public interface BoundedRangeModel

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 <= maximum

The 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.
• 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 Separable model architecture in A Swing Architecture Overview.

int getMinimum()

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.

int getMaximum()

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.

int getValue()

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 <= maximum

Otherwise, 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.

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.

boolean getValueIsAdjusting()

int getExtent()

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.

void setRangeProperties(int value,
                        int extent,
                        int min,
                        int max,
                        boolean adjusting)

void addChangeListener(ChangeListener x)

void removeChangeListener(ChangeListener x)