com.lowagie.text.pdf.MultiColumnText Maven / Gradle / Ivy
/*
* $Id: MultiColumnText.java 3936 2009-05-27 12:40:12Z blowagie $
*
* Copyright 2004 Steve Appling
*
* The contents of this file are subject to the Mozilla Public License Version 1.1
* (the "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the License.
*
* The Original Code is 'iText, a free JAVA-PDF library'.
*
* The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
* the Initial Developer are Copyright (C) 1999-2005 by Bruno Lowagie.
* All Rights Reserved.
* Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
* are Copyright (C) 2000-2005 by Paulo Soares. All Rights Reserved.
*
* Contributor(s): all the names of the contributors are added in the source code
* where applicable.
*
* Alternatively, the contents of this file may be used under the terms of the
* LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
* provisions of LGPL are applicable instead of those above. If you wish to
* allow use of your version of this file only under the terms of the LGPL
* License and not to allow others to use your version of this file under
* the MPL, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the LGPL.
* If you do not delete the provisions above, a recipient may use your version
* of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the MPL as stated above or under the terms of the GNU
* Library General Public License as published by the Free Software Foundation;
* either version 2 of the License, or any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
* details.
*
* If you didn't download this code from the following link, you should check if
* you aren't using an obsolete version:
* http://www.lowagie.com/iText/
*/
package com.lowagie.text.pdf;
import java.util.ArrayList;
import com.lowagie.text.Chunk;
import com.lowagie.text.DocumentException;
import com.lowagie.text.Element;
import com.lowagie.text.ElementListener;
import com.lowagie.text.Phrase;
import com.lowagie.text.Rectangle;
/**
* Formats content into one or more columns bounded by a
* rectangle. The columns may be simple rectangles or
* more complicated shapes. Add all of the columns before
* adding content. Column continuation is supported. A MultiColumnText object may be added to
* a document using Document.add.
*
* @author Steve Appling
*/
public class MultiColumnText implements Element {
/** special constant for automatic calculation of height */
public static final float AUTOMATIC = -1f;
/**
* total desiredHeight of columns. If AUTOMATIC, this means fill pages until done.
* This may be larger than one page
*/
private float desiredHeight;
/**
* total height of element written out so far
*/
private float totalHeight;
/**
* true if all the text could not be written out due to height restriction
*/
private boolean overflow;
/**
* Top of the columns - y position on starting page.
* If AUTOMATIC, it means current y position when added to document
*/
private float top;
/**
* ColumnText object used to do all the real work. This same object is used for all columns
*/
private ColumnText columnText;
/**
* Array of ColumnDef objects used to define the columns
*/
private ArrayList columnDefs;
/**
* true if all columns are simple (rectangular)
*/
private boolean simple = true;
private int currentColumn = 0;
private float nextY = AUTOMATIC;
private boolean columnsRightToLeft = false;
private PdfDocument document;
/**
* Default constructor. Sets height to AUTOMATIC.
* Columns will repeat on each page as necessary to accommodate content length.
*/
public MultiColumnText() {
this(AUTOMATIC);
}
/**
* Construct a MultiColumnText container of the specified height.
* If height is AUTOMATIC, fill complete pages until done.
* If a specific height is used, it may span one or more pages.
*
* @param height
*/
public MultiColumnText(float height) {
columnDefs = new ArrayList();
desiredHeight = height;
top = AUTOMATIC;
// canvas will be set later
columnText = new ColumnText(null);
totalHeight = 0f;
}
/**
* Construct a MultiColumnText container of the specified height
* starting at the specified Y position.
*
* @param height
* @param top
*/
public MultiColumnText(float top, float height) {
columnDefs = new ArrayList();
desiredHeight = height;
this.top = top;
nextY = top;
// canvas will be set later
columnText = new ColumnText(null);
totalHeight = 0f;
}
/**
* Indicates that all of the text did not fit in the
* specified height. Note that isOverflow will return
* false before the MultiColumnText object has been
* added to the document. It will always be false if
* the height is AUTOMATIC.
*
* @return true if there is still space left in the column
*/
public boolean isOverflow() {
return overflow;
}
/**
* Copy the parameters from the specified ColumnText to use
* when rendering. Parameters like setArabicOptions
* must be set in this way.
*
* @param sourceColumn
*/
public void useColumnParams(ColumnText sourceColumn) {
// note that canvas will be overwritten later
columnText.setSimpleVars(sourceColumn);
}
/**
* Add a new column. The parameters are limits for each column
* wall in the format of a sequence of points (x1,y1,x2,y2,...).
*
* @param left limits for left column
* @param right limits for right column
*/
public void addColumn(float[] left, float[] right) {
ColumnDef nextDef = new ColumnDef(left, right);
if (!nextDef.isSimple())
simple = false;
columnDefs.add(nextDef);
}
/**
* Add a simple rectangular column with specified left
* and right x position boundaries.
*
* @param left left boundary
* @param right right boundary
*/
public void addSimpleColumn(float left, float right) {
ColumnDef newCol = new ColumnDef(left, right);
columnDefs.add(newCol);
}
/**
* Add the specified number of evenly spaced rectangular columns.
