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/*
This file is part of the iText (R) project.
Copyright (c) 1998-2024 Apryse Group NV
Authors: Apryse Software.
This program is offered under a commercial and under the AGPL license.
For commercial licensing, contact us at https://itextpdf.com/sales. For AGPL licensing, see below.
AGPL licensing:
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
*/
package com.itextpdf.layout.margincollapse;
import com.itextpdf.io.logs.IoLogMessageConstant;
import com.itextpdf.commons.utils.MessageFormatUtil;
import com.itextpdf.kernel.geom.Rectangle;
import com.itextpdf.layout.IPropertyContainer;
import com.itextpdf.layout.properties.FloatPropertyValue;
import com.itextpdf.layout.properties.Property;
import com.itextpdf.layout.properties.UnitValue;
import com.itextpdf.layout.renderer.AbstractRenderer;
import com.itextpdf.layout.renderer.BlockFormattingContextUtil;
import com.itextpdf.layout.renderer.BlockRenderer;
import com.itextpdf.layout.renderer.CellRenderer;
import com.itextpdf.layout.renderer.IRenderer;
import com.itextpdf.layout.renderer.LineRenderer;
import com.itextpdf.layout.renderer.TableRenderer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.List;
/**
* Rules of the margins collapsing are taken from Mozilla Developer Network:
* https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Box_Model/Mastering_margin_collapsing
* See also:
* https://www.w3.org/TR/CSS2/box.html#collapsing-margins
*/
public class MarginsCollapseHandler {
private IRenderer renderer;
private MarginsCollapseInfo collapseInfo;
private MarginsCollapseInfo childMarginInfo;
private MarginsCollapseInfo prevChildMarginInfo;
private int firstNotEmptyKidIndex = 0;
private int processedChildrenNum = 0;
private List rendererChildren = new ArrayList<>();
// Layout box and collapse info are saved before processing the next kid, in order to be able to restore it in case
// the next kid is not placed. These values are not null only between startChildMarginsHandling and endChildMarginsHandling calls.
private Rectangle backupLayoutBox;
private MarginsCollapseInfo backupCollapseInfo;
private boolean lastKidCollapsedAfterHasClearanceApplied;
public MarginsCollapseHandler(IRenderer renderer, MarginsCollapseInfo marginsCollapseInfo) {
this.renderer = renderer;
this.collapseInfo = marginsCollapseInfo != null ? marginsCollapseInfo : new MarginsCollapseInfo();
}
public void processFixedHeightAdjustment(float heightDelta) {
collapseInfo.setBufferSpaceOnTop(collapseInfo.getBufferSpaceOnTop() + heightDelta);
collapseInfo.setBufferSpaceOnBottom(collapseInfo.getBufferSpaceOnBottom() + heightDelta);
}
public MarginsCollapseInfo startChildMarginsHandling(IRenderer child, Rectangle layoutBox) {
if (backupLayoutBox != null) {
// this should happen only if previous kid was floated
restoreLayoutBoxAfterFailedLayoutAttempt(layoutBox);
removeRendererChild(--processedChildrenNum);
childMarginInfo = null;
}
rendererChildren.add(child);
int childIndex = processedChildrenNum++;
// If renderer is floated, prepare layout box as if it was inline,
// however it will be restored from backup when next kid processing will start.
boolean childIsBlockElement = !rendererIsFloated(child) && isBlockElement(child);
backupLayoutBox = layoutBox.clone();
backupCollapseInfo = new MarginsCollapseInfo();
collapseInfo.copyTo(backupCollapseInfo);
prepareBoxForLayoutAttempt(layoutBox, childIndex, childIsBlockElement);
if (childIsBlockElement) {
childMarginInfo = createMarginsInfoForBlockChild(childIndex);
}
return this.childMarginInfo;
}
public void applyClearance(float clearHeightCorrection) {
// Actually, clearance is applied only in case margins were not enough,
// however I wasn't able to notice difference in browsers behaviour.
