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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.60 by root, Fri Jun 15 13:21:59 2012 UTC vs.
Revision 1.70 by root, Mon Jul 2 01:35:37 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 is evaluated once per hour. It will set F<sunday.png> as	78	This inner expression is evaluated once per hour (and whenever the
		79	temrinal window is resized). It sets F<sunday.png> as background on
77	background on Sundays, and F<weekday.png> on all other days.	80	Sundays, and F<weekday.png> on all other days.
78		81
79	Fortunately, we expect that most expressions will be much simpler, with	82	Fortunately, we expect that most expressions will be much simpler, with
80	little Perl knowledge needed.	83	little Perl knowledge needed.
81		84
82	Basically, you always start with a function that "generates" an image	85	Basically, you always start with a function that "generates" an image
…		…
115	horizontal and vertical dimensions. For example, this halves the image	118	horizontal and vertical dimensions. For example, this halves the image
116	width and doubles the image height:	119	width and doubles the image height:
117		120
118	scale 0.5, 2, load "$HOME/mypic.png"	121	scale 0.5, 2, load "$HOME/mypic.png"
119		122
120	Other effects than scaling are also readily available, for example, you can	123	IF you try out these expressions, you might suffer from some sluggishness,
121	tile the image to fill the whole window, instead of resizing it:	124	because each time the terminal is resized, it loads the PNG image agin
		125	and scales it. Scaling is usually fast (and unavoidable), but loading the
		126	image can be quite time consuming. This is where C<keep> comes in handy:
122		127
		128	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		129
		130	The C<keep> operator executes all the statements inside the braces only
		131	once, or when it thinks the outcome might change. In other cases it
		132	returns the last value computed by the brace block.
		133
		134	This means that the C<load> is only executed once, which makes it much
		135	faster, but also means that more memory is being used, because the loaded
		136	image must be kept in memory at all times. In this expression, the
		137	trade-off is likely worth it.
		138
		139	But back to effects: Other effects than scaling are also readily
		140	available, for example, you can tile the image to fill the whole window,
		141	instead of resizing it:
		142
123	tile load "$HOME/mypic.png"	143	tile keep { load "$HOME/mypic.png" }
124		144
125	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	145	In fact, images returned by C<load> are in C<tile> mode by default, so the
126	is kind of superfluous.	146	C<tile> operator is kind of superfluous.
127		147
128	Another common effect is to mirror the image, so that the same edges touch:	148	Another common effect is to mirror the image, so that the same edges
		149	touch:
129		150
130	mirror load "$HOME/mypic.png"	151	mirror keep { load "$HOME/mypic.png" }
131		152
132	This is also a typical background expression:	153	Another common background expression is:
133		154
134	rootalign root	155	rootalign root
135		156
136	It first takes a snapshot of the screen background image, and then	157	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	158	moves it to the upper left corner of the screen (as opposed to the upper
138	pseudo-transparency, as the image seems to be static while the window is	159	left corner of the terminal window)- the result is pseudo-transparency:
139	moved around.	160	the image seems to be static while the window is moved around.
140		161
141	=head2 CYCLES AND CACHING	162	=head2 CACHING AND SENSITIVITY
142		163
143	As has been mentioned before, the expression might be evaluated multiple	164	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	165	caching results can be very important for a smooth operation. Caching can
145	have begun. Many operators cache their results till the next cycle.	166	also be useful to reduce memory usage, though, for example, when an image
		167	is cached by C<load>, it could be shared by multiple terminal windows
		168	running inside urxvtd.
146		169
147	For example, the C<load> operator keeps a copy of the image. If it is	170	=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		171
151	This only works for one cycle though, so as long as you load the same	172	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	173	... }>. The C<keep> operator takes a block of multiple statements enclosed
153	image, it will forget about the first one.	174	by C<{}> and keeps the return value in memory.
154		175
155	This allows you to either speed things up by keeping multiple images in	176	An expression can be "sensitive" to various external events, such as
156	memory, or conserve memory by loading images more often.	177	scaling or moving the window, root background changes and timers. Simply
		178	using an expression (such as C<scale> without parameters) that depends on
		179	certain changing values (called "variables"), or using those variables
		180	directly, will make an expression sensitive to these events - for example,
		181	using C<scale> or C<TW> will make the expression sensitive to the terminal
		182	size, and thus to resizing events.
157		183
158	For example, you can keep two images in memory and use a random one like	184	When such an event happens, C<keep> will automatically trigger a
159	this:	185	reevaluation of the whole expression with the new value of the expression.
