| |||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
JScrollBar scrollbar = …;
BoundedRangeModel model = scrollbar.getModel();
Based on 6 examples
JTextField textField = …;
BoundedRangeModel model = textField.getHorizontalVisibility();
Based on 6 examples
public interface BoundedRangeModel
Defines the data model used by components like Slider
s
and ProgressBar
s.
Defines four interrelated integer properties: minimum, maximum, extent
and value. These four integers define two nested ranges like this:
minimum <= value <= value+extent <= maximumThe outer range is
minimum,maximum
and the inner
range is value,value+extent
. The inner range
must lie within the outer one, i.e. value
must be
less than or equal to maximum
and value+extent
must greater than or equal to minimum
, and maximum
must be greater than or equal to minimum
.
There are a few features of this model that one might find a little
surprising. These quirks exist for the convenience of the
Swing BoundedRangeModel clients, such as Slider
and
ScrollBar
.
value == maximum
, setExtent(10)
would change the extent (back) to zero.
For an example of specifying custom bounded range models used by sliders, see The Anatomy of a Swing-Based Program in The Java Tutorial.
Method Summary | |
---|---|
void |
Adds a ChangeListener to the model's listener list. |
int |
Returns the model's extent, the length of the inner range that begins at the model's value. |
int |
Returns the model's maximum. |
int |
Returns the minimum acceptable value. |
int |
getValue() Returns the model's current value. |
boolean |
Returns true if the current changes to the value property are part of a series of changes. |
void |
Removes a ChangeListener from the model's listener list. |
void |
setExtent(int newExtent) Sets the model's extent. |
void |
setMaximum(int newMaximum) Sets the model's maximum to newMaximum. |
void |
setMinimum(int newMinimum) Sets the model's minimum to newMinimum. |
void |
setRangeProperties(int value, int extent, int min, int max, boolean adjusting) This method sets all of the model's data with a single method call. |
void |
setValue(int newValue) Sets the model's current value to newValue if newValue
satisfies the model's constraints.
|
void |
setValueIsAdjusting(boolean b) This attribute indicates that any upcoming changes to the value of the model should be considered a single event. |
Method Detail |
---|
public void addChangeListener(ChangeListener x)
x
- the ChangeListener to addpublic int getExtent()
public int getMaximum()
public int getMinimum()
public int getValue()
maximum - extent
and the lower limit is minimum
.
public boolean getValueIsAdjusting()
public void removeChangeListener(ChangeListener x)
x
- the ChangeListener to removepublic void setExtent(int newExtent)
When a BoundedRange model is used with a scrollbar the extent defines the length of the scrollbar knob (aka the "thumb" or "elevator"). The extent usually represents how much of the object being scrolled is visible. When used with a slider, the extent determines how much the value can "jump", for example when the user presses PgUp or PgDn.
Notifies any listeners if the model changes.
newExtent
- the model's new extentpublic void setMaximum(int newMaximum)
minimum <= value <= value+extent <= maximum
Notifies any listeners if the model changes.
newMaximum
- the model's new maximumpublic void setMinimum(int newMinimum)
minimum <= value <= value+extent <= maximum
Notifies any listeners if the model changes.
newMinimum
- the model's new minimumpublic void setRangeProperties(int value, int extent, int min, int max, boolean adjusting)
value
- an int giving the current valueextent
- an int giving the amount by which the value can "jump"min
- an int giving the minimum valuemax
- an int giving the maximum valueadjusting
- a boolean, true if a series of changes are in
progresspublic void setValue(int newValue)
newValue
if newValue
satisfies the model's constraints. Those constraints are:
minimum <= value <= value+extent <= maximumOtherwise, if
newValue
is less than minimum
it's set to minimum
, if its greater than
maximum
then it's set to maximum
, and
if it's greater than value+extent
then it's set to
value+extent
.
When a BoundedRange model is used with a scrollbar the value specifies the origin of the scrollbar knob (aka the "thumb" or "elevator"). The value usually represents the origin of the visible part of the object being scrolled.
Notifies any listeners if the model changes.
newValue
- the model's new valuepublic void setValueIsAdjusting(boolean b)
Sliders and scrollbars use this property when a drag is underway.
b
- true if the upcoming changes to the value property are part of a series
| |||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |