/*
 * TextAreaPainter.java - Paints the text area
 * Copyright (C) 1999 Slava Pestov
 *
 * You may use and modify this package for any purpose. Redistribution is
 * permitted, in both source and binary form, provided that this notice
 * remains intact in all source distributions of this package.
 */
package com.pironet.tda.utils.jedit;

import javax.swing.ToolTipManager;
import javax.swing.text.*;
import javax.swing.JComponent;
import java.awt.event.MouseEvent;
import java.awt.*;

/**
 * The text area repaint manager. It performs double buffering and paints
 * lines of text.
 * @author Slava Pestov
 * @version $Id: TextAreaPainter.java,v 1.1 2007-10-03 12:50:26 irockel Exp $
 */
public class TextAreaPainter extends JComponent implements TabExpander
{
	/**
	 * Creates a new repaint manager. This should be not be called
	 * directly.
	 */
	public TextAreaPainter(JEditTextArea textArea, TextAreaDefaults defaults)
	{
		this.textArea = textArea;

		setAutoscrolls(true);
		setDoubleBuffered(true);
		setOpaque(true);

		ToolTipManager.sharedInstance().registerComponent(this);

		currentLine = new Segment();
		currentLineIndex = -1;

		setCursor(Cursor.getPredefinedCursor(Cursor.TEXT_CURSOR));

		setFont(new Font("Monospaced",Font.PLAIN,14));
		setForeground(Color.black);
		setBackground(Color.white);

		blockCaret = defaults.blockCaret;
		styles = defaults.styles;
		cols = defaults.cols;
		rows = defaults.rows;
		caretColor = defaults.caretColor;
		selectionColor = defaults.selectionColor;
		lineHighlightColor = defaults.lineHighlightColor;
		lineHighlight = defaults.lineHighlight;
		bracketHighlightColor = defaults.bracketHighlightColor;
		bracketHighlight = defaults.bracketHighlight;
		paintInvalid = defaults.paintInvalid;
		eolMarkerColor = defaults.eolMarkerColor;
		eolMarkers = defaults.eolMarkers;
	}

	/**
	 * Returns if this component can be traversed by pressing the
	 * Tab key. This returns false.
	 */
	public final boolean isManagingFocus()
	{
		return false;
	}

	/**
	 * Returns the syntax styles used to paint colorized text. Entry <i>n</i>
	 * will be used to paint tokens with id = <i>n</i>.
	 * @see org.gjt.sp.jedit.syntax.Token
	 */
	public final SyntaxStyle[] getStyles()
	{
		return styles;
	}

	/**
	 * Sets the syntax styles used to paint colorized text. Entry <i>n</i>
	 * will be used to paint tokens with id = <i>n</i>.
	 * @param styles The syntax styles
	 * @see org.gjt.sp.jedit.syntax.Token
	 */
	public final void setStyles(SyntaxStyle[] styles)
	{
		this.styles = styles;
		repaint();
	}

	/**
	 * Returns the caret color.
	 */
	public final Color getCaretColor()
	{
		return caretColor;
	}

	/**
	 * Sets the caret color.
	 * @param caretColor The caret color
	 */
	public final void setCaretColor(Color caretColor)
	{
		this.caretColor = caretColor;
		invalidateSelectedLines();
	}

	/**
	 * Returns the selection color.
	 */
	public final Color getSelectionColor()
	{
		return selectionColor;
	}

	/**
	 * Sets the selection color.
	 * @param selectionColor The selection color
	 */
	public final void setSelectionColor(Color selectionColor)
	{
		this.selectionColor = selectionColor;
		invalidateSelectedLines();
	}

	/**
	 * Returns the line highlight color.
	 */
	public final Color getLineHighlightColor()
	{
		return lineHighlightColor;
	}

	/**
	 * Sets the line highlight color.
	 * @param lineHighlightColor The line highlight color
	 */
	public final void setLineHighlightColor(Color lineHighlightColor)
	{
		this.lineHighlightColor = lineHighlightColor;
		invalidateSelectedLines();
	}

