javax.swing.text
Class CompositeView

java.lang.Object
  |
  +--javax.swing.text.View
        |
        +--javax.swing.text.CompositeView

All Implemented Interfaces:

SwingConstants

Direct Known Subclasses:

BoxView

public abstract class CompositeView

extends View

CompositeView is an abstract View implementation which manages one or more child views. (Note that CompositeView is intended for managing relatively small numbers of child views.) CompositeView is intended to be used as a starting point for View implementations, such as BoxView, that will contain child Views. Subclasses that wish to manage the collection of child Views should use the replace(int, int, javax.swing.text.View[]) method. As View invokes replace during DocumentListener notification, you normally won't need to directly invoke replace.

While CompositeView does not impose a layout policy on its child Views, it does allow for inseting the child Views it will contain. The insets can be set by either setInsets(short, short, short, short) or setParagraphInsets(javax.swing.text.AttributeSet).

In addition to the abstract methods of View, subclasses of CompositeView will need to override:

• isBefore(int, int, java.awt.Rectangle) - Used to test if a given View location is before the visual space of the CompositeView.
• isAfter(int, int, java.awt.Rectangle) - Used to test if a given View location is after the visual space of the CompositeView.
• getViewAtPoint(int, int, java.awt.Rectangle) - Returns the view at a given visual location.
• childAllocation(int, java.awt.Rectangle) - Returns the bounds of a particular child View. getChildAllocation will invoke childAllocation after offseting the bounds by the Insets of the CompositeView.

Field Summary

Fields inherited from class javax.swing.text.View

BadBreakWeight, ExcellentBreakWeight, ForcedBreakWeight, GoodBreakWeight, X_AXIS, Y_AXIS

Fields inherited from interface javax.swing.SwingConstants

BOTTOM, CENTER, EAST, HORIZONTAL, LEADING, LEFT, NEXT, NORTH, NORTH_EAST, NORTH_WEST, PREVIOUS, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TOP, TRAILING, VERTICAL, WEST

Constructor Summary

CompositeView(Element elem)
Constructs a CompositeView for the given element.

Method Summary

protected abstract void	childAllocation(int index, Rectangle a) Returns the allocation for a given child.
protected boolean	flipEastAndWestAtEnds(int position, Position.Bias bias) Determines in which direction the next view lays.
protected short	getBottomInset() Gets the bottom inset.
Shape	getChildAllocation(int index, Shape a) Fetches the allocation for the given child view to render into.
protected Rectangle	getInsideAllocation(Shape a) Translates the immutable allocation given to the view to a mutable allocation that represents the interior allocation (i.e.
protected short	getLeftInset() Gets the left inset.
protected int	getNextEastWestVisualPositionFrom(int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet) Returns the next visual position for the cursor, in either the east or west direction.
protected int	getNextNorthSouthVisualPositionFrom(int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet) Returns the next visual position for the cursor, in either the north or south direction.
int	getNextVisualPositionFrom(int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet) Provides a way to determine the next visually represented model location that one might place a caret.
protected short	getRightInset() Gets the right inset.
protected short	getTopInset() Gets the top inset.
View	getView(int n) Returns the n-th view in this container.
protected abstract View	getViewAtPoint(int x, int y, Rectangle alloc) Fetches the child view at the given coordinates.
protected View	getViewAtPosition(int pos, Rectangle a) Fetches the child view that represents the given position in the model.
int	getViewCount() Returns the number of child views of this view.
int	getViewIndex(int pos, Position.Bias b) Returns the child view index representing the given position in the model.
protected int	getViewIndexAtPosition(int pos) Fetches the child view index representing the given position in the model.
protected abstract boolean	isAfter(int x, int y, Rectangle alloc) Tests whether a point lies after the rectangle range.
protected abstract boolean	isBefore(int x, int y, Rectangle alloc) Tests whether a point lies before the rectangle range.
protected void	loadChildren(ViewFactory f) Loads all of the children to initialize the view.
Shape	modelToView(int p0, Position.Bias b0, int p1, Position.Bias b1, Shape a) Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.
Shape	modelToView(int pos, Shape a, Position.Bias b) Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.
void	replace(int offset, int length, View[] views) Replaces child views.
protected void	setInsets(short top, short left, short bottom, short right) Sets the insets for the view.
protected void	setParagraphInsets(AttributeSet attr) Sets the insets from the paragraph attributes specified in the given attributes.
void	setParent(View parent) Sets the parent of the view.
int	viewToModel(float x, float y, Shape a, Position.Bias[] bias) Provides a mapping from the view coordinate space to the logical coordinate space of the model.