// Also, iText behaviour concerning margins self collapsing and clearance differs from browsers in some cases.
collapseInfo.setClearanceApplied(true);
collapseInfo.getCollapseBefore().joinMargin(clearHeightCorrection);
}
private MarginsCollapseInfo createMarginsInfoForBlockChild(int childIndex) {
boolean ignoreChildTopMargin = false;
// always assume that current child might be the last on this area
boolean ignoreChildBottomMargin = lastChildMarginAdjoinedToParent(renderer);
if (childIndex == firstNotEmptyKidIndex) {
ignoreChildTopMargin = firstChildMarginAdjoinedToParent(renderer);
}
MarginsCollapse childCollapseBefore;
if (childIndex == 0) {
MarginsCollapse parentCollapseBefore = collapseInfo.getCollapseBefore();
childCollapseBefore = ignoreChildTopMargin ? parentCollapseBefore : new MarginsCollapse();
} else {
MarginsCollapse prevChildCollapseAfter = prevChildMarginInfo != null ? prevChildMarginInfo.getOwnCollapseAfter() : null;
childCollapseBefore = prevChildCollapseAfter != null ? prevChildCollapseAfter : new MarginsCollapse();
}
MarginsCollapse parentCollapseAfter = collapseInfo.getCollapseAfter().clone();
MarginsCollapse childCollapseAfter = ignoreChildBottomMargin ? parentCollapseAfter : new MarginsCollapse();
MarginsCollapseInfo childMarginsInfo = new MarginsCollapseInfo(ignoreChildTopMargin, ignoreChildBottomMargin, childCollapseBefore, childCollapseAfter);
if (ignoreChildTopMargin && childIndex == firstNotEmptyKidIndex) {
childMarginsInfo.setBufferSpaceOnTop(collapseInfo.getBufferSpaceOnTop());
}
if (ignoreChildBottomMargin) {
childMarginsInfo.setBufferSpaceOnBottom(collapseInfo.getBufferSpaceOnBottom());
}
return childMarginsInfo;
}
/**
* This method shall be called after child occupied area is included into parent occupied area.
*
* @param layoutBox available area for child and its siblings layout. It might be adjusted inside the method
*/
public void endChildMarginsHandling(Rectangle layoutBox) {
int childIndex = processedChildrenNum - 1;
if (rendererIsFloated(getRendererChild(childIndex))) {
return;
}
if (childMarginInfo != null) {
if (firstNotEmptyKidIndex == childIndex && childMarginInfo.isSelfCollapsing()) {
firstNotEmptyKidIndex = childIndex + 1;
}
collapseInfo.setSelfCollapsing(collapseInfo.isSelfCollapsing() && childMarginInfo.isSelfCollapsing());
lastKidCollapsedAfterHasClearanceApplied = childMarginInfo.isSelfCollapsing() && childMarginInfo.isClearanceApplied();
} else {
lastKidCollapsedAfterHasClearanceApplied = false;
collapseInfo.setSelfCollapsing(false);
}
if (prevChildMarginInfo != null) {
fixPrevChildOccupiedArea(childIndex);
updateCollapseBeforeIfPrevKidIsFirstAndSelfCollapsed(prevChildMarginInfo.getOwnCollapseAfter());
}
if (firstNotEmptyKidIndex == childIndex && firstChildMarginAdjoinedToParent(renderer)) {
if (!collapseInfo.isSelfCollapsing()) {
getRidOfCollapseArtifactsAtopOccupiedArea();
if (childMarginInfo != null) {
processUsedChildBufferSpaceOnTop(layoutBox);
}
}
}
prevChildMarginInfo = childMarginInfo;
childMarginInfo = null;
backupLayoutBox = null;
backupCollapseInfo = null;
}
public void startMarginsCollapse(Rectangle parentBBox) {
collapseInfo.getCollapseBefore().joinMargin(defineTopMarginValueForCollapse(renderer));
collapseInfo.getCollapseAfter().joinMargin(defineBottomMarginValueForCollapse(renderer));
if (!firstChildMarginAdjoinedToParent(renderer)) {
float topIndent = collapseInfo.getCollapseBefore().getCollapsedMarginsSize();
