jdk.awt.Scrollbar — clojure-interop/java.awt 1.0.5

The Scrollbar class embodies a scroll bar, a familiar user-interface object. A scroll bar provides a convenient means for allowing a user to select from a range of values. The following three vertical scroll bars could be used as slider controls to pick the red, green, and blue components of a color:

Each scroll bar in this example could be created with code similar to the following:

redSlider=new Scrollbar(Scrollbar.VERTICAL, 0, 1, 0, 255); add(redSlider);

Alternatively, a scroll bar can represent a range of values. For example, if a scroll bar is used for scrolling through text, the width of the "bubble" (also called the "thumb" or "scroll box") can be used to represent the amount of text that is visible. Here is an example of a scroll bar that represents a range:

The value range represented by the bubble in this example is the visible amount. The horizontal scroll bar in this example could be created with code like the following:

ranger = new Scrollbar(Scrollbar.HORIZONTAL, 0, 60, 0, 300); add(ranger);

Note that the actual maximum value of the scroll bar is the maximum minus the visible amount. In the previous example, because the maximum is 300 and the visible amount is 60, the actual maximum value is 240. The range of the scrollbar track is 0 - 300. The left side of the bubble indicates the value of the scroll bar.

Normally, the user changes the value of the scroll bar by making a gesture with the mouse. For example, the user can drag the scroll bar's bubble up and down, or click in the scroll bar's unit increment or block increment areas. Keyboard gestures can also be mapped to the scroll bar. By convention, the Page Up and Page Down keys are equivalent to clicking in the scroll bar's block increment and block decrement areas.

When the user changes the value of the scroll bar, the scroll bar receives an instance of AdjustmentEvent. The scroll bar processes this event, passing it along to any registered listeners.

Any object that wishes to be notified of changes to the scroll bar's value should implement AdjustmentListener, an interface defined in the package java.awt.event. Listeners can be added and removed dynamically by calling the methods addAdjustmentListener and removeAdjustmentListener.

The AdjustmentEvent class defines five types of adjustment event, listed here:

AdjustmentEvent.TRACK is sent out when the user drags the scroll bar's bubble. AdjustmentEvent.UNIT_INCREMENT is sent out when the user clicks in the left arrow of a horizontal scroll bar, or the top arrow of a vertical scroll bar, or makes the equivalent gesture from the keyboard. AdjustmentEvent.UNIT_DECREMENT is sent out when the user clicks in the right arrow of a horizontal scroll bar, or the bottom arrow of a vertical scroll bar, or makes the equivalent gesture from the keyboard. AdjustmentEvent.BLOCK_INCREMENT is sent out when the user clicks in the track, to the left of the bubble on a horizontal scroll bar, or above the bubble on a vertical scroll bar. By convention, the Page Up key is equivalent, if the user is using a keyboard that defines a Page Up key. AdjustmentEvent.BLOCK_DECREMENT is sent out when the user clicks in the track, to the right of the bubble on a horizontal scroll bar, or below the bubble on a vertical scroll bar. By convention, the Page Down key is equivalent, if the user is using a keyboard that defines a Page Down key.

The JDK 1.0 event system is supported for backwards compatibility, but its use with newer versions of the platform is discouraged. The five types of adjustment events introduced with JDK 1.1 correspond to the five event types that are associated with scroll bars in previous platform versions. The following list gives the adjustment event type, and the corresponding JDK 1.0 event type it replaces.

AdjustmentEvent.TRACK replaces Event.SCROLL_ABSOLUTE AdjustmentEvent.UNIT_INCREMENT replaces Event.SCROLL_LINE_UP AdjustmentEvent.UNIT_DECREMENT replaces Event.SCROLL_LINE_DOWN AdjustmentEvent.BLOCK_INCREMENT replaces Event.SCROLL_PAGE_UP AdjustmentEvent.BLOCK_DECREMENT replaces Event.SCROLL_PAGE_DOWN

Note: We recommend using a Scrollbar for value selection only. If you want to implement a scrollable component inside a container, we recommend you use a ScrollPane. If you use a Scrollbar for this purpose, you are likely to encounter issues with painting, key handling, sizing and positioning.

*-horizontal clj

Static Constant.

A constant that indicates a horizontal scroll bar.

type: int

*-vertical clj

Static Constant.

A constant that indicates a vertical scroll bar.

type: int

->scrollbar clj

(->scrollbar)

(->scrollbar orientation)

(->scrollbar orientation value visible minimum maximum)

Constructor.

Constructs a new scroll bar with the specified orientation, initial value, visible amount, and minimum and maximum values.

The orientation argument must take one of the two values Scrollbar.HORIZONTAL, or Scrollbar.VERTICAL, indicating a horizontal or vertical scroll bar, respectively.

