javax.swing.text
Class CompositeView

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

Direct Known Subclasses:

BoxView

public abstract class CompositeView

extends View

A view that is composed of other views (has children). As a container of children, the composite view needs to provide:

services to manage the collection of children

The following methods can be used to manage the collection.

• removeAll
• insert
• append
• replace
• getViewCount
• getView
• loadChildren

layout of the children

This class does not implement a layout policy as it is abstract. A subclass will determine how the children are laid out by implementing the setSize method to position the children when the size has been changed.

paint the children

This class does not attempt to paint the children. Subclasses will want to use the layout information and call paint on the children that are visible (intersect the clipping region) with the Shape argument set to the location of the child view.

propagation of DocumentEvent information to the appropriate children.

propagation of model/view translation to the proper child.

Fields inherited from class javax.swing.text.View

BadBreakWeight, ExcellentBreakWeight, ForcedBreakWeight, GoodBreakWeight, X_AXIS, Y_AXIS

Constructor Summary

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

Method Summary

void	append(View v) Appends a single child view.
void	changedUpdate(DocumentEvent e, Shape a, ViewFactory f) Gives notification from the document that attributes were changed in a location that this view is responsible for.
protected abstract void	childAllocation(int index, Rectangle a) Returns the allocation for a given child.
protected boolean	flipEastAndWestAtEnds(int position, Position.Bias bias) Subclasses may wish to subclass this and conditionally return true based on the position.
protected short	getBottomInset() Gets the bottom inset.
Shape	getChildAllocation(int index, Shape a) Fetches the allocation for the given child view.
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 east or west 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) Gets the n-th view in this container.
protected abstract View	getViewAtPoint(int x, int y, Rectangle alloc) Fetches the child view at the given point.
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.
protected int	getViewIndexAtPosition(int pos) Fetches the child view index representing the given position in the model.
void	insert(int offs, View v) Inserts a single child view.
void	insertUpdate(DocumentEvent e, Shape a, ViewFactory f) Gives notification that something was inserted into the document in a location that this view is responsible for.
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	removeAll() Removes all of the children.
void	removeUpdate(DocumentEvent e, Shape a, ViewFactory f) Gives notification that something was removed from the document in a location that this view is responsible for.
void	replace(int offset, int length, View[] views) Replace 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

breakView, createFragment, getAlignment, getAttributes, getBreakWeight, getContainer, getDocument, getElement, getEndOffset, getMaximumSpan, getMinimumSpan, getParent, getPreferredSpan, getResizeWeight, getStartOffset, getViewFactory, isVisible, modelToView, paint, preferenceChanged, setSize, 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 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)

removeAll

public void removeAll()

Removes all of the children.

insert

public void insert(int offs,
                   View v)

Inserts a single child view. This is a convenience call to replace.

Parameters:

offs - the offset of the view to insert before >= 0

v - the view

See Also:

replace(int, int, javax.swing.text.View[])

append

public void append(View v)

Appends a single child view. This is a convenience call to replace.

Parameters:

v - the view

See Also:

replace(int, int, javax.swing.text.View[])

replace

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

Replace 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 can be garbage collected.

Parameters:

index - the starting index into the child views to insert the new views >= 0

length - the number of existing child views to remove >= 0

views - the child views to add

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)

Gets the n-th view in this container.

Overrides:

getView in class View

Parameters:

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

Returns:

the view

getChildAllocation

public Shape getChildAllocation(int index,
                                Shape a)

Fetches the allocation for the given child view. 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.

Overrides:

modelToView in class View

Parameters:

pos - the position to convert >= 0

a - the allocated region to render into

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.

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.

Overrides:

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

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.

Overrides:

getNextVisualPositionFrom in class View

Parameters:

pos - the position to convert >= 0

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 SwingConstants.WEST, SwingConstants.EAST, SwingConstants.NORTH, or SwingConstants.SOUTH.

Returns:

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

Throws:

BadLocationException -

IllegalArgumentException - for an invalid direction

insertUpdate

public void insertUpdate(DocumentEvent e,
                         Shape a,
                         ViewFactory f)

Gives notification that something was inserted into the document in a location that this view is responsible for. To reduce the burden to subclasses, this functionality is spread out into the following calls that subclasses can reimplement:

1. updateChildren is called if there were any changes to the element this view is responsible for. If this view has child views that are represent the child elements, then this method should do whatever is necessary to make sure the child views correctly represent the model.
2. forwardUpdate is called to forward the DocumentEvent to the appropriate child views.
3. updateLayout is called to give the view a chance to either repair it's layout, to reschedule layout, or do nothing.

Overrides:

insertUpdate in class View

Parameters:

e - the change information from the associated document

a - the current allocation of the view

f - the factory to use to rebuild if the view has children

See Also:

View.insertUpdate(javax.swing.event.DocumentEvent, java.awt.Shape, javax.swing.text.ViewFactory)

removeUpdate

public void removeUpdate(DocumentEvent e,
                         Shape a,
                         ViewFactory f)

Gives notification that something was removed from the document in a location that this view is responsible for. To reduce the burden to subclasses, this functionality is spread out into the following calls that subclasses can reimplement:

1. updateChildren is called if there were any changes to the element this view is responsible for. If this view has child views that are represent the child elements, then this method should do whatever is necessary to make sure the child views correctly represent the model.
2. forwardUpdate is called to forward the DocumentEvent to the appropriate child views.
3. updateLayout is called to give the view a chance to either repair it's layout, to reschedule layout, or do nothing.

Overrides:

removeUpdate in class View

Parameters:

e - the change information from the associated document

a - the current allocation of the view

f - the factory to use to rebuild if the view has children

See Also:

View.removeUpdate(javax.swing.event.DocumentEvent, java.awt.Shape, javax.swing.text.ViewFactory)

changedUpdate

public void changedUpdate(DocumentEvent e,
                          Shape a,
                          ViewFactory f)

Gives notification from the document that attributes were changed in a location that this view is responsible for. To reduce the burden to subclasses, this functionality is spread out into the following calls that subclasses can reimplement:

1. updateChildren is called if there were any changes to the element this view is responsible for. If this view has child views that are represent the child elements, then this method should do whatever is necessary to make sure the child views correctly represent the model.
2. forwardUpdate is called to forward the DocumentEvent to the appropriate child views.
3. updateLayout is called to give the view a chance to either repair it's layout, to reschedule layout, or do nothing.

Overrides:

changedUpdate in class View

Parameters:

e - the change information from the associated document

a - the current allocation of the view

f - the factory to use to rebuild if the view has children

See Also:

View.changedUpdate(javax.swing.event.DocumentEvent, java.awt.Shape, javax.swing.text.ViewFactory)

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 point.

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

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

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.

setParagraphInsets

protected final void setParagraphInsets(AttributeSet attr)

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

Parameters:

attr - the attributes

setInsets

protected final 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 final short getLeftInset()

Gets the left inset.

Returns:

the inset >= 0

getRightInset

protected final short getRightInset()

Gets the right inset.

Returns:

the inset >= 0

getTopInset

protected final short getTopInset()

Gets the top inset.

Returns:

the inset >= 0

getBottomInset

protected final 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 east or west direction.

Returns:

next position west of the passed in position.

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.

Returns:

next position west of the passed in position.

flipEastAndWestAtEnds

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

Subclasses may wish to subclass this and conditionally return true based on the position. A return value of true indicates that when a View returns -1 from getNextVisualPositionFrom the next view for east should be the current index offset by -1, and for west it means offset by 1. The normal direction (for left to right text) is to offset east by 1 and west by -1.

Returns:

false