A
Frame
represents a top-level application window that is implemented using Java's
AWT Frame class.
A frame consumes system resources that are currently only returned after
the frame is explicitly disposed, which happens when your program stores
a non-zero value in the frame's
dispose
field.
Yoix programs normally interact with a
Frame
using event handlers and by reading or writing the following fields:
| autodeiconify |
An
int
that arranges to deiconify the frame,
exactly as if a zero value had been stored in the
iconified
field, whenever the frame is made visible by storing a non-zero
value in the frame's
visible
field while
autodeiconify
is non-zero (the default).
| | autodispose |
An
int
that arranges to dispose the frame,
exactly as if a non-zero value had been stored in the
dispose
field, whenever a visible frame is hidden while
autodispose
is non-zero.
Failure to dispose of unused frames means system resources are lost,
and that can eventually affect the performance of your program.
| | autoraise |
An
int
that automatically puts the frame on top of all other windows whenever
a non-zero value is stored in the frame's
visible
field.
| | background |
The
Color
that is used to paint the background of the frame.
It is also the default background color assigned to components in the
layout
array that do not pick their own.
A frame that does not set its own background color uses
VM.screen.background.
Reading returns a snapshot of the current color.
Writing immediately sets the frame's background,
and the background of components contained in the frame
that do not pick their own, to the new color.
| | backgroundhints |
An
int
that controls how
backgroundimage
is displayed in the frame.
The value should be one of
SCALE_AREA,
SCALE_DEFAULT,
SCALE_FAST,
SCALE_NONE,
SCALE_REPLICATE,
SCALE_SMOOTH,
or
SCALE_TILE,
which are all defined in
yoix.image.
SCALE_NONE
places the unscaled image in the upper left corner of the frame,
while
SCALE_TILE
(the default) tiles the entire frame with the unscaled image.
The other values select the algorithm used to scale
backgroundimage
so it fills the entire frame.
Reading returns the current hints.
Writing immediately repaints the frame using the new hints to
display the background image.
| | backgroundimage |
An
Object
that should be an
Image
or
String
that identifies an image that is automatically displayed as part of the
frame's background in a way that is controlled by the value assigned to
backgroundhints.
A
NULL
value, which is the default, means there is no image.
A
backgroundimage
that is a
String
should name a local a file or URL that contains a GIF or JPEG image.
Reading returns the current image.
Writing immediately repaints the frame using the new image.
| | components |
A
Dictionary
maintained by the interpreter's layout machinery that maps
tag
fields to actual components;
every component contained in the frame has an entry in the dictionary.
In addition, the
root
field in each component is automatically set to the frame, so the
components
dictionary is easy to find, and that means individual components
can find each other by name using the
root.components
dictionary.
| | cursor |
An
Object
that should be an
int,
Image,
or
String
that selects the cursor shown when the pointer is over the frame.
It is also the default cursor assigned to components in the frame's
layout
array that do not pick their own.
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 sets the frame's cursor,
and the cursor of components contained in the frame
that do not pick their own, to the new value.
A frame that does not set its own cursor uses
DEFAULT_CURSOR.
| | dispose |
An
int
that is
1
when the frame has been properly disposed and
0
otherwise.
Reading returns the current dispose state.
Writing a non-zero value
immediately disposes the frame;
writing
0
has no effect, which means you cannot
resurrect a disposed frame.
Failure to dispose of unused frames means system resources are lost,
and that can eventually affect the performance of your program.
| | enabled |
An
int
that is
1
when the frame,
or any of the components contained in the frame,
can respond to user input, and
0
when they can not.
Reading returns the current state.
Writing immediately sets the frame's state to the new value.
| | focusowner |
A read-only
int
that is non-zero when the frame has the focus.
| | font |
The
Font,
or font name if it is a
String,
that is used as the default font assigned to components in the
layout
array that do not pick their own.
Reading returns a snapshot of the current font.
Writing immediately changes the frame's font,
and the font used by all components contained in the frame
that do not pick their own, to the new font.
| | foreground |
The
Color
that is used as the default foreground color assigned to components in the
layout
array that do not pick their own.
A frame that does not set its own foreground color uses
VM.screen.foreground.
Reading returns a snapshot of the current color.
Writing immediately sets the frame's foreground,
and the foreground of components contained in the frame
that do not pick their own, to the new color.
| | fronttoback |
An
int
that is
1
when components that appear earlier in the
layout
array are placed on top of components that appear later, and
0
when the stacking order is reversed.
In practice,
GridBagLayout
and
CardLayout
are only layout managers where stacking components makes sense.
Reading returns the current stacking order.
Writing immediately tries to change the stacking order.
| | graphics |
A
Graphics
object that defines properties and built-ins that are used to apply
graphics operations to this frame.
Writing after a frame has been created is not allowed and will result in an
invalidaccess
error.
| | iconified |
An
int
that is
1
when the frame has been iconified, and
0
otherwise.
Reading returns the current iconified state.
Writing immediately sets the frames's iconified state to the new value.
| | layout |
An
Array
of objects, often just components, that the
layoutmanager
arranges in the frame.
Reading returns the current array.
Writing immediately clears frame and then arranges the new
set of components in the frame.
| | layoutmanager |
A
LayoutManager
that takes components from the
layout
array, arranges them in the frame, updates the frame's
components
dictionary, and makes sure the
root
field in each component is set to the frame.
