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Open HTML to PDF is a CSS 2.1 renderer written in Java. This artifact contains the core rendering and layout code.
/*
* Copyright (c) 2005 Patrick Wright
* Copyright (c) 2007 Wisconsin Court System
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
package com.openhtmltopdf.css.style.derived;
import java.util.logging.Level;
import org.w3c.dom.css.CSSPrimitiveValue;
import com.openhtmltopdf.css.constants.CSSName;
import com.openhtmltopdf.css.constants.ValueConstants;
import com.openhtmltopdf.css.parser.PropertyValue;
import com.openhtmltopdf.css.style.CalculatedStyle;
import com.openhtmltopdf.css.style.CssContext;
import com.openhtmltopdf.css.style.DerivedValue;
import com.openhtmltopdf.css.value.FontSpecification;
import com.openhtmltopdf.util.XRLog;
public class LengthValue extends DerivedValue {
private final static int MM__PER__CM = 10;
private final static float CM__PER__IN = 2.54F;
private final static float PT__PER__IN = 1f / 72f;
private final static float PC__PER__PT = 12;
/**
* The specified length value, as a float; pulled from the CSS text
*/
private float _lengthAsFloat;
private CalculatedStyle _style;
/**
* The specified primitive SAC data type given for this length, from the CSS text
*/
private short _lengthPrimitiveType;
public LengthValue(CalculatedStyle style, CSSName name, PropertyValue value) {
super(name, value.getPrimitiveType(), value.getCssText(), value.getCssText());
_style = style;
_lengthAsFloat = value.getFloatValue();
_lengthPrimitiveType = value.getPrimitiveType();
}
public float asFloat() {
return _lengthAsFloat;
}
/**
* Computes a relative unit (e.g. percentage) as an absolute value, using
* the input value. Used for such properties whose parent value cannot be
* known before layout/render
*
* @param cssName Name of the property
* @param baseValue
* @param ctx
* @return the absolute value or computed absolute value
*/
public float getFloatProportionalTo(CSSName cssName,
float baseValue,
CssContext ctx) {
return calcFloatProportionalValue(getStyle(),
cssName,
getStringValue(),
_lengthAsFloat,
_lengthPrimitiveType,
baseValue,
ctx);
}
public boolean hasAbsoluteUnit() {
return ValueConstants.isAbsoluteUnit(getCssSacUnitType());
}
public boolean isDependentOnFontSize() {
return _lengthPrimitiveType == CSSPrimitiveValue.CSS_EXS ||
_lengthPrimitiveType == CSSPrimitiveValue.CSS_EMS;
}
public static float calcFloatProportionalValue(CalculatedStyle style,
CSSName cssName,
String stringValue,
float relVal,
short primitiveType,
float baseValue,
CssContext ctx) {
float absVal = Float.MIN_VALUE;
// NOTE: we used to cache absolute values, but have removed that to see if it
// really makes a difference, since the calcs are so simple. In any case, for DPI-relative
// values we shouldn't be caching, unless we also check if the DPI is changed, which
// would seem to obviate the advantage of caching anyway.
switch (primitiveType) {
case CSSPrimitiveValue.CSS_PX:
absVal = relVal * ctx.getDotsPerPixel();
break;
case CSSPrimitiveValue.CSS_IN:
absVal = (((relVal * CM__PER__IN) * MM__PER__CM) / ctx.getMmPerDot());
break;
case CSSPrimitiveValue.CSS_CM:
absVal = ((relVal * MM__PER__CM) / ctx.getMmPerDot());
break;
case CSSPrimitiveValue.CSS_MM:
absVal = relVal / ctx.getMmPerDot();
break;
case CSSPrimitiveValue.CSS_PT:
absVal = (((relVal * PT__PER__IN) * CM__PER__IN) * MM__PER__CM) / ctx.getMmPerDot();
break;
case CSSPrimitiveValue.CSS_PC:
absVal = ((((relVal * PC__PER__PT) * PT__PER__IN) * CM__PER__IN) * MM__PER__CM) / ctx.getMmPerDot();
break;
case CSSPrimitiveValue.CSS_EMS:
// EM is equal to font-size of element on which it is used
// The exception is when ?em? occurs in the value of
// the ?font-size? property itself, in which case it refers
// to the calculated font size of the parent element
// http://www.w3.org/TR/CSS21/fonts.html#font-size-props
if (cssName == CSSName.FONT_SIZE) {
FontSpecification parentFont = style.getParent().getFont(ctx);
//font size and FontSize2D should be identical
absVal = relVal * parentFont.size;//ctx.getFontSize2D(parentFont);
} else {
absVal = relVal * style.getFont(ctx).size;//ctx.getFontSize2D(style.getFont(ctx));
}
break;
case CSSPrimitiveValue.CSS_EXS:
// To convert EMS to pixels, we need the height of the lowercase 'Xx' character in the current
// element...
// to the font size of the parent element (spec: 4.3.2)
float xHeight;
if (cssName == CSSName.FONT_SIZE) {
FontSpecification parentFont = style.getParent().getFont(ctx);
xHeight = ctx.getXHeight(parentFont);
} else {
FontSpecification font = style.getFont(ctx);
xHeight = ctx.getXHeight(font);
}
absVal = relVal * xHeight;
break;
case CSSPrimitiveValue.CSS_PERCENTAGE:
// percentage depends on the property this value belongs to
if (cssName == CSSName.VERTICAL_ALIGN) {
baseValue = style.getParent().getLineHeight(ctx);
} else if (cssName == CSSName.FONT_SIZE) {
// same as with EM
FontSpecification parentFont = style.getParent().getFont(ctx);
baseValue = ctx.getFontSize2D(parentFont);
} else if (cssName == CSSName.LINE_HEIGHT) {
FontSpecification font = style.getFont(ctx);
baseValue = ctx.getFontSize2D(font);
}
absVal = (relVal / 100F) * baseValue;
break;
case CSSPrimitiveValue.CSS_NUMBER:
absVal = relVal;
break;
default:
// nothing to do, we only convert those listed above
XRLog.cascade(Level.SEVERE,
"Asked to convert " + cssName + " from relative to absolute, " +
" don't recognize the datatype " +
"'" + ValueConstants.stringForSACPrimitiveType(primitiveType) + "' "
+ primitiveType + "(" + stringValue + ")");
}
//assert (new Float(absVal).intValue() >= 0);
if (XRLog.isLoggingEnabled()) {
if (cssName == CSSName.FONT_SIZE) {
XRLog.cascade(Level.FINEST, cssName + ", relative= " +
relVal + " (" + stringValue + "), absolute= "
+ absVal);
} else {
XRLog.cascade(Level.FINEST, cssName + ", relative= " +
relVal + " (" + stringValue + "), absolute= "
+ absVal + " using base=" + baseValue);
}
}
double d = Math.round((double) absVal);
absVal = new Float(d).floatValue();
return absVal;
}
private CalculatedStyle getStyle() {
return _style;
}
}
/*
* $Id$
*/