| java.lang.Object
 javax.microedition.lcdui.Displayable
All known Subclasses: javax.microedition.lcdui.Canvas, javax.microedition.lcdui.Screen,
| Displayable | | abstract public class Displayable (Code) | | An object that has the capability of being placed on the display. A
Displayable object may have a title, a ticker,
zero or more commands and a listener associated with it. The
contents displayed and their interaction with the user are defined by
subclasses.
The title string may contain
line breaks.
The display of the title string must break accordingly.
For example, if only a single line is available for a
title and the string contains a line break then only the characters
up to the line break are displayed.
Unless otherwise specified by a subclass, the default state of newly
created Displayable objects is as follows:
- it is not visible on the
Display;
- there is no
Ticker associated with this
Displayable;
- the title is
null;
- there are no
Commands present; and
- there is no
CommandListener present.
since:
MIDP 1.0 |
| Method Summary | |
| public void | addCommand(Command cmd)
Adds a command to the Displayable. | | int | addCommandImpl(Command cmd)
| | public int | getHeight()
Gets the height in pixels of the displayable area available to the
application. | | DisplayableLF | getLF()
Gets look&feel for this Displayable object
This method is implemented in the subclasses. | | public Ticker | getTicker()
Gets the ticker used by this Displayable. | | public String | getTitle()
Gets the title of the Displayable. | | public int | getWidth()
Gets the width in pixels of the displayable area available to the
application. | | public boolean | isShown()
Checks if the Displayable is actually visible
on the display. | | void | itemStateChanged(Item src)
Called to schedule a call to itemStateChanged() due to
a change in the given Item. | | public void | removeCommand(Command cmd)
Removes a command from the Displayable. | | int | removeCommandImpl(Command cmd)
| | public void | setCommandListener(CommandListener l)
Sets a listener for
Command Commands to this
Displayable,
replacing any previous CommandListener. | | public void | setTicker(Ticker ticker)
Sets a ticker for use with this Displayable,
replacing any
previous ticker.
If null, removes the ticker object
from this Displayable. | | public void | setTitle(String s)
Sets the title of the Displayable. | | protected void | sizeChanged(int w, int h)
The implementation calls this method when the available area of the
Displayable has been changed. | | void | uCallItemStateChanged(Item src)
Called by the event handler to notify any ItemStateListener
of a change in the given Item. |
| commands | | Command commands(Code) | | An array of Commands added to this Displayable
|
| displayableLF | | DisplayableLF displayableLF(Code) | | The Look &s; Feel object associated with this Displayable
|
| isInFullScreenMode | | boolean isInFullScreenMode(Code) | | True, if this Displayable is in full screen mode
|
| isRotated | | boolean isRotated(Code) | | True, if this Displayable is rotated
|
| numCommands | | int numCommands(Code) | | The number of Commands added to this Displayable
|
| ticker | | Ticker ticker(Code) | | The ticker that may be set for this Displayable
|
| Displayable | | Displayable()(Code) | | Create a new Displayable
|
| Displayable | | Displayable(String title)(Code) | | Create a new Displayable with a passed in title
Parameters:
title - the Displayable's title, or null for no title |
| addCommand | | public void addCommand(Command cmd)(Code) | | Adds a command to the Displayable. The
implementation may choose,
for example,
to add the command to any of the available soft buttons or place it
in a menu.
If the added command is already in the screen (tested by comparing the
object references), the method has no effect.
If the Displayable is actually visible on the
display, and this call
affects the set of visible commands, the implementation should update
the display as soon as it is feasible to do so.
Parameters:
cmd - the command to be added
throws:
NullPointerException - if cmd isnull |
| addCommandImpl | | int addCommandImpl(Command cmd)(Code) | | Add a Command to this Displayable
Parameters:
cmd - The Command to add to this Displayable command index |
| getHeight | | public int getHeight()(Code) | | Gets the height in pixels of the displayable area available to the
application. The value returned is appropriate for the particular
Displayable subclass. This value may depend
on how the device uses the
display and may be affected by the presence of a title, a ticker, or
commands.
This method returns the proper result at all times, even if the
Displayable object has not yet been shown.
height of the area available to the application |
| getLF | | DisplayableLF getLF()(Code) | | Gets look&feel for this Displayable object
This method is implemented in the subclasses.
- DisplayableLF for this Displayable object |
| getTitle | | public String getTitle()(Code) | | Gets the title of the Displayable. Returns
null if there is no title.
the title of the instance, or null if no title
See Also: Displayable.setTitle |
| getWidth | | public int getWidth()(Code) | | Gets the width in pixels of the displayable area available to the
application. The value returned is appropriate for the particular
Displayable subclass. This value may depend
on how the device uses the
display and may be affected by the presence of a title, a ticker, or
commands.
