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java.lang.Object | +--javax.microedition.lcdui.Item | +--javax.microedition.lcdui.ChoiceGroup
A ChoiceGroup
is a group of selectable elements intended to be
placed within a
Form
. The group may be created with a mode that requires a
single choice to be made or that allows multiple choices. The
implementation is responsible for providing the graphical representation of
these modes and must provide visually different graphics for different
modes. For example, it might use "radio buttons" for the
single choice
mode and "check boxes" for the multiple choice mode.
Note: most of the essential methods have been
specified in the Choice
interface.
Fields inherited from class javax.microedition.lcdui.Item |
BUTTON, HYPERLINK, LAYOUT_2, LAYOUT_BOTTOM, LAYOUT_CENTER, LAYOUT_DEFAULT, LAYOUT_EXPAND, LAYOUT_LEFT, LAYOUT_NEWLINE_AFTER, LAYOUT_NEWLINE_BEFORE, LAYOUT_RIGHT, LAYOUT_SHRINK, LAYOUT_TOP, LAYOUT_VCENTER, LAYOUT_VEXPAND, LAYOUT_VSHRINK, PLAIN |
Fields inherited from interface javax.microedition.lcdui.Choice |
EXCLUSIVE, IMPLICIT, MULTIPLE, POPUP, TEXT_WRAP_DEFAULT, TEXT_WRAP_OFF, TEXT_WRAP_ON |
Constructor Summary | |
ChoiceGroup(String label,
int choiceType)
Creates a new, empty ChoiceGroup , specifying its
title and its type. |
|
ChoiceGroup(String label,
int choiceType,
String[] stringElements,
Image[] imageElements)
Creates a new ChoiceGroup , specifying its title,
the type of the
ChoiceGroup , and an array of Strings
and Images to be used as its
initial contents. |
Method Summary | |
int |
append(String stringPart,
Image imagePart)
Appends an element to the ChoiceGroup . |
void |
delete(int elementNum)
Deletes the element referenced by elementNum . |
void |
deleteAll()
Deletes all elements from this ChoiceGroup . |
int |
getFitPolicy()
Gets the application's preferred policy for fitting Choice element
contents to the available screen space. |
Font |
getFont(int elementNum)
Gets the application's preferred font for rendering the specified element of this Choice . |
Image |
getImage(int elementNum)
Gets the Image part of the element referenced by
elementNum . |
int |
getSelectedFlags(boolean[] selectedArray_return)
Queries the state of a ChoiceGroup and returns the state of
all elements in the
boolean array
selectedArray_return . |
int |
getSelectedIndex()
Returns the index number of an element in the ChoiceGroup that is
selected. |
String |
getString(int elementNum)
Gets the String part of the element referenced by
elementNum . |
void |
insert(int elementNum,
String stringPart,
Image imagePart)
Inserts an element into the ChoiceGroup just prior to
the element specified. |
boolean |
isSelected(int elementNum)
Gets a boolean value indicating whether this element is selected. |
void |
set(int elementNum,
String stringPart,
Image imagePart)
Sets the String and Image parts of the
element referenced by elementNum ,
replacing the previous contents of the element. |
void |
setFitPolicy(int fitPolicy)
Sets the application's preferred policy for fitting Choice element
contents to the available screen space. |
void |
setFont(int elementNum,
Font font)
Sets the application's preferred font for rendering the specified element of this Choice . |
void |
setSelectedFlags(boolean[] selectedArray)
Attempts to set the selected state of every element in the ChoiceGroup . |
void |
setSelectedIndex(int elementNum,
boolean selected)
For ChoiceGroup objects of type
MULTIPLE , this simply sets an
individual element's selected state. |
int |
size()
Returns the number of elements in the ChoiceGroup . |
Methods inherited from class javax.microedition.lcdui.Item |
addCommand, getLabel, getLayout, getMinimumHeight, getMinimumWidth, getPreferredHeight, getPreferredWidth, notifyStateChanged, removeCommand, setDefaultCommand, setItemCommandListener, setLabel, setLayout, setPreferredSize |
Methods inherited from class java.lang.Object |
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
public ChoiceGroup(String label, int choiceType)
ChoiceGroup
, specifying its
title and its type.
