//  Job: Jay's Own Browser, a web browser written in Java by Jay Skeer
//  Copyright (C) 1996 Jay Skeer, Jay Prime Positive
//
//  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., 675 Mass Ave, Cambridge, MA 02139, USA.
//

import java.awt.*;
import HtmlDocumentArea;
import HtmlDocumentAreaVector;
import HtmlDocumentAreaStream;

/**
  A panel (containing a display area and a vertical scroll bar) for
  showing (Html)Documents.  Assumes the ducument is all broken up into
  displayable HtmlDocumentArea's.
*/
public class HtmlDocumentAreaPanel extends Panel {
		  /* * * the data being displayed */
    HtmlDocumentAreaVector area_cache= null;
    HtmlDocumentAreaStream area_stream= null;
    /** the position of the last area read from the stream */
    int last_read_area_x= 999;
    int last_read_area_y= 999;

		/* * * The portion begin displayed */
    /** top line displayed */
    public int top_line= 0;
    /** botom line displayed */
    public int bot_line= -1;
    /** number of lines displayed */
    public int disp_lines= 0;
    /** number of lines in doc */
    public int doc_lines= 0;

	      /* * * The widgets doing the displaying */
    /** the scroll bar which reflects the position (and amount) of doc */
    Scrollbar scrollbar= null;
    /** the canvas the document is drawn on */
    Canvas    display= null;
    /** the Normal body font the text is drawn in */
    Font appBodyFont= null;
    /** the Bold font the text is drawn in */
    Font appBoldFont= null;
    /** the Typewriter font the text is drawn in */
    Font appTypeFont= null;
    /** the top level heading font */
    Font appH1Font= null;
    /** the second level heading font */
    Font appH2Font= null;
    /** the third level heading font */
    Font appH3Font= null;
    /** the fourth level heading font */
    Font appH4Font= null;
    /** the fifth level heading font */
    Font appH5Font= null;

    /** graphics device on which we are did the displaying most recently */
    Graphics saved_graphics= null;
    /** the document region stream we convert to areas -- must keep this
	around cause we need to build the area stream based on the graphics
	device. */
    HtmlDocumentRegionStream region_stream= null;

    public HtmlDocumentAreaPanel() {
	/* area{stream,cache} stuff */
	area_cache= new HtmlDocumentAreaVector();
Jdb.trace("area_cache set to new (1)");
	area_stream= null;
	top_line= 0;
	bot_line= 0;
	doc_lines= 0;
	disp_lines= 0;
	last_read_area_x= -1;
	last_read_area_y= -1;
	
	/* display stuff */
	display= new Canvas();
	scrollbar= new Scrollbar(Scrollbar.VERTICAL);

	this.setLayout(new BorderLayout());
	this.add("East", scrollbar);
	this.add("Center", display);

	appH1Font= new Font("TimesRoman", Font.BOLD,  28);
	appH2Font= new Font("TimesRoman", Font.BOLD,  25);
	appH3Font= new Font("TimesRoman", Font.BOLD,  22);
	appH4Font= new Font("TimesRoman", Font.BOLD,  19);
	appH5Font= new Font("TimesRoman", Font.BOLD,  17);
	appBodyFont= new Font("TimesRoman", Font.PLAIN, 15);
	appBoldFont= new Font("TimesRoman", Font.BOLD,  15);
	appTypeFont= new Font("Courier", Font.PLAIN, 15);
	display.setFont(appBodyFont);
	HtmlDocumentArea.initFonts
	    (appH1Font, appH2Font, appH3Font, appH4Font, appH5Font,
	     appBodyFont, appBoldFont, appTypeFont);
	display.setForeground(Color.black);
	display.setBackground(Color.white);

