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FixedHeightLayoutCache (Java Platform SE 6) - JDK 5 Documentation v6.0, Java 2 SDK 英文文档


Java™ Platform
Standard Ed. 6

javax.swing.tree
Class FixedHeightLayoutCache

java.lang.Object
  extended by javax.swing.tree.AbstractLayoutCache
      extended by javax.swing.tree.FixedHeightLayoutCache
All Implemented Interfaces:
RowMapper

public class FixedHeightLayoutCache
extends AbstractLayoutCache

NOTE: This will become more open in a future release.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeansTM has been added to the java.beans package. Please see XMLEncoder.


Nested Class Summary
 
Nested classes/interfaces inherited from class javax.swing.tree.AbstractLayoutCache
AbstractLayoutCache.NodeDimensions
 
Field Summary
 
Fields inherited from class javax.swing.tree.AbstractLayoutCache
nodeDimensions, rootVisible, rowHeight, treeModel, treeSelectionModel
 
Constructor Summary
FixedHeightLayoutCache()
           
 
Method Summary
 Rectangle getBounds(TreePath path, Rectangle placeIn)
          Returns a rectangle giving the bounds needed to draw path.
 boolean getExpandedState(TreePath path)
          Returns true if the path is expanded, and visible.
 TreePath getPathClosestTo(int x, int y)
          Returns the path to the node that is closest to x,y.
 TreePath getPathForRow(int row)
          Returns the path for passed in row.
 int getRowCount()
          Returns the number of visible rows.
 int getRowForPath(TreePath path)
          Returns the row that the last item identified in path is visible at.
 int getVisibleChildCount(TreePath path)
          Returns the number of visible children for row.
 Enumeration<TreePath> getVisiblePathsFrom(TreePath path)
          Returns an Enumerator that increments over the visible paths starting at the passed in location.
 void invalidatePathBounds(TreePath path)
          Does nothing, FixedHeightLayoutCache doesn't cache width, and that is all that could change.
 void invalidateSizes()
          Informs the TreeState that it needs to recalculate all the sizes it is referencing.
 boolean isExpanded(TreePath path)
          Returns true if the value identified by row is currently expanded.
 void setExpandedState(TreePath path, boolean isExpanded)
          Marks the path path expanded state to isExpanded.
 void setModel(TreeModel newModel)
          Sets the TreeModel that will provide the data.
 void setRootVisible(boolean rootVisible)
          Determines whether or not the root node from the TreeModel is visible.
 void setRowHeight(int rowHeight)
          Sets the height of each cell.
 void treeNodesChanged(TreeModelEvent e)
          Invoked after a node (or a set of siblings) has changed in some way.
 void treeNodesInserted(TreeModelEvent e)
          Invoked after nodes have been inserted into the tree.
 void treeNodesRemoved(TreeModelEvent e)
          Invoked after nodes have been removed from the tree.
 void treeStructureChanged(TreeModelEvent e)
          Invoked after the tree has drastically changed structure from a given node down.
 
Methods inherited from class javax.swing.tree.AbstractLayoutCache
getModel, getNodeDimensions, getNodeDimensions, getPreferredHeight, getPreferredWidth, getRowHeight, getRowsForPaths, getSelectionModel, isFixedRowHeight, isRootVisible, setNodeDimensions, setSelectionModel
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

FixedHeightLayoutCache

public FixedHeightLayoutCache()
Method Detail

setModel

public void setModel(TreeModel newModel)
Sets the TreeModel that will provide the data.

Overrides:
setModel in class AbstractLayoutCache
Parameters:
newModel - the TreeModel that is to provide the data

setRootVisible

public void setRootVisible(boolean rootVisible)
Determines whether or not the root node from the TreeModel is visible.

Overrides:
setRootVisible in class AbstractLayoutCache
Parameters:
rootVisible - true if the root node of the tree is to be displayed
See Also:
AbstractLayoutCache.rootVisible

setRowHeight

public void setRowHeight(int rowHeight)
Sets the height of each cell. If rowHeight is less than or equal to 0 this will throw an IllegalArgumentException.

Overrides:
setRowHeight in class AbstractLayoutCache
Parameters:
rowHeight - the height of each cell, in pixels

getRowCount

public int getRowCount()
Returns the number of visible rows.

Specified by:
getRowCount in class AbstractLayoutCache
Returns:
the number of rows being displayed

invalidatePathBounds

public void invalidatePathBounds(TreePath path)
Does nothing, FixedHeightLayoutCache doesn't cache width, and that is all that could change.

Specified by:
invalidatePathBounds in class AbstractLayoutCache
Parameters:
path - the path being updated

invalidateSizes

public void invalidateSizes()
Informs the TreeState that it needs to recalculate all the sizes it is referencing.