Reading returns the current layout manager.
Writing, when
validate
is non-zero, immediately clears the frame and then rearranges
the components in the
layout
array using the new layout manager.
Yoix frames use a
BorderLayout
as their default layout manager.
| | location |
A
Point
that determines the location of the frame's upper left corner
in the default Yoix coordinate system,
which has its origin at the upper left corner of the screen,
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 immediately moves the frame to the new location.
| | maximized |
An
int
that is
1
when the frame has been maximized, and
0
otherwise.
Reading returns the current maximized state.
Writing immediately sets the frame's maximized state to the new value.
| | menubar |
A
MenuBar
that is attached to the frame.
Reading returns the current menubar.
Writing immediately removes the current menubar,
if there is one and it is different than the new one,
and attaches the new menubar.
| | nextcard |
An
Object
that
CardLayout
layout managers use to pick the next component that is displayed in the
frame.
See the description of
CardLayout
for more details.
| | paint([Rectangle rect]) |
A
Function
that is called, if it is not
NULL,
whenever the frame needs to be painted.
The optional
rect
argument describes the rectangle that needs repainting in the
coordinate system specified by
graphics.CTM,
which by default has its origin at the frame's upper left corner,
positive x to the right, positive y down, and a resolution of 72 dots per inch.
| | parent |
A window, which usually should be a
Frame,
Dialog,
FileDialog,
or
Window,
that is responsible for the frame.
Hiding, disposing, iconifying or deiconifying the parent does the same
thing to its children, so using a parent is a convenient way to manage
a group of windows.
Reading returns the current parent.
Writing immediately sets the frame's parent to the new value.
| | popup |
A
PopupMenu
that is associated with the frame.
Reading returns the current popup menu.
Writing immediately shows the popup menu at the point in the frame's coordinate
system specified by the popup menu's
location
field, assuming of course that the frame 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 frame.
| | repaint() |
A
Builtin
that tells the frame to completely repaint itself,
which means the background is regenerated and then the frame's
paint
function is called.
Obviously
repaint
should not be called, either directly or indirectly, from the frame's
paint
function, however
erasedrawable
is safe because it does not trigger a
paint
call.
| | 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.
| | resizable |
An
int
that is
1
(the default)
when the frame can be resized by user actions, and
0
when its size is fixed.
| | root |
A read-only field that for convenience always points to the frame itself.
| | showing |
A read-only
int
that is non-zero when the frame is showing on the screen.
Reading
showing
or
visible
produce identical results for a top-level container like a frame.
| | size |
A
Dimension
that determines the size of the frame
in units of 72 dots per inch.
Reading returns a snapshot of the current size.
Writing immediately changes the frame's size to the new value.
Setting
size
to
NULL
means the
layoutmanager
determines the size of the frame based on the preferred size
of the components in the
layout
array.
| | tag |
A
String
used to identify the frame that is either supplied when
the frame is declared, or automatically generated otherwise.
Frames are top-level containers, so the
tag
field is not particularly useful and may be deleted in future releases.
| | title |
A
String
that is used as the frame's title.
Reading returns a snapshot of the current title.
Writing immediately changes the title to the new value.
| | validate |
An
int
that is
1
when changing the
layoutmanager
field takes effect immediately, and
0
when the change is delayed, often until after the
layout,
size,
or
validate
fields change.
Storing a
1
in
validate
always runs Java's layout manager, even when nothing has changed.
| | visible |
An
int
that is
1
when the frame is visible, and
0
otherwise.
Reading returns the current visibility.
Writing immediately sets the frame'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 frame when it is
declared.
The handlers that work with frames 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,
windowActivated,
windowClosed,
windowClosing,
windowDeactivated,
windowDeiconified,
windowIconified,
windowOpened
| | |
| Example: |
The program,
import yoix.*.*;
Frame main = {
String title = "Parent";
Array layout = {
new Button {
String text = "Show Child";
actionPerformed(e) {
child.visible = TRUE;
}
}, CENTER,
new Button {
String text = "Exit";
actionPerformed(e) {
exit(0);
}
}, SOUTH,
};
};
Frame child = {
String title = "Child";
Frame parent = main;
String font = "Courier-bold-16";
Dimension size = NULL;
Array layout = {
new Button {
String text = "HIDE THIS BUTTON";
actionPerformed(e) {
root.visible = FALSE;
}
}
};
windowOpened(e) {
Point location = parent.location;
Dimension size = parent.size;
location.x += (size.width - this.size.width)/2;
location.y += (size.height - this.size.height)/2;
this.location = location;
}
};
main.visible = TRUE;
shows how to use some of the fields in a frame, including how
how to make one frame a child of another.
Try iconifying the parent frame when the parent and child are
both visible.
| | |
| See Also: |
BorderLayout,
Button,
Canvas,
CardLayout,
Checkbox,
Choice,
CustomLayout,
Dialog,
FileDialog,
FlowLayout,
GridBagLayout,
GridLayout,
Image,
Label,
List,
Menu,
MenuBar,
Panel,
PopupMenu,
postEvent,
printAll,
ScrollPane,
Scrollbar,
TableColumn,
TableManager,
TextArea,
TextCanvas,
TextField,
TextTerm,
toBack,
toFront,
Window
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