applyTopMargin(parentBBox, topIndent);
}
if (!lastChildMarginAdjoinedToParent(renderer)) {
float bottomIndent = collapseInfo.getCollapseAfter().getCollapsedMarginsSize();
applyBottomMargin(parentBBox, bottomIndent);
}
// ignore current margins for now
ignoreModelTopMargin(renderer);
ignoreModelBottomMargin(renderer);
}
public void endMarginsCollapse(Rectangle layoutBox) {
if (backupLayoutBox != null) {
restoreLayoutBoxAfterFailedLayoutAttempt(layoutBox);
}
if (prevChildMarginInfo != null) {
updateCollapseBeforeIfPrevKidIsFirstAndSelfCollapsed(prevChildMarginInfo.getCollapseAfter());
}
boolean couldBeSelfCollapsing = MarginsCollapseHandler.marginsCouldBeSelfCollapsing(renderer) && !lastKidCollapsedAfterHasClearanceApplied;
boolean blockHasNoKidsWithContent = collapseInfo.isSelfCollapsing();
if (firstChildMarginAdjoinedToParent(renderer)) {
if (blockHasNoKidsWithContent && !couldBeSelfCollapsing) {
addNotYetAppliedTopMargin(layoutBox);
}
}
collapseInfo.setSelfCollapsing(collapseInfo.isSelfCollapsing() && couldBeSelfCollapsing);
if (!blockHasNoKidsWithContent && lastKidCollapsedAfterHasClearanceApplied) {
applySelfCollapsedKidMarginWithClearance(layoutBox);
}
MarginsCollapse ownCollapseAfter;
boolean lastChildMarginJoinedToParent = prevChildMarginInfo != null && prevChildMarginInfo.isIgnoreOwnMarginBottom() && !lastKidCollapsedAfterHasClearanceApplied;
if (lastChildMarginJoinedToParent) {
ownCollapseAfter = prevChildMarginInfo.getOwnCollapseAfter();
} else {
ownCollapseAfter = new MarginsCollapse();
}
ownCollapseAfter.joinMargin(defineBottomMarginValueForCollapse(renderer));
collapseInfo.setOwnCollapseAfter(ownCollapseAfter);
if (collapseInfo.isSelfCollapsing()) {
if (prevChildMarginInfo != null) {
collapseInfo.setCollapseAfter(prevChildMarginInfo.getCollapseAfter());
} else {
collapseInfo.getCollapseAfter().joinMargin(collapseInfo.getCollapseBefore());
collapseInfo.getOwnCollapseAfter().joinMargin(collapseInfo.getCollapseBefore());
}
if (!collapseInfo.isIgnoreOwnMarginBottom() && !collapseInfo.isIgnoreOwnMarginTop()) {
float collapsedMargins = collapseInfo.getCollapseAfter().getCollapsedMarginsSize();
overrideModelBottomMargin(renderer, collapsedMargins);
}
} else {
MarginsCollapse marginsCollapseBefore = collapseInfo.getCollapseBefore();
if (!collapseInfo.isIgnoreOwnMarginTop()) {
float collapsedMargins = marginsCollapseBefore.getCollapsedMarginsSize();
overrideModelTopMargin(renderer, collapsedMargins);
}
if (lastChildMarginJoinedToParent) {
collapseInfo.setCollapseAfter(prevChildMarginInfo.getCollapseAfter());
}
if (!collapseInfo.isIgnoreOwnMarginBottom()) {
float collapsedMargins = collapseInfo.getCollapseAfter().getCollapsedMarginsSize();
overrideModelBottomMargin(renderer, collapsedMargins);
}
}
if (lastChildMarginAdjoinedToParent(renderer) && (prevChildMarginInfo != null || blockHasNoKidsWithContent)) {
// Adjust layout box here in order to make it represent the available area left.
float collapsedMargins = collapseInfo.getCollapseAfter().getCollapsedMarginsSize();
// May be in case of self-collapsed margins it would make more sense to apply this value to topMargin,
// because that way the layout box would represent the area left after the empty self-collapsed block, not
// before it. However at the same time any considerations about the layout (i.e. content) area in case
// of the self-collapsed block seem to be invalid, because self-collapsed block shall have content area
// of zero height.