Methods inherited from class javax.swing.text.View

append, breakView, changedUpdate, createFragment, forwardUpdate, forwardUpdateToView, getAlignment, getAttributes, getBreakWeight, getContainer, getDocument, getElement, getEndOffset, getGraphics, getMaximumSpan, getMinimumSpan, getParent, getPreferredSpan, getResizeWeight, getStartOffset, getToolTipText, getViewFactory, getViewIndex, insert, insertUpdate, isVisible, modelToView, paint, preferenceChanged, remove, removeAll, removeUpdate, setSize, updateChildren, updateLayout, viewToModel

Methods inherited from class java.lang.Object

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

Constructor Detail

CompositeView

public CompositeView(Element elem)

Constructs a CompositeView for the given element.

Parameters:

elem - the element this view is responsible for

Method Detail

loadChildren

protected void loadChildren(ViewFactory f)

Loads all of the children to initialize the view. This is called by the setParent(javax.swing.text.View) method. Subclasses can reimplement this to initialize their child views in a different manner. The default implementation creates a child view for each child element.

Parameters:

f - the view factory

See Also:

setParent(javax.swing.text.View)

setParent

public void setParent(View parent)

Sets the parent of the view. This is reimplemented to provide the superclass behavior as well as calling the loadChildren method if this view does not already have children. The children should not be loaded in the constructor because the act of setting the parent may cause them to try to search up the hierarchy (to get the hosting Container for example). If this view has children (the view is being moved from one place in the view hierarchy to another), the loadChildren method will not be called.

Overrides:

setParent in class View

Parameters:

parent - the parent of the view, null if none

getViewCount

public int getViewCount()

Returns the number of child views of this view.

Overrides:

getViewCount in class View

Returns:

the number of views >= 0

See Also:

getView(int)

getView

public View getView(int n)

Returns the n-th view in this container.

Overrides:

getView in class View

Parameters:

n - the number of the desired view, >= 0 && < getViewCount()

Returns:

the view at index n

replace

public void replace(int offset,
                    int length,
                    View[] views)

Replaces child views. If there are no views to remove this acts as an insert. If there are no views to add this acts as a remove. Views being removed will have the parent set to null, and the internal reference to them removed so that they may be garbage collected.

Overrides:

replace in class View

Parameters:

length - the number of existing child views to remove; this should be a value >= 0 and <= (getViewCount() - offset)

views - the child views to add; this value can be null to indicate no children are being added (useful to remove)

getChildAllocation

public Shape getChildAllocation(int index,
                                Shape a)

Fetches the allocation for the given child view to render into. This enables finding out where various views are located.

Overrides:

getChildAllocation in class View

Parameters:

index - the index of the child, >= 0 && < getViewCount()

a - the allocation to this view

Returns:

the allocation to the child

modelToView

public Shape modelToView(int pos,
                         Shape a,
                         Position.Bias b)
                  throws BadLocationException

Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.

Specified by:

modelToView in class View

Parameters:

pos - the position to convert >= 0

a - the allocated region to render into

b - a bias value of either Position.Bias.Forward or Position.Bias.Backward

Returns:

the bounding box of the given position

Throws:

BadLocationException - if the given position does not represent a valid location in the associated document

See Also:

View.modelToView(int, java.awt.Shape, javax.swing.text.Position.Bias)

modelToView

public Shape modelToView(int p0,
                         Position.Bias b0,
                         int p1,
                         Position.Bias b1,
                         Shape a)
                  throws BadLocationException

Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.

Overrides:

modelToView in class View

Parameters:

p0 - the position to convert >= 0

b0 - the bias toward the previous character or the next character represented by p0, in case the position is a boundary of two views; either Position.Bias.Forward or Position.Bias.Backward

p1 - the position to convert >= 0

b1 - the bias toward the previous character or the next character represented by p1, in case the position is a boundary of two views

a - the allocated region to render into

Returns:

the bounding box of the given position is returned

Throws:

BadLocationException - if the given position does not represent a valid location in the associated document

IllegalArgumentException - for an invalid bias argument

See Also:

View.viewToModel(float, float, java.awt.Shape, javax.swing.text.Position.Bias[])

viewToModel

public int viewToModel(float x,
                       float y,
                       Shape a,
                       Position.Bias[] bias)

Provides a mapping from the view coordinate space to the logical coordinate space of the model.