160		186
161	my $img1 = load "img1.png";	187	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		188
165	Since both images are "loaded" every time the expression is evaluated,	189	rootalign keep { blur 20, root }
166	they are always kept in memory. Contrast this version:
167		190
168	my $path1 = "img1.png";	191	This makes a blurred copy of the root background once, and on subsequent
169	my $path2 = "img2.png";	192	calls, just root-aligns it. Since C<blur> is usually quite slow and
170	load ((0.5 > rand) ? $path1 : $path2)	193	C<rootalign> is quite fast, this trades extra memory (for the cached
		194	blurred pixmap) with speed (blur only needs to be redone when root
		195	changes).
171		196
172	Here, a path is selected randomly, and load is only called for one image,	197	=head3 C<load> caching
173	so keeps only one image in memory. If, on the next evaluation, luck	198
174	decides to use the other path, then it will have to load that image again.	199	The C<load> operator itself does not keep images in memory, but as long as
		200	the image is still in memory, C<load> will use the in-memory image instead
		201	of loading it freshly from disk.
		202
		203	That means that this expression:
		204
		205	keep { load "$HOME/path..." }
		206
		207	Not only caches the image in memory, other terminal instances that try to
		208	C<load> it can reuse that in-memory copy.
175		209
176	=head1 REFERENCE	210	=head1 REFERENCE
177		211
178	=head2 COMMAND LINE SWITCHES	212	=head2 COMMAND LINE SWITCHES
179		213
…		…
204		238
205	=cut	239	=cut
206		240
207	our %_IMG_CACHE;	241	our %_IMG_CACHE;
208	our $HOME;	242	our $HOME;
209	our ($self, $old, $new);	243	our ($self, $frame);
210	our ($x, $y, $w, $h);	244	our ($x, $y, $w, $h);
211		245
212	# enforce at least this interval between updates	246	# enforce at least this interval between updates
213	our $MIN_INTERVAL = 6/59.951;	247	our $MIN_INTERVAL = 6/59.951;
214		248
215	{	249	{
216	package urxvt::bgdsl; # background language	250	package urxvt::bgdsl; # background language
		251
		252	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		253	sub FR_CACHE () { 1 } # cached values
		254	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		255	sub FR_STATE () { 3 } # watchers etc.
217		256
218	use List::Util qw(min max sum shuffle);	257	use List::Util qw(min max sum shuffle);
219		258
220	=head2 PROVIDERS/GENERATORS	259	=head2 PROVIDERS/GENERATORS
221		260
…		…
228	=item load $path	267	=item load $path
229		268
230	Loads the image at the given C<$path>. The image is set to plane tiling	269	Loads the image at the given C<$path>. The image is set to plane tiling
231	mode.	270	mode.
232		271
233	Loaded images will be cached for one cycle, and shared between temrinals	272	If the image is already in memory (e.g. because another terminal instance
234	running in the same process (e.g. in C<urxvtd>).	273	uses it), then the in-memory copy us returned instead.
235		274
236	=item load_uc $path	275	=item load_uc $path
237		276
238	Load uncached - same as load, but does not cache the image. This function	277	Load uncached - same as load, but does not cache the image, which means it
239	is most useufl if you want to optimise a background expression in some	278	is I<always> loaded from the filesystem again.
240	way.
241		279
242	=cut	280	=cut
243		281
244	sub load_uc($) {	282	sub load($) {
245	my ($path) = @_;	283	my ($path) = @_;
246		284
247	$_IMG_CACHE{$path} \|\| do {	285	$_IMG_CACHE{$path} \|\| do {
248	my $img = $self->new_img_from_file ($path);	286	my $img = $self->new_img_from_file ($path);
249	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);	287	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
250	$img	288	$img
251	}	289	}
252	}	290	}
253		291
254	sub load($) {
255	my ($path) = @_;
256
257	$new->{load}{$path} = $old->{load}{$path} \|\| load_uc $path;
258	}
259
260	=item root	292	=item root
261		293
262	Returns the root window pixmap, that is, hopefully, the background image	294	Returns the root window pixmap, that is, hopefully, the background image
263	of your screen. The image is set to extend mode.	295	of your screen.
264		296
265	This function makes your expression root sensitive, that means it will be	297	This function makes your expression root sensitive, that means it will be
266	reevaluated when the bg image changes.	298	reevaluated when the bg image changes.
