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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.54 by root, Thu Jun 14 16:22:20 2012 UTC vs.
Revision 1.67 by sf-exg, Fri Jun 29 18:12:25 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 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
…		…
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 fast, 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 "$HOME/mypic.png" }
		128
		129	The C<keep> operator executes all the statements inside the braces only
		130	once, or when it thinks the outcome might change. In other cases it
		131	returns the last value computed by the brace block.
		132
		133	This means that the C<load> is only executed once, which makes it much
		134	faster, but also means that more memory is being used, because the loaded
		135	image must be kept in memory at all times. In this expression, the
		136	trade-off is likely worth it.
		137
		138	But back to effects: Other effects than scaling are also readily
		139	available, for example, you can tile the image to fill the whole window,
		140	instead of resizing it:
		141
123	tile load "$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 upper
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 background changes and timers. Simply
		177	using an expression (such as C<scale> without parameters) that depends 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, and shared between temrinals	271	If the image is already in memory (e.g. because another terminal instance
235	running in the same process (e.g. in C<urxvtd>).	272	uses it), then the in-memory copy us returned instead.
236		273
237	=item load_uc $path	274	=item load_uc $path
238		275
239	Load uncached - same as load, but does not cache the image. This function	276	Load uncached - same as load, but does not cache the image, which means it
240	is most useufl if you want to optimise a background expression in some	277	is I<always> loaded from the filesystem again.
241	way.
242		278
243	=cut	279	=cut
244		280
245	sub load_uc($) {	281	sub load_uc($) {
		282	$self->new_img_from_file ($path)
		283	}
		284
		285	sub load($) {
246	my ($path) = @_;	286	my ($path) = @_;
247		287
248	$_IMG_CACHE{$path} \|\| do {	288	$_IMG_CACHE{$path} \|\| do {
249	my $img = $self->new_img_from_file ($path);	289	my $img = load_uc $path;
250	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);	290	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
251	$img	291	$img
252	}	292	}
253	}	293	}
254		294
255	sub load($) {
256	my ($path) = @_;
257
258	$new->{load}{$path} = $old->{load}{$path} \|\| load_uc $path;
259	}
260
261	=item root	295	=item root
262		296
263	Returns the root window pixmap, that is, hopefully, the background image	297	Returns the root window pixmap, that is, hopefully, the background image
264	of your screen. The image is set to extend mode.	298	of your screen.
265		299
266	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
267	reevaluated when the bg image changes.	301	reevaluated when the bg image changes.
268		302
269	=cut	303	=cut
270		304
271	sub root() {	305	sub root() {
272	$new->{rootpmap_sensitive} = 1;	306	$frame->[FR_AGAIN]{rootpmap} = 1;
273	$self->new_img_from_root	307	$self->new_img_from_root
274	}	308	}
275		309
276	=item solid $colour	310	=item solid $colour
277		311
…		…
286	=cut	320	=cut
287		321
288	sub solid($;$$) {	322	sub solid($;$$) {
289	my $colour = pop;	323	my $colour = pop;
290		324
291	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);
292	$img->fill ($colour);	326	$img->fill ($colour);
293	$img	327	$img
294	}	328	}
295		329
296	=item clone $img	330	=item clone $img
…		…
300		334
301	=cut	335	=cut
302		336
303	sub clone($) {	337	sub clone($) {
304	$_[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 mode 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
305	}	383	}
306		384
307	=head2 TILING MODES	385	=head2 TILING MODES
308		386
309	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
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407	Using these functions make your expression sensitive to window moves.	485	Using these functions make your expression sensitive to window moves.
408		486
409	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.
410		488
411	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
412	background.	490	background (that's exactly what C<rootalign> does btw.):
413		491
414	move -TX, -TY, load "mybg.png"	492	move -TX, -TY, keep { load "mybg.png" }
415		493
416	=item TW	494	=item TW
417		495
418	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
419	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
…		…
425	the window size to conserve memory.	503	the window size to conserve memory.
426		504
427	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
428	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.
429		507
430	clip move -TX, -TY, blur 5, root	508	clip move -TX, -TY, keep { blur 5, root }
431		509
432	=cut	510	=cut
433		511
434	sub TX() { $new->{position_sensitive} = 1; $x }	512	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
435	sub TY() { $new->{position_sensitive} = 1; $y }	513	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
436	sub TW() { $new->{size_sensitive} = 1; $w }	514	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
437	sub TH() { $new->{size_sensitive} = 1; $h }	515	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
438		516
439	=item now	517	=item now
440		518
441	Returns the current time as (fractional) seconds since the epoch.	519	Returns the current time as (fractional) seconds since the epoch.
442		520
…		…
449	C<$seconds> seconds.	527	C<$seconds> seconds.
450		528
451	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
452	the hour pointer of a clock). Update this image every minute.	530	the hour pointer of a clock). Update this image every minute.
453		531
		532	again 60;
454	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" }
455		534
456	=item counter $seconds	535	=item counter $seconds
457		536
458	Like C<again>, but also returns an increasing counter value, starting at	537	Like C<again>, but also returns an increasing counter value, starting at
459	0, which might be useful for some simple animation effects.	538	0, which might be useful for some simple animation effects.
