[ViewVC] Diff of: cvs/rxvt-unicode/src/perl/background

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.53 by root, Tue Jun 12 18:25:57 2012 UTC vs.
Revision 1.64 by root, Tue Jun 19 20:49:53 2012 UTC

…		…
26	to be as simple as possible.	26	to be as simple as possible.
27		27
28	For example, to load an image and scale it to the window size, you would	28	For example, to load an image and scale it to the window size, you would
29	use:	29	use:
30		30
31	urxvt --background-expr 'scale load "/path/to/mybg.png"'	31	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
32		32
33	Or specified as a X resource:	33	Or specified as a X resource:
34		34
35	URxvt.background-expr: scale load "/path/to/mybg.png"	35	URxvt.background-expr: scale keep { load "/path/to/mybg.png" }
36		36
37	=head1 THEORY OF OPERATION	37	=head1 THEORY OF OPERATION
38		38
39	At startup, just before the window is mapped for the first time, the	39	At startup, just before the window is mapped for the first time, the
40	expression is evaluated and must yield an image. The image is then	40	expression is evaluated and must yield an image. The image is then
…		…
53	If any of the parameters that the expression relies on changes (when the	53	If any of the parameters that the expression relies on changes (when the
54	window is moved or resized, its position or size changes; when the root	54	window is moved or resized, its position or size changes; when the root
55	pixmap is replaced by another one the root background changes; or when the	55	pixmap is replaced by another one the root background changes; or when the
56	timer elapses), then the expression will be evaluated again.	56	timer elapses), then the expression will be evaluated again.
57		57
58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the	58	For example, an expression such as C<scale keep { load "$HOME/mybg.png"
59	image to the window size, so it relies on the window size and will	59	}> scales the image to the window size, so it relies on the window size
60	be reevaluated each time it is changed, but not when it moves for	60	and will be reevaluated each time it is changed, but not when it moves for
61	example. That ensures that the picture always fills the terminal, even	61	example. That ensures that the picture always fills the terminal, even
62	after its size changes.	62	after its size changes.
63		63
64	=head2 EXPRESSIONS	64	=head2 EXPRESSIONS
65		65
66	Expressions are normal Perl expressions, in fact, they are Perl blocks -	66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
67	which means you could use multiple lines and statements:	67	which means you could use multiple lines and statements:
68		68
		69	scale keep {
69	again 3600;	70	again 3600;
70	if (localtime now)[6]) {	71	if (localtime now)[6]) {
71	return scale load "$HOME/weekday.png";	72	return load "$HOME/weekday.png";
72	} else {	73	} else {
73	return scale load "$HOME/sunday.png";	74	return load "$HOME/sunday.png";
		75	}
74	}	76	}
75		77
76	This expression gets evaluated once per hour. It will set F<sunday.png> as	78	This expression is evaluated once per hour. It will set F<sunday.png> as
77	background on Sundays, and F<weekday.png> on all other days.	79	background on Sundays, and F<weekday.png> on all other days.
78		80
79	Fortunately, we expect that most expressions will be much simpler, with	81	Fortunately, we expect that most expressions will be much simpler, with
80	little Perl knowledge needed.	82	little Perl knowledge needed.
81		83
…		…
115	horizontal and vertical dimensions. For example, this halves the image	117	horizontal and vertical dimensions. For example, this halves the image
116	width and doubles the image height:	118	width and doubles the image height:
117		119
118	scale 0.5, 2, load "$HOME/mypic.png"	120	scale 0.5, 2, load "$HOME/mypic.png"
119		121
120	Other effects than scaling are also readily available, for example, you can	122	IF you try out these expressions, you might suffer from sluggishness,
121	tile the image to fill the whole window, instead of resizing it:	123	because each time the terminal is resized, it again loads the PNG image
		124	and scales it. Scaling is usually fats, but loading the image can be quite
		125	time consuming. This is where C<keep> comes in handy:
122		126
		127	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		128
		129	The C<keep> operator executes all the statements inside the braces only
		130	once, or when it thinks the outcome might change. In other cases it
		131	returns the last value computed by the brace block.