This method returns the proper result at all times, even if the
Displayable object has not yet been shown.
width of the area available to the application |
| isShown | | public boolean isShown()(Code) | | Checks if the Displayable is actually visible
on the display. In order
for a Displayable to be visible, all of the
following must be true:
the Display's MIDlet must be
running in the foreground, the Displayable
must be the Display's current screen, and the
Displayable must not be
obscured by a
system screen.
true if theDisplayable is currently visible |
| itemStateChanged | | void itemStateChanged(Item src)(Code) | | Called to schedule a call to itemStateChanged() due to
a change in the given Item.
Parameters:
src - the Item which has changed |
| removeCommand | | public void removeCommand(Command cmd)(Code) | | Removes a command from the Displayable.
If the command is not in the Displayable
(tested by comparing the
object references), the method has no effect.
If the Displayable is actually visible on the
display, and this call
affects the set of visible commands, the implementation should update
the display as soon as it is feasible to do so.
If cmd is null, this method
does nothing.
Parameters:
cmd - the command to be removed |
| removeCommandImpl | | int removeCommandImpl(Command cmd)(Code) | | Remove a Command from this Displayable
Parameters:
cmd - The Command to remove from this Displayable command index |
| setCommandListener | | public void setCommandListener(CommandListener l)(Code) | | Sets a listener for
Command Commands to this
Displayable,
replacing any previous CommandListener. A
null reference is
allowed and has the effect of removing any existing listener.
Parameters:
l - the new listener, or null. |
| setTicker | | public void setTicker(Ticker ticker)(Code) | | Sets a ticker for use with this Displayable,
replacing any
previous ticker.
If null, removes the ticker object
from this Displayable. The same ticker may be shared by
several Displayable
objects within an application. This is done by calling
setTicker()
with the same Ticker object on several
different Displayable objects.
If the Displayable is actually visible on the display,
the implementation should update
the display as soon as it is feasible to do so.
The existence of a ticker may affect the size
of the area available for Displayable's contents.
Addition, removal, or the setting of the ticker at runtime
may dynamically change the size of the content area.
This is most important to be aware of when using the
Canvas class.
If the available area does change, the application will be notified
via a call to
Displayable.sizeChanged(int,int) sizeChanged() .
Parameters:
ticker - the ticker object used on this screen
See Also: Displayable.getTicker |
| setTitle | | public void setTitle(String s)(Code) | | Sets the title of the Displayable. If
null is given,
removes the title.
If the Displayable is actually visible on
the display,
the implementation should update
the display as soon as it is feasible to do so.
The existence of a title may affect the size
of the area available for Displayable content.
Addition, removal, or the setting of the title text at runtime
may dynamically change the size of the content area.
This is most important to be aware of when using the
Canvas class.
If the available area does change, the application will be notified
via a call to
Displayable.sizeChanged(int,int) sizeChanged() .
Parameters:
s - the new title, or null for no title
See Also: Displayable.getTitle |
| sizeChanged | | protected void sizeChanged(int w, int h)(Code) | | The implementation calls this method when the available area of the
Displayable has been changed.
The "available area" is the area of the display that
may be occupied by
the application's contents, such as Items in a
Form or graphics within
a Canvas. It does not include space occupied
by a title, a ticker,
command labels, scroll bars, system status area, etc. A size change
can occur as a result of the addition, removal, or changed contents of
any of these display features.
This method is called at least once before the
Displayable is shown for the first time.
If the size of a Displayable changes while
it is visible,
sizeChanged will be called. If the size of a
Displayable
changes while it is not visible, calls to
sizeChanged may be deferred. If the size had changed
while the Displayable was not visible,
sizeChanged will be
called at least once at the time the
Displayable becomes visible once
again.
The default implementation of this method in Displayable
and its
subclasses defined in this specification must be empty.
This method is intended solely for being overridden by the
application. This method is defined on Displayable
even though applications are prohibited from creating
direct subclasses of Displayable.
It is defined here so that applications can override it in
subclasses of Canvas and Form.
This is useful for Canvas subclasses to tailor
their graphics and for Forms to modify
Item sizes and layout
directives in order to fit their contents within the the available
display area.
Parameters:
w - the new width in pixels of the available area
Parameters:
h - the new height in pixels of the available area |
| uCallItemStateChanged | | void uCallItemStateChanged(Item src)(Code) | | Called by the event handler to notify any ItemStateListener
of a change in the given Item.
The default implementation of this function does nothing.
Parameters:
src - The Item which has changed |
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