当前页面: 在线文档首页 > JDK 5 Documentation v1.4.1, Java 2 SDK 英文文档
javax.swing.text
Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
AsyncBoxView.ChildLocator (Java 2 Platform SE v1.4.1) - JDK 5 Documentation v1.4.1, Java 2 SDK 英文文档
|
JavaTM 2 Platform Std. Ed. v1.4.1 |
||||||||||
| PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||||
| SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD | ||||||||||
javax.swing.text
Class AsyncBoxView.ChildLocator
java.lang.Object | +--javax.swing.text.AsyncBoxView.ChildLocator
- Enclosing class:
- AsyncBoxView
- public class AsyncBoxView.ChildLocator
- extends Object
A class to manage the effective position of the child views in a localized area while changes are being made around the localized area. The AsyncBoxView may be continuously changing, but the visible area needs to remain fairly stable until the layout thread decides to publish an update to the parent.
| Field Summary | |
protected Rectangle |
childAlloc
A shape to use for the child allocation to avoid creating a lot of garbage. |
protected Rectangle |
lastAlloc
The last seen allocation (for repainting when changes are flushed upward). |
protected AsyncBoxView.ChildState |
lastValidOffset
The location of the last offset calculation that is valid. |
| Constructor Summary | |
AsyncBoxView.ChildLocator()
construct a child locator. |
|
| Method Summary | |
void |
childChanged(AsyncBoxView.ChildState cs)
Notification that a child changed. |
protected Shape |
getChildAllocation(int index)
Fetch the allocation to use for a child view. |
Shape |
getChildAllocation(int index,
Shape a)
Fetch the allocation to use for a child view. |
int |
getViewIndexAtPoint(float x,
float y,
Shape a)
Fetches the child view index at the given point. |
protected int |
getViewIndexAtVisualOffset(float targetOffset)
Locate the view responsible for an offset into the box along the major axis. |
void |
paintChildren(Graphics g)
Paint the children that intersect the clip area. |
protected void |
setAllocation(Shape a)
Copy the currently allocated shape into the Rectangle used to store the current allocation. |
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Field Detail |
lastValidOffset
protected AsyncBoxView.ChildState lastValidOffset
- The location of the last offset calculation
that is valid.
lastAlloc
protected Rectangle lastAlloc
- The last seen allocation (for repainting when changes
are flushed upward).
childAlloc
protected Rectangle childAlloc
- A shape to use for the child allocation to avoid
creating a lot of garbage.
| Constructor Detail |
AsyncBoxView.ChildLocator
public AsyncBoxView.ChildLocator()
- construct a child locator.
| Method Detail |
childChanged
public void childChanged(AsyncBoxView.ChildState cs)
- Notification that a child changed. This can effect
whether or not new offset calculations are needed.
This is called by a ChildState object that has
changed it's major span. This can therefore be
called by multiple threads.
paintChildren
public void paintChildren(Graphics g)
- Paint the children that intersect the clip area.
getChildAllocation
public Shape getChildAllocation(int index, Shape a)
- Fetch the allocation to use for a child view.
This will update the offsets for all children
not yet updated before the given index.
getViewIndexAtPoint
public int getViewIndexAtPoint(float x,
float y,
Shape a)
- Fetches the child view index at the given point.
This is called by the various View methods that
need to calculate which child to forward a message
to. This should be called by a block synchronized
on this object, and would typically be followed
with one or more calls to getChildAllocation that
should also be in the synchronized block.
- Parameters:
x- the X coordinate >= 0y- the Y coordinate >= 0a- the allocation to the View- Returns:
- the nearest child index
getChildAllocation
protected Shape getChildAllocation(int index)
- Fetch the allocation to use for a child view.
This does not update the offsets in the ChildState
records.
setAllocation
protected void setAllocation(Shape a)
- Copy the currently allocated shape into the Rectangle
used to store the current allocation. This would be
a floating point rectangle in a Java2D-specific implmentation.
getViewIndexAtVisualOffset
protected int getViewIndexAtVisualOffset(float targetOffset)
- Locate the view responsible for an offset into the box
along the major axis. Make sure that offsets are set
on the ChildState objects up to the given target span
past the desired offset.
- Returns:
- index of the view representing the given visual location (targetOffset), or -1 if no view represents that location
|
JavaTM 2 Platform Std. Ed. v1.4.1 |
||||||||||
| PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||||
| SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD | ||||||||||
Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright 2002 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.