/jEdit/tags/jedit-4-5-pre1/org/gjt/sp/jedit/textarea/ElasticTabstopsTabExpander.java

/*

 * jEdit - Programmer's Text Editor

 * :tabSize=8:indentSize=8:noTabs=false:

 * :folding=explicit:collapseFolds=1:

 *

 * Copyright Š 2010 jEdit contributors

 *

 * 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 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.

 */

package org.gjt.sp.jedit.textarea;



import java.awt.font.TextLayout;

import java.util.Vector;



import javax.swing.text.TabExpander;



public class ElasticTabstopsTabExpander implements TabExpander 

{

	TextArea textArea;

	

	//{{{ ElasticTabstopsTabExpander() method

	public ElasticTabstopsTabExpander(TextArea textArea)

	{

		this.textArea = textArea;

	}//}}}

	

	//{{{ nextTabStop() method

	@Override

	public float nextTabStop(float x, int tabOffset) 

	{

		float _tabSize = 0;

		if(textArea.buffer.getBooleanProperty("elasticTabstops")&&textArea.buffer.getColumnBlock()!=null)

		{

			int line = textArea.buffer.getLineOfOffset(tabOffset);

			_tabSize = getTabSize(textArea.buffer.getColumnBlock().getColumnBlock(line, tabOffset),line);

			if(_tabSize<0)

			{

				throw new IllegalArgumentException("Unaccounted tab at line "+textArea.buffer.getLineOfOffset(tabOffset)+" at index "+tabOffset);

			}

		}

		//keep minimum tab size of  textArea.tabSize

		_tabSize+= textArea.tabSize;

		return (x+_tabSize);

	}//}}}

	

	//{{{ getTabSize() method

	private float getTabSize(ColumnBlock columnBlock, int line) 

	{

		float ret = -5;

		if(columnBlock!=null)

		{	

			Vector lines = columnBlock.getLines();

			if(columnBlock.areTabSizesDirty())

			{

				float colBlockWidth = -1;

				for(int i= 0;i<lines.size();i++)

				{

					ColumnBlockLine colBlockLine = (ColumnBlockLine)lines.elementAt(i);

					int startOffset = colBlockLine.getColumnStartIndex()+textArea.buffer.getLineStartOffset(colBlockLine.getLine());

					String str = textArea.buffer.getText(startOffset,colBlockLine.getColumnEndIndex()-colBlockLine.getColumnStartIndex());

					float width = 0;

					if(str.length()!=0)

					{	

						TextLayout layout = new TextLayout(str,textArea.painter.getFont(),textArea.painter.getFontRenderContext());

						width = layout.getAdvance();

					}

					colBlockLine.lineLength = width;

					//colBlockLine.lineLength = textArea.painter.getFontMetrics().stringWidth(str);

					if((colBlockWidth<0)||(colBlockLine.lineLength>colBlockWidth))

					{

						colBlockWidth = colBlockLine.lineLength;

					}

				}

				columnBlock.columnBlockWidth = colBlockWidth;

				columnBlock.setTabSizeDirtyStatus(false, false);

			}

			ret = columnBlock.columnBlockWidth-((ColumnBlockLine)lines.get(line-columnBlock.startLine)).lineLength;

		}	

		return ret;

	}//}}}



}