		132
		133	This means that the C<load> is only executed once, which makes it much
		134	faster, but alos means that more memory is being used, because the loaded
		135	image must be kept in memory at all times. In this expression, the
		136	trade-off is likely worth it.
		137
		138	But back to effects: Other effects than scaling are also readily
		139	available, for example, you can tile the image to fill the whole window,
		140	instead of resizing it:
		141
123	tile load "$HOME/mypic.png"	142	tile keep { load "$HOME/mypic.png" }
124		143
125	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	144	In fact, images returned by C<load> are in C<tile> mode by default, so the
126	is kind of superfluous.	145	C<tile> operator is kind of superfluous.
127		146
128	Another common effect is to mirror the image, so that the same edges touch:	147	Another common effect is to mirror the image, so that the same edges
		148	touch:
129		149
130	mirror load "$HOME/mypic.png"	150	mirror keep { load "$HOME/mypic.png" }
131		151
132	This is also a typical background expression:	152	Another common background expression is:
133		153
134	rootalign root	154	rootalign root
135		155
136	It first takes a snapshot of the screen background image, and then	156	This one first takes a snapshot of the screen background image, and then
137	moves it to the upper left corner of the screen - the result is	157	moves it to the upper left corner of the screen (as opposed to the upepr
138	pseudo-transparency, as the image seems to be static while the window is	158	left corner of the terminal window)- the result is pseudo-transparency:
139	moved around.	159	the image seems to be static while the window is moved around.
140		160
141	=head2 CYCLES AND CACHING	161	=head2 CACHING AND SENSITIVITY
142		162
143	As has been mentioned before, the expression might be evaluated multiple	163	Since some operations (such as C<load> and C<blur>) can take a long time,
144	times. Each time the expression is reevaluated, a new cycle is said to	164	caching results can be very important for a smooth operation. Caching can
145	have begun. Many operators cache their results till the next cycle.	165	also be useful to reduce memory usage, though, for example, when an image
		166	is cached by C<load>, it could be shared by multiple terminal windows
		167	running inside urxvtd.
146		168
147	For example, the C<load> operator keeps a copy of the image. If it is	169	=head3 C<keep { ... }> caching
148	asked to load the same image on the next cycle it will not load it again,
149	but return the cached copy.
150		170
151	This only works for one cycle though, so as long as you load the same	171	The most important way to cache expensive operations is to use C<keep {
152	image every time, it will always be cached, but when you load a different	172	... }>. The C<keep> operator takes a block of multiple statements enclosed
153	image, it will forget about the first one.	173	by C<{}> and keeps the return value in memory.
154		174
155	This allows you to either speed things up by keeping multiple images in	175	An expression can be "sensitive" to various external events, such as
156	memory, or conserve memory by loading images more often.	176	scaling or moving the window, root backgorund changes and timers. Simply
		177	using an expression (such as C<scale> without parameters) that depend on
		178	certain changing values (called "variables"), or using those variables
		179	directly, will make an expression sensitive to these events - for example,
		180	using C<scale> or C<TW> will make the expression sensitive to the terminal
		181	size, and thus to resizing events.
157		182
158	For example, you can keep two images in memory and use a random one like	183	When such an event happens, C<keep> will automatically trigger a
159	this:	184	reevaluation of the whole expression with the new value of the expression.
160		185
161	my $img1 = load "img1.png";	186	C<keep> is most useful for expensive operations, such as C<blur>:
162	my $img2 = load "img2.png";
163	(0.5 > rand) ? $img1 : $img2
164		187
165	Since both images are "loaded" every time the expression is evaluated,	188	rootalign once { blur 20, root }
166	they are always kept in memory. Contrast this version:
167		189
168	my $path1 = "img1.png";	190	This makes a blurred copy of the root background once, and on subsequent
169	my $path2 = "img2.png";	191	calls, just root-aligns it. Since C<blur> is usually quite slow and
170	load ((0.5 > rand) ? $path1 : $path2)	192	C<rootalign> is quite fast, this trades extra memory (for the cached
		193	blurred pixmap) with speed (blur only needs to be redone when root
		194	changes).
