This file: CHANGES.
Describes day to day progress of the XmHTML development.

October 7
	Dithering to a fixed palette is now fully possible. There are four
	different methods available (closest match without error correction,
	ordered with and without error correction and closest match with error
	correction). You can specify a palette using the XmNimagePalette resource
	or let XmHTML create one for you. 

October 6
	Working on implementing support for the XmNimageMapToPalette and
	XmNimagePalette resources, which allow you to define a palette for XmHTML
	to use. Besides the obvious advantages this can offer, another advantage
	is a rather large speedup when switching pages: since a palette contains a
	fixed number of colors, XmHTML can allocate all colors on startup and 
	doesn't have to free them until it is destroyed. This obliterates the need
	to release allocated colors each time a new page is loaded.

October 3
	Replaced the current quantizer with a compacter and faster one. Previously
	XmHTML carried two quantizers: one for global use and one specifically
	for PNG images.

	Fixed a bug in the colormap reading code of GIF images.

October 2
	Fixed a small bug in form handling: optionmenu's didn't get reset when
	the reset button was pressed.

September 28
	Added support for Fast Loadable Graphics. This is a format especially
	designed for XmHTML and optimized for *very* fast loading of images.
	The FLG format is actually nothing more than a compacted version of the
	XmImageInfo structure, and as such it supports plain transparency,
	alpha channel and animations (with all GIF disposal methods).

	Data can be stored either compressed or uncompressed. Uncompressed FLG's
	are the fastest possible way to load an image into XmHTML, but they can
	take up a huge amount of space. A funny thing I noticed though is that,
	quite often, an uncompressed FLG takes up less space
	than the same image saved as a GIF image...

	Animation support: the global colormap of an animation is now only
	allocated once for the entire animation instead of being allocated for
	each frame separatly. This has two significant advantages: memory usage is
	reduced and less time is spent in allocating colors. XmHTML will now also
	use the global colormap if the local colormap of an animation frame is
	equal to the global colormap.

September 26
	Some changes to reduce memory usage:

	-   Changed the type of the color component fields of the XmImageInfo
		structure from signed int to unsigned short (can save up to 1.5kb
		per image). Modified all internal color allocation routines as well;
	-   the size of the clipmasks is now computed correctly: storage
		occupied by clipmask data has been reduced by a factor 8;
	-   alpha channel processing of PNG images been modified to use a colormap 
		instead of full RGBA quartets: the 24bit RGB data is converted to an
		8bit paletted image and the alpha channel is stored separatly.
		This reduces the memory occupied by these images with at least a
		factor two;

September 22
	A lot of improvements in the font allocation/caching routines:

	-   a separate font cache for each display is now maintained.
		The previous scheme didn't look at which display it was running while
		the font cache was shared between every XmHTML instance.
		Displaying multiple instances of a XmHTML widget on different
		displays should now be possible;
	-   made the font caching scheme a lot more efficient and removed the
		limit on the maximum number of loadable fonts (it now uses a binary
		tree lookup instead of a lineair search through a table with fixed
		size;
	-   fonts are now freed when the widget is destroyed (that is, the actual
		font data is only freed if the widget being destroyed is the last
		widget using a display-bound font cache);
	-   modified the internal data structures so font properties are now
		stored with each font instead of calculating them each time the layout
		needs to be recalculated;

	One very major performance enhancement is the introduction of a
	smart font mapping scheme which maps unknown font names to known ones. 
	I am particularly pleased with this scheme, it allows XmHTML to map fonts
	it does not know in the beginning to known ones later one. Assuming the
	helvetica font is present in your font path and arial isn't, the following
	happens: when XmHTML encounters a <FONT FACE="Arial">
	tag, it will not know to which font it should be mapped and it will use the
	default font (whatever that is). However, when at a later stage a
	<FONT FACE="Arial,Helvetica"> is encountered, XmHTML
	will see that this Arial font can be mapped to the
	Helvetica font (which it does known), and as a result, any future
	reference to the Arial font will be mapped to the
	Helvetica font. XmHTML is smart enough to take any
	combination of weight, slant and size into account when making these
	decisions.

	Performance tests with the new font caching and mapping schemes show some
	very satisfactory results: the cache hit ratio is steadily increasing,
	approaching 90 or more percent after about 10 documents with different
	fonts have been loaded. The average number of search actions seems to
	remain steady around 7 in this case. The font cache contained 55 fonts
	(including 10 font mappings) in various families, sizes and styles.

	As a side note: this new ``font technology'' allows users to define
	their own font mapping by providing a document with a list of simple font
	mappings. See html/font_map.html for a sample document.

	Before I forget: I made the builtin cursor allocation display-independant
	as well.

September 21
	First success at flowing text around images with the ALIGN="LEFT"
	or ALIGN="RIGHT" attribute set.

September 20
	Small parser bugfix: mime type of a new document wasn't properly saved.

	Added a ``View Document Source'' menu item to example_2 and fixed a bug
	in jumping to locations in different files.

September 18
	Fixed a few important bugs:

	-   imagemap list wasn't properly reset when a document was
		reformatted. Could lead to a SIGSEGV in some cases;
	-   list of anchor data wasn't properly reset in some cases;

	XmHTML now properly honors the XmNstringDirection resource:
	when set to XmSTRING_DIRECTION_R_TO_L, text is properly inversed.
	Paragraphs contents are ordered from bottom to top. Needs a bit more
	work though: list markers are always left-aligned at the first line of
	a paragraph instead of right aligned at the bottom.

	Modified the linebreaking algorithm to handle line/paragraph breaks
	properly when the paragraphs contain non-text objects (HTML form components
	and images).

	Table support: changed the text layout algorithms to work independantly of
	XmHTML's dimensions. They now use a (dynamically adjustable) bounding box.

September 16
	When the title of a document is requested, leading and trailing spaces
	are now removed.
	Added the HeadDocType mask bit to the XmHTMLGetHeadAttributes()
	convenience function. When set, the value of the <!DOCTYPE> tag
	will be returned.