applyBottomMargin(layoutBox, collapsedMargins);
}
}
private void updateCollapseBeforeIfPrevKidIsFirstAndSelfCollapsed(MarginsCollapse collapseAfter) {
if (prevChildMarginInfo.isSelfCollapsing() && prevChildMarginInfo.isIgnoreOwnMarginTop()) {
// prevChildMarginInfo.isIgnoreOwnMarginTop() is true only if it's the first kid and is adjoined to parent margin
collapseInfo.getCollapseBefore().joinMargin(collapseAfter);
}
}
private void prepareBoxForLayoutAttempt(Rectangle layoutBox, int childIndex, boolean childIsBlockElement) {
if (prevChildMarginInfo != null) {
boolean prevChildHasAppliedCollapseAfter = !prevChildMarginInfo.isIgnoreOwnMarginBottom()
&& (!prevChildMarginInfo.isSelfCollapsing() || !prevChildMarginInfo.isIgnoreOwnMarginTop());
if (prevChildHasAppliedCollapseAfter) {
layoutBox.setHeight(layoutBox.getHeight() + prevChildMarginInfo.getCollapseAfter().getCollapsedMarginsSize());
}
boolean prevChildCanApplyCollapseAfter = !prevChildMarginInfo.isSelfCollapsing() || !prevChildMarginInfo.isIgnoreOwnMarginTop();
if (!childIsBlockElement && prevChildCanApplyCollapseAfter) {
MarginsCollapse ownCollapseAfter = prevChildMarginInfo.getOwnCollapseAfter();
float ownCollapsedMargins = ownCollapseAfter == null ? 0 : ownCollapseAfter.getCollapsedMarginsSize();
layoutBox.setHeight(layoutBox.getHeight() - ownCollapsedMargins);
}
} else if (childIndex > firstNotEmptyKidIndex) {
if (lastChildMarginAdjoinedToParent(renderer)) {
// restore layout box after inline element
// used space shall be always less or equal to collapsedMarginAfter size
float bottomIndent = collapseInfo.getCollapseAfter().getCollapsedMarginsSize() - collapseInfo.getUsedBufferSpaceOnBottom();
collapseInfo.setBufferSpaceOnBottom(collapseInfo.getBufferSpaceOnBottom() + collapseInfo.getUsedBufferSpaceOnBottom());
collapseInfo.setUsedBufferSpaceOnBottom(0);
layoutBox.setY(layoutBox.getY() - bottomIndent);
layoutBox.setHeight(layoutBox.getHeight() + bottomIndent);
}
}
if (!childIsBlockElement) {
if (childIndex == firstNotEmptyKidIndex && firstChildMarginAdjoinedToParent(renderer)) {
float topIndent = collapseInfo.getCollapseBefore().getCollapsedMarginsSize();
applyTopMargin(layoutBox, topIndent);
}
// if not adjoined - bottom margin have been already applied on startMarginsCollapse
if (lastChildMarginAdjoinedToParent(renderer)) {
float bottomIndent = collapseInfo.getCollapseAfter().getCollapsedMarginsSize();
applyBottomMargin(layoutBox, bottomIndent);
}
}
}
private void restoreLayoutBoxAfterFailedLayoutAttempt(Rectangle layoutBox) {
layoutBox.setX(backupLayoutBox.getX()).setY(backupLayoutBox.getY())
.setWidth(backupLayoutBox.getWidth()).setHeight(backupLayoutBox.getHeight());
backupCollapseInfo.copyTo(collapseInfo);
backupLayoutBox = null;
backupCollapseInfo = null;
}
private void applyTopMargin(Rectangle box, float topIndent) {
float bufferLeftoversOnTop = collapseInfo.getBufferSpaceOnTop() - topIndent;
float usedTopBuffer = bufferLeftoversOnTop > 0 ? topIndent : collapseInfo.getBufferSpaceOnTop();
collapseInfo.setUsedBufferSpaceOnTop(usedTopBuffer);
subtractUsedTopBufferFromBottomBuffer(usedTopBuffer);
if (bufferLeftoversOnTop >= 0) {
collapseInfo.setBufferSpaceOnTop(bufferLeftoversOnTop);
box.moveDown(topIndent);
} else {
box.moveDown(collapseInfo.getBufferSpaceOnTop());
collapseInfo.setBufferSpaceOnTop(0);
box.setHeight(box.getHeight() + bufferLeftoversOnTop);
}
}
private void applyBottomMargin(Rectangle box, float bottomIndent) {
// Here we don't subtract used buffer space from topBuffer, because every kid is assumed to be
// the last one on the page, and so every kid always has parent's bottom buffer, however only the true last kid
// uses it for real. Also, bottom margin are always applied after top margins, so it doesn't matter anyway.