The parameters supplied to this constructor are subject to the constraints described in setValues(int, int, int, int).

orientation - indicates the orientation of the scroll bar. - int value - the initial value of the scroll bar - int visible - the visible amount of the scroll bar, typically represented by the size of the bubble - int minimum - the minimum value of the scroll bar - int maximum - the maximum value of the scroll bar - int

throws: java.lang.IllegalArgumentException - when an illegal value for the orientation argument is supplied

add-adjustment-listener clj

(add-adjustment-listener this l)

Adds the specified adjustment listener to receive instances of AdjustmentEvent from this scroll bar. If l is null, no exception is thrown and no action is performed. Refer to AWT Threading Issues for details on AWT's threading model.

l - the adjustment listener - java.awt.event.AdjustmentListener

add-notify clj

(add-notify this)

Creates the Scrollbar's peer. The peer allows you to modify the appearance of the Scrollbar without changing any of its functionality.

get-accessible-context clj

(get-accessible-context this)

Gets the AccessibleContext associated with this Scrollbar. For scrollbars, the AccessibleContext takes the form of an AccessibleAWTScrollBar. A new AccessibleAWTScrollBar instance is created if necessary.

returns: an AccessibleAWTScrollBar that serves as the AccessibleContext of this ScrollBar - javax.accessibility.AccessibleContext

get-adjustment-listeners clj

(get-adjustment-listeners this)

Returns an array of all the adjustment listeners registered on this scrollbar.

returns: all of this scrollbar's AdjustmentListeners or an empty array if no adjustment listeners are currently registered - java.awt.event.AdjustmentListener[]

get-block-increment clj

(get-block-increment this)

Gets the block increment of this scroll bar.

The block increment is the value that is added or subtracted when the user activates the block increment area of the scroll bar, generally through a mouse or keyboard gesture that the scroll bar receives as an adjustment event. The block increment must be greater than zero.

returns: the block increment of this scroll bar - int

get-line-increment clj

(get-line-increment this)

Deprecated. As of JDK version 1.1, replaced by getUnitIncrement().

returns: int

get-listeners clj

(get-listeners this listener-type)

Returns an array of all the objects currently registered as FooListeners upon this Scrollbar. FooListeners are registered using the addFooListener method.

You can specify the listenerType argument with a class literal, such as FooListener.class. For example, you can query a Scrollbar c for its mouse listeners with the following code:

MouseListener[] mls = (MouseListener[])(c.getListeners(MouseListener.class));

If no such listeners exist, this method returns an empty array.

listener-type - the type of listeners requested; this parameter should specify an interface that descends from java.util.EventListener - java.lang.Class

returns: an array of all objects registered as FooListeners on this component, or an empty array if no such listeners have been added - <T extends java.util.EventListener> T[]

throws: java.lang.ClassCastException - if listenerType doesn't specify a class or interface that implements java.util.EventListener

get-maximum clj

(get-maximum this)

Gets the maximum value of this scroll bar.

returns: the maximum value of this scroll bar - int

get-minimum clj

(get-minimum this)

Gets the minimum value of this scroll bar.

returns: the minimum value of this scroll bar - int

get-orientation clj

(get-orientation this)

Returns the orientation of this scroll bar.

returns: the orientation of this scroll bar, either Scrollbar.HORIZONTAL or Scrollbar.VERTICAL - int

get-page-increment clj

(get-page-increment this)

Deprecated. As of JDK version 1.1, replaced by getBlockIncrement().

returns: int

get-unit-increment clj

(get-unit-increment this)

Gets the unit increment for this scrollbar.

The unit increment is the value that is added or subtracted when the user activates the unit increment area of the scroll bar, generally through a mouse or keyboard gesture that the scroll bar receives as an adjustment event. The unit increment must be greater than zero.

In some operating systems, this property can be ignored by the underlying controls.

returns: the unit increment of this scroll bar - int

get-value clj

(get-value this)

Gets the current value of this scroll bar.

returns: the current value of this scroll bar - int

get-value-is-adjusting? clj

(get-value-is-adjusting? this)

Returns true if the value is in the process of changing as a result of actions being taken by the user.

returns: the value of the valueIsAdjusting property - boolean

get-visible clj

(get-visible this)

Deprecated. As of JDK version 1.1, replaced by getVisibleAmount().

returns: int

get-visible-amount clj

(get-visible-amount this)

Gets the visible amount of this scroll bar.

When a scroll bar is used to select a range of values, the visible amount is used to represent the range of values that are currently visible. The size of the scroll bar's bubble (also called a thumb or scroll box), usually gives a visual representation of the relationship of the visible amount to the range of the scroll bar. Note that depending on platform, the value of the visible amount property may not be visually indicated by the size of the bubble.

The scroll bar's bubble may not be displayed when it is not moveable (e.g. when it takes up the entire length of the scroll bar's track, or when the scroll bar is disabled). Whether the bubble is displayed or not will not affect the value returned by getVisibleAmount.

returns: the visible amount of this scroll bar - int

remove-adjustment-listener clj

(remove-adjustment-listener this l)

Removes the specified adjustment listener so that it no longer receives instances of AdjustmentEvent from this scroll bar. If l is null, no exception is thrown and no action is performed. Refer to AWT Threading Issues for details on AWT's threading model.

l - the adjustment listener - java.awt.event.AdjustmentListener

set-block-increment clj

(set-block-increment this v)

Sets the block increment for this scroll bar.

