A
JTextArea
is the interface to the Java Swing JTextArea Component.
Yoix programs normally interact with a
JTextArea
using event handlers and by reading or writing the following fields:
| autotrim |
An
int
that is
1
when white space is automatically trimmed from both ends of every string
read from or written to the
text
field, and
0
otherwise.
| | background |
The
Color
that is used to paint the background of the textarea.
Reading returns a snapshot of the current color.
Writing immediately changes the background to the new color.
Storing
NULL
in
background
is special and means use the background of the nearest component
that contains the textarea and was assigned a background color other than
NULL;
if no component qualifies the textarea uses white.
| | border |
An
Object
that should be a
Border,
Insets,
Number,
or
String
that describes the border that is drawn around this textarea.
A
NULL
value, which is the default, means no border.
A
border
that is an
Insets
or
Number
is an easy way to describe margins
(i.e., an
EmptyBorder),
in units of 72 dots per inch, that are left around the sides of this textarea.
A
border
that is a
String
is a quick way to surround this textarea with a border that uses the
String
as its title.
Reading returns a snapshot of the current border.
Writing immediately sets the textarea's border to the new value.
| | caret |
An
int
that represents the position of the text insertion caret.
Reading returns the current position.
Writing immediately moves the caret to the new position.
| | caretcolor |
The
Color
used to paint the text caret.
Reading returns the current color.
Writing immediately repaints the text caret using the new color.
| | caretmodel |
An
int
that should be
0
(the default)
or
1
and currently is only used during a drag and drop operation that
is managed by drag and drop event handlers.
A value of
0
tries to reproduce the caret and selection behavior that Swing's
automatic drag handling provides.
A value of
1
means the caret and selection will not moved or hidden during the
drag and drop operation.
| | caretownercolor |
The
Color
used to paint the owner of the caret, if there is one.
The caret owner is a special highlight that can be set using the
setHighlights
builtin that is defined in
yoix.swing,
but only if
highlightflags
explicitly allows a caret owner.
Reading returns the current color.
Writing immediately repaints the caret owner using the new color.
| | columns |
An
int
that specifies the number of columns in a textarea.
Layout managers usually get the final say, so setting
columns
should be viewed as a request that will not always be honored.
Reading returns the number of columns currently used by the textarea.
Writing tries to immediately change the number of columns.
| | cursor |
An
Object
that should be an
int,
Image,
or
String
that selects the cursor shown when the pointer is over the textarea.
A
cursor
that is an
int
should be one of the cursors defined in the
yoix.awt.Cursor
dictionary.
A
cursor
that is an
Image
can describe the cursor using its
size
and
hotspot
fields and often draws it using its
paint
function.
A
cursor
that is a
String
should be the name of a cursor that is already defined in
yoix.awt.Cursor
or the name a local a file or URL that contains a GIF or JPEG image
that will be used as the cursor.
Reading returns the current cursor.
Writing immediately changes the textarea's cursor to the new value.
Storing
STANDARD_CURSOR
(the default) or
NULL
in
cursor
is special and means use the cursor assigned to the nearest component
that contains the textarea and was assigned a cursor other than
STANDARD_CURSOR;
if no component qualifies the textarea uses
TEXT_CURSOR.
| | doublebuffered |
An
int
that is
1
when the textarea uses double-buffering to draw itself,
0
when it does not, and starts with a default value that is
selected by Java for the textarea.
Reading returns the current double-buffering behavior.
Writing immediately sets the textarea's double-buffering behavior to the new value.
Note that double-buffering may be required when transparent components are used.
| | dragenabled |
An
int
that should be set to
1
when this textarea wants to use the automatic drag handling that Swing provides
for some components, and
0
(the default)
when it does not.
Components that do not provide automatic drag handling always return
0
when their
dragenabled
field is read, so storing
1
in
dragenabled
should only be viewed as a request for a service that may not be available.
Swing components can always take complete control of their drag and drop
handling using their
transferhandler
field or special drag and drop event handlers.
| | edit |
An
int
that is
1
when the contents of the textarea can be changed, and
0
otherwise.
Reading returns the current edit flag.
Writing immediately sets the textarea's edit flag to the new state.
| | enabled |
An
Object
that is
1
when the textarea can respond to user input,
0
when it can not respond, and
NULL
(the default)
when the textarea inherits the value from the nearest lightweight container,
like a
JPanel,
that contains the textarea and has its
enabled
field set to something other than
NULL.
The top-level application window that contains the textarea always gets the
final say, so disabling that window always disables the textarea.
Reading returns the current state.
Writing immediately sets the textarea's state to the new value.
| | focusowner |
A read-only
int
that is non-zero when the textarea has the focus.
| | font |
The
Font,
or font name if it is a
String,
used to paint the characters stored in the
text
field.
Reading returns a snapshot of the current font.
Writing immediately repaints the text in the new font.
| | foreground |
The
Color
that is used to paint the characters stored in the
text
field.
Reading returns a snapshot of the current color.
Writing immediately repaints the text in the new color.
Storing
NULL
in
foreground
is special and means use the foreground of the nearest component
that contains the textarea and was assigned a foreground color other than
NULL;
if no component qualifies the textarea uses black.
| | highlightflags |
An
int
that controls special text highlighting capabilities that are available using
the
getHighlights
and
setHighlights
builtins that are defined in
yoix.swing.
The two most common settings are 0 (all flags off) which is the default
and produces normal behavior, and 0xFF (almost all flags on) which enables fancy
things like multiple highlights (0x04) that are not changed by user actions
(0x02) and are not removed when the focus changes (0x01).
In addition one highlight can be marked as a caret (0x10)
and different highlight can be marked as the owner of the caret (0x20),
which restricts the movement of the caret to the bounds of its owner.
| | insets |
An
Object,
usually an
Insets
or
Number,
that describes the margins, in units of 72 dots per inch, that
separate the textarea from its default border.
This field is not automatically used when the textarea builds its own
border.
An
insets
that is a number is an easy way to describe a uniform margin.
Writing immediately changes the margins that are drawn around the textarea
by the default border.
| | layer |
An
int,
often a small number between 0 and 99,
that identifies the depth of this textarea when it is added to a
JLayeredPane
or
JDesktopPane.
Components assigned to lower numbered layers are drawn before
the components in higher numbered layers.
Writing immediately changes the textarea's layer, which usually means the
JLayeredPane
or
JDesktopPane
that contains the textarea will be repainted.
| | location |
A
Point
that determines the location of the textarea
in a coordinate system that has its origin at the upper left corner
of the container closest to the textarea (in the component hierarchy)
that actually contains it, positive x to the right, positive y down,
and a resolution of 72 dots per inch.
Reading returns a snapshot of the current location.
Writing is allowed, but layout managers usually get the final say, so setting
location
should be viewed as a request that may not be honored.
| | modelToView(Number index) |
A
Builtin
that returns a
Point
that is the location of the character closest to
index
in
text
in a coordinate system that has its origin at the upper left corner of
the textarea, positive x to the right, positive y down,
and a resolution of 72 dots per inch.
| | nextfocus |
An
Object
that is the component that receives the focus after this textarea
when the focus traverses from one component to the next
(usually by means of the keyboard
TAB
character).
A
NULL
value indicates that the default Java focus traversal is in effect.
Reading returns the value last stored.
Writing immediately sets the new focus traversal behavior.
| | opaque |
An
Object
that is
1
when the textarea is opaque,
0
when it is transparent, and
NULL
(the default)
when the textarea inherits the value from the nearest component that
contains the textarea and has its
opaque
field set to something other than
NULL.
| | popup |
A
JPopupMenu
that is associated with the textarea.
Reading returns the current popup menu.
Writing immediately shows the popup menu at the point in the textarea's coordinate
system specified by the popup menu's
location
field, assuming of course that the textarea is showing on the screen.
Storing
TRUE
in the popup menu's
visible
field, which was added in release 1.2.0, is an easy way to show the
popup menu that currently belongs to the textarea.
| | preferredsize |
A
Dimension
that is used by layout managers when they need to know the textarea's
preferred size in units of 72 dots per inch.
A
NULL
value means the textarea has no preference.
A non-positive height or width is allowed and simply means the textarea
has no preference for that dimension.
Reading returns the current preferred size.
