public class

ParagraphView

extends FlowView
implements TabExpander
java.lang.Object
   ↳ javax.swing.text.View
     ↳ javax.swing.text.CompositeView
       ↳ javax.swing.text.BoxView
         ↳ javax.swing.text.FlowView
           ↳ javax.swing.text.ParagraphView
Known Direct Subclasses

Class Overview

View of a simple line-wrapping paragraph that supports multiple fonts, colors, components, icons, etc. It is basically a vertical box with a margin around it. The contents of the box are a bunch of rows which are special horizontal boxes. This view creates a collection of views that represent the child elements of the paragraph element. Each of these views are placed into a row directly if they will fit, otherwise the breakView method is called to try and carve the view into pieces that fit.

See Also

Summary

[Expand]
Inherited Constants
From class javax.swing.text.View
From interface javax.swing.SwingConstants
Fields
protected int firstLineIndent Indentation for the first line, from the left inset.
[Expand]
Inherited Fields
From class javax.swing.text.FlowView
Public Constructors
ParagraphView(Element elem)
Constructs a ParagraphView for the given element.
Public Methods
View breakView(int axis, float len, Shape a)
Breaks this view on the given axis at the given length.
void changedUpdate(DocumentEvent changes, Shape a, ViewFactory f)
Gives notification from the document that attributes were changed in a location that this view is responsible for.
float getAlignment(int axis)
Determines the desired alignment for this view along an axis.
int getBreakWeight(int axis, float len)
Gets the break weight for a given location.
int getFlowSpan(int index)
Fetches the constraining span to flow against for the given child index.
int getFlowStart(int index)
Fetches the location along the flow axis that the flow span will start at.
float nextTabStop(float x, int tabOffset)
Returns the next tab stop position given a reference position.
void paint(Graphics g, Shape a)
Renders using the given rendering surface and area on that surface.
Protected Methods
void adjustRow(ParagraphView.Row r, int desiredSpan, int x)
Adjusts the given row if possible to fit within the layout span.
View createRow()
Create a View that should be used to hold a a row's worth of children in a flow.
int findOffsetToCharactersInString(char[] string, int start)
Finds the next character in the document with a character in string, starting at offset start.
boolean flipEastAndWestAtEnds(int position, Position.Bias bias)
Determines in which direction the next view lays.
int getClosestPositionTo(int pos, Position.Bias b, Shape a, int direction, Bias[] biasRet, int rowIndex, int x)
Returns the closest model position to x.
View getLayoutView(int index)
Returns the view at a given index.
int getLayoutViewCount()
Returns the number of views that this view is responsible for.
int getNextNorthSouthVisualPositionFrom(int pos, Position.Bias b, Shape a, int direction, Bias[] biasRet)
Returns the next visual position for the cursor, in either the east or west direction.
float getPartialSize(int startOffset, int endOffset)
Returns the size used by the views between startOffset and endOffset.
float getTabBase()
Returns where the tabs are calculated from.
TabSet getTabSet()
Gets the Tabset to be used in calculating tabs.
void setFirstLineIndent(float fi)
Sets the indent on the first line.
void setJustification(int j)
Sets the type of justification.
void setLineSpacing(float ls)
Sets the line spacing.
void setPropertiesFromAttributes()
Set the cached properties from the attributes.
[Expand]
Inherited Methods
From class javax.swing.text.FlowView
From class javax.swing.text.BoxView
From class javax.swing.text.CompositeView
From class javax.swing.text.View
From class java.lang.Object
From interface javax.swing.text.TabExpander

Fields

protected int firstLineIndent

Indentation for the first line, from the left inset.

Public Constructors

public ParagraphView (Element elem)

Constructs a ParagraphView for the given element.

Parameters
elem the element that this view is responsible for

Public Methods

public View breakView (int axis, float len, Shape a)

Breaks this view on the given axis at the given length.

ParagraphView instances are breakable along the Y_AXIS only, and only if len is after the first line.

Parameters
axis may be either View.X_AXIS or View.Y_AXIS
len specifies where a potential break is desired along the given axis >= 0
a the current allocation of the view
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
See Also

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

Gives notification from the document that attributes were changed in a location that this view is responsible for.

Parameters
changes 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

public float getAlignment (int axis)

Determines the desired alignment for this view along an axis. This is implemented to give the alignment to the center of the first row along the y axis, and the default along the x axis.

Parameters
axis may be either View.X_AXIS or View.Y_AXIS
Returns
  • the desired alignment. This should be a value between 0.0 and 1.0 inclusive, where 0 indicates alignment at the origin and 1.0 indicates alignment to the full span away from the origin. An alignment of 0.5 would be the center of the view.

public int getBreakWeight (int axis, float len)

Gets the break weight for a given location.

ParagraphView instances are breakable along the Y_AXIS only, and only if len is after the first row. If the length is less than one row, a value of BadBreakWeight is returned.

Parameters
axis may be either View.X_AXIS or View.Y_AXIS
len specifies where a potential break is desired >= 0
Returns
  • a value indicating the attractiveness of breaking here; either GoodBreakWeight or BadBreakWeight
See Also

public int getFlowSpan (int index)

Fetches the constraining span to flow against for the given child index.