The type must be one of EXCLUSIVE
,
MULTIPLE
, or POPUP
. The
IMPLICIT
choice type is not allowed within a ChoiceGroup
.label
- the item's label (see Item
)choiceType
- EXCLUSIVE
, MULTIPLE
,
or POPUP
IllegalArgumentException
- if choiceType
is not one of
EXCLUSIVE
, MULTIPLE
, or POPUP
Choice.EXCLUSIVE
,
Choice.MULTIPLE
,
Choice.IMPLICIT
,
Choice.POPUP
public ChoiceGroup(String label, int choiceType, String[] stringElements, Image[] imageElements)
ChoiceGroup
, specifying its title,
the type of the
ChoiceGroup
, and an array of Strings
and Images
to be used as its
initial contents.
The type must be one of EXCLUSIVE
,
MULTIPLE
, or POPUP
. The
IMPLICIT
type is not allowed for ChoiceGroup
.
The stringElements
array must be non-null and
every array element
must also be non-null. The length of the
stringElements
array
determines the number of elements in the ChoiceGroup
. The
imageElements
array
may be null
to indicate that the
ChoiceGroup
elements have no images.
If the
imageElements
array is non-null, it must be the
same length as the
stringElements
array. Individual elements of the
imageElements
array
may be null
in order to indicate the absence of an
image for the
corresponding ChoiceGroup
element. Non-null elements
of the
imageElements
array may refer to mutable or
immutable images.
label
- the item's label (see Item
)choiceType
- EXCLUSIVE
, MULTIPLE
,
or POPUP
stringElements
- set of strings specifying the string parts of the
ChoiceGroup
elementsimageElements
- set of images specifying the image parts of
the ChoiceGroup
elementsNullPointerException
- if stringElements
is null
NullPointerException
- if the stringElements
array contains
any null
elementsIllegalArgumentException
- if the imageElements
array is non-null
and has a different length from the stringElements
arrayIllegalArgumentException
- if choiceType
is not one of
EXCLUSIVE
, MULTIPLE
, or POPUP
Choice.EXCLUSIVE
,
Choice.MULTIPLE
,
Choice.IMPLICIT
,
Choice.POPUP
Method Detail |
public int size()
ChoiceGroup
.size
in interface Choice
ChoiceGroup
public String getString(int elementNum)
String
part of the element referenced by
elementNum
.getString
in interface Choice
elementNum
- the index of the element to be queriedIndexOutOfBoundsException
- if elementNum
is invalidgetImage(int)
public Image getImage(int elementNum)
Image
part of the element referenced by
elementNum
.getImage
in interface Choice
elementNum
- the number of the element to be queriedIndexOutOfBoundsException
- if elementNum is invalidgetString(int)
public int append(String stringPart, Image imagePart)
ChoiceGroup
.append
in interface Choice
stringPart
- the string part of the element to be addedimagePart
- the image part of the element to be added, or
null
if there is no image partNullPointerException
- if stringPart
is
null
public void insert(int elementNum, String stringPart, Image imagePart)
ChoiceGroup
just prior to
the element specified.insert
in interface Choice
elementNum
- the index of the element where insertion is to occurstringPart
- the string part of the element to be insertedimagePart
- the image part of the element to be inserted,
or null
if there is no image partIndexOutOfBoundsException
- if elementNum
is invalidNullPointerException
- if stringPart
is null
public void delete(int elementNum)
elementNum
.delete
in interface Choice
elementNum
- the index of the element to be deletedIndexOutOfBoundsException
- if elementNum
is invalidpublic void deleteAll()
ChoiceGroup
.deleteAll
in interface Choice
public void set(int elementNum, String stringPart, Image imagePart)
String
and Image
parts of the
element referenced by elementNum
,
replacing the previous contents of the element.set
in interface Choice
elementNum
- the index of the element to be setstringPart
- the string part of the new elementimagePart
- the image part of the element, or null
if there is no image partIndexOutOfBoundsException
- if elementNum
is invalidNullPointerException
- if stringPart
is
null
public boolean isSelected(int elementNum)
isSelected
in interface Choice
elementNum
- the index of the element to be queriedIndexOutOfBoundsException
- if elementNum
is invalidpublic int getSelectedIndex()
ChoiceGroup
that is
selected. For ChoiceGroup
objects of type
EXCLUSIVE
and POPUP
there is at most one element selected, so
this method is useful for determining the user's choice.
Returns -1
if
there are no elements in the ChoiceGroup
.
For ChoiceGroup
objects of type
MULTIPLE
, this always
returns -1
because no
single value can in general represent the state of such a
ChoiceGroup
.