Specified by:

viewToModel in class View

Parameters:

x - x coordinate of the view location to convert >= 0

y - y coordinate of the view location to convert >= 0

a - the allocated region to render into

bias - either Position.Bias.Forward or Position.Bias.Backward

Returns:

the location within the model that best represents the given point in the view >= 0

See Also:

View.viewToModel(float, float, java.awt.Shape, javax.swing.text.Position.Bias[])

getNextVisualPositionFrom

public int getNextVisualPositionFrom(int pos,
                                     Position.Bias b,
                                     Shape a,
                                     int direction,
                                     Position.Bias[] biasRet)
                              throws BadLocationException

Provides a way to determine the next visually represented model location that one might place a caret. Some views may not be visible, they might not be in the same order found in the model, or they just might not allow access to some of the locations in the model. This is a convenience method for getNextNorthSouthVisualPositionFrom(int, javax.swing.text.Position.Bias, java.awt.Shape, int, javax.swing.text.Position.Bias[]) and getNextEastWestVisualPositionFrom(int, javax.swing.text.Position.Bias, java.awt.Shape, int, javax.swing.text.Position.Bias[]).

Overrides:

getNextVisualPositionFrom in class View

Parameters:

pos - the position to convert >= 0

b - a bias value of either Position.Bias.Forward or Position.Bias.Backward

a - the allocated region to render into

direction - the direction from the current position that can be thought of as the arrow keys typically found on a keyboard; this may be one of the following:

• SwingConstants.WEST
• SwingConstants.EAST
• SwingConstants.NORTH
• SwingConstants.SOUTH

biasRet - an array containing the bias that was checked

Returns:

the location within the model that best represents the next location visual position

Throws:

BadLocationException

IllegalArgumentException - if direction is invalid

getViewIndex

public int getViewIndex(int pos,
                        Position.Bias b)

Returns the child view index representing the given position in the model. This is implemented to call the getViewIndexByPosition method for backward compatibility.

Overrides:

getViewIndex in class View

Parameters:

pos - the position >= 0

Returns:

index of the view representing the given position, or -1 if no view represents that position

isBefore

protected abstract boolean isBefore(int x,
                                    int y,
                                    Rectangle alloc)

Tests whether a point lies before the rectangle range.

Parameters:

x - the X coordinate >= 0

y - the Y coordinate >= 0

alloc - the rectangle

Returns:

true if the point is before the specified range

isAfter

protected abstract boolean isAfter(int x,
                                   int y,
                                   Rectangle alloc)

Tests whether a point lies after the rectangle range.

Parameters:

x - the X coordinate >= 0

y - the Y coordinate >= 0

alloc - the rectangle

Returns:

true if the point is after the specified range

getViewAtPoint

protected abstract View getViewAtPoint(int x,
                                       int y,
                                       Rectangle alloc)

Fetches the child view at the given coordinates.

Parameters:

x - the X coordinate >= 0

y - the Y coordinate >= 0

alloc - the parent's allocation on entry, which should be changed to the child's allocation on exit

Returns:

the child view

childAllocation

protected abstract void childAllocation(int index,
                                        Rectangle a)

Returns the allocation for a given child.

Parameters:

index - the index of the child, >= 0 && < getViewCount()

a - the allocation to the interior of the box on entry, and the allocation of the child view at the index on exit.

getViewAtPosition

protected View getViewAtPosition(int pos,
                                 Rectangle a)

Fetches the child view that represents the given position in the model. This is implemented to fetch the view in the case where there is a child view for each child element.

Parameters:

pos - the position >= 0

a - the allocation to the interior of the box on entry, and the allocation of the view containing the position on exit

Returns:

the view representing the given position, or null if there isn't one

getViewIndexAtPosition

protected int getViewIndexAtPosition(int pos)

Fetches the child view index representing the given position in the model. This is implemented to fetch the view in the case where there is a child view for each child element.