* Columns will be separated by the specified gutterWidth.
*
* @param left left boundary of first column
* @param right right boundary of last column
* @param gutterWidth width of gutter spacing between columns
* @param numColumns number of columns to add
*/
public void addRegularColumns(float left, float right, float gutterWidth, int numColumns) {
float currX = left;
float width = right - left;
float colWidth = (width - (gutterWidth * (numColumns - 1))) / numColumns;
for (int i = 0; i < numColumns; i++) {
addSimpleColumn(currX, currX + colWidth);
currX += colWidth + gutterWidth;
}
}
/**
* Adds a Phrase to the current text array.
* Will not have any effect if addElement() was called before.
*
* @param phrase the text
* @since 2.1.5
*/
public void addText(Phrase phrase) {
columnText.addText(phrase);
}
/**
* Adds a Chunk to the current text array.
* Will not have any effect if addElement() was called before.
*
* @param chunk the text
* @since 2.1.5
*/
public void addText(Chunk chunk) {
columnText.addText(chunk);
}
/**
* Add an element to be rendered in a column.
* Note that you can only add a Phrase
* or a Chunk if the columns are
* not all simple. This is an underlying restriction in
* {@link com.lowagie.text.pdf.ColumnText}
*
* @param element element to add
* @throws DocumentException if element can't be added
*/
public void addElement(Element element) throws DocumentException {
if (simple) {
columnText.addElement(element);
} else if (element instanceof Phrase) {
columnText.addText((Phrase) element);
} else if (element instanceof Chunk) {
columnText.addText((Chunk) element);
} else {
throw new DocumentException("Can't add " + element.getClass() + " to MultiColumnText with complex columns");
}
}
/**
* Write out the columns. After writing, use
* {@link #isOverflow()} to see if all text was written.
*
* @param canvas PdfContentByte to write with
* @param document document to write to (only used to get page limit info)
* @param documentY starting y position to begin writing at
* @return the current height (y position) after writing the columns
* @throws DocumentException on error
*/
public float write(PdfContentByte canvas, PdfDocument document, float documentY) throws DocumentException {
this.document = document;
columnText.setCanvas(canvas);
if (columnDefs.isEmpty()) {
throw new DocumentException("MultiColumnText has no columns");
}
overflow = false;
float currentHeight = 0;
boolean done = false;
try {
while (!done) {
if (top == AUTOMATIC) {
top = document.getVerticalPosition(true); // RS - 07/07/2005 - Get current doc writing position for top of columns on new page.
} else if (nextY == AUTOMATIC) {
nextY = document.getVerticalPosition(true); // RS - 07/07/2005 - - Get current doc writing position for top of columns on new page.
}
ColumnDef currentDef = (ColumnDef) columnDefs.get(getCurrentColumn());
columnText.setYLine(top);
float[] left = currentDef.resolvePositions(Rectangle.LEFT);
float[] right = currentDef.resolvePositions(Rectangle.RIGHT);
if (document.isMarginMirroring() && document.getPageNumber() % 2 == 0) {
float delta = document.rightMargin() - document.left();
left = (float[]) left.clone();
right = (float[]) right.clone();
for (int i = 0; i < left.length; i += 2) {
left[i] -= delta;
}
for (int i = 0; i < right.length; i += 2) {
right[i] -= delta;
}
}
currentHeight = Math.max(currentHeight, getHeight(left, right));
if (currentDef.isSimple()) {
columnText.setSimpleColumn(left[2], left[3], right[0], right[1]);
} else {
columnText.setColumns(left, right);
}
int result = columnText.go();
if ((result & ColumnText.NO_MORE_TEXT) != 0) {
done = true;
top = columnText.getYLine();
} else if (shiftCurrentColumn()) {
top = nextY;
} else { // check if we are done because of height
totalHeight += currentHeight;
if ((desiredHeight != AUTOMATIC) && (totalHeight >= desiredHeight)) {
overflow = true;
break;
} else { // need to start new page and reset the columns
documentY = nextY;
newPage();
currentHeight = 0;
}
}
}
} catch (DocumentException ex) {
ex.printStackTrace();
throw ex;
}
if (desiredHeight == AUTOMATIC && columnDefs.size() == 1) {
currentHeight = documentY - columnText.getYLine();
}
return currentHeight;
}
private void newPage() throws DocumentException {
resetCurrentColumn();
if (desiredHeight == AUTOMATIC) {
top = nextY = AUTOMATIC;
} else {
top = nextY;
}
totalHeight = 0;
if (document != null) {
document.newPage();
}
}
/**
* Figure out the height of a column from the border extents
*
* @param left left border
* @param right right border
* @return height
*/
private float getHeight(float[] left, float[] right) {
float max = Float.MIN_VALUE;
float min = Float.MAX_VALUE;
for (int i = 0; i < left.length; i += 2) {
min = Math.min(min, left[i + 1]);
max = Math.max(max, left[i + 1]);
}
for (int i = 0; i < right.length; i += 2) {
min = Math.min(min, right[i + 1]);
max = Math.max(max, right[i + 1]);
}
return max - min;
}
/**
* Processes the element by adding it to an
* ElementListener.