	/**
	 * Returns true if line highlight is enabled, false otherwise.
	 */
	public final boolean isLineHighlightEnabled()
	{
		return lineHighlight;
	}

	/**
	 * Enables or disables current line highlighting.
	 * @param lineHighlight True if current line highlight should be enabled,
	 * false otherwise
	 */
	public final void setLineHighlightEnabled(boolean lineHighlight)
	{
		this.lineHighlight = lineHighlight;
		invalidateSelectedLines();
	}

	/**
	 * Returns the bracket highlight color.
	 */
	public final Color getBracketHighlightColor()
	{
		return bracketHighlightColor;
	}

	/**
	 * Sets the bracket highlight color.
	 * @param bracketHighlightColor The bracket highlight color
	 */
	public final void setBracketHighlightColor(Color bracketHighlightColor)
	{
		this.bracketHighlightColor = bracketHighlightColor;
		invalidateLine(textArea.getBracketLine());
	}

	/**
	 * Returns true if bracket highlighting is enabled, false otherwise.
	 * When bracket highlighting is enabled, the bracket matching the
	 * one before the caret (if any) is highlighted.
	 */
	public final boolean isBracketHighlightEnabled()
	{
		return bracketHighlight;
	}

	/**
	 * Enables or disables bracket highlighting.
	 * When bracket highlighting is enabled, the bracket matching the
	 * one before the caret (if any) is highlighted.
	 * @param bracketHighlight True if bracket highlighting should be
	 * enabled, false otherwise
	 */
	public final void setBracketHighlightEnabled(boolean bracketHighlight)
	{
		this.bracketHighlight = bracketHighlight;
		invalidateLine(textArea.getBracketLine());
	}

	/**
	 * Returns true if the caret should be drawn as a block, false otherwise.
	 */
	public final boolean isBlockCaretEnabled()
	{
		return blockCaret;
	}

	/**
	 * Sets if the caret should be drawn as a block, false otherwise.
	 * @param blockCaret True if the caret should be drawn as a block,
	 * false otherwise.
	 */
	public final void setBlockCaretEnabled(boolean blockCaret)
	{
		this.blockCaret = blockCaret;
		invalidateSelectedLines();
	}

	/**
	 * Returns the EOL marker color.
	 */
	public final Color getEOLMarkerColor()
	{
		return eolMarkerColor;
	}

	/**
	 * Sets the EOL marker color.
	 * @param eolMarkerColor The EOL marker color
	 */
	public final void setEOLMarkerColor(Color eolMarkerColor)
	{
		this.eolMarkerColor = eolMarkerColor;
		repaint();
	}

	/**
	 * Returns true if EOL markers are drawn, false otherwise.
	 */
	public final boolean getEOLMarkersPainted()
	{
		return eolMarkers;
	}

	/**
	 * Sets if EOL markers are to be drawn.
	 * @param eolMarkers True if EOL markers should be drawn, false otherwise
	 */
	public final void setEOLMarkersPainted(boolean eolMarkers)
	{
		this.eolMarkers = eolMarkers;
		repaint();
	}

	/**
	 * Returns true if invalid lines are painted as red tildes (~),
	 * false otherwise.
	 */
	public boolean getInvalidLinesPainted()
	{
		return paintInvalid;
	}

	/**
	 * Sets if invalid lines are to be painted as red tildes.
	 * @param paintInvalid True if invalid lines should be drawn, false otherwise
	 */
	public void setInvalidLinesPainted(boolean paintInvalid)
	{
		this.paintInvalid = paintInvalid;
	}

	/**
	 * Adds a custom highlight painter.
	 * @param highlight The highlight
	 */
	public void addCustomHighlight(Highlight highlight)
	{
		highlight.init(textArea,highlights);
		highlights = highlight;
	}