171		195
172	Here, a path is selected randomly, and load is only called for one image,	196	=head3 C<load> caching
173	so keeps only one image in memory. If, on the next evaluation, luck	197
174	decides to use the other path, then it will have to load that image again.	198	The C<load> operator itself does not keep images in memory, but as long as
		199	the image is still in memory, C<load> will use the in-memory image instead
		200	of loading it freshly from disk.
		201
		202	That means that this expression:
		203
		204	keep { load "$HOME/path..." }
		205
		206	Not only caches the image in memory, other terminal instances that try to
		207	C<load> it can reuse that in-memory copy.
175		208
176	=head1 REFERENCE	209	=head1 REFERENCE
177		210
178	=head2 COMMAND LINE SWITCHES	211	=head2 COMMAND LINE SWITCHES
179		212
…		…
203	=back	236	=back
204		237
205	=cut	238	=cut
206		239
207	our %_IMG_CACHE;	240	our %_IMG_CACHE;
208	our %_ONCE_CACHE;
209	our $HOME;	241	our $HOME;
210	our ($self, $old, $new);	242	our ($self, $frame);
211	our ($x, $y, $w, $h);	243	our ($x, $y, $w, $h);
212		244
213	# enforce at least this interval between updates	245	# enforce at least this interval between updates
214	our $MIN_INTERVAL = 6/59.951;	246	our $MIN_INTERVAL = 6/59.951;
215		247
216	{	248	{
217	package urxvt::bgdsl; # background language	249	package urxvt::bgdsl; # background language
		250
		251	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		252	sub FR_CACHE () { 1 } # cached values
		253	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		254	sub FR_STATE () { 3 } # watchers etc.
218		255
219	use List::Util qw(min max sum shuffle);	256	use List::Util qw(min max sum shuffle);
220		257
221	=head2 PROVIDERS/GENERATORS	258	=head2 PROVIDERS/GENERATORS
222		259
…		…
229	=item load $path	266	=item load $path
230		267
231	Loads the image at the given C<$path>. The image is set to plane tiling	268	Loads the image at the given C<$path>. The image is set to plane tiling
232	mode.	269	mode.
233		270
234	Loaded images will be cached for one cycle.	271	If the image is already in memory (e.g. because another temrinal instance
		272	uses it), then the in-memory copy us returned instead.
235		273
		274	=item load_uc $path
		275
		276	Load uncached - same as load, but does not cache the image, which means it
		277	is I<always> loaded from the filesystem again.
		278
236	=cut	279	=cut
		280
		281	sub load_uc($) {
		282	$self->new_img_from_file ($path)
		283	}
237		284
238	sub load($) {	285	sub load($) {
239	my ($path) = @_;	286	my ($path) = @_;
240		287
241	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	288	$_IMG_CACHE{$path} \|\| do {
		289	my $img = load_uc $path;
		290	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		291	$img
		292	}
242	}	293	}
243		294
244	=item root	295	=item root
245		296
246	Returns the root window pixmap, that is, hopefully, the background image	297	Returns the root window pixmap, that is, hopefully, the background image
247	of your screen. The image is set to extend mode.	298	of your screen.
248		299
249	This function makes your expression root sensitive, that means it will be	300	This function makes your expression root sensitive, that means it will be
250	reevaluated when the bg image changes.	301	reevaluated when the bg image changes.
251		302
252	=cut	303	=cut
253		304
254	sub root() {	305	sub root() {
255	$new->{rootpmap_sensitive} = 1;	306	$frame->[FR_AGAIN]{rootpmap} = 1;
256	$self->new_img_from_root	307	$self->new_img_from_root
257	}	308	}
258		309
259	=item solid $colour	310	=item solid $colour
260		311
…		…
269	=cut	320	=cut
270		321
271	sub solid($;$$) {	322	sub solid($;$$) {
272	my $colour = pop;	323	my $colour = pop;
273		324
274	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	325	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
275	$img->fill ($colour);	326	$img->fill ($colour);
276	$img	327	$img
277	}	328	}
278		329
279	=item clone $img	330	=item clone $img
…		…
283		334
284	=cut	335	=cut
285		336
286	sub clone($) {	337	sub clone($) {
287	$_[0]->clone	338	$_[0]->clone
		339	}
		340
		341	=item merge $img ...