	Improved path resolution and mime detection routines in example_2.c


September 10-12
	Some prelimenary work on XmHTMLTextGetFormatted()

September 4
	Fixed a few important memory leaks. One of those caused the stored anchor
	data never to be freed.

	Reverted a few bad fixes.

September 1
	XmHTMLTextSetString fix, text was always rendered twice.

	Moved all resources into a stringtable. This actually seems to introduce
	a rather noticable speedup in document loading. Haven't got the slightest
	clue why this happens.

August 29-31
	Numerous bugfixes & memory leak fixups. A GRAND applause to
	Ricky Ralston <rlr@wscoe5.atl.hp.com> for having the
	courage to run XmHTML through purify. Thanks Ricky!!

	Started with daily snapshot distribution.

August 28
	Released XmHTML/Alpha Version 1.0.21, last Alpha release. The
	next release will be the first publically available Beta.

August 26
	Rewrote and extended <PRE> support greatly. Plain text, form
	components and images can now be mixed freely.

	Some minor changes in anchor rendering: anchors are now only extended to
	the right when there is room for it, they no longer cover adjacent text
	when activated.

	Added the XmNimageRGBConversion resource which allows one to select
	the conversion method XmHTML should use when converting 24bit to 8bit
	images.

August 25
	Changed the proto's for XmHTMLImageReplace() and XmHTMLImageUpdate():
	they now return a status indicating whether or not the document needs
	a recomputation of document layout if an image is replaced or updated.

	Fixed a bug in the default image processing: when images are delayed, the
	delayed icon wouldn't show up. I forgot to properly propagate the image
	dimensions.

August 21, evening
	Fully restored PNG alpha channeling support, there was a silly bug in
	doing the 24 to 8 bit conversion. Alpha channeling is now also supported
	for delayed images and any combination of background setting, set either
	via the loaded document or the SetValues method.
	See XmHTML PNG Demo for some screenshots.

	Transparent background images are now also supported.

August 21, morning
	Fixed a bug in delayed image loading that caused a fatal crash when
	the delayed image was freed.

	Progressive and normal image loading now share the same XImage creation
	and update routines. Also fixed clipmask creation for progressively
	loaded images.

	Rewrote most part of the handling of PNG images with an alpha channel.

	Several bugfixes and changes to example_2 and it's caching routines.

August 20
	HTML form support: vertical scrolling of a document with a HTML form in
	it should now be correct whether or not a horizontal scrollbar is present.
	Also fixed a bug in the SetValues method which caused XmHTML to ignore the
	already present form widgets.

	Modified the debug routines, output can now be sent to a file.

	Eliminated some dead/duplicate code in the painter and widget methods.

August 19
	HTML form support:

	-	The traversal stuff for tabbing between all HTML form components
		almost works. Still need to figure out the proper XmTextField
		translations so the tab key can be used instead of the enter key;
	-	added support for the HTML <TEXTAREA> form component and got
		form resetting working. HTML form support is nearly completed: only
		submit is still missing;
	-	scrollbars are no longer covered by the form widgets when the
		document is scrolled.

	Some code cleanup in the document formatter.

	Experimented with the BaseClass stuff. Gave up on it after half a day
	or so, implementing it would require a totally different approach and
	a lot of information on Motif's BaseClass. XmHTML is very much
	an Intrinsics widget with some added Motif value, and I would keep to
	like it that way, at least for a while.

August 18
	Small performance increase: XmHTML now uses Manager's GC's (XmHTML is a
	subclass of Manager) to paint the anchorbuttons and horizontal rules
	instead of using it's own GC (and switching colors all the time).

	Changed the XmNanchorHighlightOnArm resource to the standard
	XmNhighlightOnEnter resource. The highlight color is now computed
	dynamically depending on the current background color, which makes a
	lot more sense than having a fixed highlight color.

	Modified the anchor highlighting stuff when anchors are displayed as
	buttons: with highlighting enabled they now really resemble pushbuttons.

	Extended the supported HTML extensions to now also recognize a color
	attribute on the <P>, <DIV> and <CENTER> tags. 
	The color attribute is now also supported for <HR> with the
	noshade attribute set, so you can now have colored lines in your
	document.

	Progressively loaded images can be scaled on the fly (and as a side
	effect it resolved a fatal bug in the plc code).

August 16-17
	Took two days off, needed some rest drastically...

August 15
	Changing any font resource should now work properly. There was a bug
	in the font cache and the SetValues method which prevented XmHTML
	from properly honoring this change. Most of the time XmHTML choose to
	ignore any changes to the font resources altogether...

	Fixed a very nasty bug which occured with the
	SetValues/XmNdocumentCallback combination: setting any formatting
	resource from within the XmNdocumentCallback would sometimes lead to
	a document being loaded twice, but mostly it just caused a sigsegv.

	SetValues fix: changing the XmNimageEnable, XmNenableBodyImages and
	XmNbodyImage resources should work properly.

August 14
	Added the XmNanchorHighlightOnArm resource. Enabling this resource
	provides a constant visual feedback as each anchor the user moves his/hers
	mouse over will receive highlighting. The XmNarmColor resource allows
	one to set the color to use for this anchor highlighting.

August 10-13
	Lots of bugfixes in the progressive image loading routines. They finally
	seem to behave in an orderly manner.

	Rather large performance increase in color allocation on PseudoColor and
	StaticColor displays. XmHTML now uses a hashtable instead of querying the
	X server.

	Dynamically changing of resource setting revealed a couple of bugs in the
	SetValues method. One of those bugs caused XmHTML to overlook internally
	cached images.

August 6
	Setting XmNscrollBarDisplayPolicy to XmSTATIC will now also force
	a horizontal scrollbar to appear.

	Modified the parser so it will now properly remove the contents of the
	<SCRIPT> and <STYLE> tags when these tags aren't placed in the <HEAD>
	tag (which is the *only* place where they may occur).

