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java.lang.Objectjavax.microedition.lcdui.Item
javax.microedition.lcdui.ImageItem
public class ImageItem
A class that provides layout control when Image objects are added
to a Form or to an Alert.
Each ImageItem object contains a reference to an Image object. This image
must be immutable. (If the image object were not required to be immutable,
the application could paint into it at any time, potentially requiring
the containing Form or Alert to be updated on every graphics call.) See
the definition of the Image object for further details on
image mutability how to create immutable images.
The value null may be specified for the image contents of an ImageItem. If this occurs (and if the label is also null) the ImageItem will occupy no space on the screen.
ImageItem contains layout directives that were originally
defined in MIDP 1.0. These layout directives have been moved to the
Item class and now apply to all items. The declarations
are left in ImageItem for source compatibility purposes.
The altText parameter specifies a string to be displayed in place of the image if the image exceeds the capacity of the display. The altText parameter may be null.
| Field Summary | ||
|---|---|---|
static int |
LAYOUT_CENTER
See Item.LAYOUT_CENTER. |
|
static int |
LAYOUT_DEFAULT
Use the default formatting of the "container" of the image. |
|
static int |
LAYOUT_LEFT
See Item.LAYOUT_DEFAULT. |
|
static int |
LAYOUT_NEWLINE_AFTER
See Item.LAYOUT_NEWLINE_AFTER. |
|
static int |
LAYOUT_NEWLINE_BEFORE
See Item.LAYOUT_NEWLINE_BEFORE. |
|
static int |
LAYOUT_RIGHT
See Item.LAYOUT_RIGHT. |
|
| Fields inherited from class javax.microedition.lcdui.Item |
|---|
BUTTON, HYPERLINK, LAYOUT_2, LAYOUT_BOTTOM, LAYOUT_EXPAND, LAYOUT_SHRINK, LAYOUT_TOP, LAYOUT_VCENTER, LAYOUT_VEXPAND, LAYOUT_VSHRINK, PLAIN |
| Constructor Summary | ||
|---|---|---|
ImageItem(String label,
Image img,
int layout,
String altText)
Creates a new ImageItem with the given label, image, layout directive, and alternate text string. |
||
ImageItem(String label,
Image image,
int layout,
String altText,
int appearanceMode)
Creates a new ImageItem object with the given label, image,
layout directive, alternate text string, and appearance mode. |
||
| Method Summary | ||
|---|---|---|
String |
getAltText()
Gets the text string to be used if the image exceeds the device's capacity to display it. |
|
int |
getAppearanceMode()
Returns the appearance mode of the ImageItem. |
|
Image |
getImage()
Gets the image contained within the ImageItem, or null if there is no contained image. |
|
String |
getLabel()
Gets the label of this Item object. |
|
void |
setAltText(String text)
Sets the alternate text of the ImageItem, or null if no alternate text is provided. |
|
void |
setImage(Image img)
Sets the image object contained within the ImageItem. |
|
void |
setLabel(String label)
Sets the label of the Item. |
|
void |
setLayout(int layout)
Sets the layout directives. |
|
| Methods inherited from class javax.microedition.lcdui.Item |
|---|
addCommand, getLayout, getMinimumHeight, getMinimumWidth, getPreferredHeight, getPreferredWidth, notifyStateChanged, removeCommand, setDefaultCommand, setItemCommandListener, setPreferredSize |
| Methods inherited from class java.lang.Object |
|---|
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Field Detail |
|---|
public static final int LAYOUT_DEFAULT
Use the default formatting of the "container" of the image.
Value 0 is assigned to LAYOUT_DEFAULT.
public static final int LAYOUT_LEFT
See Item.LAYOUT_DEFAULT.
Value 1 is assigned to LAYOUT_LEFT.
public static final int LAYOUT_RIGHT
See Item.LAYOUT_RIGHT.
Value 2 is assigned to LAYOUT_RIGHT.
public static final int LAYOUT_CENTER
See Item.LAYOUT_CENTER.
Value 3 is assigned to LAYOUT_CENTER.
public static final int LAYOUT_NEWLINE_BEFORE
See Item.LAYOUT_NEWLINE_BEFORE.
Value 0x100 is assigned to LAYOUT_NEWLINE_BEFORE.
public static final int LAYOUT_NEWLINE_AFTER
See Item.LAYOUT_NEWLINE_AFTER.
Value 0x200 is assigned to LAYOUT_NEWLINE_AFTER.
| Constructor Detail |
|---|
public ImageItem(String label,
Image img,
int layout,
String altText)
Creates a new ImageItem with the given label, image, layout directive, and alternate text string. Calling this constructor is equivalent to calling:
ImageItem(label, image, layout, altText, PLAIN);
label - the label stringimg - the image, must be immutablelayout - a combination of layout directivesaltText - the text that may be used in place of the image
IllegalArgumentException - if the image is mutable
IllegalArgumentException - if the layout value is not
a legal combination of directives
public ImageItem(String label,
Image image,
int layout,
String altText,
int appearanceMode)
ImageItem object with the given label, image,
layout directive, alternate text string, and appearance mode.
Either label or alternative text may be present or null.
The appearanceMode parameter
(see Appearance Modes)
is a hint to the platform of the application's intended use
for this ImageItem. To provide hyperlink- or
button-like behavior,
the application should associate a default Command with this
ImageItem and add an
ItemCommandListener to this
ImageItem.
Here is an example showing the use of an
ImageItem as a button:
|
label - the label stringimage - the image, can be mutable or immutablelayout - a combination of layout directivesaltText - the text that may be used in place of the imageappearanceMode - the appearance mode of the ImageItem,
one of Item.PLAIN, Item.HYPERLINK, or Item.BUTTON
IllegalArgumentException - if the layout value is not
a legal combination of directives
IllegalArgumentException - if appearanceMode invalid| Method Detail |
|---|
public Image getImage()
public void setImage(Image img)
Sets the image object contained within the ImageItem. The image may be
mutable or immutable. If img is null, the ImageItem is set to be empty.
If img is mutable, the effect is as if a snapshot is taken of img's
contents immediately prior to the call to setImage. This snapshot is
used whenever the contents of the ImageItem are to be displayed. If
img is already the Image of this ImageItem, the effect is as if a
new snapshot of img's contents is taken. Thus, after painting into
a mutable image contained by an ImageItem, the application can call
imageItem.setImage(imageItem.getImage());
to refresh the ImageItem's snapshot of its Image.
If the ImageItem is visible on the display when the snapshot is updated
through a call to setImage, the display is updated with the new snapshot as
soon as it is feasible for the implementation to so do.
img - the new image
IllegalArgumentException - if the image is mutablepublic void setLabel(String label)
Item
setLabel in class Itemlabel - the label stringpublic String getLabel()
Item
getLabel in class Itempublic String getAltText()
public void setAltText(String text)
text - the new alternate textpublic void setLayout(int layout)
setLayout in class Itemlayout - a combination of layout directive values
IllegalArgumentException - if the value of layout is not a valid
combination of layout directivesItem.getLayout()public int getAppearanceMode()
ImageItem.
See Appearance Modes.
Item.PLAIN, Item.HYPERLINK, or Item.BUTTON
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