		342
		343	Takes any number of images and merges them together, creating a single
		344	image containing them all. The tiling mode of the first image is used as
		345	the tiling mdoe of the resulting image.
		346
		347	This function is called automatically when an expression returns multiple
		348	images.
		349
		350	=cut
		351
		352	sub merge(@) {
		353	return $_[0] unless $#_;
		354
		355	# rather annoyingly clumsy, but optimisation is for another time
		356
		357	my $x0 = +1e9;
		358	my $y0 = +1e9;
		359	my $x1 = -1e9;
		360	my $y1 = -1e9;
		361
		362	for (@_) {
		363	my ($x, $y, $w, $h) = $_->geometry;
		364
		365	$x0 = $x if $x0 > $x;
		366	$y0 = $y if $y0 > $y;
		367
		368	$x += $w;
		369	$y += $h;
		370
		371	$x1 = $x if $x1 < $x;
		372	$y1 = $y if $y1 < $y;
		373	}
		374
		375	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		376	$base->repeat_mode ($_[0]->repeat_mode);
		377	$base->fill ([0, 0, 0, 0]);
		378
		379	$base->draw ($_)
		380	for @_;
		381
		382	$base
288	}	383	}
289		384
290	=head2 TILING MODES	385	=head2 TILING MODES
291		386
292	The following operators modify the tiling mode of an image, that is, the	387	The following operators modify the tiling mode of an image, that is, the
…		…
390	Using these functions make your expression sensitive to window moves.	485	Using these functions make your expression sensitive to window moves.
391		486
392	These functions are mainly useful to align images to the root window.	487	These functions are mainly useful to align images to the root window.
393		488
394	Example: load an image and align it so it looks as if anchored to the	489	Example: load an image and align it so it looks as if anchored to the
395	background.	490	background (that's exactly what C<rootalign> does btw.):
396		491
397	move -TX, -TY, load "mybg.png"	492	move -TX, -TY, keep { load "mybg.png" }
398		493
399	=item TW	494	=item TW
400		495
401	Return the width (C<TW>) and height (C<TH>) of the terminal window (the	496	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
402	terminal window is the full window by default, and the character area only	497	terminal window is the full window by default, and the character area only
…		…
408	the window size to conserve memory.	503	the window size to conserve memory.
409		504
410	Example: take the screen background, clip it to the window size, blur it a	505	Example: take the screen background, clip it to the window size, blur it a
411	bit, align it to the window position and use it as background.	506	bit, align it to the window position and use it as background.
412		507
413	clip move -TX, -TY, blur 5, root	508	clip move -TX, -TY, keep { blur 5, root }
414		509
415	=cut	510	=cut
416		511
417	sub TX() { $new->{position_sensitive} = 1; $x }	512	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
418	sub TY() { $new->{position_sensitive} = 1; $y }	513	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
419	sub TW() { $new->{size_sensitive} = 1; $w }	514	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
420	sub TH() { $new->{size_sensitive} = 1; $h }	515	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
421		516
422	=item now	517	=item now
423		518
424	Returns the current time as (fractional) seconds since the epoch.	519	Returns the current time as (fractional) seconds since the epoch.
425		520
…		…
432	C<$seconds> seconds.	527	C<$seconds> seconds.
433		528
434	Example: load some image and rotate it according to the time of day (as if it were	529	Example: load some image and rotate it according to the time of day (as if it were
435	the hour pointer of a clock). Update this image every minute.	530	the hour pointer of a clock). Update this image every minute.
436		531
		532	again 60;
437	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	533	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
438		534
439	=item counter $seconds	535	=item counter $seconds
440		536
441	Like C<again>, but also returns an increasing counter value, starting at	537	Like C<again>, but also returns an increasing counter value, starting at
442	0, which might be useful for some simple animation effects.	538	0, which might be useful for some simple animation effects.