//	this.layout();
//	scrollbar.show();
//	display.show();
//	this.show();
    }

//    public void setAreas(HtmlDocumentAreaVector a) {
//	this.area_cache= a;
//	if (null != area_cache) {
//	    doc_lines= area_cache.size();
//	    if (doc_lines < top_line) {
//		top_line= 0;
//		bot_line= -1;
//	    }
//	} else {
//          setTopLine(0);
//	    doc_lines= 0;
//	}
//    }

    public void setAreas(HtmlDocumentRegionStream rs) {
	this.area_cache= new HtmlDocumentAreaVector();
Jdb.enter("HDAP.setAreas()");
Jdb.trace("area_cache set to new (2)");
	this.region_stream= rs; // cause we need the graphics device to
				// build the area_stream;
	this.area_stream= null;
        setTopLine(0);
        doc_lines= 0;
	last_read_area_x= -1;
	last_read_area_y= -1;
Jdb.exit("HDAP.setAreas()");
    }

    public void blank_and_repaint(int msdelay) {
Jdb.enter("HDAP.blank_and_repaint(msdelay "+msdelay+")");
	Graphics myg= display.getGraphics();
	Rectangle cr= bounds();
Jdb.trace("bounds == " + cr);
Jdb.trace("cliprect == " + myg.getClipRect());
	myg.clearRect(cr.x, cr.y, cr.width, cr.height);
	repaint(msdelay);
Jdb.exit("HDAP.blank_and_repaint(msdelay "+msdelay+")");
    }

    public void blank_and_repaint() {
Jdb.enter("HDAP.blank_and_repaint()");
	blank_and_repaint(0);
Jdb.exit("HDAP.blank_and_repaint()");
    }

    private boolean can_read_from_stream() {
//Jdb.enter("HDAP.can_read_from_stream()");
	boolean rv= false;
	boolean nn= (null != area_stream);
	if (nn) {
	    boolean ne= (!area_stream.eof());
	    rv= ne;
	} else {
	    rv= false;
	}
//Jdb.exit("HDAP.can_read_from_stream() => " + rv);
	return rv;
    }

    private HtmlDocumentArea read_from_stream() {
//Jdb.enter("HDAP.read_from_stream()");
	HtmlDocumentArea rv= null;
	if (can_read_from_stream()) {
	    rv= area_stream.readHtmlDocumentArea();
	    if (null != rv) {
		last_read_area_y= rv.getY();
		last_read_area_x= rv.getX();
		if (null != area_cache) {
		    area_cache.add(rv);
		}
	    }
	}
//Jdb.trace("area_cache == "+area_cache.jtoString());
//Jdb.exit("HDAP.read_from_stream() => " + rv);
	return rv;
    }

    private HtmlDocumentArea findArea
        (Graphics g, int look_x, int look_y)
    {
//Jdb.enter("HDAP.findArea(g"+g+", "+look_x+", "+look_y+")");
	HtmlDocumentArea this_area= null;
	if (null != area_cache)
	    this_area= area_cache.findArea(look_x, look_y);
	if ((null == this_area) && can_read_from_stream()) {
	    int best_area_x= 999;
	    int best_area_y= 999;
	    HtmlDocumentArea best_area= null;
	    if (last_read_area_y <= look_y) {
		while ((can_read_from_stream())
		   &&  (last_read_area_y <= look_y))
		{
		    this_area= read_from_stream();
//(null != this_area)
//		    &&  
		    if (this_area.inside(look_x, look_y)) {
			best_area= this_area;
		    }
		}
	    }
	    this_area= best_area;
	}
//Jdb.exit("HDAP.findArea(g"+g+", "+look_x+", "+look_y+") => "+this_area);
	return this_area;
    }

    private HtmlDocumentArea findAreaRight
        (Graphics g, int look_x, int look_y)
    {
	// assume look_y fall in discrete line sized peices
Jdb.enter("HDAP.findAreaRight(g"+g+", "+look_x+", "+look_y+")");
	HtmlDocumentArea this_area= null;
	if (null != area_cache)
	    this_area= area_cache.findAreaRight(look_x, look_y);
	if (null == this_area) {
	    int this_area_x= 999;
	    int this_area_y= 999;
	    HtmlDocumentArea best_area= null;
	    int best_area_x= 999;
	    int best_area_y= 999;
	    while ((can_read_from_stream())
	       &&  (last_read_area_y <= look_y))
	    {
		this_area= read_from_stream();
		if (null != this_area) {
		    this_area_x= this_area.getX();
		    this_area_y= this_area.getY();
		    if ((look_y == this_area_y)
		    &&  (look_x <= this_area_x))
		    {
			if (last_read_area_x < best_area_x) {
			    best_area= this_area;
			    best_area_x= this_area_x;
			    best_area_y= this_area_y;
			}
		    }
		}
	    }
	    this_area= best_area;
	}
Jdb.exit("HDAP.findAreaRight(g"+g+", "+look_x+", "+look_y+") => "+this_area);
	return this_area;
    }