To get the complete state of a MULTIPLE
Choice
, see getSelectedFlags
.
getSelectedIndex
in interface Choice
-1
if nonesetSelectedIndex(int, boolean)
public int getSelectedFlags(boolean[] selectedArray_return)
ChoiceGroup
and returns the state of
all elements in the
boolean array
selectedArray_return
. Note: this
is a result parameter.
It must be at least as long as the size
of the ChoiceGroup
as returned by size()
.
If the array is longer, the extra
elements are set to false
.
For ChoiceGroup
objects of type
MULTIPLE
, any
number of elements may be selected and set to true in the result
array. For ChoiceGroup
objects of type
EXCLUSIVE
and POPUP
exactly one element will be selected, unless there are
zero elements in the ChoiceGroup
.
getSelectedFlags
in interface Choice
selectedArray_return
- array to contain the resultsChoiceGroup
IllegalArgumentException
- if selectedArray_return
is shorter than the size of the ChoiceGroup
NullPointerException
- if selectedArray_return
is nullsetSelectedFlags(boolean[])
public void setSelectedIndex(int elementNum, boolean selected)
ChoiceGroup
objects of type
MULTIPLE
, this simply sets an
individual element's selected state.
For ChoiceGroup
objects of type
EXCLUSIVE
and POPUP
, this can be used only to
select an element. That is, the selected
parameter must
be true
. When an element is selected, the previously
selected element is deselected. If selected
is
false
, this call is ignored.
For both list types, the elementNum
parameter
must be within
the range
[0..size()-1]
, inclusive.
setSelectedIndex
in interface Choice
elementNum
- the number of the element. Indexing of the
elements is zero-basedselected
- the new state of the element true=selected
,
false=not
selectedIndexOutOfBoundsException
- if elementNum
is invalidgetSelectedIndex()
public void setSelectedFlags(boolean[] selectedArray)
ChoiceGroup
. The array
must be at least as long as the size of the
ChoiceGroup
. If the array is
longer, the additional values are ignored.
For ChoiceGroup
objects of type
MULTIPLE
, this sets the selected
state of every
element in the Choice
. An arbitrary number of
elements may be selected.
For ChoiceGroup
objects of type
EXCLUSIVE
and POPUP
, exactly one array
element must have the value true
. If no element is
true
,
the first element
in the Choice
will be selected. If two or more
elements are true
, the
implementation will choose the first true
element
and select it.
setSelectedFlags
in interface Choice
selectedArray
- an array in which the method collect the
selection statusIllegalArgumentException
- if selectedArray
is shorter than the size of the ChoiceGroup
NullPointerException
- if the selectedArray
is null
getSelectedFlags(boolean[])
public void setFitPolicy(int fitPolicy)
Choice
element
contents to the available screen space. The set policy applies for all
elements of the Choice
object. Valid values are
Choice.TEXT_WRAP_DEFAULT
, Choice.TEXT_WRAP_ON
,
and Choice.TEXT_WRAP_OFF
. Fit policy is a hint, and the
implementation may disregard the application's preferred policy.setFitPolicy
in interface Choice
fitPolicy
- preferred content fit policy for choice elementsIllegalArgumentException
- if fitPolicy
is invalidgetFitPolicy()
public int getFitPolicy()
Choice
element
contents to the available screen space. The value returned is the
policy that had been set by the application, even if that value had
been disregarded by the implementation.getFitPolicy
in interface Choice
Choice.TEXT_WRAP_DEFAULT
, Choice.TEXT_WRAP_ON
, or
Choice.TEXT_WRAP_OFF
setFitPolicy(int)
public void setFont(int elementNum, Font font)
Choice
.
An element's font is a hint, and the implementation may disregard
the application's preferred font.
The elementNum
parameter must be within the range
[0..size()-1]
, inclusive.
The font
parameter must be a valid Font
object or null
. If the font
parameter is
null
, the implementation must use its default font
to render the element.
setFont
in interface Choice
elementNum
- the index of the element, starting from zerofont
- the preferred font to use to render the elementIndexOutOfBoundsException
- if elementNum
is invalidgetFont(int)
public Font getFont(int elementNum)
Choice
. The
value returned is the font that had been set by the application,
even if that value had been disregarded by the implementation.
If no font had been set by the application, or if the application
explicitly set the font to null
, the value is the default
font chosen by the implementation.
The elementNum
parameter must be within the range
[0..size()-1]
, inclusive.
getFont
in interface Choice
elementNum
- the index of the element, starting from zeroIndexOutOfBoundsException
- if elementNum
is invalidsetFont(int elementNum, Font font)
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