267		299
268	=cut	300	=cut
269		301
270	sub root() {	302	sub root() {
271	$new->{again}{rootpmap} = 1;	303	$frame->[FR_AGAIN]{rootpmap} = 1;
272	$self->new_img_from_root	304	$self->new_img_from_root
273	}	305	}
274		306
275	=item solid $colour	307	=item solid $colour
276		308
…		…
304	}	336	}
305		337
306	=item merge $img ...	338	=item merge $img ...
307		339
308	Takes any number of images and merges them together, creating a single	340	Takes any number of images and merges them together, creating a single
309	image containing them all.	341	image containing them all. The tiling mode of the first image is used as
		342	the tiling mode of the resulting image.
		343
		344	This function is called automatically when an expression returns multiple
		345	images.
310		346
311	=cut	347	=cut
312		348
313	sub merge(@) {	349	sub merge(@) {
		350	return $_[0] unless $#_;
		351
314	# rather annoyingly clumsy, but optimisation is for another time	352	# rather annoyingly clumsy, but optimisation is for another time
315		353
316	my $x0 = +1e9;	354	my $x0 = +1e9;
317	my $y0 = +1e9;	355	my $y0 = +1e9;
318	my $x1 = -1e9;	356	my $x1 = -1e9;
…		…
330	$x1 = $x if $x1 < $x;	368	$x1 = $x if $x1 < $x;
331	$y1 = $y if $y1 < $y;	369	$y1 = $y if $y1 < $y;
332	}	370	}
333		371
334	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);	372	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		373	$base->repeat_mode ($_[0]->repeat_mode);
335	$base->fill ([0, 0, 0, 0]);	374	$base->fill ([0, 0, 0, 0]);
336		375
337	$base->draw ($_)	376	$base->draw ($_)
338	for @_;	377	for @_;
339		378
…		…
443	Using these functions make your expression sensitive to window moves.	482	Using these functions make your expression sensitive to window moves.
444		483
445	These functions are mainly useful to align images to the root window.	484	These functions are mainly useful to align images to the root window.
446		485
447	Example: load an image and align it so it looks as if anchored to the	486	Example: load an image and align it so it looks as if anchored to the
448	background.	487	background (that's exactly what C<rootalign> does btw.):
449		488
450	move -TX, -TY, load "mybg.png"	489	move -TX, -TY, keep { load "mybg.png" }
451		490
452	=item TW	491	=item TW
453		492
454	Return the width (C<TW>) and height (C<TH>) of the terminal window (the	493	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
455	terminal window is the full window by default, and the character area only	494	terminal window is the full window by default, and the character area only
…		…
461	the window size to conserve memory.	500	the window size to conserve memory.
462		501
463	Example: take the screen background, clip it to the window size, blur it a	502	Example: take the screen background, clip it to the window size, blur it a
464	bit, align it to the window position and use it as background.	503	bit, align it to the window position and use it as background.
465		504
466	clip move -TX, -TY, once { blur 5, root }	505	clip move -TX, -TY, keep { blur 5, root }
467		506
468	=cut	507	=cut
469		508
470	sub TX() { $new->{again}{position} = 1; $x }	509	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
471	sub TY() { $new->{again}{position} = 1; $y }	510	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
472	sub TW() { $new->{again}{size} = 1; $w }	511	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
473	sub TH() { $new->{again}{size} = 1; $h }	512	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
474		513
475	=item now	514	=item now
476		515
477	Returns the current time as (fractional) seconds since the epoch.	516	Returns the current time as (fractional) seconds since the epoch.
478		517
…		…
485	C<$seconds> seconds.	524	C<$seconds> seconds.
486		525
487	Example: load some image and rotate it according to the time of day (as if it were	526	Example: load some image and rotate it according to the time of day (as if it were
488	the hour pointer of a clock). Update this image every minute.	527	the hour pointer of a clock). Update this image every minute.
489		528
		529	again 60;
490	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	530	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
491		531
492	=item counter $seconds	532	=item counter $seconds
493		533
494	Like C<again>, but also returns an increasing counter value, starting at	534	Like C<again>, but also returns an increasing counter value, starting at
495	0, which might be useful for some simple animation effects.	535	0, which might be useful for some simple animation effects.