…		…
444	=cut	540	=cut
445		541
446	sub now() { urxvt::NOW }	542	sub now() { urxvt::NOW }
447		543
448	sub again($) {	544	sub again($) {
449	$new->{again} = $_[0];	545	$frame->[FR_AGAIN]{time} = $_[0];
450	}	546	}
451		547
452	sub counter($) {	548	sub counter($) {
453	$new->{again} = $_[0];	549	$frame->[FR_AGAIN]{time} = $_[0];
454	$self->{counter} + 0	550	$frame->[FR_STATE]{counter} + 0
455	}	551	}
456		552
457	=back	553	=back
458		554
459	=head2 SHAPE CHANGING OPERATORS	555	=head2 SHAPE CHANGING OPERATORS
…		…
479	assumed.	575	assumed.
480		576
481	Example: load an image, blur it, and clip it to the window size to save	577	Example: load an image, blur it, and clip it to the window size to save
482	memory.	578	memory.
483		579
484	clip blur 10, load "mybg.png"	580	clip keep { blur 10, load "mybg.png" }
485		581
486	=cut	582	=cut
487		583
488	sub clip($;$$;$$) {	584	sub clip($;$$;$$) {
489	my $img = pop;	585	my $img = pop;
…		…
583	the terminal window (or the box specified by C<$width> and C<$height> if	679	the terminal window (or the box specified by C<$width> and C<$height> if
584	given).	680	given).
585		681
586	Example: load an image and center it.	682	Example: load an image and center it.
587		683
588	center pad load "mybg.png"	684	center keep { pad load "mybg.png" }
589		685
590	=item rootalign $img	686	=item rootalign $img
591		687
592	Moves the image so that it appears glued to the screen as opposed to the	688	Moves the image so that it appears glued to the screen as opposed to the
593	window. This gives the illusion of a larger area behind the window. It is	689	window. This gives the illusion of a larger area behind the window. It is
594	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	690	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
595	top left of the screen.	691	top left of the screen.
596		692
597	Example: load a background image, put it in mirror mode and root align it.	693	Example: load a background image, put it in mirror mode and root align it.
598		694
599	rootalign mirror load "mybg.png"	695	rootalign keep { mirror load "mybg.png" }
600		696
601	Example: take the screen background and align it, giving the illusion of	697	Example: take the screen background and align it, giving the illusion of
602	transparency as long as the window isn't in front of other windows.	698	transparency as long as the window isn't in front of other windows.
603		699
604	rootalign root	700	rootalign root
…		…
629		725
630	sub rootalign($) {	726	sub rootalign($) {
631	move -TX, -TY, $_[0]	727	move -TX, -TY, $_[0]
632	}	728	}
633		729
634	=item rotate $center_x, $center_y, $degrees	730	=item rotate $center_x, $center_y, $degrees, $img
635		731
636	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	732	Rotates the image clockwise by C<$degrees> degrees, around the point at
637	pointer at C<$center_x> and C<$center_y> (specified as factor of image	733	C<$center_x> and C<$center_y> (specified as factor of image width/height).
638	width/height).
639		734
640	#TODO# new width, height, maybe more operators?
641
642	Example: rotate the image by 90 degrees	735	Example: rotate the image by 90 degrees around it's center.
		736
		737	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
643		738
644	=cut	739	=cut
645		740
646	sub rotate($$$$) {	741	sub rotate($$$$) {
647	my $img = pop;	742	my $img = pop;
648	$img->rotate (	743	$img->rotate (
649	$_[0] * $img->w,	744	$_[0] * ($img->w + $img->x),
650	$_[1] * $img->h,	745	$_[1] * ($img->h + $img->y),
651	$_[2] * (3.14159265 / 180),	746	$_[2] * (3.14159265 / 180),
652	)	747	)
653	}	748	}
654		749
655	=back	750	=back
…		…
745		840
746	=back	841	=back
747		842
748	=head2 OTHER STUFF	843	=head2 OTHER STUFF
749		844
750	Anything that didn't fit any of the other categories, even after appliyng	845	Anything that didn't fit any of the other categories, even after applying
751	force and closing our eyes.	846	force and closing our eyes.
752		847
753	=over 4	848	=over 4
754		849
755	=item once { ... }	850	=item once { ... }
…		…
759		854
760	The trick is that this code block is only evaluated once - future calls	855	The trick is that this code block is only evaluated once - future calls
761	will simply return the original image (yes, it should only be used with	856	will simply return the original image (yes, it should only be used with
762	images).	857	images).
