ParagraphView (Java 2 Platform SE 5.0) (original) (raw)

javax.swing.text

Class ParagraphView

java.lang.Object javax.swing.text.View javax.swing.text.CompositeView javax.swing.text.BoxView javax.swing.text.FlowView javax.swing.text.ParagraphView

All Implemented Interfaces:

SwingConstants, TabExpander

Direct Known Subclasses:

ParagraphView

public class ParagraphView

extends FlowView

implements TabExpander

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:

View

firstLineIndent

protected int firstLineIndent

Indentation for the first line, from the left inset.

ParagraphView

public ParagraphView(Element elem)

Constructs a ParagraphView for the given element.

Parameters:

elem - the element that this view is responsible for

setJustification

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

setLineSpacing

protected void setLineSpacing(float ls)

Sets the line spacing.

Parameters:

ls - the value is a factor of the line hight

setFirstLineIndent

protected void setFirstLineIndent(float fi)

Sets the indent on the first line.

Parameters:

fi - the value in points

setPropertiesFromAttributes

protected void setPropertiesFromAttributes()

Set the cached properties from the attributes.

getLayoutViewCount

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

getLayoutView

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

adjustRow

protected void adjustRow(javax.swing.text.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

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. Overridden from CompositeView.

Overrides:

[getNextNorthSouthVisualPositionFrom](../../../javax/swing/text/CompositeView.html#getNextNorthSouthVisualPositionFrom%28int, javax.swing.text.Position.Bias, java.awt.Shape, int, javax.swing.text.Position.Bias[]%29) in class [CompositeView](../../../javax/swing/text/CompositeView.html "class in javax.swing.text")

Parameters:

pos - position into the model

b - either Position.Bias.Forward orPosition.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](../../../javax/swing/text/BadLocationException.html "class in javax.swing.text")

See Also:

[CompositeView.getNextVisualPositionFrom(int, javax.swing.text.Position.Bias, java.awt.Shape, int, javax.swing.text.Position.Bias[])](../../../javax/swing/text/CompositeView.html#getNextVisualPositionFrom%28int, javax.swing.text.Position.Bias, java.awt.Shape, int, javax.swing.text.Position.Bias[]%29)

getClosestPositionTo

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

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](../../../javax/swing/text/BadLocationException.html "class in javax.swing.text")

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 theView 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.

Overrides:

[flipEastAndWestAtEnds](../../../javax/swing/text/BoxView.html#flipEastAndWestAtEnds%28int, javax.swing.text.Position.Bias%29) in class [BoxView](../../../javax/swing/text/BoxView.html "class in javax.swing.text")

Parameters:

position - position into the model

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

Returns:

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

getFlowSpan

public int getFlowSpan(int index)

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

Overrides:

[getFlowSpan](../../../javax/swing/text/FlowView.html#getFlowSpan%28int%29) in class [FlowView](../../../javax/swing/text/FlowView.html "class in javax.swing.text")

Parameters:

index - the index of the view being queried

Returns:

the constraining span for the given view atindex

See Also:

FlowView.getFlowStart(int)

getFlowStart

public int getFlowStart(int index)

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

Overrides:

[getFlowStart](../../../javax/swing/text/FlowView.html#getFlowStart%28int%29) in class [FlowView](../../../javax/swing/text/FlowView.html "class in javax.swing.text")

Parameters:

index - the index of the view being queried

Returns:

the location for the given view atindex

See Also:

FlowView.getFlowSpan(int)

createRow

protected View createRow()

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

Specified by:

[createRow](../../../javax/swing/text/FlowView.html#createRow%28%29) in class [FlowView](../../../javax/swing/text/FlowView.html "class in javax.swing.text")

Returns:

the new View

nextTabStop

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 callsgetTabbedSpan 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).

Specified by:

[nextTabStop](../../../javax/swing/text/TabExpander.html#nextTabStop%28float, int%29) in interface [TabExpander](../../../javax/swing/text/TabExpander.html "interface in javax.swing.text")

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:

TabSet, TabStop, LabelView

getTabSet

protected TabSet getTabSet()

Gets the Tabset to be used in calculating tabs.

Returns:

the TabSet

getPartialSize

protected float getPartialSize(int startOffset, int endOffset)

Returns the size used by the views betweenstartOffset 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

findOffsetToCharactersInString

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

Finds the next character in the document with a character instring, 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

getTabBase

protected float getTabBase()

Returns where the tabs are calculated from.

Returns:

where tabs are calculated from

paint

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.

Overrides:

[paint](../../../javax/swing/text/BoxView.html#paint%28java.awt.Graphics, java.awt.Shape%29) in class [BoxView](../../../javax/swing/text/BoxView.html "class in javax.swing.text")

Parameters:

g - the rendering surface to use

a - the allocated region to render into

See Also:

[View.paint(java.awt.Graphics, java.awt.Shape)](../../../javax/swing/text/View.html#paint%28java.awt.Graphics, java.awt.Shape%29)

getAlignment

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.

Overrides:

[getAlignment](../../../javax/swing/text/BoxView.html#getAlignment%28int%29) in class [BoxView](../../../javax/swing/text/BoxView.html "class in javax.swing.text")

Parameters:

axis - may be either View.X_AXIS orView.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.

breakView

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 iflen 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:

[View.breakView(int, int, float, float)](../../../javax/swing/text/View.html#breakView%28int, int, float, float%29)

getBreakWeight

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:

[View.getBreakWeight(int, float, float)](../../../javax/swing/text/View.html#getBreakWeight%28int, float, float%29)

changedUpdate

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.

Overrides:

[changedUpdate](../../../javax/swing/text/FlowView.html#changedUpdate%28javax.swing.event.DocumentEvent, java.awt.Shape, javax.swing.text.ViewFactory%29) in class [FlowView](../../../javax/swing/text/FlowView.html "class in javax.swing.text")

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:

[View.changedUpdate(javax.swing.event.DocumentEvent, java.awt.Shape, javax.swing.text.ViewFactory)](../../../javax/swing/text/View.html#changedUpdate%28javax.swing.event.DocumentEvent, java.awt.Shape, javax.swing.text.ViewFactory%29)

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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

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