/*
* Copyright (c) 2011, the Dart project authors.
*
* Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.eclipse.org/legal/epl-v10.html
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.dart.tools.ui.internal.text.html;
import com.ibm.icu.text.BreakIterator;
import org.eclipse.jface.text.DefaultInformationControl;
import org.eclipse.jface.text.Region;
import org.eclipse.jface.text.TextPresentation;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.graphics.Drawable;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.widgets.Display;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.util.Iterator;
/**
* <p>
* Moved into this package from <code>org.eclipse.jface.internal.text.revisions</code>.
* </p>
*/
public class HTMLTextPresenter implements DefaultInformationControl.IInformationPresenter,
DefaultInformationControl.IInformationPresenterExtension {
public class LineBreakingReader {
private BufferedReader fReader;
private GC fGC;
private int fMaxWidth;
private String fLine;
private int fOffset;
private BreakIterator fLineBreakIterator;
private boolean fBreakWords;
/**
* Creates a reader that breaks an input text to fit in a given width.
*
* @param reader Reader of the input text
* @param gc The graphic context that defines the currently used font sizes
* @param maxLineWidth The max width (pixels) where the text has to fit in
*/
public LineBreakingReader(Reader reader, GC gc, int maxLineWidth) {
fReader = new BufferedReader(reader);
fGC = gc;
fMaxWidth = maxLineWidth;
fOffset = 0;
fLine = null;
fLineBreakIterator = BreakIterator.getLineInstance();
fBreakWords = true;
}
public boolean isFormattedLine() {
return fLine != null;
}
/**
* Reads the next line. The lengths of the line will not exceed the given maximum width.
*
* @return the next line
* @throws IOException
*/
public String readLine() throws IOException {
if (fLine == null) {
String line = fReader.readLine();
if (line == null) {
return null;
}
int lineLen = fGC.textExtent(line).x;
if (lineLen < fMaxWidth) {
return line;
}
fLine = line;
fLineBreakIterator.setText(line);
fOffset = 0;
}
int breakOffset = findNextBreakOffset(fOffset);
String res;
if (breakOffset != BreakIterator.DONE) {
res = fLine.substring(fOffset, breakOffset);
fOffset = findWordBegin(breakOffset);
if (fOffset == fLine.length()) {
fLine = null;
}
} else {
res = fLine.substring(fOffset);
fLine = null;
}
return res;
}
private int findNextBreakOffset(int currOffset) {
int currWidth = 0;
int nextOffset = fLineBreakIterator.following(currOffset);
while (nextOffset != BreakIterator.DONE) {
String word = fLine.substring(currOffset, nextOffset);
int wordWidth = fGC.textExtent(word).x;
int nextWidth = wordWidth + currWidth;
if (nextWidth > fMaxWidth) {
if (currWidth > 0) {
return currOffset;
}
if (!fBreakWords) {
return nextOffset;
}
// need to fit into fMaxWidth
int length = word.length();
while (length >= 0) {
length--;
word = word.substring(0, length);
wordWidth = fGC.textExtent(word).x;
if (wordWidth + currWidth < fMaxWidth) {
return currOffset + length;
}
}
return nextOffset;
}
currWidth = nextWidth;
currOffset = nextOffset;
nextOffset = fLineBreakIterator.next();
}
return nextOffset;
}
private int findWordBegin(int idx) {
while (idx < fLine.length() && Character.isWhitespace(fLine.charAt(idx))) {
idx++;
}
return idx;
}
}
private static final String LINE_DELIM = System.getProperty("line.separator", "\n"); //$NON-NLS-1$ //$NON-NLS-2$
private int fCounter;
private boolean fEnforceUpperLineLimit;
public HTMLTextPresenter() {
this(true);
}
public HTMLTextPresenter(boolean enforceUpperLineLimit) {
super();
fEnforceUpperLineLimit = enforceUpperLineLimit;
}
/*
* @see IHoverInformationPresenter#updatePresentation(Display display, String, TextPresentation,
