javax.swing.text
Class BoxView

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

Direct Known Subclasses:

BlockView, ParagraphView, TableView, TableView.TableCell, TableView.TableRow, WrappedPlainView

public class BoxView

extends CompositeView

A view of a text model that arranges its children into a box. It might be useful to represent something like a collection of lines, paragraphs, list items, chunks of text, etc. The box is somewhat like that found in TeX where there is alignment of the children, flexibility of the children is considered, etc.

Fields inherited from class javax.swing.text.View

BadBreakWeight, ExcellentBreakWeight, ForcedBreakWeight, GoodBreakWeight, X_AXIS, Y_AXIS

Constructor Summary

BoxView(Element elem, int axis)
Constructs a BoxView.

Method Summary

protected void	baselineLayout(int targetSpan, int axis, int[] offsets, int[] spans)
protected SizeRequirements	baselineRequirements(int axis, SizeRequirements r)
protected SizeRequirements	calculateMajorAxisRequirements(int axis, SizeRequirements r)
protected SizeRequirements	calculateMinorAxisRequirements(int axis, SizeRequirements r)
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 void	childAllocation(int index, Rectangle alloc) Allocates a region for a child view.
protected boolean	flipEastAndWestAtEnds(int position, Position.Bias bias)
float	getAlignment(int axis) Determines the desired alignment for this view along an axis.
int	getHeight() The current height of the box.
float	getMaximumSpan(int axis) Determines the maximum span for this view along an axis.
float	getMinimumSpan(int axis) Determines the minimum span for this view along an axis.
protected int	getOffset(int axis, int childIndex) Fetch the offset of a particular childs current layout
float	getPreferredSpan(int axis) Determines the preferred span for this view along an axis.
int	getResizeWeight(int axis) Gets the resize weight.
protected int	getSpan(int axis, int childIndex) Fetch the span of a particular childs current layout
protected View	getViewAtPoint(int x, int y, Rectangle alloc) Fetches the child view at the given point.
int	getWidth() The current width of the box.
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 boolean	isAfter(int x, int y, Rectangle innerAlloc) Determines if a point falls after an allocated region.
protected boolean	isAllocationValid() Are the allocations for the children still valid?
protected boolean	isBefore(int x, int y, Rectangle innerAlloc) Determines if a point falls before an allocated region.
protected void	layout(int width, int height) Performs layout of the children.
protected void	layoutMajorAxis(int targetSpan, int axis, int[] offsets, int[] spans) Perform layout for the major axis of the box (i.e.
protected void	layoutMinorAxis(int targetSpan, int axis, int[] offsets, int[] spans) Perform layout for the minor axis of the box (i.e.
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	paint(Graphics g, Shape allocation) Renders using the given rendering surface and area on that surface.
protected void	paintChild(Graphics g, Rectangle alloc, int index) Paints a child.
void	preferenceChanged(View child, boolean width, boolean height) This is called by a child to indicated its preferred span has changed.
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[] elems) Invalidates the layout and resizes the cache of requests/allocations.
void	setSize(float width, float height) Sets the size 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.CompositeView

append, getBottomInset, getChildAllocation, getInsideAllocation, getLeftInset, getNextEastWestVisualPositionFrom, getNextNorthSouthVisualPositionFrom, getNextVisualPositionFrom, getRightInset, getTopInset, getView, getViewAtPosition, getViewCount, getViewIndexAtPosition, insert, loadChildren, modelToView, removeAll, setInsets, setParagraphInsets, setParent

Methods inherited from class javax.swing.text.View

breakView, createFragment, getAttributes, getBreakWeight, getContainer, getDocument, getElement, getEndOffset, getParent, getStartOffset, getViewFactory, isVisible, modelToView, viewToModel

Methods inherited from class java.lang.Object

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

Constructor Detail

BoxView

public BoxView(Element elem,
               int axis)

Constructs a BoxView.

Parameters:

elem - the element this view is responsible for

axis - either View.X_AXIS or View.Y_AXIS

Method Detail

paintChild

protected void paintChild(Graphics g,
                          Rectangle alloc,
                          int index)

Paints a child. By default that is all it does, but a subclass can use this to paint things relative to the child.

Parameters:

g - the graphics context

alloc - the allocated region to paint into

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

replace

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

Invalidates the layout and resizes the cache of requests/allocations.

Parameters:

offset - the starting offset into the child views >= 0

length - the number of existing views to replace >= 0

elems - the child views to insert

Overrides:

replace in class CompositeView

preferenceChanged

public void preferenceChanged(View child,
                              boolean width,
                              boolean height)

This is called by a child to indicated its preferred span has changed. This is implemented to throw away cached layout information so that new calculations will be done the next time the children need an allocation.

Parameters:

child - the child view

width - true if the width preference should change

height - true if the height preference should change

Overrides:

preferenceChanged in class View

getResizeWeight

public int getResizeWeight(int axis)

Gets the resize weight. A value of 0 or less is not resizable.

Parameters:

axis - may be either View.X_AXIS or View.Y_AXIS

Returns:

the weight

Throws:

IllegalArgumentException - for an invalid axis

Overrides:

getResizeWeight in class View

setSize

public void setSize(float width,
                    float height)

Sets the size of the view. If the size has changed, layout is redone. The size is the full size of the view including the inset areas.

Parameters:

width - the width >= 0

height - the height >= 0

Overrides:

setSize in class View

paint

public void paint(Graphics g,
                  Shape allocation)

Renders using the given rendering surface and area on that surface.

