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Java™ Platform Standard Ed. 6 |
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java.lang.Object java.awt.Component java.awt.Container javax.swing.JComponent javax.swing.JProgressBar
public class JProgressBar
A component that visually displays the progress of some task. As the task progresses towards completion, the progress bar displays the task's percentage of completion. This percentage is typically represented visually by a rectangle which starts out empty and gradually becomes filled in as the task progresses. In addition, the progress bar can display a textual representation of this percentage.
JProgressBar
uses a BoundedRangeModel
as its data model,
with the value
property representing the "current" state of the task,
and the minimum
and maximum
properties representing the
beginning and end points, respectively.
To indicate that a task of unknown length is executing, you can put a progress bar into indeterminate mode. While the bar is in indeterminate mode, it animates constantly to show that work is occurring. As soon as you can determine the task's length and amount of progress, you should update the progress bar's value and switch it back to determinate mode.
Here is an example of creating a progress bar,
where task
is an object (representing some piece of work)
which returns information about the progress of the task:
progressBar = new JProgressBar(0, task.getLengthOfTask()); progressBar.setValue(0); progressBar.setStringPainted(true);Here is an example of querying the current state of the task, and using the returned value to update the progress bar:
progressBar.setValue(task.getCurrent());Here is an example of putting a progress bar into indeterminate mode, and then switching back to determinate mode once the length of the task is known:
progressBar = new JProgressBar(); ...//when the task of (initially) unknown length begins: progressBar.setIndeterminate(true); ...//do some work; get length of task... progressBar.setMaximum(newLength); progressBar.setValue(newValue); progressBar.setIndeterminate(false);
For complete examples and further documentation see How to Monitor Progress, a section in The Java Tutorial.
Warning: Swing is not thread safe. For more information see Swing's Threading Policy.
Warning:
Serialized objects of this class will not be compatible with
future Swing releases. The current serialization support is
appropriate for short term storage or RMI between applications running
the same version of Swing. As of 1.4, support for long term storage
of all JavaBeansTM
has been added to the java.beans
package.
Please see XMLEncoder
.
BasicProgressBarUI
,
BoundedRangeModel
,
SwingWorker
Nested Class Summary | |
---|---|
protected class |
JProgressBar.AccessibleJProgressBar
This class implements accessibility support for the JProgressBar class. |
Nested classes/interfaces inherited from class javax.swing.JComponent |
---|
JComponent.AccessibleJComponent |
Nested classes/interfaces inherited from class java.awt.Container |
---|
Container.AccessibleAWTContainer |
Nested classes/interfaces inherited from class java.awt.Component |
---|
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy |
Field Summary | |
---|---|
protected ChangeEvent |
changeEvent
Only one ChangeEvent is needed per instance since the
event's only interesting property is the immutable source, which
is the progress bar. |
protected ChangeListener |
changeListener
Listens for change events sent by the progress bar's model, redispatching them to change-event listeners registered upon this progress bar. |
protected BoundedRangeModel |
model
The object that holds the data for the progress bar. |
protected int |
orientation
Whether the progress bar is horizontal or vertical. |
protected boolean |
paintBorder
Whether to display a border around the progress bar. |
protected boolean |
paintString
Whether to display a string of text on the progress bar. |
protected String |
progressString
An optional string that can be displayed on the progress bar. |
Fields inherited from class javax.swing.JComponent |
---|
accessibleContext, listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW |
Fields inherited from class java.awt.Component |
---|
BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT |
Fields inherited from interface javax.swing.SwingConstants |
---|
BOTTOM, CENTER, EAST, HORIZONTAL, LEADING, LEFT, NEXT, NORTH, NORTH_EAST, NORTH_WEST, PREVIOUS, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TOP, TRAILING, VERTICAL, WEST |
Fields inherited from interface java.awt.image.ImageObserver |
---|
ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH |
Constructor Summary | |
---|---|
JProgressBar()
Creates a horizontal progress bar that displays a border but no progress string. |
|
JProgressBar(BoundedRangeModel newModel)
Creates a horizontal progress bar that uses the specified model to hold the progress bar's data. |
|
JProgressBar(int orient)
Creates a progress bar with the specified orientation, which can be either SwingConstants.VERTICAL or
SwingConstants.HORIZONTAL . |
|