float bottomIndentLeftovers = bottomIndent - collapseInfo.getBufferSpaceOnBottom();
if (bottomIndentLeftovers < 0) {
collapseInfo.setUsedBufferSpaceOnBottom(bottomIndent);
collapseInfo.setBufferSpaceOnBottom(-bottomIndentLeftovers);
} else {
collapseInfo.setUsedBufferSpaceOnBottom(collapseInfo.getBufferSpaceOnBottom());
collapseInfo.setBufferSpaceOnBottom(0);
box.setY(box.getY() + bottomIndentLeftovers);
box.setHeight(box.getHeight() - bottomIndentLeftovers);
}
}
private void processUsedChildBufferSpaceOnTop(Rectangle layoutBox) {
float childUsedBufferSpaceOnTop = childMarginInfo.getUsedBufferSpaceOnTop();
if (childUsedBufferSpaceOnTop > 0) {
if (childUsedBufferSpaceOnTop > collapseInfo.getBufferSpaceOnTop()) {
childUsedBufferSpaceOnTop = collapseInfo.getBufferSpaceOnTop();
}
collapseInfo.setBufferSpaceOnTop(collapseInfo.getBufferSpaceOnTop() - childUsedBufferSpaceOnTop);
collapseInfo.setUsedBufferSpaceOnTop(childUsedBufferSpaceOnTop);
// usage of top buffer space on child is expressed by moving layout box down instead of making it smaller,
// so in order to process next kids correctly, we need to move parent layout box also
layoutBox.moveDown(childUsedBufferSpaceOnTop);
subtractUsedTopBufferFromBottomBuffer(childUsedBufferSpaceOnTop);
}
}
private void subtractUsedTopBufferFromBottomBuffer(float usedTopBuffer) {
if (collapseInfo.getBufferSpaceOnTop() > collapseInfo.getBufferSpaceOnBottom()) {
float bufferLeftoversOnTop = collapseInfo.getBufferSpaceOnTop() - usedTopBuffer;
if (bufferLeftoversOnTop < collapseInfo.getBufferSpaceOnBottom()) {
collapseInfo.setBufferSpaceOnBottom(bufferLeftoversOnTop);
}
} else {
collapseInfo.setBufferSpaceOnBottom(collapseInfo.getBufferSpaceOnBottom() - usedTopBuffer);
}
}
private void fixPrevChildOccupiedArea(int childIndex) {
IRenderer prevRenderer = getRendererChild(childIndex - 1);
Rectangle bBox = prevRenderer.getOccupiedArea().getBBox();
boolean prevChildHasAppliedCollapseAfter = !prevChildMarginInfo.isIgnoreOwnMarginBottom()
&& (!prevChildMarginInfo.isSelfCollapsing() || !prevChildMarginInfo.isIgnoreOwnMarginTop());
if (prevChildHasAppliedCollapseAfter) {
float bottomMargin = prevChildMarginInfo.getCollapseAfter().getCollapsedMarginsSize();
bBox.setHeight(bBox.getHeight() - bottomMargin);
bBox.moveUp(bottomMargin);
ignoreModelBottomMargin(prevRenderer);
}
boolean isNotBlockChild = !isBlockElement(getRendererChild(childIndex));
boolean prevChildCanApplyCollapseAfter = !prevChildMarginInfo.isSelfCollapsing() || !prevChildMarginInfo.isIgnoreOwnMarginTop();
if (isNotBlockChild && prevChildCanApplyCollapseAfter) {
float ownCollapsedMargins = prevChildMarginInfo.getOwnCollapseAfter().getCollapsedMarginsSize();
bBox.setHeight(bBox.getHeight() + ownCollapsedMargins);
bBox.moveDown(ownCollapsedMargins);
overrideModelBottomMargin(prevRenderer, ownCollapsedMargins);
}
}
private void addNotYetAppliedTopMargin(Rectangle layoutBox) {
// normally, space for margins is added when content is met, however if all kids were self-collapsing (i.e.