August 5
	Added the XmNenableColorSwitching and XmNenableFontSwitching resources.
	XmNenableColorSwitching allows one to disable support for the color tag
	while XmNenableFontSwitching allows one to disable support for the
	<FONT> element.

	Added an options menu to example_2.

August 4
	Fixed a parser bug: elements with an optional closure are now being
	flushed when they prevent a new element from becoming legal. Previously
	the new element was discarded, which sometimes lead to bad results
	(pointed out by Danny Backx <u27113@kb.be>).

August 3
	Added an additional pass to the font loading algorithm to search for a
	font when it can't be found with the current value of the XmNcharset
	resource.

	Modified the PLC routines to share a single GC for every image that is
	being loaded.

July 17
	Released XmHTML/Alpha Version 1.0.20.

July 15
	Fixed a few bugs in font loading:

	- font changes after a <FONT FACE="SomeTypeFace"> used the document font
	  instead of the new font;
	- successive font changes did not always yield the proper result;
	- incrementing/decrementing the size of a font did not always yield the
	  correct result.

	Text enclosed in a paragraph (<P>...</P> or <DIV>...</DIV>) now also gets
	a trailing linefeed.

July 13,14
	Made a start at making XmHTML's image support self-sustaining for various
	reasons:

	1. allows implementation of a primary and secondary image cache. A primary
	   image cache could for example contain the real image data XmHTML uses
	   internally (pixmaps and thelike) and have a short-time lifespan, while
	   the secondary image cache could contain the XmImageInfo structures
	   required for creating XmHTML's internal images and have a long
	   lifespan.
	   This would gain a huge performance increase in switching between
	   documents.
	2. makes it a lot easier for other people to add image capability to
	   their own applications without needing to use XmHTML;
	3.and last but not least, it would make the core of XmHTML a *lot* lighter.

	Form image buttons work correctly.

July 11
	Fixed a baseline adjustment bug for image objects.
	Fixed a GIF animation bug with dispose by background disposal method.

	Modified the parser so it is now able to backtrack when unbalanced HTML
	tags are encountered.

	Fixed progressive image loading to work with buffers as small as 
	one byte. Progressively loading XBM images now works correctly.

July 9
	More work on forms:

	- fixed XmFontList problems (text on form widgets is now rendered
	  using the default font);
	- added support for <SELECT> form components;
	- form widgets now use the background and foreground colors specified
	  in the document itself.
	- removed highlight rectangle.

	Fixed a memory leak: when freeing anchor data, the value of named anchors
	wasn't freed properly.

July 4
	I've found the wonderfull XtInsertEventHandler function! This
	finally got me to get form scrolling correctly working: I can now simply
	choose to ignore <b>all</b> exposure events generated all over the place
	when the form components are being scrolled!

	Fixed a bug in baseline adjustment for form components.

July 3
	Made a few changes in the text outlining routines, should
	look a lot better now (the words on a line are distributed more evenly).

	Detected and fixed a number of bugs:

	- lines with different words on them (font, fontstyle, image object,
	  form components and anchors) didn't always get the baseline
	  correct;
	- lineheight of images wasn't always computed correctly;
	- before updating the background image a check is done if the
	  background gc is really present and that the background image isn't
	  delayed or being loaded.

	The background image and X11 Bitmaps can now also be loaded progressively.

July 2
	Fixed a number of bugs in the progressive JPEG loader that showed up
	when experimenting with PLC buffer resizing.

	All PLC routines are finally fully reentrant.

July 1
	The buffers used by the progressive image loader can now be resized by
	an application.

	GIF images can now also be loaded progressively by using an external GIF
	decoder installed on the XmNdecodeGIFProc resource. Introduced the
	XmHTMLGIFStream object which is now the sole argument to any
	function attached to this resource.

	Modified progressive decoding of GIF images when using the internal GIF
	decoder to wait until all compressed raster data has been received;
	progressive decoding of a GIF image by the internal GIF decoder is
	impossible due to the forking of uncompress(1) (a well, it's
	not impossible but terribly slow).

	Added a new resource, XmNprogressivePerfectColors, which allows
	one to instruct XmHTML when and if a final color quantization pass 
	should be performed once a progressive image has been loaded. I've made
	this into an option instead of doing it always as this is a rather
	time-consuming operation. Possible values are Never, Always or Automatic
	(let XmHTML decide when a quality increase can be expected).

June 26
	Fixed simultaneous updating of multiple copies of the same, progressively
	loaded, image in the current document.

	Modified XmHTMLXYToInfo() to ignore images that are currently being loaded
	progressively: most of the XmImageInfo fields returned have a very>
	limited lifespan (a few or so polling intervals) during image load.

June 25
	Progressive JPEG images that are loaded progressively are now also
	displayed properly: each pass adds additional detail.
	XmHTML now requires libjpeg version 6 or above for full jpeg support.

	Added a final color quantization pass in progressive JPEG support (first
	passes are dithered against a fixed palette, the final pass will do
	Floyd-Steinberg using a histogram of the image itself).

	Added three convenience functions to suspend, continue and kill progressive
	image loading.

	Fixed a serious bug in the main plc engine which caused a total
	server (and system) lock when any mouse button was activated on
	the display area.

June 20
	Baseline JPEG images can now also be loaded progressively.

June 19
	Fixed a bug for transparent frames in animated gifs with dispose by
	background disposal method; clipmask was used incorrectly when restoring to
	background.

June 18
	Interlaced GIF & GZF images are loaded properly now.

June 17
	First success at progressive image loading!!

June 16
	Modified XmHTMLAllocColor and XmHTMLFreeColor (two non-XmHTML supporting
	routines) so they no longer interfere with XmHTML's private color
	allocation.

	Fixed a bug in the color matching algorithm, RGB values were shifted out
	of range, causing colors to be mapped to the wrong color or even worse
	(to black).

June 15
	All PLC interfacing routines written. Image PLC interfacing routines
	written and verified. First tests show the scheme is working better than
	expected.

June 14
	Most top-level PLC routines written. Image PLC routines nearly finished,
	GIF and GZF progressive image decoders written.

