/*
* Copyright (c) 2002-2007 JGoodies Karsten Lentzsch. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* o Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* o Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* o Neither the name of JGoodies Karsten Lentzsch nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.jgoodies.forms.util;
import java.awt.Component;
import java.awt.FontMetrics;
import java.awt.Toolkit;
/**
* An abstract implementation of the {@link UnitConverter} interface that
* minimizes the effort required to convert font-dependent sizes to pixels.
*
* @author Karsten Lentzsch
* @version $Revision$
*
* @see DefaultUnitConverter
* @see com.jgoodies.forms.layout.Size
* @see com.jgoodies.forms.layout.Sizes
*/
public abstract class AbstractUnitConverter implements UnitConverter {
private static final int DTP_RESOLUTION = 72;
// Unit Converter Implementation *********************************************
/**
* Converts Inches and returns pixels using the specified resolution.
*
* @param in the Inches
* @param component the component that provides the graphics object
* @return the given Inches as pixels
*/
public int inchAsPixel(double in, Component component) {
return inchAsPixel(in, getScreenResolution(component));
}
/**
* Converts Millimeters and returns pixels using the resolution of the
* given component's graphics object.
*
* @param mm Millimeters
* @param component the component that provides the graphics object
* @return the given Millimeters as pixels
*/
public int millimeterAsPixel(double mm, Component component) {
return millimeterAsPixel(mm, getScreenResolution(component));
}
/**
* Converts Centimeters and returns pixels using the resolution of the
* given component's graphics object.
*
* @param cm Centimeters
* @param component the component that provides the graphics object
* @return the given Centimeters as pixels
*/
public int centimeterAsPixel(double cm, Component component) {
return centimeterAsPixel(cm, getScreenResolution(component));
}
/**
* Converts DTP Points and returns pixels using the resolution of the
* given component's graphics object.
*
* @param pt DTP Points
* @param component the component that provides the graphics object
* @return the given Points as pixels
*/
public int pointAsPixel(int pt, Component component) {
return pointAsPixel(pt, getScreenResolution(component));
}
/**
* Converts horizontal dialog units and returns pixels.
* Honors the resolution, dialog font size, platform, and l&f.
*
* @param dluX the horizontal dialog units
* @param c a Component that provides the font and graphics
* @return the given horizontal dialog units as pixels
*/
public int dialogUnitXAsPixel(int dluX, Component c) {
return dialogUnitXAsPixel(dluX, getDialogBaseUnitsX(c));
}
/**
* Converts vertical dialog units and returns pixels.
* Honors the resolution, dialog font size, platform, and l&f.
*
* @param dluY the vertical dialog units
* @param c a Component that provides the font and graphics
* @return the given vertical dialog units as pixels
*/
public int dialogUnitYAsPixel(int dluY, Component c) {
return dialogUnitYAsPixel(dluY, getDialogBaseUnitsY(c));
}
// Abstract Behavior *****************************************************
/**
* Gets and returns the horizontal dialog base units.
* Implementations are encouraged to cache previously computed
* dialog base units.
*
* @param component a Component that provides the font and graphics
* @return the horizontal dialog base units
*/
protected abstract double getDialogBaseUnitsX(Component component);
/**
* Gets and returns the vertical dialog base units.
* Implementations are encouraged to cache previously computed
* dialog base units.
*
* @param component a Component that provides the font and graphics
* @return the vertical dialog base units
*/
protected abstract double getDialogBaseUnitsY(Component component);
// Convenience Methods ***************************************************
/**
* Converts Inches and returns pixels using the specified resolution.
*
* @param in the Inches
* @param dpi the resolution
* @return the given Inches as pixels
*/
protected final int inchAsPixel(double in, int dpi) {
return (int) Math.round(dpi * in);
}
/**
* Converts Millimeters and returns pixels using the specified resolution.
*
* @param mm Millimeters
* @param dpi the resolution
* @return the given Millimeters as pixels
*/
protected final int millimeterAsPixel(double mm, int dpi) {
return (int) Math.round(dpi * mm * 10 / 254);
}
/**
* Converts Centimeters and returns pixels using the specified resolution.
*
* @param cm Centimeters
* @param dpi the resolution
* @return the given Centimeters as pixels
*/
protected final int centimeterAsPixel(double cm, int dpi) {
return (int) Math.round(dpi * cm * 100 / 254);
}
/**
* Converts DTP Points and returns pixels using the specified resolution.
*
* @param pt DTP Points
* @param dpi the resolution in dpi
* @return the given Points as pixels
*/
protected final int pointAsPixel(int pt, int dpi) {
return Math.round(dpi * pt / DTP_RESOLUTION);
}
/**
* Converts horizontal dialog units and returns pixels.
*
* @param dluX the horizontal dialog units
* @param dialogBaseUnitsX the horizontal dialog base units
* @return the given dialog base units as pixels
*/
protected int dialogUnitXAsPixel(int dluX, double dialogBaseUnitsX) {
return (int) Math.round(dluX * dialogBaseUnitsX / 4);
}
/**
* Converts vertical dialog units and returns pixels.
*
* @param dluY the vertical dialog units
* @param dialogBaseUnitsY the vertical dialog base units
* @return the given dialog base units as pixels
*/
protected int dialogUnitYAsPixel(int dluY, double dialogBaseUnitsY) {
return (int) Math.round(dluY * dialogBaseUnitsY / 8);
}
// Helper Code ************************************************************
/**
* Computes and returns the average character width
* of the specified test string using the given FontMetrics.
* The test string shall represent an "average" text.
*
* @param metrics used to compute the test string's width
* @param testString the string that shall represent an "average" text
* @return the test string's average character width.
*/
protected double computeAverageCharWidth(FontMetrics metrics,
String testString) {
int width = metrics.stringWidth(testString);
double average = (double) width / testString.length();
//System.out.println("Average width of '" + testString + "'=" + average);
return average;
}
/**
* Returns the components screen resolution or the default screen
* resolution if the component is null or has no toolkit assigned yet.
*
* @param c the component to ask for a toolkit
* @return the component's screen resolution
*/
protected int getScreenResolution(Component c) {
if (c == null) {
return getDefaultScreenResolution();
}
Toolkit toolkit = c.getToolkit();
return toolkit != null ? toolkit.getScreenResolution()
: getDefaultScreenResolution();
}
private static int defaultScreenResolution = -1;
/**
* Computes and returns the default resolution.
*
* @return the default screen resolution
*/
protected int getDefaultScreenResolution() {
if (defaultScreenResolution == -1) {
defaultScreenResolution = Toolkit.getDefaultToolkit()
.getScreenResolution();
}
return defaultScreenResolution;
}
}