JProgressBar(int min,
int max)
Creates a horizontal progress bar with the specified minimum and maximum. |
|
JProgressBar(int orient,
int min,
int max)
Creates a progress bar using the specified orientation, minimum, and maximum. |
Method Summary | |
---|---|
void |
addChangeListener(ChangeListener l)
Adds the specified ChangeListener to the progress bar. |
protected ChangeListener |
createChangeListener()
Subclasses that want to handle change events from the model differently can override this to return an instance of a custom ChangeListener implementation. |
protected void |
fireStateChanged()
Send a ChangeEvent , whose source is this JProgressBar , to
all ChangeListener s that have registered interest in
ChangeEvent s. |
AccessibleContext |
getAccessibleContext()
Gets the AccessibleContext associated with this
JProgressBar . |
ChangeListener[] |
getChangeListeners()
Returns an array of all the ChangeListener s added
to this progress bar with addChangeListener . |
int |
getMaximum()
Returns the progress bar's maximum value
from the BoundedRangeModel . |
int |
getMinimum()
Returns the progress bar's minimum value
from the BoundedRangeModel . |
BoundedRangeModel |
getModel()
Returns the data model used by this progress bar. |
int |
getOrientation()
Returns SwingConstants.VERTICAL or
SwingConstants.HORIZONTAL , depending on the orientation
of the progress bar. |
double |
getPercentComplete()
Returns the percent complete for the progress bar. |
String |
getString()
Returns a String representation of the current progress. |
ProgressBarUI |
getUI()
Returns the look-and-feel object that renders this component. |
String |
getUIClassID()
Returns the name of the look-and-feel class that renders this component. |
int |
getValue()
Returns the progress bar's current value
from the BoundedRangeModel . |
boolean |
isBorderPainted()
Returns the borderPainted property. |
boolean |
isIndeterminate()
Returns the value of the indeterminate property. |
boolean |
isStringPainted()
Returns the value of the stringPainted property. |
protected void |
paintBorder(Graphics g)
Paints the progress bar's border if the borderPainted
property is true . |
protected String |
paramString()
Returns a string representation of this JProgressBar . |
void |
removeChangeListener(ChangeListener l)
Removes a ChangeListener from the progress bar. |
void |
setBorderPainted(boolean b)
Sets the borderPainted property, which is
true if the progress bar should paint its border. |
void |
setIndeterminate(boolean newValue)
Sets the indeterminate property of the progress bar,
which determines whether the progress bar is in determinate
or indeterminate mode. |
void |
setMaximum(int n)
Sets the progress bar's maximum value (stored in the progress bar's data model) to n . |
void |
setMinimum(int n)
Sets the progress bar's minimum value (stored in the progress bar's data model) to n . |
void |
setModel(BoundedRangeModel newModel)
Sets the data model used by the JProgressBar . |
void |
setOrientation(int newOrientation)
Sets the progress bar's orientation to newOrientation ,
which must be SwingConstants.VERTICAL or
SwingConstants.HORIZONTAL . |
void |
setString(String s)
Sets the value of the progress string. |
void |
setStringPainted(boolean b)
Sets the value of the stringPainted property,
which determines whether the progress bar
should render a progress string. |
void |
setUI(ProgressBarUI ui)
Sets the look-and-feel object that renders this component. |
void |
setValue(int n)
Sets the progress bar's current value to n . |
void |
updateUI()
Resets the UI property to a value from the current look and feel. |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Field Detail |
---|
protected int orientation
HORIZONTAL
.
setOrientation(int)
protected boolean paintBorder
true
.
setBorderPainted(boolean)
protected BoundedRangeModel model
setModel(javax.swing.BoundedRangeModel)
protected String progressString
null
. Setting this to a non-null
value does not imply that the string will be displayed.
To display the string, paintString
must be true
.
setString(java.lang.String)
,
setStringPainted(boolean)
protected boolean paintString
false
.
Setting this to true
causes a textual
display of the progress to be rendered on the progress bar. If
the progressString
is null
,
the percentage of completion is displayed on the progress bar.
Otherwise, the progressString
is
rendered on the progress bar.
setStringPainted(boolean)
,
setString(java.lang.String)
protected transient ChangeEvent changeEvent
ChangeEvent
is needed per instance since the
event's only interesting property is the immutable source, which
is the progress bar.
The event is lazily created the first time that an
event notification is fired.
fireStateChanged()
protected ChangeListener changeListener
createChangeListener()
Constructor Detail |
---|
public JProgressBar()
setOrientation(int)
,
setBorderPainted(boolean)
,
setStringPainted(boolean)
,
setString(java.lang.String)
,
setIndeterminate(boolean)
public JProgressBar(int orient)
SwingConstants.VERTICAL
or
SwingConstants.HORIZONTAL
.
By default, a border is painted but a progress string is not.