    private HtmlDocumentArea findAreaBelow
        (Graphics g, int look_x, int look_y)
    {
Jdb.enter("HDAP.findAreaBelow("+g+", "+look_x+", "+look_y+")");
        HtmlDocumentArea this_area= null;
        if (null != area_cache) {
Jdb.trace("area_cache.size() == "+area_cache.size());
	    this_area= area_cache.findAreaBelow(look_x, look_y);
Jdb.trace("area_cache.findBelow("+g+", "+look_x+", "+look_y+") == "+this_area);
	}
//Jdb.trace("area_cache == "+area_cache);
//Jdb.trace("area_stream == "+area_stream);
        if (null == this_area) {
	    int this_area_x= 999;
	    int this_area_y= 999;
	    HtmlDocumentArea best_area= null;
	    int best_area_x= 999;
	    int best_area_y= 999;
	    while ((can_read_from_stream())
//	       &&  (last_read_area_y <= look_y))
	       &&  (null == best_area))
	    {
		this_area= read_from_stream();
//Jdb.trace("read_from_stream() == "+this_area);
		if (null != this_area) {
		    this_area_x= this_area.getX();
		    this_area_y= this_area.getY();
		    if (look_y < this_area_y) {
			if (   (this_area_y < best_area_y)
			    || (   (this_area_y == best_area_y)
				&& (this_area_x < best_area_x)))
			{
			    best_area= this_area;
			    best_area_x= this_area_x;
			    best_area_y= this_area_y;
			}
		    }
		}
	    }
	    this_area= best_area;
	}
Jdb.exit("HDAP.findAreaBelow("+g+", "+look_x+", "+look_y+") == "+this_area);
      return this_area;
    }

    private HtmlDocumentArea findAreaInRightBelow
        (Graphics g, int look_x, int look_y)
    {
Jdb.enter("HDAP.findAreaIRB("+g+", "+look_x+", "+look_y+")");
        HtmlDocumentArea this_area= null;
        if (null != area_cache)
	    this_area= area_cache.findAreaInRightBelow(look_x, look_y);
Jdb.trace("area_cache.size() == "+area_cache.size());
Jdb.trace("area_cache.findIRB("+g+", "+look_x+", "+look_y+") == "+this_area);
//Jdb.trace("area_cache == "+area_cache);
//Jdb.trace("area_stream == "+area_stream);
        if (null == this_area) {
	    int this_area_x= 999;
	    int this_area_y= 999;
	    HtmlDocumentArea best_area= null;
	    int best_area_x= 999;
	    int best_area_y= 999;
	    while ((can_read_from_stream())
//	       &&  (last_read_area_y <= look_y))
	       &&  (null == best_area)
	       )
	    {
		this_area= read_from_stream();
Jdb.trace("read_from_stream() == "+this_area);
		if (null != this_area) {
		    this_area_x= this_area.getX();
		    this_area_y= this_area.getY();
		    if (this_area.inside(look_x, look_y)) {
Jdb.trace("area inside");
			if (   (this_area_y < best_area_y)
			    || (   (this_area_y == best_area_y)
				&& (this_area_x < best_area_x))
			   )
			{
Jdb.trace("best");
			    best_area= this_area;
			    best_area_x= this_area_x;
			    best_area_y= this_area_y;
			}
		    } else
		    if ((look_x <= this_area_x)
		    &&  (look_y <= this_area_y))
		    {
Jdb.trace("area RB");
		        if (   (this_area_y < best_area_y)
//			    || (   (this_area_y == best_area_y)
//			        && (this_area_x < best_area_x))
			   )
		        {
Jdb.trace("best");
			    best_area= this_area;
			    best_area_x= this_area_x;
			    best_area_y= this_area_y;
			}
		    } else {
Jdb.trace("area not inside, and not RB");
		    }
		}
	    }
	    this_area= best_area;
	}
Jdb.exit("HDAP.findAreaIRB("+g+", "+look_x+", "+look_y+") == "+this_area);
      return this_area;
    }