* int, int)
*/
@Override
public String updatePresentation(Display display, String hoverInfo,
TextPresentation presentation, int maxWidth, int maxHeight) {
return updatePresentation((Drawable) display, hoverInfo, presentation, maxWidth, maxHeight);
}
/*
* @see IHoverInformationPresenterExtension#updatePresentation(Drawable drawable, String,
* TextPresentation, int, int)
*/
@Override
public String updatePresentation(Drawable drawable, String hoverInfo,
TextPresentation presentation, int maxWidth, int maxHeight) {
if (hoverInfo == null) {
return null;
}
GC gc = new GC(drawable);
try {
StringBuffer buffer = new StringBuffer();
int maxNumberOfLines = Math.round(maxHeight / gc.getFontMetrics().getHeight());
fCounter = 0;
LineBreakingReader reader = new LineBreakingReader(
createReader(hoverInfo, presentation),
gc,
maxWidth);
boolean lastLineFormatted = false;
String lastLineIndent = null;
String line = reader.readLine();
boolean lineFormatted = reader.isFormattedLine();
boolean firstLineProcessed = false;
while (line != null) {
if (fEnforceUpperLineLimit && maxNumberOfLines <= 0) {
break;
}
if (firstLineProcessed) {
if (!lastLineFormatted) {
append(buffer, LINE_DELIM, null);
} else {
append(buffer, LINE_DELIM, presentation);
if (lastLineIndent != null) {
append(buffer, lastLineIndent, presentation);
}
}
}
append(buffer, line, null);
firstLineProcessed = true;
lastLineFormatted = lineFormatted;
if (!lineFormatted) {
lastLineIndent = null;
} else if (lastLineIndent == null) {
lastLineIndent = getIndent(line);
}
line = reader.readLine();
lineFormatted = reader.isFormattedLine();
maxNumberOfLines--;
}
if (line != null) {
append(buffer, LINE_DELIM, lineFormatted ? presentation : null);
append(buffer, HTMLMessages.getString("HTMLTextPresenter.ellipse"), presentation); //$NON-NLS-1$
}
return trim(buffer, presentation);
} catch (IOException e) {
// ignore TODO do something else?
return null;
} finally {
gc.dispose();
}
}
protected void adaptTextPresentation(TextPresentation presentation, int offset, int insertLength) {
int yoursStart = offset;
int yoursEnd = offset + insertLength - 1;
yoursEnd = Math.max(yoursStart, yoursEnd);
@SuppressWarnings("rawtypes")
Iterator e = presentation.getAllStyleRangeIterator();
while (e.hasNext()) {
StyleRange range = (StyleRange) e.next();
int myStart = range.start;
int myEnd = range.start + range.length - 1;
myEnd = Math.max(myStart, myEnd);
if (myEnd < yoursStart) {
continue;
}
if (myStart < yoursStart) {
range.length += insertLength;
} else {
range.start += insertLength;
}
}
}
protected Reader createReader(String hoverInfo, TextPresentation presentation) {
return new HTML2TextReader(new StringReader(hoverInfo), presentation);
}
private void append(StringBuffer buffer, String string, TextPresentation presentation) {
int length = string.length();
buffer.append(string);
if (presentation != null) {
adaptTextPresentation(presentation, fCounter, length);
}
fCounter += length;
}
private String getIndent(String line) {
int length = line.length();
int i = 0;
while (i < length && Character.isWhitespace(line.charAt(i))) {
++i;
}
return (i == length ? line : line.substring(0, i)) + " "; //$NON-NLS-1$
}
private String trim(StringBuffer buffer, TextPresentation presentation) {
int length = buffer.length();
int end = length - 1;
while (end >= 0 && Character.isWhitespace(buffer.charAt(end))) {
--end;
}
if (end == -1) {
return ""; //$NON-NLS-1$
}
if (end < length - 1) {
buffer.delete(end + 1, length);
} else {
end = length;
}
int start = 0;
while (start < end && Character.isWhitespace(buffer.charAt(start))) {
++start;
}
buffer.delete(0, start);
presentation.setResultWindow(new Region(start, buffer.length()));
return buffer.toString();
}
}