FlexApplierUtil.java

/*
    This file is part of the iText (R) project.
    Copyright (c) 1998-2022 iText Group NV
    Authors: Bruno Lowagie, Paulo Soares, et al.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License version 3
    as published by the Free Software Foundation with the addition of the
    following permission added to Section 15 as permitted in Section 7(a):
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    or FITNESS FOR A PARTICULAR PURPOSE.
    See the GNU Affero General Public License for more details.
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 */
package com.itextpdf.html2pdf.css.apply.util;

import com.itextpdf.html2pdf.attach.ProcessorContext;
import com.itextpdf.html2pdf.css.CssConstants;
import com.itextpdf.html2pdf.logs.Html2PdfLogMessageConstant;
import com.itextpdf.commons.utils.MessageFormatUtil;
import com.itextpdf.layout.IPropertyContainer;
import com.itextpdf.layout.properties.AlignmentPropertyValue;
import com.itextpdf.layout.properties.JustifyContent;
import com.itextpdf.layout.properties.Property;
import com.itextpdf.layout.properties.UnitValue;
import com.itextpdf.styledxmlparser.css.CommonCssConstants;
import com.itextpdf.styledxmlparser.css.util.CssDimensionParsingUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

/**
 * Utilities class to apply flex properties.
 */
final public class FlexApplierUtil {

    private static final Logger LOGGER = LoggerFactory.getLogger(FlexApplierUtil.class);

    private FlexApplierUtil() {
    }

    /**
     * Applies properties to a flex item.
     *
     * @param cssProps the map of the CSS properties
     * @param context  the context of the converter processor
     * @param element  the element to set the properties
     */
    public static void applyFlexItemProperties(Map<String, String> cssProps, ProcessorContext context,
            IPropertyContainer element) {
        element.setProperty(Property.COLLAPSING_MARGINS, null);

        logWarningIfThereAreNotSupportedPropertyValues(createSupportedFlexItemPropertiesAndValuesMap(), cssProps);

        final String flexGrow = cssProps.get(CommonCssConstants.FLEX_GROW);
        if (flexGrow != null) {
            final Float flexGrowValue = CssDimensionParsingUtils.parseFloat(flexGrow);
            element.setProperty(Property.FLEX_GROW, flexGrowValue);
        }

        final String flexShrink = cssProps.get(CommonCssConstants.FLEX_SHRINK);
        if (flexShrink != null) {
            final Float flexShrinkValue = CssDimensionParsingUtils.parseFloat(flexShrink);
            element.setProperty(Property.FLEX_SHRINK, flexShrinkValue);
        }

        final String flexBasis = cssProps.get(CommonCssConstants.FLEX_BASIS);
        if (flexBasis == null || CommonCssConstants.AUTO.equals(flexBasis)) {
            // TODO DEVSIX-5003 use height as the main size if flex-direction: column.
            // we use main size property as a flex-basis value (when flex-basis: auto) in
            // corresponding with documentation https://www.w3.org/TR/css-flexbox-1/#valdef-flex-flex-basis
            final String flexElementWidth = cssProps.get(CommonCssConstants.WIDTH);
            if (flexElementWidth != null) {
                final float em = CssDimensionParsingUtils.parseAbsoluteLength(cssProps.get(CssConstants.FONT_SIZE));
                final float rem = context.getCssContext().getRootFontSize();
                final UnitValue flexElementWidthAbsoluteLength = CssDimensionParsingUtils
                        .parseLengthValueToPt(flexElementWidth, em, rem);
                element.setProperty(Property.FLEX_BASIS, flexElementWidthAbsoluteLength);
            }
        } else if (!CommonCssConstants.CONTENT.equals(flexBasis)) {
            final float em = CssDimensionParsingUtils.parseAbsoluteLength(cssProps.get(CssConstants.FONT_SIZE));
            final float rem = context.getCssContext().getRootFontSize();
            final UnitValue flexBasisAbsoluteLength = CssDimensionParsingUtils
                    .parseLengthValueToPt(flexBasis, em, rem);
            element.setProperty(Property.FLEX_BASIS, flexBasisAbsoluteLength);
        } else {
            // The case when we don't set the flex-basis property should be identified
            // as flex-basis: content
            LOGGER.warn(MessageFormatUtil.format(Html2PdfLogMessageConstant.FLEX_PROPERTY_IS_NOT_SUPPORTED_YET,
                    CommonCssConstants.FLEX_BASIS, CommonCssConstants.CONTENT));
        }
    }

    /**
     * Applies properties to a flex container.
     *
     * @param cssProps the CSS properties
     * @param element  the element
     */
    public static void applyFlexContainerProperties(Map<String, String> cssProps, IPropertyContainer element) {
        logWarningIfThereAreNotSupportedPropertyValues(createSupportedFlexContainerPropertiesAndValuesMap(), cssProps);
        applyAlignItems(cssProps, element);
        applyJustifyContent(cssProps, element);
    }

