Overview | Package | Class | Tree | Deprecated | Index | Help			Java Platform 1.1.7
PREV CLASS | NEXT CLASS	FRAMES | NO FRAMES
SUMMARY: INNER | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

Class com.sun.java.swing.text.LabelView

java.lang.Object
  |
  +--com.sun.java.swing.text.View
        |
        +--com.sun.java.swing.text.LabelView

public class LabelView

extends View

implements TabableView

A LabelView is a styled chunk of text that represents a view mapped over an element in the text model. The view supports breaking for the purpose of formatting. The fragments produced by breaking share the view that has primary responsibility for the element (i.e. they are nested classes and carry only a small amount of state of their own) so they can share its resources.

This view is generally responsible for displaying character level attributes in some way. Since this view represents text that may have tabs embedded in it, it implements the TabableView interface. Tabs will only be expanded if this view is embedded in a container that does tab expansion. ParagraphView is an example of a container that does tab expansion.

Fields inherited from class com.sun.java.swing.text.View

BadBreakWeight, ExcellentBreakWeight, ForcedBreakWeight, GoodBreakWeight, X_AXIS, Y_AXIS

Constructor Summary

LabelView(Element elem)
Constructs a new view wrapped on an element.

Method Summary

View	breakView(int axis, int p0, float pos, float len) Breaks this view on the given axis at the given length.
void	changedUpdate(DocumentEvent e, java.awt.Shape a, ViewFactory f) Gives notification from the document that attributes were changed in a location that this view is responsible for.
View	createFragment(int p0, int p1) Creates a view that represents a portion of the element.
float	getAlignment(int axis) Determines the desired alignment for this view along an axis.
int	getBreakWeight(int axis, float pos, float len) Determines how attractive a break opportunity in this view is.
float	getPartialSpan(int p0, int p1) Determines the span along the same axis as tab expansion for a portion of the view.
float	getPreferredSpan(int axis) Determines the preferred span for this view along an axis.
float	getTabbedSpan(float x, TabExpander e) Determines the desired span when using the given tab expansion implementation.
java.awt.Shape	modelToView(int pos, java.awt.Shape a) Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.
void	paint(java.awt.Graphics g, java.awt.Shape a) Renders a portion of a text style run.
int	viewToModel(float x, float y, java.awt.Shape a) Provides a mapping from the view coordinate space to the logical coordinate space of the model.

Methods inherited from class com.sun.java.swing.text.View

breakView, changedUpdate, createFragment, getAlignment, getBreakWeight, getChildAllocation, getContainer, getDocument, getElement, getEndOffset, getParent, getPreferredSpan, getResizeWeight, getStartOffset, getViewCount, getViewFactory, getView, insertUpdate, modelToView, paint, preferenceChanged, removeUpdate, setParent, setSize, viewToModel

Methods inherited from class java.lang.Object

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

Constructor Detail

LabelView

public LabelView(Element elem)

Constructs a new view wrapped on an element.

Parameters:

elem - the element

Method Detail

getTabbedSpan

public float getTabbedSpan(float x,
                           TabExpander e)

Determines the desired span when using the given tab expansion implementation.

Specified by:

getTabbedSpan in interface TabableView

Parameters:

x - the position the view would be located at for the purpose of tab expansion >= 0.

e - how to expand the tabs when encountered.

Returns:

the desired span >= 0

See Also:

getTabbedSpan

getPartialSpan

public float getPartialSpan(int p0,
                            int p1)

Determines the span along the same axis as tab expansion for a portion of the view. This is intended for use by the TabExpander for cases where the tab expansion involves aligning the portion of text that doesn't have whitespace relative to the tab stop. There is therefore an assumption that the range given does not contain tabs.

This method can be called while servicing the getTabbedSpan or getPreferredSize. It has to arrange for its own text buffer to make the measurements.

Specified by:

getPartialSpan in interface TabableView

Parameters:

p0 - the starting document offset >= 0

p1 - the ending document offset >= p0

Returns:

the span >= 0

paint

public void paint(java.awt.Graphics g,
                  java.awt.Shape a)

Renders a portion of a text style run.

Parameters:

g - the rendering surface to use

a - the allocated region to render into

Overrides:

paint 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

Overrides:

getPreferredSpan in class View

getAlignment

public float getAlignment(int axis)

Determines the desired alignment for this view along an axis. For the label, the alignment is along the font baseline for the y axis, and the superclasses alignment along the x axis.

Parameters:

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

Overrides:

getAlignment in class View

modelToView

public java.awt.Shape modelToView(int pos,
                         java.awt.Shape a)
                          throws BadLocationException

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

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 View

See Also:

modelToView

viewToModel

public int viewToModel(float x,
                       float y,
                       java.awt.Shape a)

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

Parameters:

x - the X coordinate >= 0

y - the Y coordinate >= 0

a - the allocated region to render into

Returns:

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

Overrides:

viewToModel in class View

See Also:

viewToModel

changedUpdate

public void changedUpdate(DocumentEvent e,
                          java.awt.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:

changedUpdate

getBreakWeight

public int getBreakWeight(int axis,
                          float pos,
                          float len)

Determines how attractive a break opportunity in this view is. This can be used for determining which view is the most attractive to call breakView on in the process of formatting. The higher the weight, the more attractive the break. A value equal to or lower than View.BadBreakWeight should not be considered for a break. A value greater than or equal to View.ForcedBreakWeight should be broken.

This is implemented to forward to the superclass for the Y_AXIS. Along the X_AXIS the following values may be returned.

View.ExcellentBreakWeight

if there is whitespace proceeding the desired break location.

View.BadBreakWeight

if the desired break location results in a break location of the starting offset.

View.GoodBreakWeight

if the other conditions don't occur.

This will normally result in the behavior of breaking on a whitespace location if one can be found, otherwise breaking between characters.

Parameters:

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

pos - the potential location of the start of the broken view >= 0. This may be useful for calculating tab positions.

len - specifies the relative length from pos where a potential break is desired >= 0.

Returns:

the weight, which should be a value between View.ForcedBreakWeight and View.BadBreakWeight.

Overrides:

getBreakWeight in class View

See Also:

LabelView, ParagraphView, BadBreakWeight, GoodBreakWeight, ExcellentBreakWeight, ForcedBreakWeight

breakView

public View breakView(int axis,
                      int p0,
                      float pos,
                      float len)

Breaks this view on the given axis at the given length. This is implemented to attempt to break on a whitespace location, and returns a fragment with the whitespace at the end. If a whitespace location can't be found, the nearest character is used.

Parameters:

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

p0 - the location in the model where the fragment should start it's representation >= 0.

pos - the position along the axis that the broken view would occupy >= 0. This may be useful for things like tab calculations.

len - specifies the distance along the axis where a potential break is desired >= 0.

Returns:

the fragment of the view that represents the given span, if the view can be broken. If the view doesn't support breaking behavior, the view itself is returned.

Overrides:

breakView in class View

See Also:

breakView

createFragment

public View createFragment(int p0,
                           int p1)

Creates a view that represents a portion of the element. This is potentially useful during formatting operations for taking measurements of fragments of the view. If the view doesn't support fragmenting (the default), it should return itself.

This view does support fragmenting. It is implemented to return a nested class that shares state in this view representing only a portion of the view.

Parameters:

p0 - the starting offset >= 0. This should be a value greater or equal to the element starting offset and less than the element ending offset.

p1 - the ending offset > p0. This should be a value less than or equal to the elements end offset and greater than the elements starting offset.

Overrides:

createFragment in class View

See Also:

LabelView