// had no content) or if there were no kids, we need to add it when no more adjoining margins will be met
float indentTop = collapseInfo.getCollapseBefore().getCollapsedMarginsSize();
renderer.getOccupiedArea().getBBox().moveDown(indentTop);
// Even though all kids have been already drawn, we still need to adjust layout box here
// in order to make it represent the available area for element content (e.g. needed for fixed height elements).
applyTopMargin(layoutBox, indentTop);
}
// Actually, this should be taken into account when layouting a kid and assuming it's the last one on page.
// However it's not feasible, because
// - before kid layout, we don't know if it's self-collapsing or if we have applied clearance to it;
// - this might be very difficult to correctly change kid and parent occupy area, based on if it's
// the last kid on page or not;
// - in the worst case scenario (which is kinda rare) page last kid (self-collapsed and with clearance)
// margin applying would result in margins page overflow, which will not be visible except
// margins would be visually less than expected.
private void applySelfCollapsedKidMarginWithClearance(Rectangle layoutBox) {
// Self-collapsed kid margin with clearance will not be applied to parent top margin
// if parent is not self-collapsing. It's self-collapsing kid, thus we just can
// add this area to occupied area of parent.
float clearedKidMarginWithClearance = prevChildMarginInfo.getOwnCollapseAfter().getCollapsedMarginsSize();
renderer.getOccupiedArea().getBBox().
increaseHeight(clearedKidMarginWithClearance)
.moveDown(clearedKidMarginWithClearance);
layoutBox.decreaseHeight(clearedKidMarginWithClearance);
}
private IRenderer getRendererChild(int index) {
return rendererChildren.get(index);
}
private IRenderer removeRendererChild(int index) {
return rendererChildren.remove(index);
}
private void getRidOfCollapseArtifactsAtopOccupiedArea() {
Rectangle bBox = renderer.getOccupiedArea().getBBox();
bBox.decreaseHeight(collapseInfo.getCollapseBefore().getCollapsedMarginsSize());
}
private static boolean marginsCouldBeSelfCollapsing(IRenderer renderer) {
return !(renderer instanceof TableRenderer)
&& !rendererIsFloated(renderer)
&& !hasBottomBorders(renderer) && !hasTopBorders(renderer)
&& !hasBottomPadding(renderer) && !hasTopPadding(renderer) && !hasPositiveHeight(renderer)
// inline block
&& !(isBlockElement(renderer) && renderer instanceof AbstractRenderer && ((AbstractRenderer) renderer).getParent() instanceof LineRenderer);
}
private static boolean firstChildMarginAdjoinedToParent(IRenderer parent) {
return !BlockFormattingContextUtil.isRendererCreateBfc(parent)
&& !(parent instanceof TableRenderer)
&& !hasTopBorders(parent) && !hasTopPadding(parent);
}
private static boolean lastChildMarginAdjoinedToParent(IRenderer parent) {
return !BlockFormattingContextUtil.isRendererCreateBfc(parent)
&& !(parent instanceof TableRenderer)
&& !hasBottomBorders(parent) && !hasBottomPadding(parent) && !hasHeightProp(parent);
}
private static boolean isBlockElement(IRenderer renderer) {
return renderer instanceof BlockRenderer || renderer instanceof TableRenderer;
}
private static boolean hasHeightProp(IRenderer renderer) {
// in mozilla and chrome height always prevents margins collapse in all cases.
return renderer.getModelElement().hasProperty(Property.HEIGHT);
// "min-height" property affects margins collapse differently in chrome and mozilla. While in chrome, this property
// seems to not have any effect on collapsing margins at all (child margins collapse with parent margins even if
// there is a considerable space between them due to the min-height property on parent), mozilla behaves better
// and collapse happens only in case min-height of parent is less than actual height of the content and therefore
// collapse really should happen. However even in mozilla, if parent has min-height which is a little bigger then
// it's content actual height and margin collapse doesn't happen, in this case the child's margin is not shown fully however.
//
// || styles.containsKey(CssConstants.MIN_HEIGHT)
// "max-height" doesn't seem to affect margins collapse in any way at least in chrome.
// In mozilla it affects collapsing when parent's max-height is less than children actual height,
// in this case collapse doesn't happen. However, at the moment in iText we won't show anything at all if
// kid's height is bigger than parent's max-height, therefore this logic is irrelevant now anyway.
