BoundedRangeModel
| javax.swing.BoundedRangeModel |
 Known Indirect Subclasses
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Class Overview
Defines the data model used by components like Sliders
and ProgressBars.
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.
- The minimum and maximum set methods "correct" the other three properties to accommodate their new value argument. For example setting the model's minimum may change its maximum, value, and extent properties (in that order), to maintain the constraints specified above.
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The value and extent set methods "correct" their argument to
fit within the limits defined by the other three properties.
For example if
value == maximum,setExtent(10)would change the extent (back) to zero. - The four BoundedRangeModel values are defined as Java Beans properties however Swing ChangeEvents are used to notify clients of changes rather than PropertyChangeEvents. This was done to keep the overhead of monitoring a BoundedRangeModel low. Changes are often reported at MouseDragged rates.
For an example of specifying custom bounded range models used by sliders, see The Anatomy of a Swing-Based Program in The Java Tutorial.
See Also
Summary
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Adds a ChangeListener to the model's listener list.
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Returns the model's extent, the length of the inner range that
begins at the model's value.
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Returns the model's maximum.
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Returns the minimum acceptable value.
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Returns the model's current value.
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Returns true if the current changes to the value property are part
of a series of changes.
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Removes a ChangeListener from the model's listener list.
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Sets the model's extent.
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Sets the model's maximum to newMaximum.
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Sets the model's minimum to newMinimum.
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This method sets all of the model's data with a single method call.
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Sets the model's current value to
newValue if newValue
satisfies the model's constraints. | |||||||||||
This attribute indicates that any upcoming changes to the value
of the model should be considered a single event.
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Public Methods
public abstract void addChangeListener (ChangeListener x)
Adds a ChangeListener to the model's listener list.
Parameters
| x | the ChangeListener to add |
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See Also
public abstract int getExtent ()
Returns the model's extent, the length of the inner range that begins at the model's value.
Returns
- the value of the model's extent property
See Also
public abstract int getMaximum ()
Returns the model's maximum. Note that the upper limit on the model's value is (maximum - extent).
Returns
- the value of the maximum property.
See Also
public abstract int getMinimum ()
Returns the minimum acceptable value.
Returns
- the value of the minimum property
See Also
public abstract int getValue ()
Returns the model's current value. Note that the upper
limit on the model's value is maximum - extent
and the lower limit is minimum.
Returns
- the model's value
See Also
public abstract boolean getValueIsAdjusting ()
Returns true if the current changes to the value property are part of a series of changes.
Returns
- the valueIsAdjustingProperty.
See Also
public abstract void removeChangeListener (ChangeListener x)
Removes a ChangeListener from the model's listener list.
Parameters
| x | the ChangeListener to remove |
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See Also
public abstract void setExtent (int newExtent)
Sets the model's extent. The newExtent is forced to be greater than or equal to zero and less than or equal to maximum - value.
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.
Parameters
| newExtent | the model's new extent |
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See Also
public abstract void setMaximum (int newMaximum)
Sets the model's maximum to newMaximum. The other three properties may be changed as well, to ensure that
minimum <= value <= value+extent <= maximum
Notifies any listeners if the model changes.
Parameters
| newMaximum | the model's new maximum |
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public abstract void setMinimum (int newMinimum)
Sets the model's minimum to newMinimum. The other three properties may be changed as well, to ensure that:
minimum <= value <= value+extent <= maximum
Notifies any listeners if the model changes.
Parameters
| newMinimum | the model's new minimum |
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public abstract 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. The method results in a single change event being generated. This is convenient when you need to adjust all the model data simultaneously and do not want individual change events to occur.
Parameters
| value | an int giving the current value |
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| extent | an int giving the amount by which the value can "jump" |
| min | an int giving the minimum value |
| max | an int giving the maximum value |
| adjusting | a boolean, true if a series of changes are in progress |
public abstract void setValue (int newValue)
Sets the model's current value to 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.
Parameters
| newValue | the model's new value |
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See Also
public abstract void setValueIsAdjusting (boolean b)
This attribute indicates that any upcoming changes to the value of the model should be considered a single event. This attribute will be set to true at the start of a series of changes to the value, and will be set to false when the value has finished changing. Normally this allows a listener to only take action when the final value change in committed, instead of having to do updates for all intermediate values.
Sliders and scrollbars use this property when a drag is underway.
Parameters
| b | true if the upcoming changes to the value property are part of a series |
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