Writing changes the preferred size and immediately notifies
root.layoutmanager,
which means the components contained in
root
may be repositioned and resized.
| | requestfocus |
An
int
that can be used to request or transfer the keyboard focus.
Storing a non-zero value in
requestfocus
tries to get the focus.
Storing
0
tries to transfer the focus.
Reading
requestfocus
does not currently return any useful information.
| | requestfocusenabled |
An
int
that is
1
(the default)
when actions, like mouse clicks or changes to the
requestfocus
field, can steal the keyboard focus and
0
when they can not.
Note that this field does not affect acceptance of the keyboard focus
during normal focus traversal.
Reading returns the current state.
Writing immediately sets the textarea's state to the new value.
| | root |
An
Object
that is automatically updated by the interpreter's layout machinery
so it is always the top-level object that contains the textarea.
For example, put a textarea in a panel and
root
will be set to that panel;
add the panel to a frame and the textarea's
root
field will be set to that frame.
A textarea's event handlers can use
root
when they need to interact with the other components in the container.
| | rows |
An
int
that specifies the number of rows in a textarea.
Layout managers usually get the final say, so setting
rows
should be viewed as a request that will not always be honored.
Reading returns the number of rows currently used by the textarea.
Writing tries to immediately change the number of rows.
| | scroll |
An
int
that controls how scrollbars are added to a new textarea.
The value should normally be one of
NONE,
HORIZONTAL,
VERTICAL,
BOTH,
or
AS_NEEDED
(the default), which are all defined in
yoix.swing.
Fancier controls described in the
JScrollPane
reference page are allowed here, but in practice they are rarely needed.
In addition you can explicitly set
scroll
to zero to permanently disable scrolling in this textarea.
| | selected |
Reading returns a
String
with the currently selected text.
Writing a
String
replaces the currently selected text with the supplied text.
The insertion caret is left at the end of the added text.
| | selectedends |
An
Array
that contains entries that are used to set the starting
and ending positions of the current selection.
Writing
NULL
to
selectedends
clears the current selection,
otherwise the first array element controls the start position,
while the second element controls the end position.
The starting position is either 0 or the integer value of the number at
selectedends[0].
The ending position is either the length of the
text
string, which puts it just to the right of the last character,
or the integer value of the number at
selectedends[1].
Requesting an ending value that is less than or equal to the starting
value also clears the current selection.
Reading returns an
Array
of two integers that are the starting and ending positions of the
current selection.
When writing, the insertion caret is set to the end of the selection.
| | selectionbackground |
The
Color
used to highlight the selected text.
Reading returns the current color.
Writing immediately repaints the selected text using the new color.
| | selectionforeground |
The
Color
used to paint the characters of the text that has been selected.
Reading returns the current color.
Writing immediately repaints the selected text using the new color.
| | showing |
A read-only
int
that is non-zero when the textarea is showing on the screen.
| | size |
A
Dimension
that determines the size of the textarea
in units of 72 dots per inch.
Reading returns a snapshot of the current size.
Writing is allowed, but layout managers usually get the final say, so setting
size
should be viewed as a request that may not be honored.
| | subtext([int offset[, int length]]) |
A built-in that returns the current text within the given range.
When absent,
offset
defaults to the zero position and
length
defaults to the length from the offset to the end of the current text.
| | tag |
A
String
used to identify the textarea that is either supplied when
the textarea is declared, or automatically generated otherwise.
Add a textarea to a container, like a
Frame
or
Panel,
and the interpreter's layout machinery updates the
root
field so it points at the top-level container and then adds the textarea, as
tag,
to the
root.components
dictionary.
| | text |
A
String
of characters that is displayed in the textarea.
Reading returns the current text.
Writing immediately paints the new text.
| | textwrap |
An
int
that is
1
when the textarea wraps long lines at word boundaries,
-1
when the textarea wraps long lines at character boundaries and
0
(the default) when the textarea does not do any wrapping of long lines.
Reading returns the current wrap style.
Writing immediately changes to the new wrap style.
| | tooltiptext |
A
String
of characters that is displayed in a tightly sized pop-up window that
appears near the cursor whenever the cursor lingers over the textarea.
Setting this value to
NULL
(the default)
disables the tooltip mechanism.
Reading returns the current tooltip text.