The block increment is the value that is added or subtracted when the user activates the block increment area of the scroll bar, generally through a mouse or keyboard gesture that the scroll bar receives as an adjustment event. The block increment must be greater than zero. Attepts to set the block increment to a value lower than 1 will result in a value of 1 being set.

v - the amount by which to increment or decrement the scroll bar's value - int

set-line-increment clj

(set-line-increment this v)

Deprecated. As of JDK version 1.1, replaced by setUnitIncrement(int).

v - int

set-maximum clj

(set-maximum this new-maximum)

Sets the maximum value of this scroll bar.

When setMaximum is called, the maximum value is changed, and other values (including the minimum, the visible amount, and the current scroll bar value) are changed to be consistent with the new maximum.

Normally, a program should change a scroll bar's maximum value only by calling setValues. The setValues method simultaneously and synchronously sets the minimum, maximum, visible amount, and value properties of a scroll bar, so that they are mutually consistent.

Note that setting the maximum value to Integer.MIN_VALUE will result in the new maximum value being set to Integer.MIN_VALUE 1.

new-maximum - the new maximum value for this scroll bar - int

set-minimum clj

(set-minimum this new-minimum)

Sets the minimum value of this scroll bar.

When setMinimum is called, the minimum value is changed, and other values (including the maximum, the visible amount, and the current scroll bar value) are changed to be consistent with the new minimum.

Normally, a program should change a scroll bar's minimum value only by calling setValues. The setValues method simultaneously and synchronously sets the minimum, maximum, visible amount, and value properties of a scroll bar, so that they are mutually consistent.

Note that setting the minimum value to Integer.MAX_VALUE will result in the new minimum value being set to Integer.MAX_VALUE - 1.

new-minimum - the new minimum value for this scroll bar - int

set-orientation clj

(set-orientation this orientation)

Sets the orientation for this scroll bar.

orientation - the orientation of this scroll bar, either Scrollbar.HORIZONTAL or Scrollbar.VERTICAL - int

throws: java.lang.IllegalArgumentException - if the value supplied for orientation is not a legal value

set-page-increment clj

(set-page-increment this v)

Deprecated. As of JDK version 1.1, replaced by setBlockIncrement().

v - int

set-unit-increment clj

(set-unit-increment this v)

Sets the unit increment for this scroll bar.

The unit increment is the value that is added or subtracted when the user activates the unit increment area of the scroll bar, generally through a mouse or keyboard gesture that the scroll bar receives as an adjustment event. The unit increment must be greater than zero. Attepts to set the unit increment to a value lower than 1 will result in a value of 1 being set.

In some operating systems, this property can be ignored by the underlying controls.

v - the amount by which to increment or decrement the scroll bar's value - int

set-value clj

(set-value this new-value)

Sets the value of this scroll bar to the specified value.

If the value supplied is less than the current minimum or greater than the current maximum - visibleAmount, then either minimum or maximum - visibleAmount is substituted, as appropriate.

Normally, a program should change a scroll bar's value only by calling setValues. The setValues method simultaneously and synchronously sets the minimum, maximum, visible amount, and value properties of a scroll bar, so that they are mutually consistent.

Calling this method does not fire an AdjustmentEvent.

new-value - the new value of the scroll bar - int

set-value-is-adjusting clj

(set-value-is-adjusting this b)

Sets the valueIsAdjusting property.

b - new adjustment-in-progress status - boolean

set-values clj

(set-values this value visible minimum maximum)

Sets the values of four properties for this scroll bar: value, visibleAmount, minimum, and maximum. If the values supplied for these properties are inconsistent or incorrect, they will be changed to ensure consistency.

This method simultaneously and synchronously sets the values of four scroll bar properties, assuring that the values of these properties are mutually consistent. It enforces the following constraints: maximum must be greater than minimum, maximum - minimum must not be greater than Integer.MAX_VALUE, visibleAmount must be greater than zero. visibleAmount must not be greater than maximum - minimum, value must not be less than minimum, and value must not be greater than maximum - visibleAmount

Calling this method does not fire an AdjustmentEvent.

value - is the position in the current window - int visible - is the visible amount of the scroll bar - int minimum - is the minimum value of the scroll bar - int maximum - is the maximum value of the scroll bar - int

set-visible-amount clj

(set-visible-amount this new-amount)

Sets the visible amount of this scroll bar.

When a scroll bar is used to select a range of values, the visible amount is used to represent the range of values that are currently visible. The size of the scroll bar's bubble (also called a thumb or scroll box), usually gives a visual representation of the relationship of the visible amount to the range of the scroll bar. Note that depending on platform, the value of the visible amount property may not be visually indicated by the size of the bubble.

The scroll bar's bubble may not be displayed when it is not moveable (e.g. when it takes up the entire length of the scroll bar's track, or when the scroll bar is disabled). Whether the bubble is displayed or not will not affect the value returned by getVisibleAmount.

If the visible amount supplied is less than one or greater than the current maximum - minimum, then either one or maximum - minimum is substituted, as appropriate.

Normally, a program should change a scroll bar's value only by calling setValues. The setValues method simultaneously and synchronously sets the minimum, maximum, visible amount, and value properties of a scroll bar, so that they are mutually consistent.

new-amount - the new visible amount - int