The initial and minimum values are 0,
and the maximum is 100.
orient
- the desired orientation of the progress bar
IllegalArgumentException
- if orient
is an illegal valuesetOrientation(int)
,
setBorderPainted(boolean)
,
setStringPainted(boolean)
,
setString(java.lang.String)
,
setIndeterminate(boolean)
public JProgressBar(int min, int max)
The BoundedRangeModel
that holds the progress bar's data
handles any issues that may arise from improperly setting the
minimum, initial, and maximum values on the progress bar.
See the BoundedRangeModel
documentation for details.
min
- the minimum value of the progress barmax
- the maximum value of the progress barBoundedRangeModel
,
setOrientation(int)
,
setBorderPainted(boolean)
,
setStringPainted(boolean)
,
setString(java.lang.String)
,
setIndeterminate(boolean)
public JProgressBar(int orient, int min, int max)
The BoundedRangeModel
that holds the progress bar's data
handles any issues that may arise from improperly setting the
minimum, initial, and maximum values on the progress bar.
See the BoundedRangeModel
documentation for details.
orient
- the desired orientation of the progress barmin
- the minimum value of the progress barmax
- the maximum value of the progress bar
IllegalArgumentException
- if orient
is an illegal valueBoundedRangeModel
,
setOrientation(int)
,
setBorderPainted(boolean)
,
setStringPainted(boolean)
,
setString(java.lang.String)
,
setIndeterminate(boolean)
public JProgressBar(BoundedRangeModel newModel)
newModel
- the data model for the progress barsetOrientation(int)
,
setBorderPainted(boolean)
,
setStringPainted(boolean)
,
setString(java.lang.String)
,
setIndeterminate(boolean)
Method Detail |
---|
public int getOrientation()
SwingConstants.VERTICAL
or
SwingConstants.HORIZONTAL
, depending on the orientation
of the progress bar. The default orientation is
SwingConstants.HORIZONTAL
.
HORIZONTAL
or VERTICAL
setOrientation(int)
public void setOrientation(int newOrientation)
newOrientation
,
which must be SwingConstants.VERTICAL
or
SwingConstants.HORIZONTAL
. The default orientation
is SwingConstants.HORIZONTAL
.
newOrientation
- HORIZONTAL
or VERTICAL
IllegalArgumentException
- if newOrientation
is an illegal valuegetOrientation()
public boolean isStringPainted()
stringPainted
property.
stringPainted
propertysetStringPainted(boolean)
,
setString(java.lang.String)
public void setStringPainted(boolean b)
stringPainted
property,
which determines whether the progress bar
should render a progress string.
The default is false
, meaning
no string is painted.
Some look and feels might not support progress strings
or might support them only when the progress bar is in determinate mode.
b
- true
if the progress bar should render a stringisStringPainted()
,
setString(java.lang.String)
public String getString()
String
representation of the current progress.
By default, this returns a simple percentage String
based on
the value returned from getPercentComplete
. An example
would be the "42%". You can change this by calling setString
.
null
setString(java.lang.String)
public void setString(String s)
null
, implying the built-in behavior of
using a simple percent string.
If you have provided a custom progress string and want to revert to
the built-in behavior, set the string back to null
.
The progress string is painted only if
the isStringPainted
method returns true
.
s
- the value of the progress stringgetString()
,
setStringPainted(boolean)
,
isStringPainted()
public double getPercentComplete()
public boolean isBorderPainted()
borderPainted
property.
borderPainted
propertysetBorderPainted(boolean)
public void setBorderPainted(boolean b)
borderPainted
property, which is
true
if the progress bar should paint its border.
The default value for this property is true
.
Some look and feels might not implement painted borders;
they will ignore this property.
b
- true
if the progress bar
should paint its border;
otherwise, false
isBorderPainted()
protected void paintBorder(Graphics g)
borderPainted
property is true
.
paintBorder
in class JComponent
g
- the Graphics
context within which to paint the borderJComponent.paint(java.awt.Graphics)
,
JComponent.setBorder(javax.swing.border.Border)
,
isBorderPainted()
,
setBorderPainted(boolean)
public ProgressBarUI getUI()
ProgressBarUI
object that renders this componentpublic void setUI(ProgressBarUI ui)
ui
- a ProgressBarUI
objectUIDefaults.getUI(javax.swing.JComponent)
public void updateUI()
updateUI
in class JComponent
JComponent.updateUI()
public String getUIClassID()
getUIClassID
in class JComponent
JComponent.getUIClassID()
,
UIDefaults.getUI(javax.swing.JComponent)
protected ChangeListener createChangeListener()
ChangeListener
implementation.