    public void paintAreas(Graphics g) {
Jdb.enter("HDAP.paintAreas(Graphics g)");
	/* the position the scroll bar has slid us too */
	int scroll_y= top_line;
	int scroll_x= 0;
	/* the left most point we draw at in the display area */
	int line_x= scroll_x + 2;
	/* where in the document areas we are */
	int area_x= scroll_x;
	int area_y= scroll_y;
	Dimension r= size();
	int max_y= r.height + scroll_y;
	/* the tallest item found, used to advance area_y */
	int max_height= -1;
	int bot_y= doc_lines;
	HtmlDocumentArea area;
	area= findAreaInRightBelow(g, area_x, area_y);
	if (null != area) {
	    // move to start of this line;
	    // could be before or after top of display;
	    area_y= area.getY();
	}
	while ((area_y < max_y) && (null != area)) {
	    area.paint(g, scroll_x, scroll_y);
	    max_height= area.getHeight();
	    area_x= area.getX() + area.getWidth();
	    area= findAreaRight(g, area_x, area_y);
	    while (null != area) {
		area.paint(g, scroll_x, scroll_y);
		area_x= area.getX() + area.getWidth();
		max_height= Math.max(max_height, area.getHeight());
		area= findAreaRight(g, area_x, area_y);
	    }
	    area= findAreaBelow(g, area_x, area_y);
	    if (null != area) {
	        area_y= area.getY();
		bot_y= Math.max(bot_y, area_y + area.getHeight());
	    }
	}
	/* area_y is the first free row, max_y is the first roww off screen */
	bot_line= Math.max(area_y, max_y) - 1;
	
	/* ### need to correctly account for partial final lines */
//	disp_lines= bot_line - top_line + 1;
	disp_lines= r.height;

	/* if we went farther down the document, update doc_lines */
	if (doc_lines < bot_y) {
	    doc_lines= bot_y;
	}
Jdb.trace("HtmlDocumentAreaPanel.paintAreas(g) [" +
	  top_line + "-" +
	  bot_line + "==" + 
	  disp_lines + "] of " +
	  doc_lines);
Jdb.exit("HDAP.paintAreas(Graphics g)");
    }

    public void paint(Graphics g) {
Jdb.enter("HDAP.paint(g=="+g+")");
        saved_graphics= g;
//Jdb.trace("paint scrollbar");
	if (null != scrollbar) scrollbar.paint(scrollbar.getGraphics());
	if ((null == area_stream) && (null != region_stream)) {
//Jdb.trace("new area_stream");
	    area_stream=
	        new HtmlDocumentAreaStream(g, display, region_stream);
	}
	if ((area_cache != null) || (area_stream != null)) {
//Jdb.trace("paint areas");
	    paintAreas(display.getGraphics());
	} else {
//Jdb.trace("super.paint?");
//	    super.paint(g);
	}
Jdb.exit("HDAP.paint()");
    }

    public void update(Graphics g) {
Jdb.enter("HDAP.update(g=="+g+")");
        super.update(g);
Jdb.exit("HDAP.update(g=="+g+")");
    }

    public void paintAll(Graphics g) {
Jdb.enter("HDAP.paintAll(g=="+g+")");
        super.paintAll(g);
Jdb.exit("HDAP.paintAll(g=="+g+")");
    }

    public void repaint() {
Jdb.enter("HDAP.repaint()");
	super.repaint();
Jdb.exit("HDAP.repaint()");
    }

    public void repaint(long tm) {
Jdb.enter("HDAP.repaint("+tm+"ms)");
	super.repaint(tm);
Jdb.exit("HDAP.repaint("+tm+"ms)");
    }

    public void repaint(int x, int y, int wide, int tall) {
Jdb.enter("HDAP.repaint("+x+", "+y+", "+wide+", "+tall+")");
	super.repaint(x, y, wide, tall);
Jdb.exit("HDAP.repaint("+x+", "+y+", "+wide+", "+tall+")");
    }

