/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* 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 Lesser General Public License for more details.
*
* Copyright (c) 2006 - 2013 Pentaho Corporation and Contributors. All rights reserved.
*/
package org.pentaho.reporting.libraries.css.resolver.values.percentages.text;
import org.pentaho.reporting.libraries.css.StyleSheetUtility;
import org.pentaho.reporting.libraries.css.dom.DocumentContext;
import org.pentaho.reporting.libraries.css.dom.LayoutElement;
import org.pentaho.reporting.libraries.css.dom.LayoutStyle;
import org.pentaho.reporting.libraries.css.keys.font.FontStyleKeys;
import org.pentaho.reporting.libraries.css.keys.text.TextStyleKeys;
import org.pentaho.reporting.libraries.css.model.StyleKey;
import org.pentaho.reporting.libraries.css.resolver.values.ResolveHandler;
import org.pentaho.reporting.libraries.css.values.CSSNumericType;
import org.pentaho.reporting.libraries.css.values.CSSNumericValue;
import org.pentaho.reporting.libraries.css.values.CSSValue;
import org.pentaho.reporting.libraries.fonts.registry.FontMetrics;
import org.pentaho.reporting.libraries.fonts.tools.FontStrictGeomUtility;
/**
* Creation-Date: 21.12.2005, 15:12:04
*
* @author Thomas Morgner
*/
public class LetterSpacingResolveHandler implements ResolveHandler
{
public LetterSpacingResolveHandler()
{
}
/**
* This indirectly defines the resolve order. The higher the order, the more
* dependent is the resolver on other resolvers to be complete.
*
* @return
*/
public StyleKey[] getRequiredStyles()
{
return new StyleKey[]{
FontStyleKeys.FONT_SIZE,
FontStyleKeys.FONT_FAMILY,
FontStyleKeys.FONT_EFFECT,
FontStyleKeys.FONT_SMOOTH,
FontStyleKeys.FONT_STRETCH,
FontStyleKeys.FONT_VARIANT,
FontStyleKeys.FONT_WEIGHT,
};
}
/**
* Resolves a single property.
*
* @param currentNode
*/
public void resolve(final DocumentContext process,
final LayoutElement currentNode,
final StyleKey key)
{
// Percentages get resolved against the width of a standard space (0x20)
// character.
final LayoutStyle layoutContext = currentNode.getLayoutStyle();
final FontMetrics fm = process.getOutputMetaData().getFontMetrics(layoutContext);
if (fm == null)
{
// we have no font family, so return.
layoutContext.setValue(TextStyleKeys.X_MIN_LETTER_SPACING, CSSNumericValue.ZERO_LENGTH);
layoutContext.setValue(TextStyleKeys.X_MAX_LETTER_SPACING, CSSNumericValue.ZERO_LENGTH);
layoutContext.setValue(TextStyleKeys.X_OPTIMUM_LETTER_SPACING, CSSNumericValue.ZERO_LENGTH);
return;
}
final double width = FontStrictGeomUtility.toExternalValue(fm.getCharWidth(0x20));
final CSSNumericValue percentageBase =
CSSNumericValue.createValue(CSSNumericType.PT, width);
final CSSNumericValue min = StyleSheetUtility.convertLength
(resolveValue(layoutContext, TextStyleKeys.X_MIN_LETTER_SPACING), percentageBase, currentNode);
final CSSNumericValue max = StyleSheetUtility.convertLength
(resolveValue(layoutContext, TextStyleKeys.X_MAX_LETTER_SPACING), percentageBase, currentNode);
final CSSNumericValue opt = StyleSheetUtility.convertLength
(resolveValue(layoutContext, TextStyleKeys.X_OPTIMUM_LETTER_SPACING), percentageBase, currentNode);
layoutContext.setValue(TextStyleKeys.X_MIN_LETTER_SPACING, min);
layoutContext.setValue(TextStyleKeys.X_MAX_LETTER_SPACING, max);
layoutContext.setValue(TextStyleKeys.X_OPTIMUM_LETTER_SPACING, opt);
}
private CSSNumericValue resolveValue(final LayoutStyle style, final StyleKey key)
{
final CSSValue value = style.getValue(key);
if (value instanceof CSSNumericValue == false)
{
// this also covers the valid 'normal' property.
// it simply means, dont add extra space to the already existing spaces
return CSSNumericValue.ZERO_LENGTH;
}
return (CSSNumericValue) value;
}
}