edu.northwestern.at.utils.swing.printing
Class PrintView

java.lang.Object
  javax.swing.text.View
      javax.swing.text.CompositeView
          javax.swing.text.BoxView
              edu.northwestern.at.utils.swing.printing.PrintView

All Implemented Interfaces:

javax.swing.SwingConstants

public class PrintView
extends javax.swing.text.BoxView

Arranges Swing text component page images within a rectangular area for printing.

Swing text components such as JTextPane maintain document text as a series of paragraphs. Corresponding to each paragraph is a View which may be rendered onto a graphics context. The paragraph view typically contains lines of styled text stored as child row views, or components such as labels and images.

To print the text from a text component, we create a vertical stack of the paragraph views in the document, asking each to reformat itself to the provided printer page dimensions. We try to fit as many paragraph views as possible on a single printer page. When a paragraph view won't fit within the remaining space on the page, we print as many of its child row views as will fit on the current page, and then we print the rest on the next page. We maintain state for each page to remember which view and how much of it was printed on a page, so that the next time we are called to print another page, we know where to start.

Some objects (such as images) may be too large horizontally or vertically to fit on a single printer page. We handle this by scaling the object to fit within the confines of a single printer page. Some alternative ways to handle oversized objects like images, which are not implemented here, include just not printing the oversized object at all; clipping the object in its original size to fit within the page boundaries; combining clipping/arbitrary splitting across pages; etc.

Nested Class Summary

protected class

PrintView.PageState Class holding information about last view on a printed page.

Field Summary

protected int	currentPageIndex Index of current page.
protected int	firstOnPage Index of first view to be rendered on current page.
protected int	firstOnPageOffset Offset into first view to be rendered on current page.
protected PrintHeaderFooter	headerAndFooter Header and footer.
protected PrintView.PageState	pageState Current page state.
protected java.util.HashMap	pageStateMap Hashmap holds page state for each printed page.

Fields inherited from class javax.swing.text.View

BadBreakWeight, ExcellentBreakWeight, ForcedBreakWeight, GoodBreakWeight, X_AXIS, Y_AXIS

Fields inherited from interface javax.swing.SwingConstants

BOTTOM, CENTER, EAST, HORIZONTAL, LEADING, LEFT, NEXT, NORTH, NORTH_EAST, NORTH_WEST, PREVIOUS, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TOP, TRAILING, VERTICAL, WEST

Constructor Summary

PrintView(javax.swing.text.Element elem, javax.swing.text.View root, int width, int height)
Create PrintView.

PrintView(javax.swing.text.Element elem, javax.swing.text.View root, int width, int height, PrintHeaderFooter headerAndFooter)
Create PrintView.

Method Summary

int	getScaledVerticalSpan(javax.swing.text.View view, int printerPageWidth, int printerPageHeight) Get scaled vertical span used by view.
void	printChildView(java.awt.Graphics2D graphics2D, java.awt.Rectangle rect, javax.swing.text.View view, double scaleFactor) Paint child view row using a specified scale factor.
boolean	printPage(java.awt.Graphics graphics, int pageHeight, int pageIndex) Print one page.

Methods inherited from class javax.swing.text.BoxView

baselineLayout, baselineRequirements, calculateMajorAxisRequirements, calculateMinorAxisRequirements, childAllocation, flipEastAndWestAtEnds, forwardUpdate, getAlignment, getAxis, getChildAllocation, getHeight, getMaximumSpan, getMinimumSpan, getOffset, getPreferredSpan, getResizeWeight, getSpan, getViewAtPoint, getWidth, isAfter, isAllocationValid, isBefore, isLayoutValid, layout, layoutChanged, layoutMajorAxis, layoutMinorAxis, modelToView, paint, paintChild, preferenceChanged, replace, setAxis, setSize, viewToModel

Methods inherited from class javax.swing.text.CompositeView

getBottomInset, getInsideAllocation, getLeftInset, getNextEastWestVisualPositionFrom, getNextNorthSouthVisualPositionFrom, getNextVisualPositionFrom, getRightInset, getTopInset, getView, getViewAtPosition, getViewCount, getViewIndex, getViewIndexAtPosition, loadChildren, modelToView, setInsets, setParagraphInsets, setParent

Methods inherited from class javax.swing.text.View

append, breakView, changedUpdate, createFragment, forwardUpdateToView, getAttributes, getBreakWeight, getContainer, getDocument, getElement, getEndOffset, getGraphics, getParent, getStartOffset, getToolTipText, getViewFactory, getViewIndex, insert, insertUpdate, isVisible, modelToView, remove, removeAll, removeUpdate, updateChildren, updateLayout, viewToModel

Methods inherited from class java.lang.Object

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

Field Detail

firstOnPage

protected int firstOnPage

Index of first view to be rendered on current page.

firstOnPageOffset

protected int firstOnPageOffset

Offset into first view to be rendered on current page.

pageState

protected PrintView.PageState pageState

Current page state.

pageStateMap

protected java.util.HashMap pageStateMap

Hashmap holds page state for each printed page.

currentPageIndex

protected int currentPageIndex

Index of current page.

headerAndFooter

protected PrintHeaderFooter headerAndFooter

Header and footer.

Constructor Detail

PrintView

public PrintView(javax.swing.text.Element elem,
                 javax.swing.text.View root,
                 int width,
                 int height,
                 PrintHeaderFooter headerAndFooter)

Create PrintView.

Parameters:

elem - Root element of document to print

root - Root view of document to print

width - Printing width

height - Print height

headerAndFooter - Specifies header and footer for each page

PrintView

public PrintView(javax.swing.text.Element elem,
                 javax.swing.text.View root,
                 int width,
                 int height)

Create PrintView.

Parameters:

elem - Root element of document to print

root - Root view of document to print

width - Printing width

height - Print height

Method Detail

printChildView

public void printChildView(java.awt.Graphics2D graphics2D,
                           java.awt.Rectangle rect,
                           javax.swing.text.View view,
                           double scaleFactor)

Paint child view row using a specified scale factor.

Parameters:

graphics2D - Graphics context in which to render a page.

rect - Page location and unscaled view size.

view - View to print.

scaleFactor - Scale factor to use when printing.

getScaledVerticalSpan

public int getScaledVerticalSpan(javax.swing.text.View view,
                                 int printerPageWidth,
                                 int printerPageHeight)

Get scaled vertical span used by view.

Parameters:

view - The view whose vertical span is desired.

printerPageWidth - Width of printable printer page area.

printerPageHeight - Height of printable printer page area.

Returns:

The vertical span. For most views this is just the usual maximum vertical span. For views which need to be scaled to fit the printer page, this is the usual vertical span multiplied by the scale factor for the view.

printPage

public boolean printPage(java.awt.Graphics graphics,
                         int pageHeight,
                         int pageIndex)

Print one page.

Parameters:

graphics - Graphics context in which to render a page.

pageHeight - The page height.

pageIndex - Index of page to render.

Returns:

True if given page is rendered successfully, False if end of document reached.