…		…
497	=cut	537	=cut
498		538
499	sub now() { urxvt::NOW }	539	sub now() { urxvt::NOW }
500		540
501	sub again($) {	541	sub again($) {
502	$new->{again}{time} = $_[0];	542	$frame->[FR_AGAIN]{time} = $_[0];
503	}	543	}
504		544
505	sub counter($) {	545	sub counter($) {
506	$new->{again}{time} = $_[0];	546	$frame->[FR_AGAIN]{time} = $_[0];
507	$self->{counter} + 0	547	$frame->[FR_STATE]{counter} + 0
508	}	548	}
509		549
510	=back	550	=back
511		551
512	=head2 SHAPE CHANGING OPERATORS	552	=head2 SHAPE CHANGING OPERATORS
…		…
532	assumed.	572	assumed.
533		573
534	Example: load an image, blur it, and clip it to the window size to save	574	Example: load an image, blur it, and clip it to the window size to save
535	memory.	575	memory.
536		576
537	clip blur 10, load "mybg.png"	577	clip keep { blur 10, load "mybg.png" }
538		578
539	=cut	579	=cut
540		580
541	sub clip($;$$;$$) {	581	sub clip($;$$;$$) {
542	my $img = pop;	582	my $img = pop;
…		…
636	the terminal window (or the box specified by C<$width> and C<$height> if	676	the terminal window (or the box specified by C<$width> and C<$height> if
637	given).	677	given).
638		678
639	Example: load an image and center it.	679	Example: load an image and center it.
640		680
641	center pad load "mybg.png"	681	center keep { pad load "mybg.png" }
642		682
643	=item rootalign $img	683	=item rootalign $img
644		684
645	Moves the image so that it appears glued to the screen as opposed to the	685	Moves the image so that it appears glued to the screen as opposed to the
646	window. This gives the illusion of a larger area behind the window. It is	686	window. This gives the illusion of a larger area behind the window. It is
647	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	687	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
648	top left of the screen.	688	top left of the screen.
649		689
650	Example: load a background image, put it in mirror mode and root align it.	690	Example: load a background image, put it in mirror mode and root align it.
651		691
652	rootalign mirror load "mybg.png"	692	rootalign keep { mirror load "mybg.png" }
653		693
654	Example: take the screen background and align it, giving the illusion of	694	Example: take the screen background and align it, giving the illusion of
655	transparency as long as the window isn't in front of other windows.	695	transparency as long as the window isn't in front of other windows.
656		696
657	rootalign root	697	rootalign root
…		…
682		722
683	sub rootalign($) {	723	sub rootalign($) {
684	move -TX, -TY, $_[0]	724	move -TX, -TY, $_[0]
685	}	725	}
686		726
687	=item rotate $center_x, $center_y, $degrees	727	=item rotate $center_x, $center_y, $degrees, $img
688		728
689	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	729	Rotates the image clockwise by C<$degrees> degrees, around the point at
690	pointer at C<$center_x> and C<$center_y> (specified as factor of image	730	C<$center_x> and C<$center_y> (specified as factor of image width/height).
691	width/height).
692		731
693	#TODO# new width, height, maybe more operators?
694
695	Example: rotate the image by 90 degrees	732	Example: rotate the image by 90 degrees around it's center.
		733
		734	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
696		735
697	=cut	736	=cut
698		737
699	sub rotate($$$$) {	738	sub rotate($$$$) {
700	my $img = pop;	739	my $img = pop;
…		…
711		750
712	The following operators change the pixels of the image.	751	The following operators change the pixels of the image.
713		752
714	=over 4	753	=over 4
715		754
		755	=item tint $color, $img
		756
		757	Tints the image in the given colour.
		758
		759	Example: tint the image red.
		760
		761	tint "red", load "rgb.png"
		762
		763	Example: the same, but specify the colour by component.
		764
		765	tint [1, 0, 0], load "rgb.png"
		766
		767	=cut
		768
		769	sub tint($$) {
		770	$_[1]->tint ($_[0])
		771	}
		772
716	=item contrast $factor, $img	773	=item contrast $factor, $img
717		774
718	=item contrast $r, $g, $b, $img	775	=item contrast $r, $g, $b, $img
719		776
720	=item contrast $r, $g, $b, $a, $img	777	=item contrast $r, $g, $b, $a, $img
…		…
803	Anything that didn't fit any of the other categories, even after applying	860	Anything that didn't fit any of the other categories, even after applying
804	force and closing our eyes.	861	force and closing our eyes.
805		862
806	=over 4	863	=over 4
807		864
808	=item once { ... }	865	=item keep { ... }
809		866
810	This function takes a code block as argument, that is, one or more	867	This operator takes a code block as argument, that is, one or more
811	statements enclosed by braces.	868	statements enclosed by braces.
