Java Reference
In-Depth Information
If the returned transferable isn't null,
paste()
invokes
isDataFlavorSup-
ported()
on this object with
DataFlavor.stringFlavor
as the argument.
This method returns true when the requested flavor is supported. In other words,
isDataFlavorSupported()
returns true when the clipboard contains text; it
would return false when the clipboard contained an image (for example).
If
isDataFlavorSupported()
returnstrue,
paste()
calls
getTransfer-
Data()
to return the string and then replaces the selected string with this content.
TextArea
contains built-in support for performing copy, cut, and paste operations
by pressing the Ctrl-C, Ctrl-X, and Ctrl-V key combinations. However, neither
Tex-
tArea
nor its
TextComponent
superclass provides methods for performing these
tasks.Asaresult,youwouldhavetosupplyyourown
copy()
,
cut()
,and
paste()
methods (such as those shown previously) when youwanted to programmatically per-
formtheseoperations(perhapsinresponsetotheuserselectingCopy,Cut,orPastefrom
an Edit menu).
I've created a
CopyCutAndPaste
application that demonstrates copy, cut, and
pasteonatextareaviatheprevious
copy()
,
cut()
,and
paste()
methods.Consult
thisbook'scodefilefor
CopyCutAndPaste
'ssourcecode.(Thisbook'sintroduction
presents instructions on obtaining the code file.)
Swing
Swing is a windowing system-independent API for creating GUIs that are based on
components, containers, layout managers, and events. Although Swing extends AWT
(you can use AWT layout managers and events in your Swing GUIs), this API differs
from its predecessor in several ways, including the following:
• AWT-basedGUIsadoptthelooksandfeels(behaviors)ofthewindowingsys-
temsonwhichtheyrunbecausetheyleveragewindowingsystemnativescreen
resources.Forexample,abuttonlooksandfeelslikeaWindowsbuttononWin-
dows and a Motif button on X Window-Motif. In contrast, a Swing GUI can
look and feel the same when run on any windowing system or (at the deve-
loper's discretion) adopt the look and feel of the windowing system on which
it's running.
• Tobewindowing-systemindependent,AWTcomponentsadoptthelowestcom-
mon denominator ofcomponent features. Forexample, if buttons onone win-
dowing system can display images with text whereas buttons on another win-
dowingsystemdisplaytextonly,AWTcannotprovideabuttonfeatureforop-
tionallydisplayinganimage.Incontrast,Swing'snoncontainercomponentsand
