) Update the modifiers hint.- Parameter:
mods- Current modifiers
-
getTransferable
Override to provide an appropriateTransferablerepresenting the data being dragged.- Parameter:
e- event- Gibt zurück:
Transferablerepresentation of item being dragged.
-
getDragIcon
Override this to provide a custom image. TheIconreturned by this method by default isnull, which results in no drag image.- Parameter:
e- eventsrcOffset- set this to be the offset from the drag source component's upper left corner to the image's upper left corner. For example, when dragging a row from a list, the offset would be the row's bounding rectangle's (x,y) coordinate.The default value is (0,0), so if unchanged, the image is will use the same origin as the drag source component.
- Gibt zurück:
- drag icon (defaults to none)
-
dragStarted
Override to perform any decoration of the target at the start of a drag, if desired.- Parameter:
e- event
-
dragGestureRecognized
Called when a user drag gesture is recognized. This method is responsible for initiating the drag operation.- Angegeben von:
dragGestureRecognizedin SchnittstelleDragGestureListener- Parameter:
e- event
-
scaleDragIcon
Change the size of the given drag icon, if appropriate. When using a differently-sized drag icon, we also need to adjust the cursor offset within the icon.- Parameter:
icon- Icon to be scaled.imageOffset- Modified to account for the new icon's size.- Gibt zurück:
- Scaled
Icon, or the original if there was no change.
-
createDragImage
Create an image from the given icon. The image is provided to the native handler if drag images are supported natively.- Parameter:
gc- current graphics configuration.icon- Icon on which to base the drag image.- Gibt zurück:
- image based on the given icon.
-
getCursorForAction
-
getAcceptableDropAction
protected int getAcceptableDropAction(int targetActions) Returns the first available action supported by source and target.- Parameter:
targetActions- current actions requested- Gibt zurück:
- subset of actions supported based on the input
-
getDropAction
Get the currently requested drop action.- Parameter:
ev- event- Gibt zurück:
- effective drop action
-
adjustDropAction
Pick a different drop action if the target doesn't support the current one and there are no modifiers.- Parameter:
ev- event- Gibt zurück:
- effective drop action
-
updateCursor
Hook to update the cursor on variousDragSourceEventupdates.- Parameter:
ev- event
-
actionString
-
dragDropEnd
- Angegeben von:
dragDropEndin SchnittstelleDragSourceListener
-
dragEnter
- Angegeben von:
dragEnterin SchnittstelleDragSourceListener
-
dragMouseMoved
- Angegeben von:
dragMouseMovedin SchnittstelleDragSourceMotionListener
-
dragOver
- Angegeben von:
dragOverin SchnittstelleDragSourceListener
-
dragExit
- Angegeben von:
dragExitin SchnittstelleDragSourceListener
-
dropActionChanged
- Angegeben von:
dropActionChangedin SchnittstelleDragSourceListener
-