812		869
813	The trick is that this code block is only evaluated once - future calls	870	The trick is that this code block is only evaluated when the outcome
814	will simply return the original image (yes, it should only be used with	871	changes - on other calls the C<keep> simply returns the image it computed
815	images).	872	previously (yes, it should only be used with images). Or in other words,
		873	C<keep> I<caches> the result of the code block so it doesn't need to be
		874	computed again.
816		875
817	This can be extremely useful to avoid redoign the same slow operations	876	This can be extremely useful to avoid redoing slow operations - for
818	again and again- for example, if your background expression takes the root	877	example, if your background expression takes the root background, blurs it
819	background, blurs it and then root-aligns it it would have to blur the	878	and then root-aligns it it would have to blur the root background on every
820	root background on every window move or resize.	879	window move or resize.
821		880
		881	Another example is C<load>, which can be quite slow.
		882
		883	In fact, urxvt itself encloses the whole expression in some kind of
		884	C<keep> block so it only is reevaluated as required.
		885
822	Putting the blur into a C<once> block will make sure the blur is only done	886	Putting the blur into a C<keep> block will make sure the blur is only done
823	once:	887	once, while the C<rootalign> is still done each time the window moves.
824		888
825	rootlign once { blur 10, root }	889	rootlign keep { blur 10, root }
826		890
827	This leaves the question of how to force reevaluation of the block, in	891	This leaves the question of how to force reevaluation of the block,
828	case the root background changes: Right now, all once blocks forget that	892	in case the root background changes: If expression inside the block
829	they ahve been executed before each time the root background changes (if	893	is sensitive to some event (root background changes, window geometry
830	the expression is sensitive to that) or when C<once_again> is called.	894	changes), then it will be reevaluated automatically as needed.
831		895
832	=item once_again
833
834	Resets all C<once> block as if they had never been called, i.e. on the
835	next call they will be reevaluated again.
836
837	=cut	896	=cut
838		897
839	sub once(&) {	898	sub keep(&) {
840	my $once = $self->{once_cache}{$_[0]+0} \|\|= do {	899	my $id = $_[0]+0;
841	local $new->{again};	900
842	my @res = $_[0]();	901	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
843	[$new->{again}, \@res]	902
		903	unless ($frame->[FR_CACHE]) {
		904	$frame->[FR_CACHE] = [ $_[0]() ];
		905
		906	my $self = $self;
		907	my $frame = $frame;
		908	Scalar::Util::weaken $frame;
		909	$self->compile_frame ($frame, sub {
		910	# clear this frame cache, also for all parents
		911	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		912	undef $frame->[FR_CACHE];
		913	}
		914
		915	$self->recalculate;
844	};	916	});
845
846	$new->{again} = {
847	%{ $new->{again} },
848	%{ $once->[0] }
849	};	917	};
850		918
851	# in scalar context we always return the first original result, which	919	# in scalar context we always return the first original result, which
852	# is not quite how perl works.	920	# is not quite how perl works.
853	wantarray	921	wantarray
854	? @{ $once->[1] }	922	? @{ $frame->[FR_CACHE] }
855	: $once->[1][0]	923	: $frame->[FR_CACHE][0]
		924	}
		925
		926	# sub keep_clear() {
		927	# delete $self->{frame_cache};
856	}	928	# }
857
858	sub once_again() {
859	delete $self->{once_cache};
860	}
861		929
862	=back	930	=back
863		931
864	=cut	932	=cut
865		933
866	}	934	}
867		935
868	sub parse_expr {	936	sub parse_expr {
869	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	937	my $expr = eval
		938	"sub {\n"
		939	. "package urxvt::bgdsl;\n"
		940	. "#line 0 'background expression'\n"
		941	. "$_[0]\n"
		942	. "}";
870	die if $@;	943	die if $@;
871	$expr	944	$expr
872	}	945	}
873		946
874	# compiles a parsed expression	947	# compiles a parsed expression
875	sub set_expr {	948	sub set_expr {
876	my ($self, $expr) = @_;	949	my ($self, $expr) = @_;
877		950
		951	$self->{root} = [];
878	$self->{expr} = $expr;	952	$self->{expr} = $expr;
879	$self->recalculate;	953	$self->recalculate;
		954	}
		955
		956	# takes a hash of sensitivity indicators and installs watchers
		957	sub compile_frame {
		958	my ($self, $frame, $cb) = @_;
		959