763		858
764	This can be extremely useful to avoid redoign the same slow operations	859	This can be extremely useful to avoid redoing the same slow operations
765	again and again- for example, if your background expression takes the root	860	again and again- for example, if your background expression takes the root
766	background, blurs it and then root-aligns it it would have to blur the	861	background, blurs it and then root-aligns it it would have to blur the
767	root background on every window move or resize.	862	root background on every window move or resize.
768		863
		864	In fact, urxvt itself encloses the whole expression in some kind of
		865	C<once> block so it only is reevaluated as required.
		866
769	Putting the blur into a C<once> block will make sure the blur is only done	867	Putting the blur into a C<once> block will make sure the blur is only done
770	once:	868	once:
771		869
772	rootlign once { blur 10, root }	870	rootlign once { blur 10, root }
773		871
774	This leaves the question of how to force reevaluation of the block, in	872	This leaves the question of how to force reevaluation of the block,
775	case the root background changes: Right now, all once blocks forget that	873	in case the root background changes: If expression inside the block
776	they ahve been executed before each time the root background changes (if	874	is sensitive to some event (root background changes, window geometry
777	the expression is sensitive to that) or when C<once_again> is called.	875	changes), then it will be reevaluated automatically as needed.
778		876
779	=item once_again	877	=item once_again
780		878
781	Resets all C<once> block as if they had never been called, i.e. on the	879	Resets all C<once> block as if they had never been called, i.e. on the
782	next call they will be reevaluated again.	880	next call they will be reevaluated again.
783		881
784	=cut	882	=cut
785		883
786	sub once(&) {	884	sub once(&) {
787	$_ONCE_CACHE{$_[0]+0} \|\|= $_[0]()	885	my $id = $_[0]+0;
		886
		887	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		888
		889	unless ($frame->[FR_CACHE]) {
		890	$frame->[FR_CACHE] = [ $_[0]() ];
		891
		892	my $self = $self;
		893	my $frame = $frame;
		894	Scalar::Util::weaken $frame;
		895	$self->compile_frame ($frame, sub {
		896	# clear this frame cache, also for all parents
		897	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		898	undef $frame->[FR_CACHE];
		899	}
		900
		901	$self->recalculate;
		902	});
		903	};
		904
		905	# in scalar context we always return the first original result, which
		906	# is not quite how perl works.
		907	wantarray
		908	? @{ $frame->[FR_CACHE] }
		909	: $frame->[FR_CACHE][0]
788	}	910	}
789		911
790	sub once_again() {	912	sub once_again() {
791	%_ONCE_CACHE = ();	913	delete $self->{frame_cache};
792	}	914	}
793		915
794	=back	916	=back
795		917
796	=cut	918	=cut
797		919
798	}	920	}
799		921
800	sub parse_expr {	922	sub parse_expr {
801	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	923	my $expr = eval
		924	"sub {\n"
		925	. "package urxvt::bgdsl;\n"
		926	. "#line 0 'background expression'\n"
		927	. "$_[0]\n"
		928	. "}";
802	die if $@;	929	die if $@;
803	$expr	930	$expr
804	}	931	}
805		932
806	# compiles a parsed expression	933	# compiles a parsed expression
807	sub set_expr {	934	sub set_expr {
808	my ($self, $expr) = @_;	935	my ($self, $expr) = @_;
809		936
		937	$self->{root} = [];
810	$self->{expr} = $expr;	938	$self->{expr} = $expr;
811	$self->recalculate;	939	$self->recalculate;
		940	}
		941
		942	# takes a hash of sensitivity indicators and installs watchers
		943	sub compile_frame {
		944	my ($self, $frame, $cb) = @_;
		945
		946	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		947	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		948
		949	# don't keep stuff alive
		950	Scalar::Util::weaken $state;
		951
		952	if ($again->{nested}) {
		953	$state->{nested} = 1;
		954	} else {
		955	delete $state->{nested};
		956	}
		957
		958	if (my $interval = $again->{time}) {
		959	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		960	if $state->{time}[0] != $interval;