*
* @param listener an ElementListener
* @return true if the element was processed successfully
*/
public boolean process(ElementListener listener) {
try {
return listener.add(this);
} catch (DocumentException de) {
return false;
}
}
/**
* Gets the type of the text element.
*
* @return a type
*/
public int type() {
return Element.MULTI_COLUMN_TEXT;
}
/**
* Returns null - not used
*
* @return null
*/
public ArrayList getChunks() {
return null;
}
/**
* @see com.lowagie.text.Element#isContent()
* @since iText 2.0.8
*/
public boolean isContent() {
return true;
}
/**
* @see com.lowagie.text.Element#isNestable()
* @since iText 2.0.8
*/
public boolean isNestable() {
return false;
}
/**
* Calculates the appropriate y position for the bottom
* of the columns on this page.
*
* @return the y position of the bottom of the columns
*/
private float getColumnBottom() {
if (desiredHeight == AUTOMATIC) {
return document.bottom();
} else {
return Math.max(top - (desiredHeight - totalHeight), document.bottom());
}
}
/**
* Moves the text insertion point to the beginning of the next column, issuing a page break if
* needed.
*
* @throws DocumentException on error
*/
public void nextColumn() throws DocumentException {
currentColumn = (currentColumn + 1) % columnDefs.size();
top = nextY;
if (currentColumn == 0) {
newPage();
}
}
/**
* Gets the current column.
*
* @return the current column
*/
public int getCurrentColumn() {
if (columnsRightToLeft) {
return (columnDefs.size() - currentColumn - 1);
}
return currentColumn;
}
/**
* Resets the current column.
*/
public void resetCurrentColumn() {
currentColumn = 0;
}
/**
* Shifts the current column.
*
* @return true if the current column has changed
*/
public boolean shiftCurrentColumn() {
if (currentColumn + 1 < columnDefs.size()) {
currentColumn++;
return true;
}
return false;
}
/**
* Sets the direction of the columns.
*
* @param direction true = right2left; false = left2right
*/
public void setColumnsRightToLeft(boolean direction) {
columnsRightToLeft = direction;
}
/**
* Sets the ratio between the extra word spacing and the extra character spacing
* when the text is fully justified.
* Extra word spacing will grow spaceCharRatio times more than extra character spacing.
* If the ratio is PdfWriter.NO_SPACE_CHAR_RATIO then the extra character spacing
* will be zero.
*
* @param spaceCharRatio the ratio between the extra word spacing and the extra character spacing
*/
public void setSpaceCharRatio(float spaceCharRatio) {
columnText.setSpaceCharRatio(spaceCharRatio);
}
/**
* Sets the run direction.
*
* @param runDirection the run direction
*/
public void setRunDirection(int runDirection) {
columnText.setRunDirection(runDirection);
}
/**
* Sets the arabic shaping options. The option can be AR_NOVOWEL,
* AR_COMPOSEDTASHKEEL and AR_LIG.
*
* @param arabicOptions the arabic shaping options
*/
public void setArabicOptions(int arabicOptions) {
columnText.setArabicOptions(arabicOptions);
}
/**
* Sets the default alignment
*
* @param alignment the default alignment
*/
public void setAlignment(int alignment) {
columnText.setAlignment(alignment);
}
/**
* Inner class used to define a column
*/
private class ColumnDef {
private float[] left;
private float[] right;
ColumnDef(float[] newLeft, float[] newRight) {
left = newLeft;
right = newRight;
}
ColumnDef(float leftPosition, float rightPosition) {
left = new float[4];
left[0] = leftPosition; // x1
left[1] = top; // y1
left[2] = leftPosition; // x2
if (desiredHeight == AUTOMATIC || top == AUTOMATIC) {
left[3] = AUTOMATIC;
} else {
left[3] = top - desiredHeight;
}
right = new float[4];
right[0] = rightPosition; // x1
right[1] = top; // y1
right[2] = rightPosition; // x2
if (desiredHeight == AUTOMATIC || top == AUTOMATIC) {
right[3] = AUTOMATIC;
} else {
right[3] = top - desiredHeight;
}
}
/**
* Resolves the positions for the specified side of the column
* into real numbers once the top of the column is known.
*
* @param side either Rectangle.LEFT
* or Rectangle.RIGHT
* @return the array of floats for the side
*/
float[] resolvePositions(int side) {
if (side == Rectangle.LEFT) {
return resolvePositions(left);
} else {
return resolvePositions(right);
}
}
private float[] resolvePositions(float[] positions) {
if (!isSimple()) {
positions[1] = top;
return positions;
}
if (top == AUTOMATIC) {
// this is bad - must be programmer error
throw new RuntimeException("resolvePositions called with top=AUTOMATIC (-1). " +
"Top position must be set befure lines can be resolved");
}
positions[1] = top;
positions[3] = getColumnBottom();
return positions;
}
/**
* Checks if column definition is a simple rectangle
*
* @return true if it is a simple column
*/
private boolean isSimple() {
return (left.length == 4 && right.length == 4) && (left[0] == left[2] && right[0] == right[2]);
}
}
}
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