Class MulticolRenderer

java.lang.Object

com.itextpdf.layout.renderer.AbstractRenderer

com.itextpdf.layout.renderer.MulticolRenderer

All Implemented Interfaces:

IPropertyContainer, IRenderer

public class MulticolRenderer
extends AbstractRenderer

Represents a renderer for columns.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	MulticolRenderer.ColumnHeightCalculator	Interface which used for additional height calculation
static class	MulticolRenderer.LayoutInInfiniteHeightCalculator	Default implementation of MulticolRenderer.ColumnHeightCalculator which allows 4 relayouts and performs simple additional height calculation (split the elements which don't fit).
static class	MulticolRenderer.MulticolLayoutResult	Represents result of one iteration of MulticolRenderer layouting It contains split renderers which were lauded on a given height and overflow renderer for which height should be increased, so it can be lauded.

Field Summary

Fields

Modifier and Type	Field	Description
private float	approximateHeight
private int	columnCount
private float	columnGap
private float	columnWidth
private float	containerWidth
private BlockRenderer	elementRenderer
private MulticolRenderer.ColumnHeightCalculator	heightCalculator
private Float	heightFromProperties
private boolean	isFirstLayout
private static final float	ZERO_DELTA

Fields inherited from class AbstractRenderer

BOTTOM_SIDE, childRenderers, EPS, flushed, INF, isLastRendererForModelElement, LEFT_SIDE, modelElement, occupiedArea, OVERLAP_EPSILON, parent, positionedRenderers, properties, RIGHT_SIDE, TOP_SIDE

Constructor Summary

Constructors

Constructor	Description
MulticolRenderer(MulticolContainer modelElement)	Creates a DivRenderer from its corresponding layout object.

Method Summary

Modifier and Type	Method	Description
private void	applyWidth(Rectangle parentBbox, float originalWidth)
private MulticolRenderer.MulticolLayoutResult	balanceContentAndLayoutColumns(LayoutContext prelayoutContext, Rectangle actualBbox)
private void	calculateColumnCountAndWidth(float initialWidth)
private LayoutArea	calculateContainerOccupiedArea(LayoutContext layoutContext, boolean isFull)
private void	clearOverFlowRendererIfNeeded(MulticolRenderer.MulticolLayoutResult result)
protected AbstractRenderer	createOverflowRenderer(IRenderer overflowedContentRenderer)	Creates an overflow renderer.
private Float	determineHeight(Rectangle parentBBox)
void	drawBorder(DrawContext drawContext)	Performs the drawing operation for the border of this renderer, if defined by the Property.BORDER_TOP, Property.BORDER_RIGHT, Property.BORDER_BOTTOM and Property.BORDER_LEFT values in either the layout element or this IRenderer itself.
private void	drawTaggedWhenNeeded(DrawContext drawContext, Consumer<PdfCanvas> action)
private BlockRenderer	getElementsRenderer()
IRenderer	getNextRenderer()	Gets a new instance of this class to be used as a next renderer, after this renderer is used, if IRenderer.layout(LayoutContext) is called more than once.
LayoutResult	layout(LayoutContext layoutContext)	This method simulates positioning of the renderer, including all of its children, and returns the LayoutResult, representing the layout result, including occupied area, status, i.e.
private MulticolRenderer.MulticolLayoutResult	layoutColumnsAndReturnOverflowRenderer(LayoutContext preLayoutContext, Rectangle actualBBox, float workingHeight)
protected MulticolRenderer.MulticolLayoutResult	layoutInColumns(LayoutContext layoutContext, Rectangle actualBBox)	Layouts multicol in the passed area.
final void	setHeightCalculator(MulticolRenderer.ColumnHeightCalculator heightCalculator)	Sets the height calculator to be used by this renderer.
private void	setOverflowForAllChildren(IRenderer renderer)

Methods inherited from class AbstractRenderer

addAllChildRenderers, addAllChildRenderers, addAllProperties, addChild, addChildRenderer, alignChildHorizontally, allowLastYLineRecursiveExtraction, applyAbsolutePosition, applyAbsolutePositionIfNeeded, applyAction, applyBorderBox, applyBorderBox, applyDestination, applyDestinationsAndAnnotation, applyLinkAnnotation, applyMargins, applyMargins, applyMarginsBordersPaddings, applyPaddings, applyPaddings, applyRelativePositioningTranslation, beginElementOpacityApplying, beginTransformationIfApplied, calculateAbsolutePdfBBox, calculateAdditionalWidth, calculateBBox, calculatePaddingBorderHeight, calculatePaddingBorderWidth, calculateShiftToPositionBBoxOfPointsAt, clipBackgroundArea, clipBackgroundArea, clipBorderArea, createFontCharacteristics, createXObject, deleteOwnProperty, deleteProperty, draw, drawBackground, drawChildren, drawPositionedChildren, endElementOpacityApplying, endTransformationIfApplied, getAspectRatio, getBackgroundArea, getBorderAreaBBox, getBorderRadii, getBorders, getBorders, getChildRenderers, getDefaultProperty, getFirstYLineRecursively, getInnerAreaBBox, getLastYLineRecursively, getMargins, getMinMaxWidth, getMinMaxWidth, getModelElement, getOccupiedArea, getOccupiedAreaBBox, getOwnProperties, getOwnProperty, getPaddings, getParent, getPdfDocument, getProperty, getProperty, getPropertyAsBoolean, getPropertyAsColor, getPropertyAsFloat, getPropertyAsFloat, getPropertyAsFloat, getPropertyAsFont, getPropertyAsInteger, getPropertyAsTransparentColor, getPropertyAsUnitValue, getPropertyAsUnitValue, getRootRenderer, hasAbsoluteUnitValue, hasAspectRatio, hasOwnOrModelProperty, hasOwnProperty, hasProperty, hasRelativeUnitValue, initElementAreas, isAbsolutePosition, isBorderBoxSizing, isFirstOnRootArea, isFirstOnRootArea, isFixedLayout, isFlushed, isKeepTogether, isKeepTogether, isNotFittingHeight, isNotFittingLayoutArea, isNotFittingWidth, isOverflowFit, isOverflowProperty, isOverflowProperty, isOverflowProperty, isPositioned, isRelativePosition, isStaticLayout, logWarningIfGetNextRendererNotOverridden, move, noAbsolutePositionInfo, preparePositionedRendererAndAreaForLayout, processWaitingDrawing, rectangleToPointsList, removeAllChildRenderers, removeChildRenderer, replaceOwnProperty, resolveFirstPdfFont, resolveFirstPdfFont, retrieveHeight, retrieveMaxHeight, retrieveMaxWidth, retrieveMinHeight, retrieveMinWidth, retrieveResolvedDeclaredHeight, retrieveUnitValue, retrieveUnitValue, retrieveWidth, returnBackOwnProperty, setBorders, setChildRenderer, setChildRenderers, setMinMaxWidthBasedOnFixedWidth, setParent, setProperty, setThisAsParent, shrinkOccupiedAreaForAbsolutePosition, toString, transformPoints, updateHeight, updateHeightsOnSplit, updateHeightsOnSplit, updateMaxHeight, updateMinHeight, updateWidth