    private static void applyAlignItems(Map<String, String> cssProps, IPropertyContainer element) {
        final String alignItemsString = cssProps.get(CommonCssConstants.ALIGN_ITEMS);
        if (alignItemsString != null) {
            AlignmentPropertyValue alignItems;
            switch (alignItemsString) {
                case CommonCssConstants.NORMAL:
                    alignItems = AlignmentPropertyValue.NORMAL;
                    break;
                case CommonCssConstants.START:
                    alignItems = AlignmentPropertyValue.START;
                    break;
                case CommonCssConstants.END:
                    alignItems = AlignmentPropertyValue.END;
                    break;
                case CommonCssConstants.FLEX_START:
                    alignItems = AlignmentPropertyValue.FLEX_START;
                    break;
                case CommonCssConstants.FLEX_END:
                    alignItems = AlignmentPropertyValue.FLEX_END;
                    break;
                case CommonCssConstants.CENTER:
                    alignItems = AlignmentPropertyValue.CENTER;
                    break;
                case CommonCssConstants.SELF_START:
                    alignItems = AlignmentPropertyValue.SELF_START;
                    break;
                case CommonCssConstants.SELF_END:
                    alignItems = AlignmentPropertyValue.SELF_END;
                    break;
                case CommonCssConstants.STRETCH:
                    alignItems = AlignmentPropertyValue.STRETCH;
                    break;
                default:
                    LOGGER.warn(MessageFormatUtil.format(Html2PdfLogMessageConstant.FLEX_PROPERTY_IS_NOT_SUPPORTED_YET,
                            CommonCssConstants.ALIGN_ITEMS, alignItemsString));
                    alignItems = AlignmentPropertyValue.STRETCH;
            }
            element.setProperty(Property.ALIGN_ITEMS, alignItems);
        }
    }

    private static void applyJustifyContent(Map<String, String> cssProps, IPropertyContainer element) {
        final String justifyContentString = cssProps.get(CommonCssConstants.JUSTIFY_CONTENT);
        if (justifyContentString != null) {
            JustifyContent justifyContent;
            switch (justifyContentString) {
                case CommonCssConstants.NORMAL:
                    justifyContent = JustifyContent.NORMAL;
                    break;
                case CommonCssConstants.START:
                    justifyContent = JustifyContent.START;
                    break;
                case CommonCssConstants.END:
                    justifyContent = JustifyContent.END;
                    break;
                case CommonCssConstants.FLEX_END:
                    justifyContent = JustifyContent.FLEX_END;
                    break;
                case CommonCssConstants.SELF_START:
                    justifyContent = JustifyContent.SELF_START;
                    break;
                case CommonCssConstants.SELF_END:
                    justifyContent = JustifyContent.SELF_END;
                    break;
                case CommonCssConstants.LEFT:
                    justifyContent = JustifyContent.LEFT;
                    break;
                case CommonCssConstants.RIGHT:
                    justifyContent = JustifyContent.RIGHT;
                    break;
                case CommonCssConstants.CENTER:
                    justifyContent = JustifyContent.CENTER;
                    break;
                case CommonCssConstants.STRETCH:
                    justifyContent = JustifyContent.STRETCH;
                    break;
                case CommonCssConstants.FLEX_START:
                    justifyContent = JustifyContent.FLEX_START;
                    break;
                default:
                    LOGGER.warn(MessageFormatUtil.format(Html2PdfLogMessageConstant.FLEX_PROPERTY_IS_NOT_SUPPORTED_YET,
                        CommonCssConstants.JUSTIFY_CONTENT, justifyContentString));
                    justifyContent = JustifyContent.FLEX_START;
                    break;
            }
            element.setProperty(Property.JUSTIFY_CONTENT, justifyContent);
        }
    }

    private static void logWarningIfThereAreNotSupportedPropertyValues(Map<String, Set<String>> supportedPairs,
                                                                       Map<String, String> cssProps) {
        for (Map.Entry<String, Set<String>> entry : supportedPairs.entrySet()) {
            String supportedPair = entry.getKey();
            Set<String> supportedValues = entry.getValue();
            String propertyValue = cssProps.get(supportedPair);
            if (propertyValue != null && !supportedValues.contains(propertyValue)) {
                LOGGER.warn(MessageFormatUtil.format(
                        Html2PdfLogMessageConstant.FLEX_PROPERTY_IS_NOT_SUPPORTED_YET, supportedPair, propertyValue));
            }
        }
    }

    private static Map<String, Set<String>> createSupportedFlexItemPropertiesAndValuesMap() {
        final Map<String, Set<String>> supportedPairs = new HashMap<>();

        final Set<String> supportedAlignSelfValues = new HashSet<>();
        supportedAlignSelfValues.add(CommonCssConstants.AUTO);

        supportedPairs.put(CommonCssConstants.ALIGN_SELF, supportedAlignSelfValues);

        final Set<String> supportedOrderValues = new HashSet<>();

        supportedPairs.put(CommonCssConstants.ORDER, supportedOrderValues);

        return supportedPairs;
    }

    private static Map<String, Set<String>> createSupportedFlexContainerPropertiesAndValuesMap() {
        final Map<String, Set<String>> supportedPairs = new HashMap<>();

        final Set<String> supportedFlexDirectionValues = new HashSet<>();
        supportedFlexDirectionValues.add(CommonCssConstants.ROW);

        supportedPairs.put(CommonCssConstants.FLEX_DIRECTION, supportedFlexDirectionValues);

        final Set<String> supportedFlexWrapValues = new HashSet<>();
        supportedFlexWrapValues.add(CommonCssConstants.NOWRAP);

        supportedPairs.put(CommonCssConstants.FLEX_WRAP, supportedFlexWrapValues);

        final Set<String> supportedAlignContentValues = new HashSet<>();
        supportedAlignContentValues.add(CommonCssConstants.STRETCH);
        supportedAlignContentValues.add(CommonCssConstants.NORMAL);

        supportedPairs.put(CommonCssConstants.ALIGN_CONTENT, supportedAlignContentValues);

        final Set<String> supportedRowGapValues = new HashSet<>();
        supportedRowGapValues.add(CommonCssConstants.NORMAL);

        supportedPairs.put(CommonCssConstants.ROW_GAP, supportedRowGapValues);

        final Set<String> supportedColumnGapValues = new HashSet<>();
        supportedColumnGapValues.add(CommonCssConstants.NORMAL);

        supportedPairs.put(CommonCssConstants.COLUMN_GAP, supportedColumnGapValues);

        return supportedPairs;
    }
}