		960	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		961	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		962
		963	# don't keep stuff alive
		964	Scalar::Util::weaken $state;
		965
		966	if ($again->{nested}) {
		967	$state->{nested} = 1;
		968	} else {
		969	delete $state->{nested};
		970	}
		971
		972	if (my $interval = $again->{time}) {
		973	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		974	if $state->{time}[0] != $interval;
		975
		976	# callback might have changed, although we could just rule that out
		977	$state->{time}[1]->cb (sub {
		978	++$state->{counter};
		979	$cb->();
		980	});
		981	} else {
		982	delete $state->{time};
		983	}
		984
		985	if ($again->{position}) {
		986	$state->{position} = $self->on (position_change => $cb);
		987	} else {
		988	delete $state->{position};
		989	}
		990
		991	if ($again->{size}) {
		992	$state->{size} = $self->on (size_change => $cb);
		993	} else {
		994	delete $state->{size};
		995	}
		996
		997	if ($again->{rootpmap}) {
		998	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		999	} else {
		1000	delete $state->{rootpmap};
		1001	}
880	}	1002	}
881		1003
882	# evaluate the current bg expression	1004	# evaluate the current bg expression
883	sub recalculate {	1005	sub recalculate {
884	my ($arg_self) = @_;	1006	my ($arg_self) = @_;
…		…
894		1016
895	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1017	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
896		1018
897	# set environment to evaluate user expression	1019	# set environment to evaluate user expression
898		1020
899	local $self = $arg_self;	1021	local $self = $arg_self;
900
901	local $HOME = $ENV{HOME};	1022	local $HOME = $ENV{HOME};
902	local $old = $self->{state};	1023	local $frame = [];
903	local $new = my $state = $self->{state} = {};
904		1024
905	($x, $y, $w, $h) =
906	$self->background_geometry ($self->{border});	1025	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
907		1026
908	# evaluate user expression	1027	# evaluate user expression
909		1028
910	my $img = eval { $self->{expr}->() };	1029	my @img = eval { $self->{expr}->() };
911	warn $@ if $@;#d#	1030	die $@ if $@;
912	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";	1031	die "background-expr did not return anything.\n" unless @img;
		1032	die "background-expr: expected image(s), got something else.\n"
		1033	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
		1034
		1035	my $img = urxvt::bgdsl::merge @img;
		1036
		1037	$frame->[FR_AGAIN]{size} = 1
		1038	if $img->repeat_mode != urxvt::RepeatNormal;
913		1039
914	# if the expression is sensitive to external events, prepare reevaluation then	1040	# if the expression is sensitive to external events, prepare reevaluation then
915		1041	$self->compile_frame ($frame, sub { $arg_self->recalculate });
916	my $again = delete $state->{again};
917
918	$again->{size} = 1
919	if $img->repeat_mode != urxvt::RepeatNormal;
920
921	if (my $again = $again->{time}) {
922	my $self = $self;
923	$state->{timer} = $again == $old->{again}
924	? $old->{timer}
925	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
926	++$self->{counter};
927	$self->recalculate
928	});
929	}
930
931	if ($again->{position}) {
932	$self->enable (position_change => sub { $_[0]->recalculate });
933	} else {
934	$self->disable ("position_change");
935	}
936
937	if ($again->{size}) {
938	$self->enable (size_change => sub { $_[0]->recalculate });
939	} else {
940	$self->disable ("size_change");
941	}
942
943	if ($again->{rootpmap}) {
944	$self->enable (rootpmap_change => sub {
945	delete $_[0]{once_cache}; # this will override once-block values from
946	$_[0]->recalculate;
947	});
948	} else {
949	$self->disable ("rootpmap_change");
950	}
951		1042
952	# clear stuff we no longer need	1043	# clear stuff we no longer need
953		1044
954	%$old = ();	1045	# unless (%{ $frame->[FR_STATE] }) {
955
956	unless (%$again) {
957	delete $self->{state};	1046	# delete $self->{state};
958	delete $self->{expr};	1047	# delete $self->{expr};
959	}	1048	# }
960		1049
961	# set background pixmap	1050	# set background pixmap
962		1051
963	$self->set_background ($img, $self->{border});	1052	$self->set_background ($img, $self->{border});
964	$self->scr_recolour (0);	1053	$self->scr_recolour (0);

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.60 by root, Fri Jun 15 13:21:59 2012 UTC vs. Revision 1.70 by root, Mon Jul 2 01:35:37 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.60 by root, Fri Jun 15 13:21:59 2012 UTC vs.
Revision 1.70 by root, Mon Jul 2 01:35:37 2012 UTC