Methods inherited from class Object

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

Field Details

ZERO_DELTA

private static final float ZERO_DELTA

See Also:

• Constant Field Values

heightCalculator

private MulticolRenderer.ColumnHeightCalculator heightCalculator

elementRenderer

private BlockRenderer elementRenderer

columnCount

private int columnCount

columnWidth

private float columnWidth

approximateHeight

private float approximateHeight

heightFromProperties

private Float heightFromProperties

columnGap

private float columnGap

containerWidth

private float containerWidth

isFirstLayout

private boolean isFirstLayout

Constructor Details

MulticolRenderer

public MulticolRenderer(MulticolContainer modelElement)

Creates a DivRenderer from its corresponding layout object.

Parameters:

modelElement - the MulticolContainer which this object should manage

Method Details

setHeightCalculator

public final void setHeightCalculator(MulticolRenderer.ColumnHeightCalculator heightCalculator)

Sets the height calculator to be used by this renderer.

Parameters:

heightCalculator - the height calculator to be used by this renderer.

layout

public LayoutResult layout(LayoutContext layoutContext)

This method simulates positioning of the renderer, including all of its children, and returns the LayoutResult, representing the layout result, including occupied area, status, i.e. if there was enough place to fit the renderer subtree, etc. LayoutResult can be extended to return custom layout results for custom elements, e.g. TextRenderer uses TextLayoutResult as its result. This method can be called standalone to learn how much area the renderer subtree needs, or can be called before IRenderer.draw(DrawContext), to prepare the renderer to be flushed to the output stream.

Parameters:

layoutContext - the description of layout area and any other additional information

Returns:

result of the layout process

getNextRenderer

public IRenderer getNextRenderer()

Gets a new instance of this class to be used as a next renderer, after this renderer is used, if IRenderer.layout(LayoutContext) is called more than once.

Returns:

new renderer instance

drawBorder

public void drawBorder(DrawContext drawContext)

Performs the drawing operation for the border of this renderer, if defined by the Property.BORDER_TOP, Property.BORDER_RIGHT, Property.BORDER_BOTTOM and Property.BORDER_LEFT values in either the layout element or this IRenderer itself.

Overrides:

drawBorder in class AbstractRenderer

Parameters:

drawContext - the context (canvas, document, etc) of this drawing operation.

layoutInColumns

protected MulticolRenderer.MulticolLayoutResult layoutInColumns(LayoutContext layoutContext,
 Rectangle actualBBox)

Layouts multicol in the passed area.

Parameters:

layoutContext - the layout context

actualBBox - the area to layout multicol on

Returns:

the MulticolRenderer.MulticolLayoutResult instance

createOverflowRenderer

protected AbstractRenderer createOverflowRenderer(IRenderer overflowedContentRenderer)

Creates an overflow renderer.

Parameters:

overflowedContentRenderer - an overflowed content renderer

Returns:

a new AbstractRenderer instance

setOverflowForAllChildren

private void setOverflowForAllChildren(IRenderer renderer)

drawTaggedWhenNeeded

private void drawTaggedWhenNeeded(DrawContext drawContext,
 Consumer<PdfCanvas> action)

applyWidth

private void applyWidth(Rectangle parentBbox,
 float originalWidth)

determineHeight

private Float determineHeight(Rectangle parentBBox)

balanceContentAndLayoutColumns

private MulticolRenderer.MulticolLayoutResult balanceContentAndLayoutColumns(LayoutContext prelayoutContext,
 Rectangle actualBbox)

calculateColumnCountAndWidth

private void calculateColumnCountAndWidth(float initialWidth)

clearOverFlowRendererIfNeeded

private void clearOverFlowRendererIfNeeded(MulticolRenderer.MulticolLayoutResult result)

calculateContainerOccupiedArea

private LayoutArea calculateContainerOccupiedArea(LayoutContext layoutContext,
 boolean isFull)

getElementsRenderer

private BlockRenderer getElementsRenderer()

layoutColumnsAndReturnOverflowRenderer

private MulticolRenderer.MulticolLayoutResult layoutColumnsAndReturnOverflowRenderer(LayoutContext preLayoutContext,
 Rectangle actualBBox,
 float workingHeight)