	/**
	 * Highlight interface.
	 */
	public interface Highlight
	{
		/**
		 * Called after the highlight painter has been added.
		 * @param textArea The text area
		 * @param next The painter this one should delegate to
		 */
		void init(JEditTextArea textArea, Highlight next);

		/**
		 * This should paint the highlight and delgate to the
		 * next highlight painter.
		 * @param gfx The graphics context
		 * @param line The line number
		 * @param y The y co-ordinate of the line
		 */
		void paintHighlight(Graphics gfx, int line, int y);

		/**
		 * Returns the tool tip to display at the specified
		 * location. If this highlighter doesn't know what to
		 * display, it should delegate to the next highlight
		 * painter.
		 * @param evt The mouse event
		 */
		String getToolTipText(MouseEvent evt);
	}

	/**
	 * Returns the tool tip to display at the specified location.
	 * @param evt The mouse event
	 */
	public String getToolTipText(MouseEvent evt)
	{
		if(highlights != null)
			return highlights.getToolTipText(evt);
		else
			return null;
	}

	/**
	 * Returns the font metrics used by this component.
	 */
	public FontMetrics getFontMetrics()
	{
		return fm;
	}

	/**
	 * Sets the font for this component. This is overridden to update the
	 * cached font metrics and to recalculate which lines are visible.
	 * @param font The font
	 */
	public void setFont(Font font)
	{
		super.setFont(font);
		fm = Toolkit.getDefaultToolkit().getFontMetrics(font);
		textArea.recalculateVisibleLines();
	}

	/**
	 * Repaints the text.
	 * @param g The graphics context
	 */
	public void paint(Graphics gfx)
	{
		tabSize = fm.charWidth(' ') * ((Integer)textArea
			.getDocument().getProperty(
			PlainDocument.tabSizeAttribute)).intValue();

		Rectangle clipRect = gfx.getClipBounds();

		gfx.setColor(getBackground());
		gfx.fillRect(clipRect.x,clipRect.y,clipRect.width,clipRect.height);

		// We don't use yToLine() here because that method doesn't
		// return lines past the end of the document
		int height = fm.getHeight();
		int firstLine = textArea.getFirstLine();
		int firstInvalid = firstLine + clipRect.y / height;
		// Because the clipRect's height is usually an even multiple
		// of the font height, we subtract 1 from it, otherwise one
		// too many lines will always be painted.
		int lastInvalid = firstLine + (clipRect.y + clipRect.height - 1) / height;

		try
		{
			TokenMarker tokenMarker = textArea.getDocument()
				.getTokenMarker();
			int x = textArea.getHorizontalOffset();

			for(int line = firstInvalid; line <= lastInvalid; line++)
			{
				paintLine(gfx,tokenMarker,line,x);
			}

			if(tokenMarker != null && tokenMarker.isNextLineRequested())
			{
				int h = clipRect.y + clipRect.height;
				repaint(0,h,getWidth(),getHeight() - h);
			}
		}
		catch(Exception e)
		{
			System.err.println("Error repainting line"
				+ " range {" + firstInvalid + ","
				+ lastInvalid + "}:");
			e.printStackTrace();
		}
	}

	/**
	 * Marks a line as needing a repaint.
	 * @param line The line to invalidate
	 */
	public final void invalidateLine(int line)
	{
		repaint(0,textArea.lineToY(line) + fm.getMaxDescent() + fm.getLeading(),
			getWidth(),fm.getHeight());
	}

	/**
	 * Marks a range of lines as needing a repaint.
	 * @param firstLine The first line to invalidate
	 * @param lastLine The last line to invalidate
	 */
	public final void invalidateLineRange(int firstLine, int lastLine)
	{
		repaint(0,textArea.lineToY(firstLine) + fm.getMaxDescent() + fm.getLeading(),
			getWidth(),(lastLine - firstLine + 1) * fm.getHeight());
	}