June 11
	Rewrote the color allocation routines: profiling showed that XmHTML's
	old color allocation scheme spends quite a lot of time allocating its
	colors. The new scheme is nearly 30% faster.

June 10
	Started on progressive image loading: Progressive Loading Context
	(PLC) object written. Object-specific structures written. Started
	splitting the image loading routines so they can be used for progressive
	image loading.

June 9
	Wrote a very feasible progressive object loading concept. The
	implementation will use a ringbuffer with object-specific function
	pointers, visited by XmHTML using a variable polling interval. The concept
	allows for an easy implementation of progressive document loading as well.

June 5
	Alpha channel PNG images are now created when they are needed by the
	painter. The reason behind this is that when XmHTML is resized
	horizontally, the position of the image changes with respect to the
	current background setting, making a redo of alpha channel processing
	necessary. It works but causes a very undesirable delay. Seems like
	progressive image loading is becoming a real necessity...

June 3
	PNG support: XmHTML now supports the following features as set forth in
	the decoder requirements specified in the W3C Official PNG Recommendation:

	- Gamma correction;
	- all color types and bit depths;
	- full tRNS chunk support;
	- full alpha channel support;
	- bKGD chunk support;

	The tRNS and alpha channel support both work with a fixed background color
	as well as composing against a background image. As you can see,
	everything except progressive image loading is now supported.
	Thanks to Greg Roelofs <newt@pobox.com> for the quite usefull PNG Home Page
	(http://www.wco.com/~png/png.html) usefull tips and adding XmHTML to the PNG
	Supporting Applications page.

	Also upgraded the PNG code to comply with libpng version 0.96.

June 2
	Finally fixed a transparency bug on animations with a disposal method of
	none while the first frame contains transparency. This bug has been around
	since Alpha 1.0.16 or so.

June 1
	Fixed a bug in image scaling: scaling the clipmask data of transparent
	images directly was wrong so I now simply recreate the clipmask data out
	of the scaled image data (which also gains us a small performance increase).

May 31
	More work on PNG image support: background substitution and RGB images.
	Alpha channel support and transparency support is partially in.

	Added the XmNscreenGamma resource to fully exploit the gamma correction
	capabilities of both PNG and JPEG images.

May 29
	Fixed a few more bugs in the parser: the rules for definition lists
	were not entirely correct. Added a check on invalid nesting of HTML
	markup elements.

May 27
	Added a check on the scrollbar dimensions when they are specified using
	application defaults or in a resource file. Subsequently added a section
	on specifying XmHTML's dimensions in the same way in the Programmers guide.

	More work on the XmHTML Programmers Guide.

May 26
	Bugfix 05/26/97-01, a nasty bug which caused XmHTML to crash every so
	often in the most strangest ways. It turned out to be a stupid typo...

	Rewrote the caching routines in example_2 to be more generic and robust.

May 23
	Fixed the parser to recognize the contents of the <SCRIPT> and <STYLE>
	elements. The XmHTMLGetHeadAttributes convenience function now also fills
	the appropriate fields of the XmHTMLHeadAttributes structure.

May 22
	Fixed a nasty bug in XmImageFreeImageInfo when it was called by
	application code. As a result of this the function call itself now takes
	two arguments: the widget id of a XmHTMLWidget and a pointer to the
	XmImageInfo structure that is to be released.

	Fixed a bug in comment parsing: single dashes appearing in a HTML comment
	are now properly ignored.

	Added the XmHTMLAllocColor convenience routine which can be used for
	easy color allocation using the colormap installed on a given XmHTMLWidget.

May 18
	Added the XmImageConfig structure for use with XmHTML's external image
	support. This structure allows one to configure the behaviour of the
	XmImageCreate... routines and contains various flags to set 
	(amongst others) an external gif decoder, create a clipmask, perform
	background substitution and color quantization.

May 16
	Added support for the XmNmaxImageColors resource: when an image
	contains more colors than allowed, it will be quantized (and possibly
	dithered using the Floyd-Steinberg algorithm) to match the maximum number
	of allowed colors.

May 15
	Added the XmHTMLGIFtoGZF convenience routine: this routine converts
	a gif image to a compatible image format in which the LZW compressed
	raster data has been replaced with deflate compressed raster data.
	This function can be used by application programmers that want to keep
	the slowdown caused by XmHTML's gif workaround to an absolute minimum by
	converting a GIF image to a GZF image and subsequently using the GZF
	image whenever a corresponding GIF image is to be loaded. The GZF image
	format is a compatible GIF format, in which only the raster data
	is compressed in a different format.

	GZF images can be somewhere between 5 and 60%(!) smaller than the original
	GIF image and it loads considerably faster.

May 13
	After two weeks of negotiating with Unisys to obtain a license for the
	use of their patented LZW algorithm for decoding the LZW compressed
	raster data as found in GIF images, I was utterly frustrated by their
	absolutely mindboggling attitude towards the use of the LZW algorithm for
	decoding gif images. I was even more frustrated by the ridiculous
	restrictions an LZW license would place on the distribution of XmHTML
	(for instance: a splash screen would be mandatory for every application 
	using XmHTML and I would not be allowed to distribute the LZW decoder to
	people that don't have an LZW license, even if I have a valid LZW
	license). 


	Instead of removing support for gif images, I decided to replace the
	built-in LZW decoder with a workaround that translates the LZW
	compressed raster data to the format used by <tt>compress(1)</tt>, after
	which XmHTML calls uncompress to perform the actual decoding of the
	compressed raster data. This workaround causes (surprisingly) a hardly
	noticable slowdown for single-image and small gif animations. Decoding
	large animations however takes a bit more time now.


	For those that want to take the risk of violating Unisys's patent policy
	(or those that have a valid LZW license), the XmNdecodeGIFProc resource
	has been added. One can use this resource to install an alternate gif
	decoding procedure and thus surpass XmHTML's workaround.

