/* dIntProg Browser. A webbrowser written in Java.
* Copyright (C) 2001 Martin Geisler <[email protected]>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 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
* General Public License for more details.
*
* You should have received a copy of the GNU 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.
*/
import java.awt.Graphics;
import java.awt.Color;
import java.awt.Font;
import javax.swing.*;
import java.text.*;
import java.util.*;
import java.net.*;
/** A fragment of text. This is the basic building-block of all
* paragraphs. A <code>TextFragment</code> is meant to be used
* together with other fragments to form larger pieces of text. Each
* fragment has it's own content, font, and may be a link. */
public class TextFragment extends AbstractRigidBox {
private String content;
private Graphics pen;
private Font font;
private URL url;
/* A very small font - used when switching to the real font. */
private Font switch_font = new Font(null, Font.PLAIN, 4);
/** Creates a new <code>TextFragment</code>.
* @param str the string contained within this fragment. The
* string should contain any white-space necessary to ensure
* correct spacing when this fragment is placed side-to-side with
* other fragments.
* @param f the font that will be used when rendering the
* fragment. The font is also used when the content is meassured.
* @param u the URL that this fragment links to. If the fragment
* doesn't link to anywhere <code>u</code> should be
* <code>null</code>. */
public TextFragment(String str, Font f, URL u) {
content = str;
font = f;
url = u;
}
/** Creates a new <code>TextFragment</code>. This is used when a
* fragment is split into two. The new fragments will have to be
* created by this constructor, as this is the only way to give
* the new fragments the needed graphics context.
* @param str the string contained within this fragment. The
* string should contain any white-space necessary to ensure
* correct spacing when this fragment is placed side-to-side with
* other fragments.
* @param f the font that will be used when rendering the
* fragment. The font is also used when the content is meassured.
* @param u the URL that this fragment links to. If the fragment
* doesn't link to anywhere <code>u</code> should be
* <code>null</code>. */
private TextFragment(String str, Font f, URL u, Graphics g) {
this(str, f, u);
doLayout(g, null, 0);
}
public void doLayout(Graphics g, JComponent c, int w) {
if (width == -1) {
/* Argh! Java has a strange and stupid bug that means that
* font changes doesn't apply until you change the /size/
* of the font /and/ draw with it. */
g.setFont(switch_font);
g.drawString("", 0, 0);
/* We can now use the real font. */
g.setFont(font);
width = g.getFontMetrics().stringWidth(content);
height = g.getFontMetrics().getHeight();
pen = g;
Browser.debug("TextFragment.doLayout: " + this);
}
}
/** Returns the width of it's argument.
* @param s the string to be meassured. */
private int stringWidth(String s) {
pen.setFont(font);
return pen.getFontMetrics().stringWidth(s);
}
/** Returns the minimum width of this <code>TextFragment</code>.
* The result is calculated by meassuring every word in the
* string and is only calculated once for each fragment.
* @return the minimum width.*/
public int getMinimumWidth() {
/* We calculate the minimum width, if necessary */
if (min_width == -1) {
StringTokenizer st = new StringTokenizer(content, " ");
while (st.hasMoreTokens()) {
String s = st.nextToken();
int w = stringWidth(s);
if (w > min_width) {
min_width = w;
}
}
}
return min_width;
}
/** Reports if a split is possible at <code>w</code>. For a
* fragment to be split, it must contain more than a single word.
* If it does, the width of the initial word (plus any white
* space at the beginning) is meassured and compared with
* <code>w</code>.
* @param w the desired width of the head.
* @return <code>true</code> if <code>w</code> is greather than
* the length of the initial word. */
public boolean splitIsPossible(int w) {
int offset = content.indexOf(' ');
if (offset == 0) {
/* The string starts with a space. We look the for
* next space. */
offset = content.indexOf(' ', 1);
}
if (offset == -1 || offset == content.length()-1) {
/* There is only a single word in the string, which
* might end with a space. */
return false;
} else {
/* We return the length of the first word (plus the
* initial white space, if any) */
String substr = content.substring(0, offset);
return (w > stringWidth(substr));
}
}
public void drawAt(int x, int y, DocumentView v) {
if (url != null) {
v.drawString(x, y, height, content, font,
new HyperLink(x, y, width, height, url));
} else {
v.drawString(x, y, height, content, font, null);
}
if (Browser.debugging) {
v.drawRect(x, y, width, height, Color.orange);
}
}
public Box splitHead(int w) {
StringTokenizer st = new StringTokenizer(content, " ", true);
String result = "";
String s = st.nextToken();
int x_offset = stringWidth(s);
while (st.hasMoreTokens() && x_offset < w) {
result = result + s;
s = st.nextToken();
x_offset = x_offset + stringWidth(s);
}
return new TextFragment(result, font, url, pen);
}
public Box splitTail(int w) {
StringTokenizer st = new StringTokenizer(content, " ", true);
String result = "";
String s = st.nextToken();
int x_offset = stringWidth(s);
while (st.hasMoreTokens() && x_offset < w) {
result = result + s;
s = st.nextToken();
x_offset = x_offset + stringWidth(s);
}
result = content.substring(result.length());
/* The tail shouldn't start with a space. */
if (result.charAt(0) == ' ') {
result = result.substring(1);
}
return new TextFragment(result, font, url, pen);
}
public Box getSmallestHead() {
int offset = content.indexOf(' ');
if (offset == -1 || offset == content.length()-1) {
/* There is only a single word in the string. */
return null;
} else {
return new TextFragment(content.substring(0, offset),
font, url, pen);
}
}
public Box getLargestTail() {
int offset = content.indexOf(' ');
if (offset == -1 || offset == content.length()-1) {
/* There is only a single word in the string. */
return null;
} else {
return new TextFragment(content.substring(offset + 1),
font, url, pen);
}
}
public void trim(int edge) {
Browser.debug("Trimming: " + this);
if (content.length() > 0) {
if (edge == RigidBox.LEFT &&
content.charAt(0) == ' ') {
content = content.substring(0);
} else if (edge == RigidBox.RIGHT &&
content.charAt(content.length()-1) == ' ') {
content = content.substring(0, content.length()-1);
} else if (edge == RigidBox.BOTH) {
content = content.trim();
}
width = stringWidth(content);
}
}
public String toString() {
if (content.length() > 16) {
return "'" + content.substring(0, 13) +
"...': " + width + "x" + height;
} else {
return "'" + content + "': " + width + "x" + height;
}
}
}