	/**
	 * Repaints the lines containing the selection.
	 */
	public final void invalidateSelectedLines()
	{
		invalidateLineRange(textArea.getSelectionStartLine(),
			textArea.getSelectionEndLine());
	}

	/**
	 * Implementation of TabExpander interface. Returns next tab stop after
	 * a specified point.
	 * @param x The x co-ordinate
	 * @param tabOffset Ignored
	 * @return The next tab stop after <i>x</i>
	 */
	public float nextTabStop(float x, int tabOffset)
	{
		int offset = textArea.getHorizontalOffset();
		int ntabs = ((int)x - offset) / tabSize;
		return (ntabs + 1) * tabSize + offset;
	}

	/**
	 * Returns the painter's preferred size.
	 */
	public Dimension getPreferredSize()
	{
		Dimension dim = new Dimension();
		dim.width = fm.charWidth('w') * cols;
		dim.height = fm.getHeight() * rows;
		return dim;
	}


	/**
	 * Returns the painter's minimum size.
	 */
	public Dimension getMinimumSize()
	{
		return getPreferredSize();
	}

	// package-private members
	int currentLineIndex;
	Token currentLineTokens;
	Segment currentLine;

	// protected members
	protected JEditTextArea textArea;
	
	protected SyntaxStyle[] styles;
	protected Color caretColor;
	protected Color selectionColor;
	protected Color lineHighlightColor;
	protected Color bracketHighlightColor;
	protected Color eolMarkerColor;

	protected boolean blockCaret;
	protected boolean lineHighlight;
	protected boolean bracketHighlight;
	protected boolean paintInvalid;
	protected boolean eolMarkers;
	protected int cols;
	protected int rows;
	
	protected int tabSize;
	protected FontMetrics fm;

	protected Highlight highlights;

	protected void paintLine(Graphics gfx, TokenMarker tokenMarker,
		int line, int x)
	{
		Font defaultFont = getFont();
		Color defaultColor = getForeground();

		currentLineIndex = line;
		int y = textArea.lineToY(line);

		if(line < 0 || line >= textArea.getLineCount())
		{
			if(paintInvalid)
			{
				paintHighlight(gfx,line,y);
				styles[Token.INVALID].setGraphicsFlags(gfx,defaultFont);
				gfx.drawString("~",0,y + fm.getHeight());
			}
		}
		else if(tokenMarker == null)
		{
			paintPlainLine(gfx,line,defaultFont,defaultColor,x,y);
		}
		else
		{
			paintSyntaxLine(gfx,tokenMarker,line,defaultFont,
				defaultColor,x,y);
		}
	}

	protected void paintPlainLine(Graphics gfx, int line, Font defaultFont,
		Color defaultColor, int x, int y)
	{
		paintHighlight(gfx,line,y);
		textArea.getLineText(line,currentLine);

		gfx.setFont(defaultFont);
		gfx.setColor(defaultColor);

		y += fm.getHeight();
		x = Utilities.drawTabbedText(currentLine,x,y,gfx,this,0);

		if(eolMarkers)
		{
			gfx.setColor(eolMarkerColor);
			gfx.drawString(".",x,y);
		}
	}

	protected void paintSyntaxLine(Graphics gfx, TokenMarker tokenMarker,
		int line, Font defaultFont, Color defaultColor, int x, int y)
	{
		textArea.getLineText(currentLineIndex,currentLine);
		currentLineTokens = tokenMarker.markTokens(currentLine,
			currentLineIndex);

		paintHighlight(gfx,line,y);

		gfx.setFont(defaultFont);
		gfx.setColor(defaultColor);
		y += fm.getHeight();
		x = SyntaxUtilities.paintSyntaxLine(currentLine,
			currentLineTokens,styles,this,gfx,x,y);

		if(eolMarkers)
		{
			gfx.setColor(eolMarkerColor);
			gfx.drawString(".",x,y);
		}
	}