April 30
	XmHTML will now always use any colormap provided for it (thru Core's
	XmNcolormap resource) instead of using the default colormap. It will also
	walk the widget tree to find a Shell (or a subclass of Shell) and use the
	visual provided for that Shell. XmHTML will only use the default visual if
	no Shell parent can be found. All of this also works for the XmImage type.

	Modified the HTML comment detection routine in the parser so nested
	and bad HTML comments (dashes don't occur in a multiple of four) are
	properly dealt with.

April 28
	Setting the XmNfreezeAnimations resource to True will now restart
	animations when they were previously frozen.
	Added an additional IMAGE_GIFANIMLOOP type to XmHTMLImageGetType() when
	the image is an animated gif with the NETSCAPE2.0 loop extension.

	Bugfixes:

	- truly inlined images are now repainted correctly when they are scrolled;
	- animations serving as anchors have their borders painted correctly;
	- all images serving as anchors should now appear properly centered in 
	  the anchor bounding box;
	- changing document resources without setting a new text will no longer
	  reload images;

April 27
	Still busy rewriting the documentation: programming manuals for both XmHTML
	and XmHTMLParser. The XmHTML manual is halfway now.

	Fixed a lot of minor bugs that I discovered when writing example code
	for the XmHTML programming manual:
	- XmNresizeWidth and XmNresizeHeight now work properly;
	- setting and getting the XmNtopLine resource works;
	- a few performance enhancements on document scrolling;
	- horizontal scrollbar should now be present when the width of
	  preformatted text or images is somewhere between the widget width minus
	  the margin width;
	- fixed a bug in the paint engine: height of text blocks was computed
	  incorrectly;
	- fixed another bug in the paint engine: linenumbers on preformatted text
	  wasn't set at all;
	- XmHTML's testbed crashes less frequently: both document and image cache
	  are a lot smarter now
	- also on XmHTML's testbed: added code to show possible use for
	  XmNlinkCallback callback resource and XmHTMLXYToInfo (new convenience
	  routine);
	- added the XmImageCreateFromInfo routine which creates a standalone 
	  XmImage from the data in a given (XmHTML's) XmImageInfo structure.
	- XmHTMLParserObject example now contains both normal and progressive 
	  parsing modes. Added a HTML preview.

April 20
	Reverted integration of the htmlParserObjectClass. Too many problems and
	too many overhead involved.
	Made a start with programming manuals for both XmHTML and HTMLParserObject.

	Pretty cool news: added the XmImage type which allows using XmHTML's image
	reading capability to be used by other programs as well.

April 15
	Moved XmHTML's parser into a seperate widget subclassed from Object.
	A standalone parser can now be created and configured using the standard
	X functions. Class pointer of this parser is htmlParserObjectClass.
	The standalone parser is an Intrinsic widget which can be used without
	Motif.

	Replaced XmHTML built-in parser with this HTMLParserObject (with
	surprisingly few modifications to XmHTML's interface).

April 10
	A lot of enhancements to the parser: one can now create and use a
	standalone HTML parser for a number of purposes. Features include:

	- Progressive (or incremental as you will) parser;
	- aliasing of unknown HTML elements to known ones;
	- a XmNmodifyVerifyCallback;
	- extended XmHTMLParserCallbackStruct to include description of
	  offending and proposed repair elements;
	- multiple passes to increase HTML conformance;
	- dynamic updating of the current source;
	- wrapped all of the above (and more) in a new collective example
	  which demonstrates how to use the XmHTMLParser object for interactive
	  document checking and repair.

	Modified the document verification/repair routines to use better defaults.

April 3
	Fixed a problem with scrollbars when XmHTMLRedisplay was called: document
	length wasn't updated properly.

	Fixed a two problems related to documents with a body image: images 
	serving as anchors should no longer disappear when scrolling and regular
	anchors (XmNanchorButtons == False) should now be rendered transparantly.

	Anchors with mixed fonts are now rendered as a single anchor instead of
	separate blocks.

	Underlining or striking out of Words with mixed fonts is now done properly.

April 2
	Delayed image loading now also works for the background image.
	Added the XmHTMLFrameGetChild convenience function.
	Fixed the SetValues method for enabling/disabling body colors and body
	images: the effect should be visible immediatly.

April 1
	Fixed X Protocol errors related to color freeing with StaticGray,
	GrayScale, DirectColor and TrueColor visuals.

	Fixed a number of things pointed out by Dick Porter:
	- a robuster method for body color allocation;
	- internal images no longer get freed by calling XmHTMLImageFreeImageInfo;
	- corrected layout recomputation when images are updated: XmHTML now uses 
	  the new image dimensions instead of the old ones;
	- images of which the dimensions have been specified in a HTML
	  document are now painted immediatly when replacing or updating them
	  instead of just being removed.
	- fixed image transparency problems: XmHTMLImageDefaultProc now always
	  creates a clipmask. Previously, a clipmask was only created if a document
	  contained a background image.

	Animations are now explicitly excluded as a background image. Image
	scaling now also works properly for delayed images. Finally fixed
	transparency for the default images.
	
March 27
	The parser now calls the XmNparserCallback resource when installed.
	Added a new action field to the XmHTMLParserCallbackStruct which allows
	a user to select certain actions when a fault in a document is encountered.
	Warning messages caused by the document verification/repair routines
	are no longer displayed on screen but propageted to the XmNparserCallback
	instead.

	Fixed a small bug in the text layout routines: text and images are now
	only centered or adjust to the right margin if their width doesn't exceed
	the available screen width.

	The scrolling attribute on frames is now properly handled.

	All action routines are now implemented and fully functional.

March 26
	Frames are in. Not perfect yet but it certainly works!
	Fixed a few bugs that caused XmHTML to crash when the widget's Destroy
	method was called.

	Fixed a small bug in horizontal scrolling, text should no longer flow
	onto itself when there isn't a vertical scrollbar present.
	Fixed a small bug in refreshment if image anchors, images serving as
	an anchor should now always be selectable.