    public void repaint(long tm, int x, int y, int wide, int tall) {
Jdb.enter("HDAP.repaint("+tm+"ms, "+x+", "+y+", "+wide+", "+tall+")");
	super.repaint(tm, x, y, wide, tall);
Jdb.exit("HDAP.repaint("+tm+"ms, "+x+", "+y+", "+wide+", "+tall+")");
    }

    public boolean imageUpdate(Image im, int flags, int x, int y, int wide, int tall) {
Jdb.enter("HDAP.imageUpdate(im, "+flags+"flags, "+x+", "+y+", "+wide+", "+tall+")");
	boolean rv= super.imageUpdate(im, flags, x, y, wide, tall);
Jdb.exit("HDAP.imageUpdate(im, "+flags+"flags, "+x+", "+y+", "+wide+", "+tall+") => "+rv);
	return rv;
    }

    public void setTopLine(int t) {
Jdb.enter("HDAP.setTopLine(" + t + ")");
Jdb.trace("doc_lines == " + doc_lines);
	if ((0 <= t) && (t <= doc_lines)) {
Jdb.trace("fiddle top line");
	    if (top_line != t) {
		top_line= t;
		bot_line= -1;
		blank_and_repaint(100);
	    }
	}
Jdb.exit("HDAP.setTopLine(" + t + ")");
    }

    public void softSetTopLine(int ntl) {
	ntl= Math.max(ntl, 0);
	ntl= Math.min(ntl, doc_lines - disp_lines);
	setTopLine(ntl);
    }

    public void scrollToLine(int l) {
	softSetTopLine(l);
    }

    public void scrollLines(int lines_down) {
	FontMetrics fm= display.getFontMetrics(appBodyFont);
        int fh= fm.getHeight();
	softSetTopLine(top_line + lines_down*fh);
    }

    public void scrollPages(int pages_down) {
	int lines_per_page= bot_line - top_line + 1;
	int overlap= 
	    ((0 < pages_down)
		?(-10)
		:((pages_down < 0)
		    ?(10)
		    :(0)));
        int new_top_line= top_line + ((lines_per_page+overlap)*pages_down);
	softSetTopLine(new_top_line);
    }

    public boolean handleEvent(Event e) {
	switch (e.id) {
	  case Event.UP:
	  case Event.SCROLL_LINE_UP:
	      scrollLines(-1);
	      break;
	  case Event.DOWN:
	  case Event.SCROLL_LINE_DOWN:
	      scrollLines( 1);
	      break;
	  case Event.PGUP:
	  case Event.SCROLL_PAGE_UP:
	      scrollPages(-1);
	      break;
	  case Event.PGDN:
	  case Event.SCROLL_PAGE_DOWN:
	      scrollPages( 1);
	      break;
	  case Event.HOME:
	      scrollToLine(0);
	      break;
	  case Event.SCROLL_ABSOLUTE:
	      scrollToLine(((Integer)(e.arg)).intValue());
	      break;
	  default:
	      return false;
	}
	resetScrollbar();
//JppEvent bogus= new JppEvent();
//Jdb.trace("HDAP.handleEvent("+bogus.getEventIdName(e.id)+"=="+e+")");
	return false;
    }

    public void resetScrollbar() {
	if (can_read_from_stream()) {
	    scrollbar.setValues(
		top_line,
		disp_lines,
		0,
		2*doc_lines
            );
	} else {
	    scrollbar.setValues(
		top_line,
		disp_lines,
		0,
		doc_lines
            );
	}
    }

    public boolean insideText(int x, int y) {
	if (null != display) {
//Jdb.trace("area_cache == "+area_cache.jtoString());
	    return display.inside(x, y);
	} else {
	    return false;
	}
    }

    public HotItem hotItemAt(int x, int y) {
	HotItem rv= null;
	// ###assume graphic hasn't changed
	int scroll_x= 0;
	int scroll_y= top_line;
	HtmlDocumentArea l= findArea(saved_graphics, x+scroll_x, y+scroll_y);
	resetScrollbar();
	if (null != l) {
	    rv= l.getHotItem();
	}
	return rv;
    }
}