Parameters:

pos - the position >= 0

Returns:

index of the view representing the given position, or -1 if no view represents that position

getInsideAllocation

protected Rectangle getInsideAllocation(Shape a)

Translates the immutable allocation given to the view to a mutable allocation that represents the interior allocation (i.e. the bounds of the given allocation with the top, left, bottom, and right insets removed. It is expected that the returned value would be further mutated to represent an allocation to a child view. This is implemented to reuse an instance variable so it avoids creating excessive Rectangles. Typically the result of calling this method would be fed to the childAllocation method.

Parameters:

a - the allocation given to the view

Returns:

the allocation that represents the inside of the view after the margins have all been removed; if the given allocation was null, the return value is null

setParagraphInsets

protected void setParagraphInsets(AttributeSet attr)

Sets the insets from the paragraph attributes specified in the given attributes.

Parameters:

attr - the attributes

setInsets

protected void setInsets(short top,
                         short left,
                         short bottom,
                         short right)

Sets the insets for the view.

Parameters:

top - the top inset >= 0

left - the left inset >= 0

bottom - the bottom inset >= 0

right - the right inset >= 0

getLeftInset

protected short getLeftInset()

Gets the left inset.

Returns:

the inset >= 0

getRightInset

protected short getRightInset()

Gets the right inset.

Returns:

the inset >= 0

getTopInset

protected short getTopInset()

Gets the top inset.

Returns:

the inset >= 0

getBottomInset

protected short getBottomInset()

Gets the bottom inset.

Returns:

the inset >= 0

getNextNorthSouthVisualPositionFrom

protected int getNextNorthSouthVisualPositionFrom(int pos,
                                                  Position.Bias b,
                                                  Shape a,
                                                  int direction,
                                                  Position.Bias[] biasRet)
                                           throws BadLocationException

Returns the next visual position for the cursor, in either the north or south direction.

Parameters:

pos - the position to convert >= 0

b - a bias value of either Position.Bias.Forward or Position.Bias.Backward

a - the allocated region to render into

direction - the direction from the current position that can be thought of as the arrow keys typically found on a keyboard; this may be one of the following:

• SwingConstants.NORTH
• SwingConstants.SOUTH

biasRet - an array containing the bias that was checked

Returns:

the location within the model that best represents the next north or south location

Throws:

BadLocationException

IllegalArgumentException - if direction is invalid

See Also:

getNextVisualPositionFrom(int, javax.swing.text.Position.Bias, java.awt.Shape, int, javax.swing.text.Position.Bias[])

getNextEastWestVisualPositionFrom

protected int getNextEastWestVisualPositionFrom(int pos,
                                                Position.Bias b,
                                                Shape a,
                                                int direction,
                                                Position.Bias[] biasRet)
                                         throws BadLocationException

Returns the next visual position for the cursor, in either the east or west direction.

Parameters:

pos - the position to convert >= 0

b - a bias value of either Position.Bias.Forward or Position.Bias.Backward

a - the allocated region to render into

direction - the direction from the current position that can be thought of as the arrow keys typically found on a keyboard; this may be one of the following:

• SwingConstants.WEST
• SwingConstants.EAST

biasRet - an array containing the bias that was checked

Returns:

the location within the model that best represents the next west or east location

Throws:

BadLocationException

IllegalArgumentException - if direction is invalid

See Also:

getNextVisualPositionFrom(int, javax.swing.text.Position.Bias, java.awt.Shape, int, javax.swing.text.Position.Bias[])

flipEastAndWestAtEnds

protected boolean flipEastAndWestAtEnds(int position,
                                        Position.Bias bias)

Determines in which direction the next view lays. Consider the View at index n. Typically the Views are layed out from left to right, so that the View to the EAST will be at index n + 1, and the View to the WEST will be at index n - 1. In certain situations, such as with bidirectional text, it is possible that the View to EAST is not at index n + 1, but rather at index n - 1, or that the View to the WEST is not at index n - 1, but index n + 1. In this case this method would return true, indicating the Views are layed out in descending order.

This unconditionally returns false, subclasses should override this method if there is the possibility for laying Views in descending order.

Parameters:

position - position into the model

bias - either Position.Bias.Forward or Position.Bias.Backward

Returns:

false