Parameters:

g - the rendering surface to use

allocation - the allocated region to render into

Overrides:

paint in class View

See Also:

View.paint(java.awt.Graphics, java.awt.Shape)

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. This makes sure the allocation is valid before letting the superclass do its thing.

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

Overrides:

modelToView in class CompositeView

See Also:

View.modelToView(int, 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.

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

Overrides:

viewToModel in class CompositeView

See Also:

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

getAlignment

public float getAlignment(int axis)

Determines the desired alignment for this view along an axis. This is implemented to give the total alignment needed to position the children with the alignment points lined up along the axis orthoginal to the axis that is being tiled. The axis being tiled will request to be centered (i.e. 0.5f).

Parameters:

axis - may be either View.X_AXIS or View.Y_AXIS

Throws:

IllegalArgumentException - for an invalid axis

Overrides:

getAlignment in class View

getPreferredSpan

public float getPreferredSpan(int axis)

Determines the preferred span for this view along an axis.

Parameters:

axis - may be either View.X_AXIS or View.Y_AXIS

Throws:

IllegalArgumentException - for an invalid axis type

Overrides:

getPreferredSpan in class View

getMinimumSpan

public float getMinimumSpan(int axis)

Determines the minimum span for this view along an axis.

Parameters:

axis - may be either View.X_AXIS or View.Y_AXIS

Throws:

IllegalArgumentException - for an invalid axis type

Overrides:

getMinimumSpan in class View

getMaximumSpan

public float getMaximumSpan(int axis)

Determines the maximum span for this view along an axis.

Parameters:

axis - may be either View.X_AXIS or View.Y_AXIS

Throws:

IllegalArgumentException - for an invalid axis type

Overrides:

getMaximumSpan in class View

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.

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

Overrides:

insertUpdate in class View

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.

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

Overrides:

removeUpdate in class View

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.

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

Overrides:

changedUpdate in class View

See Also:

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

isAllocationValid

protected boolean isAllocationValid()

Are the allocations for the children still valid?

Returns:

true if allocations still valid

isBefore

protected boolean isBefore(int x,
                           int y,
                           Rectangle innerAlloc)

Determines if a point falls before an allocated region.

Parameters:

x - the X coordinate >= 0

y - the Y coordinate >= 0

innerAlloc - the allocated region. This is the area inside of the insets.

Returns:

true if the point lies before the region else false

Overrides:

isBefore in class CompositeView

isAfter

protected boolean isAfter(int x,
                          int y,
                          Rectangle innerAlloc)

Determines if a point falls after an allocated region.

Parameters:

x - the X coordinate >= 0

y - the Y coordinate >= 0

innerAlloc - the allocated region. This is the area inside of the insets.

Returns:

true if the point lies after the region else false

Overrides:

isAfter in class CompositeView

getViewAtPoint

protected 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 parents inner allocation on entry, which should be changed to the childs allocation on exit.

Returns:

the view

Overrides:

getViewAtPoint in class CompositeView

childAllocation

protected void childAllocation(int index,
                               Rectangle alloc)

Allocates a region for a child view.

Parameters:

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

alloc - the allocated region

Overrides:

childAllocation in class CompositeView

layout

protected void layout(int width,
                      int height)

Performs layout of the children. The size is the area inside of the insets. This method calls the methods layoutMajorAxis and layoutMinorAxis as needed. To change how layout is done those methods should be reimplemented.

Parameters:

width - the width >= 0

height - the height >= 0

getWidth

public final int getWidth()

The current width of the box. This is the width that it was last allocated.

getHeight

public final int getHeight()

The current height of the box. This is the height that it was last allocated.

layoutMajorAxis

protected void layoutMajorAxis(int targetSpan,
                               int axis,
                               int[] offsets,
                               int[] spans)

Perform layout for the major axis of the box (i.e. the axis that it represents). The results of the layout should be placed in the given arrays which represent the allocations to the children along the major axis.

Parameters:

targetSpan - the total span given to the view, which whould be used to layout the children.

axis - the axis being layed out.

offsets - the offsets from the origin of the view for each of the child views. This is a return value and is filled in by the implementation of this method.

spans - the span of each child view. This is a return value and is filled in by the implementation of this method.

layoutMinorAxis

protected void layoutMinorAxis(int targetSpan,
                               int axis,
                               int[] offsets,
                               int[] spans)

Perform layout for the minor axis of the box (i.e. the axis orthoginal to the axis that it represents). The results of the layout should be placed in the given arrays which represent the allocations to the children along the minor axis.

Parameters:

targetSpan - the total span given to the view, which whould be used to layout the children.

axis - the axis being layed out.

offsets - the offsets from the origin of the view for each of the child views. This is a return value and is filled in by the implementation of this method.

spans - the span of each child view. This is a return value and is filled in by the implementation of this method.

calculateMajorAxisRequirements

protected SizeRequirements calculateMajorAxisRequirements(int axis,
                                                          SizeRequirements r)

calculateMinorAxisRequirements

protected SizeRequirements calculateMinorAxisRequirements(int axis,
                                                          SizeRequirements r)

baselineLayout

protected void baselineLayout(int targetSpan,
                              int axis,
                              int[] offsets,
                              int[] spans)

baselineRequirements

protected SizeRequirements baselineRequirements(int axis,
                                                SizeRequirements r)

getOffset

protected final int getOffset(int axis,
                              int childIndex)

Fetch the offset of a particular childs current layout

getSpan

protected final int getSpan(int axis,
                            int childIndex)

Fetch the span of a particular childs current layout

flipEastAndWestAtEnds

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

Overrides:

flipEastAndWestAtEnds in class CompositeView