How to calculate the length (in pixels) of a string in Java?
Preferable without using Swing.
EDIT: I would like to draw the string using the drawString() in Java2D and use the length for word wrapping.
This question is related to
java
string-length
I personally was searching for something to let me compute the multiline string area, so I could determine if given area is big enough to print the string - with preserving specific font.
private static Hashtable hash = new Hashtable();
private Font font;
private LineBreakMeasurer lineBreakMeasurer;
private int start, end;
public PixelLengthCheck(Font font) {
this.font = font;
}
public boolean tryIfStringFits(String textToMeasure, Dimension areaToFit) {
AttributedString attributedString = new AttributedString(textToMeasure, hash);
attributedString.addAttribute(TextAttribute.FONT, font);
AttributedCharacterIterator attributedCharacterIterator =
attributedString.getIterator();
start = attributedCharacterIterator.getBeginIndex();
end = attributedCharacterIterator.getEndIndex();
lineBreakMeasurer = new LineBreakMeasurer(attributedCharacterIterator,
new FontRenderContext(null, false, false));
float width = (float) areaToFit.width;
float height = 0;
lineBreakMeasurer.setPosition(start);
while (lineBreakMeasurer.getPosition() < end) {
TextLayout textLayout = lineBreakMeasurer.nextLayout(width);
height += textLayout.getAscent();
height += textLayout.getDescent() + textLayout.getLeading();
}
boolean res = height <= areaToFit.getHeight();
return res;
}
It doesn't always need to be toolkit-dependent or one doesn't always need use the FontMetrics approach since it requires one to first obtain a graphics object which is absent in a web container or in a headless enviroment.
I have tested this in a web servlet and it does calculate the text width.
import java.awt.Font;
import java.awt.font.FontRenderContext;
import java.awt.geom.AffineTransform;
...
String text = "Hello World";
AffineTransform affinetransform = new AffineTransform();
FontRenderContext frc = new FontRenderContext(affinetransform,true,true);
Font font = new Font("Tahoma", Font.PLAIN, 12);
int textwidth = (int)(font.getStringBounds(text, frc).getWidth());
int textheight = (int)(font.getStringBounds(text, frc).getHeight());
Add the necessary values to these dimensions to create any required margin.
And now for something completely different. The following assumes arial font, and makes a wild guess based on a linear interpolation of character vs width.
// Returns the size in PICA of the string, given space is 200 and 'W' is 1000.
// see https://p2p.wrox.com/access/32197-calculate-character-widths.html
static int picaSize(String s)
{
// the following characters are sorted by width in Arial font
String lookup = " .:,;'^`!|jl/\\i-()JfIt[]?{}sr*a\"ce_gFzLxkP+0123456789<=>~qvy$SbduEphonTBCXY#VRKZN%GUAHD@OQ&wmMW";
int result = 0;
for (int i = 0; i < s.length(); ++i)
{
int c = lookup.indexOf(s.charAt(i));
result += (c < 0 ? 60 : c) * 7 + 200;
}
return result;
}
Interesting, but perhaps not very practical.
I personally was searching for something to let me compute the multiline string area, so I could determine if given area is big enough to print the string - with preserving specific font.
private static Hashtable hash = new Hashtable();
private Font font;
private LineBreakMeasurer lineBreakMeasurer;
private int start, end;
public PixelLengthCheck(Font font) {
this.font = font;
}
public boolean tryIfStringFits(String textToMeasure, Dimension areaToFit) {
AttributedString attributedString = new AttributedString(textToMeasure, hash);
attributedString.addAttribute(TextAttribute.FONT, font);
AttributedCharacterIterator attributedCharacterIterator =
attributedString.getIterator();
start = attributedCharacterIterator.getBeginIndex();
end = attributedCharacterIterator.getEndIndex();
lineBreakMeasurer = new LineBreakMeasurer(attributedCharacterIterator,
new FontRenderContext(null, false, false));
float width = (float) areaToFit.width;
float height = 0;
lineBreakMeasurer.setPosition(start);
while (lineBreakMeasurer.getPosition() < end) {
TextLayout textLayout = lineBreakMeasurer.nextLayout(width);
height += textLayout.getAscent();
height += textLayout.getDescent() + textLayout.getLeading();
}
boolean res = height <= areaToFit.getHeight();
return res;
}
It doesn't always need to be toolkit-dependent or one doesn't always need use the FontMetrics approach since it requires one to first obtain a graphics object which is absent in a web container or in a headless enviroment.
I have tested this in a web servlet and it does calculate the text width.
import java.awt.Font;
import java.awt.font.FontRenderContext;
import java.awt.geom.AffineTransform;
...
String text = "Hello World";
AffineTransform affinetransform = new AffineTransform();
FontRenderContext frc = new FontRenderContext(affinetransform,true,true);
Font font = new Font("Tahoma", Font.PLAIN, 12);
int textwidth = (int)(font.getStringBounds(text, frc).getWidth());
int textheight = (int)(font.getStringBounds(text, frc).getHeight());
Add the necessary values to these dimensions to create any required margin.
And now for something completely different. The following assumes arial font, and makes a wild guess based on a linear interpolation of character vs width.
// Returns the size in PICA of the string, given space is 200 and 'W' is 1000.
// see https://p2p.wrox.com/access/32197-calculate-character-widths.html
static int picaSize(String s)
{
// the following characters are sorted by width in Arial font
String lookup = " .:,;'^`!|jl/\\i-()JfIt[]?{}sr*a\"ce_gFzLxkP+0123456789<=>~qvy$SbduEphonTBCXY#VRKZN%GUAHD@OQ&wmMW";
int result = 0;
for (int i = 0; i < s.length(); ++i)
{
int c = lookup.indexOf(s.charAt(i));
result += (c < 0 ? 60 : c) * 7 + 200;
}
return result;
}
Interesting, but perhaps not very practical.
Use the getWidth method in the following class:
import java.awt.*;
import java.awt.geom.*;
import java.awt.font.*;
class StringMetrics {
Font font;
FontRenderContext context;
public StringMetrics(Graphics2D g2) {
font = g2.getFont();
context = g2.getFontRenderContext();
}
Rectangle2D getBounds(String message) {
return font.getStringBounds(message, context);
}
double getWidth(String message) {
Rectangle2D bounds = getBounds(message);
return bounds.getWidth();
}
double getHeight(String message) {
Rectangle2D bounds = getBounds(message);
return bounds.getHeight();
}
}
Use the getWidth method in the following class:
import java.awt.*;
import java.awt.geom.*;
import java.awt.font.*;
class StringMetrics {
Font font;
FontRenderContext context;
public StringMetrics(Graphics2D g2) {
font = g2.getFont();
context = g2.getFontRenderContext();
}
Rectangle2D getBounds(String message) {
return font.getStringBounds(message, context);
}
double getWidth(String message) {
Rectangle2D bounds = getBounds(message);
return bounds.getWidth();
}
double getHeight(String message) {
Rectangle2D bounds = getBounds(message);
return bounds.getHeight();
}
}
Source: Stackoverflow.com