March 25
	Bugfix in JPEG loading.
	XmHTML now makes proper use of the core offsets: a XmHTML widget can now
	be a child of any Motif manager widget at any position.

March 23
	Fixed a buffer overrun when converting preformatted text to a series of
	words.
	Added the XmNmimeType resource: allows XmHTML to be used for documents of
	which the content-type isn't text/html. Mime types recognized by XmHTML
	are text/html, text/plain and a number of image mime type specifications.

March 21
	XmHTML recognizes character escape sequences without a trailing ;.
	Character escape sequences in the alternate image description are now
	also expanded.

	More improvements on document verification and repair: really bad
	HTML documents (numerous and consecutive misplaced elements) are now
	repaired in such a way that display is possible.

	Animation support: the first frame of an animation now also uses the
	requested disposal method.

March 20
	Completely rewrote the HTML parser: document verification and
	auto-repair of poorly formatted HTML documents has been added.
	Especially the latter is fairly powerfull. Features include 
	detection and repair of overlapping elements, omitted list start
	tags and improperly nested font switches. It also includes auto-addition
	of terminators on elements for which a terminator is optional
	(dd, dt, li, p, option, td, th and tr). XmHTML can now also handle
	documents without the equired <HTML> and optional <BODY> tags.

	More work on the mixed text/image layout: vertical alignment attributes
	on images are now properly recognized and dealt with.


March 14
	Again more work on animation frame disposal: both disposal methods (by
	background and by previous) now work with any background color or image.
	Animation support is almost fully completed, the only thing missing is
	the ability to immediatly restore composite animations that are scrolled
	off and back on screen.

	Added a workaround for incomplete screen updates when scrolling full
	screen: the XmNrepeatDelay resource now determines the minimum time a
	key must remain pressed before scrolling continues.
	Text colors are now also properly freed (and fixed a serious bug as well).
	Also some work on example_2: added a global image cache and a 
	per-document history stack.
	Added the XmHTMLImageFreeImageInfo convenience function.
	
	And last but not least, added PNG image support to the
	XmHTMLImageDefaultProc convenience function.

March 13 
	More work on animation support: all frame disposal methods are now
	supported.

	And a lot of bugfixes:
	Font stack is now properly reset when a new document is loaded;
	named anchors are now rendered in the current text color instead of 
	XmNanchorVisitedForeground;
	no more color flashing when switching between documents that make heavy
	use of color-rich images;
	Images wider than the available screen width are no longer moved 
	downwards;
	delayed images are now displayed in the correct dimensions when they
	are flushed to XmHTML and transparent XPM images are now truly
	transparent.

March 12 
	Colors allocated for images are now properly released when the images
	are freed.
	Fixed X11 bitmaps. Updated all documentation.

March 11 
	XmHTML now supports Gif89a animated gifs (Netscape Loop Extensions
	as well as multi-image Gif89a files). Scrolling composite animations
	currently doesn't work as it should. Added the XmNfreezeAnimations
	resource.
	Replaced the XmNimageDefaultProc resource by the XmHTMLImageDefaultProc
	convenience function.
	All image reading routines now use a memory buffer instead 
	of reading directly from a file. Text layout now considers text and 
	images as the same object.
	XmHTML now properly renders any alternate text if images are disabled.
	Modified the XmImageInfo structure again and renamed most of the
	convenience functions to more logical names. 

March 4
	Fixed a spacing bug in the text layout routines which caused words
	that shouldn't be glued together got glued together anyway.
	Added the animation support.

March 3
	Added polygon and default shape imagemap support.
	Delayed Image Loading: XmImageInfo structure updated and three new 
	convenience functions added: XmHTMLUpdateImage, XmHTMLReplaceImage 
	and XmHTMLRedisplay.

February 28
	A number of changes in the text-layout routines: words
	should now be glued together properly.
	Text colors are now preserved accross anchors.

February 27
	More work on Imagemaps: support for external client-side imagemaps
	has been added but not tested (yet). Added the XmHTMLAddImagemap
	convenience routine. Added default images which are displayed when
	the XmNimageEnable resource is set to False or when an unsupported
	imagetype is encountered.
	Changed the XmHTMLAnchorCallbackStruct, please be aware of this!

February 26
	Added client-side imagemaps; rectangular and circle shaped area types
	work well. Empty as well as combined anchors (both name and href in a
	single anchor) are now supported. Added the XmNimagemapCallback resource 
	and corresponding callback structure.
	Fixed a small parser bug which sometimes (only seen it once really) 
	caused wrong text alignment. A lot of small bugfixes in anchor creation 
	and selection. Removed the extra field in XmHTMLanchorCallbackStruct
	and added three new fields instead.

February 25
	Modified color allocation to get an exact, close or substituted color.
	This produces *very* nice results. The background attribute on the
	body tag is properly honored, scrolling with an image as background is
	very smooth. Images can now also serve as anchors. Mixed text and image
	layout works but needs a bit more work.

February 20
	Major News: image support is almost completely added and functional!
	The default image loading procedure supports X11 bitmaps, X11 XPM 
	pixmaps, JPEG and GIF87a and GIF89a images, PNG is being worked on. 
	This procedure should in theory work properly with every visual class,
	although only PseudoColor has been tested. I hacked this code in on
	three evenings, and I'm pretty proud of it.

	The XmImageInfo section has been updated and contains some more 
	information on image handling.

	I do owe John L. Cwikla (cwikla@wri.com) a lot of gratitude for his 
	small but very usefull XCC package!

February 18
	Internationalization: the font loading scheme employed by XmHTML 
	has been modified drastically and is much more robust now. 
	Added the XmNcharset resource to allow specification of the ISO
	character set and changed the format of the XmNfontFamily and 
	XmNfontFamilyFixed resources.

February 13
	Added support for the face tag on the font element, e.i.
	<font face="Helvetica,arial"> is now recognized.

February 12
	Vertical resizing works properly again.
	XmHTML Widgets with XmNresizeWidth/XmNresizeHeight set to True finally
	compute their initial size correctly.