The default ChangeListener
simply calls the
fireStateChanged
method to forward ChangeEvent
s
to the ChangeListener
s that have been added directly to the
progress bar.
changeListener
,
fireStateChanged()
,
ChangeListener
,
BoundedRangeModel
public void addChangeListener(ChangeListener l)
ChangeListener
to the progress bar.
l
- the ChangeListener
to addpublic void removeChangeListener(ChangeListener l)
ChangeListener
from the progress bar.
l
- the ChangeListener
to removepublic ChangeListener[] getChangeListeners()
ChangeListener
s added
to this progress bar with addChangeListener
.
ChangeListener
s added or an empty
array if no listeners have been addedprotected void fireStateChanged()
ChangeEvent
, whose source is this JProgressBar
, to
all ChangeListener
s that have registered interest in
ChangeEvent
s.
This method is called each time a ChangeEvent
is received from
the model.
The event instance is created if necessary, and stored in
changeEvent
.
addChangeListener(javax.swing.event.ChangeListener)
,
EventListenerList
public BoundedRangeModel getModel()
BoundedRangeModel
currently in usesetModel(javax.swing.BoundedRangeModel)
,
BoundedRangeModel
public void setModel(BoundedRangeModel newModel)
JProgressBar
.
Note that the BoundedRangeModel
's extent
is not used,
and is set to 0
.
newModel
- the BoundedRangeModel
to usepublic int getValue()
value
from the BoundedRangeModel
.
The value is always between the
minimum and maximum values, inclusive.
setValue(int)
,
BoundedRangeModel.getValue()
public int getMinimum()
minimum
value
from the BoundedRangeModel
.
setMinimum(int)
,
BoundedRangeModel.getMinimum()
public int getMaximum()
maximum
value
from the BoundedRangeModel
.
setMaximum(int)
,
BoundedRangeModel.getMaximum()
public void setValue(int n)
n
. This method
forwards the new value to the model.
The data model (an instance of BoundedRangeModel
)
handles any mathematical
issues arising from assigning faulty values. See the
BoundedRangeModel
documentation for details.
If the new value is different from the previous value, all change listeners are notified.
n
- the new valuegetValue()
,
addChangeListener(javax.swing.event.ChangeListener)
,
BoundedRangeModel.setValue(int)
public void setMinimum(int n)
n
.
The data model (a BoundedRangeModel
instance)
handles any mathematical
issues arising from assigning faulty values.
See the BoundedRangeModel
documentation for details.
If the minimum value is different from the previous minimum, all change listeners are notified.
n
- the new minimumgetMinimum()
,
addChangeListener(javax.swing.event.ChangeListener)
,
BoundedRangeModel.setMinimum(int)
public void setMaximum(int n)
n
.
The underlying BoundedRangeModel
handles any mathematical
issues arising from assigning faulty values.
See the BoundedRangeModel
documentation for details.
If the maximum value is different from the previous maximum, all change listeners are notified.
n
- the new maximumgetMaximum()
,
addChangeListener(javax.swing.event.ChangeListener)
,
BoundedRangeModel.setMaximum(int)
public void setIndeterminate(boolean newValue)
indeterminate
property of the progress bar,
which determines whether the progress bar is in determinate
or indeterminate mode.
An indeterminate progress bar continuously displays animation
indicating that an operation of unknown length is occurring.
By default, this property is false
.
Some look and feels might not support indeterminate progress bars;
they will ignore this property.
See How to Monitor Progress for examples of using indeterminate progress bars.
newValue
- true
if the progress bar
should change to indeterminate mode;
false
if it should revert to normal.isIndeterminate()
,
BasicProgressBarUI
public boolean isIndeterminate()
indeterminate
property.
indeterminate
propertysetIndeterminate(boolean)
protected String paramString()
JProgressBar
.
This method is intended to be used only for debugging purposes. The
content and format of the returned string may vary between
implementations. The returned string may be empty but may not
be null
.
paramString
in class JComponent
JProgressBar
public AccessibleContext getAccessibleContext()
AccessibleContext
associated with this
JProgressBar
. For progress bars, the
AccessibleContext
takes the form of an
AccessibleJProgressBar
.
A new AccessibleJProgressBar
instance is created if necessary.
getAccessibleContext
in interface Accessible
getAccessibleContext
in class JComponent
AccessibleJProgressBar
that serves as the
AccessibleContext
of this JProgressBar
|
Java™ Platform Standard Ed. 6 |
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