//
// || (includingMaxHeight && styles.containsKey(CssConstants.MAX_HEIGHT));
}
private static boolean hasPositiveHeight(IRenderer renderer) {
float height = renderer.getOccupiedArea().getBBox().getHeight();
if (height == 0) {
UnitValue heightPropVal = renderer.getProperty(Property.HEIGHT);
UnitValue minHeightPropVal = renderer.getProperty(Property.MIN_HEIGHT);
height = minHeightPropVal != null
? (float) minHeightPropVal.getValue()
: heightPropVal != null ? (float) heightPropVal.getValue() : 0;
}
return height > 0;
}
private static boolean hasTopPadding(IRenderer renderer) {
return MarginsCollapseHandler.hasPadding(renderer, Property.PADDING_TOP);
}
private static boolean hasBottomPadding(IRenderer renderer) {
return MarginsCollapseHandler.hasPadding(renderer, Property.PADDING_BOTTOM);
}
private static boolean hasTopBorders(IRenderer renderer) {
return MarginsCollapseHandler.hasBorders(renderer, Property.BORDER_TOP);
}
private static boolean hasBottomBorders(IRenderer renderer) {
return MarginsCollapseHandler.hasBorders(renderer, Property.BORDER_BOTTOM);
}
private static boolean rendererIsFloated(IRenderer renderer) {
if (renderer == null) {
return false;
}
FloatPropertyValue floatPropertyValue = renderer.getProperty(Property.FLOAT);
return floatPropertyValue != null && !floatPropertyValue.equals(FloatPropertyValue.NONE);
}
private static float defineTopMarginValueForCollapse(IRenderer renderer) {
return MarginsCollapseHandler.defineMarginValueForCollapse(renderer, Property.MARGIN_TOP);
}
private static void ignoreModelTopMargin(IRenderer renderer) {
MarginsCollapseHandler.overrideModelTopMargin(renderer, 0f);
}
private static void overrideModelTopMargin(IRenderer renderer, float collapsedMargins) {
MarginsCollapseHandler.overrideModelMargin(renderer, Property.MARGIN_TOP, collapsedMargins);
}
private static float defineBottomMarginValueForCollapse(IRenderer renderer) {
return MarginsCollapseHandler.defineMarginValueForCollapse(renderer, Property.MARGIN_BOTTOM);
}
private static void ignoreModelBottomMargin(IRenderer renderer) {
MarginsCollapseHandler.overrideModelBottomMargin(renderer, 0f);
}
private static void overrideModelBottomMargin(IRenderer renderer, float collapsedMargins) {
MarginsCollapseHandler.overrideModelMargin(renderer, Property.MARGIN_BOTTOM, collapsedMargins);
}
private static float defineMarginValueForCollapse(IRenderer renderer, int property) {
UnitValue marginUV = renderer.getModelElement().getProperty(property);
if (null != marginUV && !marginUV.isPointValue()) {
Logger logger = LoggerFactory.getLogger(MarginsCollapseHandler.class);
logger.error(MessageFormatUtil.format(IoLogMessageConstant.PROPERTY_IN_PERCENTS_NOT_SUPPORTED,
property));
}
return marginUV != null && !(renderer instanceof CellRenderer) ? marginUV.getValue() : 0;
}
private static void overrideModelMargin(IRenderer renderer, int property, float collapsedMargins) {
renderer.setProperty(property, UnitValue.createPointValue(collapsedMargins));
}
private static boolean hasPadding(IRenderer renderer, int property) {
UnitValue padding = renderer.getModelElement().getProperty(property);
if (null != padding && !padding.isPointValue()) {
Logger logger = LoggerFactory.getLogger(MarginsCollapseHandler.class);
logger.error(MessageFormatUtil.format(IoLogMessageConstant.PROPERTY_IN_PERCENTS_NOT_SUPPORTED,
property));
}
return padding != null && padding.getValue() > 0;
}
private static boolean hasBorders(IRenderer renderer, int property) {
IPropertyContainer modelElement = renderer.getModelElement();
return modelElement.hasProperty(property) || modelElement.hasProperty(Property.BORDER);
}
}