Writing immediately sets the new tooltip text.
| | transferhandler |
An
Object
that should be a
TransferHandler
or
String
that determines how the textarea handles data transfer operations
like drag and drop.
A value that is a
String
but not
""
means the field named by the
String
should be used as the source and sink of the data that is transferred by
the textarea.
The result is the same as assigning the
String
to the
property
field in a
TransferHandler
and then assigning that
TransferHandler
to
transferhandler.
The empty
String
""
is special and refers to the
TransferHandler
that Swing uses for automatic drag handling, if there is one.
Swing components that provide automatic drag handling start out with a
transferhandler
field that is not
NULL,
but the automatic drag handling is not enabled until
1
is stored in
dragenabled.
Swing components that provide their own drag and drop event handlers
currently must store
NULL
in
transferhandler
before those event handlers will start working.
| | viewToModel(Point p) |
A
Builtin
that returns an
int
that is the index in
text
of the character that is closest to
p,
which should be a
Point
in a coordinate system that has its origin at the upper left corner of
the textarea, positive x to the right, positive y down,
and a resolution of 72 dots per inch.
The
location
field in a
MouseEvent
is often used as the argument to
viewToModel.
| | visible |
An
int
that is
1
when the textarea is visible, and
0
otherwise.
Reading returns the current visibility.
Writing immediately sets the textarea's visibility to the new state.
|
Several permanent fields have not been documented and should not be
used in Yoix applications.
Event handlers are functions that must be added to a textarea when it is
declared.
The handlers that work with textareas are listed below;
the names should be familiar if you have done some Java programming.
The
actionPerformed
and
itemStateChanged
event handlers are only for menus.
| |
| Event Handlers: |
actionPerformed,
adjustmentValueChanged,
caretUpdate,
componentHidden,
componentMoved,
componentResized,
componentShown,
dragDropEnd,
dragEnter,
dragExit,
dragGestureRecognized,
dragMouseMoved,
dragOver,
drop,
dropActionChanged,
focusGained,
focusLost,
invocationRun,
itemStateChanged,
keyPressed,
keyReleased,
keyTyped,
mouseClicked,
mouseDragged,
mouseEntered,
mouseExited,
mouseMoved,
mousePressed,
mouseReleased,
mouseWheelMoved,
textValueChanged
| | |
| Example: |
The program,
import yoix.*.*;
JFrame f = {
Dimension size = {int width = 7 * 72; int height = 4 * 72;};
Array layout = {
new JTextArea {
String tag = "textarea";
Color background = Color.white;
int rows = 20;
int columns = 100;
int edit = 0;
int scroll = AS_NEEDED;
}, CENTER,
};
windowOpened(e) {
Stream stream;
if ((stream = open("http://www.att.com", "r")) != NULL) {
components.textarea.text = readStream(stream);
close(stream);
components.textarea.caret = 0;
}
}
};
f.visible = TRUE;
fills a frame with a textarea that is loaded with text read from
the AT&T homepage when the
windowOpened
event handler is called, which only happens the first time the
frame is made visible.
Incidentally, the background is specifically set to white since it
defaults to a greyish color when the edit mode is zero.
| | |
| See Also: |
appendText,
BevelBorder,
Border,
deleteText,
EmptyBorder,
EtchedBorder,
getHighlights,
insertText,
invokeLater,
JButton,
JCanvas,
JCheckBox,
JCheckBoxMenuItem,
JChoice,
JColorChooser,
JComboBox,
JDesktopPane,
JDialog,
JFileChooser,
JFileDialog,
JFrame,
JInternalFrame,
JLabel,
JLayeredPane,
JList,
JMenu,
JMenuBar,
JMenuItem,
JPanel,
JPasswordField,
JPopupMenu,
JProgressBar,
JRadioButton,
JRadioButtonMenuItem,
JScrollBar,
JScrollPane,
JSeparator,
JSlider,
JSplitPane,
JTabbedPane,
JTable,
JTextCanvas,
JTextField,
JTextPane,
JTextTerm,
JToggleButton,
JToolBar,
JTree,
JWindow,
LineBorder,
MatteBorder,
postEvent,
replaceText,
setHighlights,
SoftBevelBorder,
TransferHandler
|
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