Parameters
index the index of the view being queried
Returns
  • the constraining span for the given view at index

public int getFlowStart (int index)

Fetches the location along the flow axis that the flow span will start at.

Parameters
index the index of the view being queried
Returns
  • the location for the given view at index

public float nextTabStop (float x, int tabOffset)

Returns the next tab stop position given a reference position. This view implements the tab coordinate system, and calls getTabbedSpan on the logical children in the process of layout to determine the desired span of the children. The logical children can delegate their tab expansion upward to the paragraph which knows how to expand tabs. LabelView is an example of a view that delegates its tab expansion needs upward to the paragraph.

This is implemented to try and locate a TabSet in the paragraph element's attribute set. If one can be found, its settings will be used, otherwise a default expansion will be provided. The base location for for tab expansion is the left inset from the paragraphs most recent allocation (which is what the layout of the children is based upon).

Parameters
x the X reference position
tabOffset the position within the text stream that the tab occurred at >= 0
Returns
  • the trailing end of the tab expansion >= 0
See Also

public void paint (Graphics g, Shape a)

Renders using the given rendering surface and area on that surface. This is implemented to delgate to the superclass after stashing the base coordinate for tab calculations.

Parameters
g the rendering surface to use
a the allocated region to render into
See Also

Protected Methods

protected void adjustRow (ParagraphView.Row r, int desiredSpan, int x)

Adjusts the given row if possible to fit within the layout span. By default this will try to find the highest break weight possible nearest the end of the row. If a forced break is encountered, the break will be positioned there.

This is meant for internal usage, and should not be used directly.

Parameters
r the row to adjust to the current layout span
desiredSpan the current layout span >= 0
x the location r starts at

protected View createRow ()

Create a View that should be used to hold a a row's worth of children in a flow.

Returns
  • the new View

protected int findOffsetToCharactersInString (char[] string, int start)

Finds the next character in the document with a character in string, starting at offset start. If there are no characters found, -1 will be returned.

Parameters
string the string of characters
start where to start in the model >= 0
Returns
  • the document offset, or -1 if no characters found

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 will return true if the text is layed out right to left at position, otherwise false.

Parameters
position position into the model
bias either Position.Bias.Forward or Position.Bias.Backward
Returns
  • true if the text is layed out right to left at position, otherwise false.

protected int getClosestPositionTo (int pos, Position.Bias b, Shape a, int direction, Bias[] biasRet, int rowIndex, int x)

Returns the closest model position to x. rowIndex gives the index of the view that corresponds that should be looked in.

Parameters
pos position into the model
a the allocated region to render into
direction one of the following values:
  • SwingConstants.NORTH
  • SwingConstants.SOUTH
biasRet an array containing the bias that were checked in this method
rowIndex the index of the view
x the x coordinate of interest
Returns
  • the closest model position to x
Throws
BadLocationException

protected View getLayoutView (int index)

Returns the view at a given index. The child views of the paragraph are rows which have been used to arrange pieces of the Views that represent the child elements. This methods returns the view responsible for the child element index (prior to breaking). These are the Views that were produced from a factory (to represent the child elements) and used for layout.

Parameters
index the index of the desired view
Returns
  • the view at index

protected int getLayoutViewCount ()

Returns the number of views that this view is responsible for. The child views of the paragraph are rows which have been used to arrange pieces of the Views that represent the child elements. This is the number of views that have been tiled in two dimensions, and should be equivalent to the number of child elements to the element this view is responsible for.

Returns
  • the number of views that this ParagraphView is responsible for

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

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

Parameters
pos position into the model
b either Position.Bias.Forward or Position.Bias.Backward
a the allocated region to render into
direction either SwingConstants.NORTH or SwingConstants.SOUTH
biasRet an array containing the bias that were checked in this method
Returns
  • the location in the model that represents the next location visual position
Throws
BadLocationException

protected float getPartialSize (int startOffset, int endOffset)

Returns the size used by the views between startOffset and endOffset. This uses getPartialView to calculate the size if the child view implements the TabableView interface. If a size is needed and a View does not implement the TabableView interface, the preferredSpan will be used.

Parameters
startOffset the starting document offset >= 0
endOffset the ending document offset >= startOffset
Returns
  • the size >= 0

protected float getTabBase ()

Returns where the tabs are calculated from.

Returns
  • where tabs are calculated from

protected TabSet getTabSet ()

Gets the Tabset to be used in calculating tabs.

Returns
  • the TabSet

protected void setFirstLineIndent (float fi)

Sets the indent on the first line.

Parameters
fi the value in points

protected void setJustification (int j)

Sets the type of justification.

Parameters
j one of the following values:
  • StyleConstants.ALIGN_LEFT
  • StyleConstants.ALIGN_CENTER
  • StyleConstants.ALIGN_RIGHT

protected void setLineSpacing (float ls)

Sets the line spacing.

Parameters
ls the value is a factor of the line hight

protected void setPropertiesFromAttributes ()

Set the cached properties from the attributes.