	protected void paintHighlight(Graphics gfx, int line, int y)
	{
		if(line >= textArea.getSelectionStartLine()
			&& line <= textArea.getSelectionEndLine())
			paintLineHighlight(gfx,line,y);

		if(highlights != null)
			highlights.paintHighlight(gfx,line,y);

		if(bracketHighlight && line == textArea.getBracketLine())
			paintBracketHighlight(gfx,line,y);

		if(line == textArea.getCaretLine())
			paintCaret(gfx,line,y);
	}

	protected void paintLineHighlight(Graphics gfx, int line, int y)
	{
		int height = fm.getHeight();
		y += fm.getLeading() + fm.getMaxDescent();

		int selectionStart = textArea.getSelectionStart();
		int selectionEnd = textArea.getSelectionEnd();

		if(selectionStart == selectionEnd)
		{
			if(lineHighlight)
			{
				gfx.setColor(lineHighlightColor);
				gfx.fillRect(0,y,getWidth(),height);
			}
		}
		else
		{
			gfx.setColor(selectionColor);

			int selectionStartLine = textArea.getSelectionStartLine();
			int selectionEndLine = textArea.getSelectionEndLine();
			int lineStart = textArea.getLineStartOffset(line);

			int x1, x2;
			if(textArea.isSelectionRectangular())
			{
				int lineLen = textArea.getLineLength(line);
				x1 = textArea._offsetToX(line,Math.min(lineLen,
					selectionStart - textArea.getLineStartOffset(
					selectionStartLine)));
				x2 = textArea._offsetToX(line,Math.min(lineLen,
					selectionEnd - textArea.getLineStartOffset(
					selectionEndLine)));
				if(x1 == x2)
					x2++;
			}
			else if(selectionStartLine == selectionEndLine)
			{
				x1 = textArea._offsetToX(line,
					selectionStart - lineStart);
				x2 = textArea._offsetToX(line,
					selectionEnd - lineStart);
			}
			else if(line == selectionStartLine)
			{
				x1 = textArea._offsetToX(line,
					selectionStart - lineStart);
				x2 = getWidth();
			}
			else if(line == selectionEndLine)
			{
				x1 = 0;
				x2 = textArea._offsetToX(line,
					selectionEnd - lineStart);
			}
			else
			{
				x1 = 0;
				x2 = getWidth();
			}

			// "inlined" min/max()
			gfx.fillRect(x1 > x2 ? x2 : x1,y,x1 > x2 ?
				(x1 - x2) : (x2 - x1),height);
		}

	}

	protected void paintBracketHighlight(Graphics gfx, int line, int y)
	{
		int position = textArea.getBracketPosition();
		if(position == -1)
			return;
		y += fm.getLeading() + fm.getMaxDescent();
		int x = textArea._offsetToX(line,position);
		gfx.setColor(bracketHighlightColor);
		// Hack!!! Since there is no fast way to get the character
		// from the bracket matching routine, we use ( since all
		// brackets probably have the same width anyway
		gfx.drawRect(x,y,fm.charWidth('(') - 1,
			fm.getHeight() - 1);
	}

	protected void paintCaret(Graphics gfx, int line, int y)
	{
		if(textArea.isCaretVisible())
		{
			int offset = textArea.getCaretPosition() 
				- textArea.getLineStartOffset(line);
			int caretX = textArea._offsetToX(line,offset);
			int caretWidth = ((blockCaret ||
				textArea.isOverwriteEnabled()) ?
				fm.charWidth('w') : 1);
			y += fm.getLeading() + fm.getMaxDescent();
			int height = fm.getHeight();
			
			gfx.setColor(caretColor);

			if(textArea.isOverwriteEnabled())
			{
				gfx.fillRect(caretX,y + height - 1,
					caretWidth,1);
			}
			else
			{
				gfx.drawRect(caretX,y,caretWidth - 1,height - 1);
			}
		}
	}
}