February 10
	Fixed a number of potential buffer overruns.
	Complete rewrite of the text layout routines. Interword and interline
	spacing is adjusted depending on the current font. Simplified the
	outlining and alignment adjustment routines. 
	Removed a number of internally unused structure members.
	Changed anchor treatment: consumes less memory and is easier to use.

February 6
	Fixed interword and interline spacing when different fonts are mixed on 
	a single line: lines do no longer overlap each other and font changes
	in the middle of a word are properly attached.
	Indentation is now computed regardless of the current font.

February 4
	Added code to support the BASEFONT element and updated the code that
	deals with the FONT element accordingly.
	The parser now deals properly with overlapping tags, missing tags.
	All SHORTTAG elements are now recognized and dealt with properly by the
	parser (empty tags, empty closing tags, unclosed tags and NULL-end tags).
	XmHTML passes all example pages from (http://www.absurd.org/dark_side/) 
	the Dark Side of the HTML without even as much as a single hickup. Watch
	your browser choke on the test pages at the above URL ;-).

February 3
	First bug reports are seeping in: fixed a bug in font loading routines,
	color releasing routines and unknown anchor types
	Updated the <li> element formatting to recognize the type and value
	attributes.
	Removed default identation for preformatted text.

January 30
	Fixed a bug with jumping to anchors: when jumping to the end of a 
	document, the value of the vertical scrollbar exceeded the maximum
	allowable value.
	Final preparations for the alpha release. We'll be shipping out the
	examples any time now.

January 29
	Reworked some of the anchor parsing/handling routines: anchor activation
	and anchor tracking callbacks are a little bit more efficient now.
	XmHTML is now able to determine the type of URL referenced by an anchor:
	added the url_type field to the XmHTMLAnchorCallbackStruct.
	Updated exposure handling after tests with Motif 1.2.0/X11R5.

	Preparations for the alpha release: cleaned up the source and 
	wrote a few examples demonstrating the use of XmHTML.

January 28
	A lot of memory leaks have been fixed.
	Switching between documents with/without a <body> color specification
	seems to be working.

January 27
	Fixed a serious bug with preformatted text: multiple newlines weren't
	recognized properly and thus were rendered wrong.

January 25
	Nested aligment is now recognized properly.
	Changed the font routines to use a pointsize specification as mentioned in
	the documentation. Previously pixel size was used.
	Linespacing for text with a font other than the default font is now
	correct.

January 24
	Screen redrawing finally done: only the exposed regions are now redrawn
	instead of the entire line of which the exposed region was part.
	Preformatted text now also draws anchors correctly.

January 23
	More work on horizontal scrolling: text drawn previously in the margin
	is now properly erased. Horizontal redrawing to the right now takes the
	x position of the exposed region into account, instead of repainting the
	entire screen.
	Preformatted text is now painted properly.

January 20
	Enhanced the parser to insert closing elements on elements where they
	are optional (<P>, <LI>, <DT> and <DD>).
	Finally got round to implementing preformatted text.

January 19
	Scrolling: the widget now remembers it's current vertical text position
	when it is resized.
	Removed left and right quotes from the list of punctuation characters.

January 17
	Added the TAB element extension.
	Fixed a number of memory leaks reported by dmalloc.
	Fixed a bug in the parser which made it impossible to correctly detect
	elements with trailing spaces inside them.

January 16
	Text outlining: bugfixes and few performance enhancements.
	Added the COLOR tag extension.

January 13
	Removed the XmHTMLCallbackStruct and replaced it with callback-specific
	callback structures: 
		XmHTMLAnchorCallbackStruct, 
		XmHTMLFormCallbackStruct,
		XmHTMLLinkCallbackStruct 
		XmHTMLParserCallbackStruct.
	Added jumping to local anchors when a local anchor is pressed.
	Added the XmNanchorVisitedProc resource.
	More work on vertical scrolling.
	XmHTML can now handle named anchors by itself (but it can be vetoed by the
	programmer).
	Added the following convenience functions
		XmHTMLGetAnchorId, 
		XmHTMLScrollToAnchorById, 
		XmHTMLScrollToAnchorByName,
		XmHTMLScrollToLine.
	Enhanced HTML comment detection in the raw HTML parser.

January 12
	Accelerated screen update when scrolling vertically. Horizontal scrolling
	needs a bit more work.
	Nested lists are now rendered as they should: mixing ordered and unordered
	lists works.
	Added the XmNenableOutlining resource: when enabled (default) all text of 
	which the alignment is not explicitly set will be outlined.
	Implemented the color tag for all elements mentioned in the extensions.

January 10
	Horizontal scrolling works. 
	Fixed scrollBar offsets when XmNmarginWidth/XmNmarginHeight is smaller
	than the width of a scrollBar. sliderSize and pageIncrement now
	reflect the percantage of hidden text.
	Nesting of ordered lists and unordered lists now works when they are not 
	mixed.
	Changed the type of all positions from Position (signed short) to int. 
	Documents larger than SHRT_MAX used to cause a wrap-around of their 
	y-position.

January 9
	Working on scrolling. Scrollbars are displayed according to the
	XmNscrollBarPlacement resource. Vertical scrolling works.
	Changed the linebreaking algorithm to eat multiple block elements without
	contents. Also a number of aesthetical changes.
	I expect to have an alpha release by the end of this month. Things that
	need to be implemented before a release will be made are: 
	preformatted text, support for a few image types and nested sorted lists. 

January 8
	Added autosizing stuff: setting XmNresizeWidth and/or XmNresizeHeight
	now causes XmHTML to size itself around the document properly.
	Rewrote text alignment routines. Fixed a bug in the parser which caused an 
	anchor not be recognized if the name contained the string ``name'' or 
	``target''.

January 7
	Fixed text alignment for lines consisting of different text elements.
	Finished the text outlining algorithm: paragraphs can now be outlined
	properly, which gives pretty neat results.

