javax.swing.text
Class AsyncBoxView.ChildState

java.lang.Object
  javax.swing.text.AsyncBoxView.ChildState

All Implemented Interfaces:

Runnable

Enclosing class:

AsyncBoxView

public class AsyncBoxView.ChildState

extends Object

implements Runnable

A record representing the layout state of a child view. It is runnable as a task on another thread. All access to the child view that is based upon a read-lock on the model should synchronize on this object (i.e. The layout thread and the GUI thread can both have a read lock on the model at the same time and are not protected from each other). Access to a child view hierarchy is serialized via synchronization on the ChildState instance.

Field Summary

private float	align
private View	child
private boolean	childSizeValid
private boolean	majorValid
private float	max
private float	min
private boolean	minorValid
private float	offset
private float	pref
private float	span

Constructor Summary

AsyncBoxView.ChildState(View v)
Construct a child status.

Method Summary

View	getChildView() Fetch the child view this record represents
float	getMajorOffset() Get the offset along the major axis
float	getMajorSpan() What is the span along the major axis.
float	getMinorOffset() What is the offset along the minor axis
float	getMinorSpan() What is the span along the minor axis.
boolean	isLayoutValid() Has the child view been laid out.
void	preferenceChanged(boolean width, boolean height) Mark preferences changed for this child.
void	run() Update the child state.
void	setMajorOffset(float offs) This method should only be called by the ChildLocator, it is simply a convenient place to hold the cached location.
(package private) void	updateChild()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

min

private float min

pref

private float pref

max

private float max

align

private float align

minorValid

private boolean minorValid

span

private float span

offset

private float offset

majorValid

private boolean majorValid

child

private View child

childSizeValid

private boolean childSizeValid

Constructor Detail

AsyncBoxView.ChildState

public AsyncBoxView.ChildState(View v)

Construct a child status. This needs to start out as fairly large so we don't falsely begin with the idea that all of the children are visible.

Method Detail

getChildView

public View getChildView()

Fetch the child view this record represents

run

public void run()

Update the child state. This should be called by the thread that desires to spend time updating the child state (intended to be the layout thread).

This aquires a read lock on the associated document for the duration of the update to ensure the model is not changed while it is operating. The first thing to do would be to see if any work actually needs to be done. The following could have conceivably happened while the state was waiting to be updated:

1. The child may have been removed from the view hierarchy.
2. The child may have been updated by a higher priority operation (i.e. the child may have become visible).

Specified by:

run in interface Runnable

See Also:

Thread.run()

updateChild

void updateChild()

getMinorSpan

public float getMinorSpan()

What is the span along the minor axis.

getMinorOffset

public float getMinorOffset()

What is the offset along the minor axis

getMajorSpan

public float getMajorSpan()

What is the span along the major axis.

getMajorOffset

public float getMajorOffset()

Get the offset along the major axis

setMajorOffset

public void setMajorOffset(float offs)

This method should only be called by the ChildLocator, it is simply a convenient place to hold the cached location.

preferenceChanged

public void preferenceChanged(boolean width,
                              boolean height)

Mark preferences changed for this child.

Parameters:

width - true if the width preference has changed

height - true if the height preference has changed

See Also:

JComponent.revalidate()

isLayoutValid

public boolean isLayoutValid()

Has the child view been laid out.