Specified by:
invalidateSizes in class AbstractLayoutCache

isExpanded

public boolean isExpanded(TreePath path)
Returns true if the value identified by row is currently expanded.

Specified by:
isExpanded in class AbstractLayoutCache

getBounds

public Rectangle getBounds(TreePath path,
                           Rectangle placeIn)
Returns a rectangle giving the bounds needed to draw path.

Specified by:
getBounds in class AbstractLayoutCache
Parameters:
path - a TreePath specifying a node
placeIn - a Rectangle object giving the available space
Returns:
a Rectangle object specifying the space to be used

getPathForRow

public TreePath getPathForRow(int row)
Returns the path for passed in row. If row is not visible null is returned.

Specified by:
getPathForRow in class AbstractLayoutCache
Parameters:
row - the row being queried
Returns:
the TreePath for the given row

getRowForPath

public int getRowForPath(TreePath path)
Returns the row that the last item identified in path is visible at. Will return -1 if any of the elements in path are not currently visible.

Specified by:
getRowForPath in class AbstractLayoutCache
Parameters:
path - the TreePath being queried
Returns:
the row where the last item in path is visible or -1 if any elements in path aren't currently visible

getPathClosestTo

public TreePath getPathClosestTo(int x,
                                 int y)
Returns the path to the node that is closest to x,y. If there is nothing currently visible this will return null, otherwise it'll always return a valid path. If you need to test if the returned object is exactly at x, y you should get the bounds for the returned path and test x, y against that.

Specified by:
getPathClosestTo in class AbstractLayoutCache
Parameters:
x - the horizontal component of the desired location
y - the vertical component of the desired location
Returns:
the TreePath closest to the specified point

getVisibleChildCount

public int getVisibleChildCount(TreePath path)
Returns the number of visible children for row.

Specified by:
getVisibleChildCount in class AbstractLayoutCache
Parameters:
path - the path being queried
Returns:
the number of visible children for the specified path

getVisiblePathsFrom

public Enumeration<TreePath> getVisiblePathsFrom(TreePath path)
Returns an Enumerator that increments over the visible paths starting at the passed in location. The ordering of the enumeration is based on how the paths are displayed.

Specified by:
getVisiblePathsFrom in class AbstractLayoutCache
Parameters:
path - the starting location for the enumeration
Returns:
the Enumerator starting at the desired location

setExpandedState

public void setExpandedState(TreePath path,
                             boolean isExpanded)
Marks the path path expanded state to isExpanded.

Specified by:
setExpandedState in class AbstractLayoutCache
Parameters:
path - the path being expanded or collapsed
isExpanded - true if the path should be expanded, false otherwise

getExpandedState

public boolean getExpandedState(TreePath path)
Returns true if the path is expanded, and visible.

Specified by:
getExpandedState in class AbstractLayoutCache
Parameters:
path - the path being queried
Returns:
true if the path is expanded and visible, false otherwise

treeNodesChanged

public void treeNodesChanged(TreeModelEvent e)

Invoked after a node (or a set of siblings) has changed in some way. The node(s) have not changed locations in the tree or altered their children arrays, but other attributes have changed and may affect presentation. Example: the name of a file has changed, but it is in the same location in the file system.

e.path() returns the path the parent of the changed node(s).

e.childIndices() returns the index(es) of the changed node(s).

Specified by:
treeNodesChanged in class AbstractLayoutCache
Parameters:
e - the TreeModelEvent

treeNodesInserted

public void treeNodesInserted(TreeModelEvent e)

Invoked after nodes have been inserted into the tree.

e.path() returns the parent of the new nodes

e.childIndices() returns the indices of the new nodes in ascending order.

Specified by:
treeNodesInserted in class AbstractLayoutCache
Parameters:
e - the TreeModelEvent

treeNodesRemoved

public void treeNodesRemoved(TreeModelEvent e)

Invoked after nodes have been removed from the tree. Note that if a subtree is removed from the tree, this method may only be invoked once for the root of the removed subtree, not once for each individual set of siblings removed.

e.path() returns the former parent of the deleted nodes.

e.childIndices() returns the indices the nodes had before they were deleted in ascending order.

Specified by:
treeNodesRemoved in class AbstractLayoutCache
Parameters:
e - the TreeModelEvent

treeStructureChanged

public void treeStructureChanged(TreeModelEvent e)

Invoked after the tree has drastically changed structure from a given node down. If the path returned by e.getPath() is of length one and the first element does not identify the current root node the first element should become the new root of the tree.

e.path() holds the path to the node.

e.childIndices() returns null.

Specified by:
treeStructureChanged in class AbstractLayoutCache
Parameters:
e - the TreeModelEvent

Java™ Platform
Standard Ed. 6

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For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2006 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.