A
TextArea
is the interface to Java's AWT TextArea Component.
Yoix programs normally interact with a
TextArea
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 the textarea uses its preferred color, which is white.
| | 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.
| | 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.
| | 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
int
that is
1
when the textarea can respond to user input, and
0
otherwise.
Reading returns the current state.
Writing immediately sets the textarea's state to the new value.
| | focusable |
An
int
that is non-zero (the default)
when the textarea can accept the keyboard focus and zero
when it can not.
Reading returns the textarea's current focusable state.
Writing immediately changes the textarea's focusable state to the new value,
which means the focus is automatically transferred if the new value is zero
and the textarea is the current focus owner.
| | 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 the textarea uses its preferred color, which is black.
| | 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.
| | popup |
A
PopupMenu
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.
| | 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.
| | 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 determines where scrollbars are added to a new textarea.
The value should be
NONE,
HORIZONTAL,
VERTICAL,
or
BOTH,
which are all defined in
yoix.awt.
Changing
scroll
after a textarea has been created has no effect and eventually may
trigger an
invalidaccess
error.
| | 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.
| | 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.
| | 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.
| | 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,
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
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| Example: |
The program,
import yoix.*.*;
Frame f = {
Dimension size = NULL;
Array layout = {
new TextArea {
String tag = "textarea";
int rows = 20;
int columns = 100;
int edit = 0;
}, CENTER,
};
windowOpened(e) {
Stream stream;
if ((stream = open("http://www.att.com", "r")) != NULL) {
components.textarea.text = readStream(stream);
close(stream);
}
}
};
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.
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| See Also: |
Button,
Canvas,
Checkbox,
Choice,
Dialog,
FileDialog,
Frame,
Label,
List,
Panel,
ScrollPane,
Scrollbar,
TableColumn,
TableManager,
TextCanvas,
TextField,
TextTerm,
Window,
appendText,
deleteText,
insertText,
postEvent,
replaceText
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