January 6
	Happy Newyear
	A lot of work and thought went into the render engine. 
	The previous method proved to be very memory- and time consuming, but 
	did have a lot of potential.  After a lot of trial and error, the final 
	method is a mix of the original rendering engine and the state machine 
	approach, resulting a an even more flexible (read extensible) and less 
	memory- and time consuming.
	Changed XmNstringDirection to XmNalignment, which makes more sense. Added a
	description of the implemented HTML 3.2 extensions.  
	Added the XmNparserCallback resource.

December 19
	Changed rendering completely: a stream of paint commands is now generated
	whenever a document is loaded. The actual paint engine is represented by a 
	state machine in which parts of the painting stream are poured whenever a
	screen update is required. This is much more flexible and faster than the 
	previous setup, in which rendering was performed ``just in time''.
	This state machine approach also allows for an easy implementation of 
	forthcoming extensions such as the <OBJECT> tag and HTML math. It also 
	offers considerable advantages for a (possible) conversion of the widget to 
	an HTML editor widget, although that would require an integration of the
	raw HTML parser and paint stream generator.

December 18
	Implemented proper rendering of all attributes on horizontal rules. 
	Linefeed checking almost working properly.
	Added the XmNinputCallback and XmNmotionTrackCallback resources and 
	updated action routines accordingly (as suggested by 
	Ricky Ralston (rlr@wscoe4.atl.hp.com)
	Added the track-motion</a> and help action routines. 
	Added the XmNworkWindow resource.

December 17
	Rendering of anchors as buttons is now done properly and anchors wrapping
	around a newline are finally connected as it should: linebreaking algorithm 
	finally working properly.
	Added an outlining algorithm for blocks of plain text (this is for a future 
	OUTLINE attribute on the <DIV> element). This produces some very nice
	results!
	Furthermore a number of cosmetic updates on rules, underlining, strikeout 
	and anchor selection rendering.
	Updated the set-values method: almost all resources can now be set using
	XtSetValues.

December 16
	More work on anchor selection: pressing an anchor now highlights that 
	anchor; anchors that wrap around a newline are now redrawn correctly; anchor
	cursor setting/unsetting finally seems to be working satisfactory. Also 
	added a target field to XmHTMLCallbackStruct to support the frame extension.
	XmNarmCallback implemented.
	<HR> rules are now painted. 
	Numbered lists with type=i|I are now being rendered for roman numerals upto
	a value of 4999. Simplified list indentation.
	Corrected a few minor bugs that came up when testing multiple instances of 
	XmHTML widgets.
	Added the XmNanchorButtons resource: anchors can now be rendered as 
	pushbuttons instead of being underlined. Needs some more work though.

December 13
	XmHTML begins to take real shape!  XmNactivateCallback and 
	XmNanchorTrackCallback completely implemented: anchor selection fully
	functional now.  First real XmHTML tests by using it in
	XntHelp, and it seems to be working quite well!  
	Numbered lists with type=1|a|A are now being rendered correctly.
	Fixed a number of major memory leaks and minor small bugs in format.c and
	the set_values method.

December 12
	Solid and dashed underlines as well as strikeout are being drawn correctly. 
	List indentation finally correct. All three types of bullets in <UL> are
	also placed correctly.
	Punctuation characters have a special treatment now so they are attached to 
	words where they should be attached.
	Fixed a few bugs in the font switching routines; nested fonts are rendered 
	correctly now.
	First attempts at anchor tracking have some success, XmNanchorTrackCallback
	resource treatment partially finished.

December 10
	Linebreaking algorithm works pretty okay. Horizontal alignment is now also
	treated correctly.
	Added the XmNstringDirection resource. 
	Fixed a few bugs in format.c.

December 9
	First success at text displaying! The paint routines now can display all 
	sort of texts in the selected font and/or color. Added support for a future 
	``outline'' attribute on the <DIV> tag. 
	The linebreaking algorithm needs a lot more work. 
	Changed the XmNanchorTrackProc resource to a callback:
	XmNanchorTrackCallback (as suggested by Danny Backx, u27113@kb.be).

December 6
	ALIGN and VALIGN attributes recognized. Added a few extra attribute parsing 
	routines.  Optimized recognition for underlining, strikout and anchors: 
	nested combinations are now treated ok. Checked and corrected a few memory 
	leaks.  Performed some robustness checks and corrected bugs detected from 
	this testing.

December 5
	List support added: indentation and the TYPE attribute are recognized as 
	well as nested lists. 
	Underline, strikeout and anchor stuff written. 
	More work on font routines: nested font combinations are recognized and 
	treated ok.

December 4
	First implementation of text formatting/painting. 
	Font loading/switching routines written.

December 2
	Initialize now calls the HTML parser, creates the widget and anchor cursor 
	and calls the HTML formatting routines. XmNlinkCallback installed.
	Prelimenary tests on widget creation and resource setting/changing
	performed succesfully.

November 28
	First drafts of expose, layout, resize, set_values, get_values_hook,
	query_geometry, geometry_manager and destroy methods.

November 26
	Enhanced the parser to allow strict checking of HTML documents against
	the HTML 3.2 standard. Added the XmNstrictHTMLChecking resource.

November 22
	Changed the XmNfontSize resources to XmNfontSizeList. Added 
	XmHTMLLinkCallback, XmNanchorTrackProc, XmNanchorTarget and
	XmNenableBody resources. Figured out how to use the XmRepType functions.
	ClassInitialize, ClassPartInitialize and Initialize methods written.

November 21
	Public and private interfaces defined. Updated Widget interface definition.

November 20
	XmHTML Widget resources, callbacks and action routines
	interface definition nearly completed (you're reading it now).

November 19
	Made some performance enhancements to the HTML parser after testing. 
	When compared to NCSA, our parser is almost twice as fast!
	(Loading and parsing a 230kb HTML file with 14126 elements takes 0.16 
	seconds. NCSA takes 0.30 and does not parse table elements).

November 18
	Final HTML parser completed, performance tests started. 

November 12
	First draft of HTML parser.

November 10
	The need for XmHTML arised.