		961
		962	# callback might have changed, although we could just rule that out
		963	$state->{time}[1]->cb (sub {
		964	++$state->{counter};
		965	$cb->();
		966	});
		967	} else {
		968	delete $state->{time};
		969	}
		970
		971	if ($again->{position}) {
		972	$state->{position} = $self->on (position_change => $cb);
		973	} else {
		974	delete $state->{position};
		975	}
		976
		977	if ($again->{size}) {
		978	$state->{size} = $self->on (size_change => $cb);
		979	} else {
		980	delete $state->{size};
		981	}
		982
		983	if ($again->{rootpmap}) {
		984	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		985	} else {
		986	delete $state->{rootpmap};
		987	}
812	}	988	}
813		989
814	# evaluate the current bg expression	990	# evaluate the current bg expression
815	sub recalculate {	991	sub recalculate {
816	my ($arg_self) = @_;	992	my ($arg_self) = @_;
…		…
826		1002
827	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1003	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
828		1004
829	# set environment to evaluate user expression	1005	# set environment to evaluate user expression
830		1006
831	local $self = $arg_self;	1007	local $self = $arg_self;
832
833	local $HOME = $ENV{HOME};	1008	local $HOME = $ENV{HOME};
834	local $old = $self->{state};	1009	local $frame = [];
835	local $new = my $state = $self->{state} = {};
836		1010
837	($x, $y, $w, $h) =
838	$self->background_geometry ($self->{border});	1011	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
839		1012
840	# evaluate user expression	1013	# evaluate user expression
841		1014
842	my $img = eval { $self->{expr}->() };	1015	my @img = eval { $self->{expr}->() };
843	warn $@ if $@;#d#	1016	die $@ if $@;
844	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";	1017	die "background-expr did not return anything.\n" unless @img;
		1018	die "background-expr: expected image(s), got something else.\n"
		1019	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
845		1020
846	$state->{size_sensitive} = 1	1021	my $img = urxvt::bgdsl::merge @img;
		1022
		1023	$frame->[FR_AGAIN]{size} = 1
847	if $img->repeat_mode != urxvt::RepeatNormal;	1024	if $img->repeat_mode != urxvt::RepeatNormal;
848		1025
849	# if the expression is sensitive to external events, prepare reevaluation then	1026	# if the expression is sensitive to external events, prepare reevaluation then
850		1027	$self->compile_frame ($frame, sub { $arg_self->recalculate });
851	my $repeat;
852
853	if (my $again = $state->{again}) {
854	$repeat = 1;
855	my $self = $self;
856	$state->{timer} = $again == $old->{again}
857	? $old->{timer}
858	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
859	++$self->{counter};
860	$self->recalculate
861	});
862	}
863
864	if (delete $state->{position_sensitive}) {
865	$repeat = 1;
866	$self->enable (position_change => sub { $_[0]->recalculate });
867	} else {
868	$self->disable ("position_change");
869	}
870
871	if (delete $state->{size_sensitive}) {
872	$repeat = 1;
873	$self->enable (size_change => sub { $_[0]->recalculate });
874	} else {
875	$self->disable ("size_change");
876	}
877
878	if (delete $state->{rootpmap_sensitive}) {
879	$repeat = 1;
880	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
881	} else {
882	$self->disable ("rootpmap_change");
883	}
884		1028
885	# clear stuff we no longer need	1029	# clear stuff we no longer need
886		1030
887	%$old = ();	1031	# unless (%{ $frame->[FR_STATE] }) {
888
889	unless ($repeat) {
890	delete $self->{state};	1032	# delete $self->{state};
891	delete $self->{expr};	1033	# delete $self->{expr};
892	}	1034	# }
893		1035
894	# set background pixmap	1036	# set background pixmap
895		1037
896	$self->set_background ($img, $self->{border});	1038	$self->set_background ($img, $self->{border});
897	$self->scr_recolour (0);	1039	$self->scr_recolour (0);

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.53 by root, Tue Jun 12 18:25:57 2012 UTC vs. Revision 1.64 by root, Tue Jun 19 20:49:53 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.53 by root, Tue Jun 12 18:25:57 2012 UTC vs.
Revision 1.64 by root, Tue Jun 19 20:49:53 2012 UTC