…		…
461	=cut	540	=cut
462		541
463	sub now() { urxvt::NOW }	542	sub now() { urxvt::NOW }
464		543
465	sub again($) {	544	sub again($) {
466	$new->{again} = $_[0];	545	$frame->[FR_AGAIN]{time} = $_[0];
467	}	546	}
468		547
469	sub counter($) {	548	sub counter($) {
470	$new->{again} = $_[0];	549	$frame->[FR_AGAIN]{time} = $_[0];
471	$self->{counter} + 0	550	$frame->[FR_STATE]{counter} + 0
472	}	551	}
473		552
474	=back	553	=back
475		554
476	=head2 SHAPE CHANGING OPERATORS	555	=head2 SHAPE CHANGING OPERATORS
…		…
496	assumed.	575	assumed.
497		576
498	Example: load an image, blur it, and clip it to the window size to save	577	Example: load an image, blur it, and clip it to the window size to save
499	memory.	578	memory.
500		579
501	clip blur 10, load "mybg.png"	580	clip keep { blur 10, load "mybg.png" }
502		581
503	=cut	582	=cut
504		583
505	sub clip($;$$;$$) {	584	sub clip($;$$;$$) {
506	my $img = pop;	585	my $img = pop;
…		…
600	the terminal window (or the box specified by C<$width> and C<$height> if	679	the terminal window (or the box specified by C<$width> and C<$height> if
601	given).	680	given).
602		681
603	Example: load an image and center it.	682	Example: load an image and center it.
604		683
605	center pad load "mybg.png"	684	center keep { pad load "mybg.png" }
606		685
607	=item rootalign $img	686	=item rootalign $img
608		687
609	Moves the image so that it appears glued to the screen as opposed to the	688	Moves the image so that it appears glued to the screen as opposed to the
610	window. This gives the illusion of a larger area behind the window. It is	689	window. This gives the illusion of a larger area behind the window. It is
611	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	690	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
612	top left of the screen.	691	top left of the screen.
613		692
614	Example: load a background image, put it in mirror mode and root align it.	693	Example: load a background image, put it in mirror mode and root align it.
615		694
616	rootalign mirror load "mybg.png"	695	rootalign keep { mirror load "mybg.png" }
617		696
618	Example: take the screen background and align it, giving the illusion of	697	Example: take the screen background and align it, giving the illusion of
619	transparency as long as the window isn't in front of other windows.	698	transparency as long as the window isn't in front of other windows.
620		699
621	rootalign root	700	rootalign root
…		…
646		725
647	sub rootalign($) {	726	sub rootalign($) {
648	move -TX, -TY, $_[0]	727	move -TX, -TY, $_[0]
649	}	728	}
650		729
651	=item rotate $center_x, $center_y, $degrees	730	=item rotate $center_x, $center_y, $degrees, $img
652		731
653	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	732	Rotates the image clockwise by C<$degrees> degrees, around the point at
654	pointer at C<$center_x> and C<$center_y> (specified as factor of image	733	C<$center_x> and C<$center_y> (specified as factor of image width/height).
655	width/height).
656		734
657	#TODO# new width, height, maybe more operators?
658
659	Example: rotate the image by 90 degrees	735	Example: rotate the image by 90 degrees around it's center.
		736
		737	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
660		738
661	=cut	739	=cut
662		740
663	sub rotate($$$$) {	741	sub rotate($$$$) {
664	my $img = pop;	742	my $img = pop;
665	$img->rotate (	743	$img->rotate (
666	$_[0] * $img->w,	744	$_[0] * ($img->w + $img->x),
667	$_[1] * $img->h,	745	$_[1] * ($img->h + $img->y),
668	$_[2] * (3.14159265 / 180),	746	$_[2] * (3.14159265 / 180),
669	)	747	)
670	}	748	}
671		749
672	=back	750	=back
…		…
762		840
763	=back	841	=back
764		842
765	=head2 OTHER STUFF	843	=head2 OTHER STUFF
766		844
767	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
768	force and closing our eyes.	846	force and closing our eyes.
769		847
770	=over 4	848	=over 4
771		849
772	=item once { ... }	850	=item keep { ... }
773		851
		852	#TODO#
		853
774	This function takes a code block as argument, that is, one or more	854	This operator takes a code block as argument, that is, one or more
775	statements enclosed by braces.	855	statements enclosed by braces.
776		856
777	The trick is that this code block is only evaluated once - future calls	857	The trick is that this code block is only evaluated once - future calls
778	will simply return the original image (yes, it should only be used with	858	will simply return the original image (yes, it should only be used with
779	images).	859	images).
780		860
781	This can be extremely useful to avoid redoign the same slow operations	861	This can be extremely useful to avoid redoing the same slow operations
782	again and again- for example, if your background expression takes the root	862	again and again- for example, if your background expression takes the root
783	background, blurs it and then root-aligns it it would have to blur the	863	background, blurs it and then root-aligns it it would have to blur the
784	root background on every window move or resize.	864	root background on every window move or resize.
785		865
		866	In fact, urxvt itself encloses the whole expression in some kind of
		867	C<once> block so it only is reevaluated as required.
		868
786	Putting the blur into a C<once> block will make sure the blur is only done	869	Putting the blur into a C<once> block will make sure the blur is only done
787	once:	870	once:
788		871
789	rootlign once { blur 10, root }	872	rootlign keep { blur 10, root }
790		873
791	This leaves the question of how to force reevaluation of the block, in	874	This leaves the question of how to force reevaluation of the block,
792	case the root background changes: Right now, all once blocks forget that	875	in case the root background changes: If expression inside the block
793	they ahve been executed before each time the root background changes (if	876	is sensitive to some event (root background changes, window geometry
794	the expression is sensitive to that) or when C<once_again> is called.	877	changes), then it will be reevaluated automatically as needed.
795		878
796	=item once_again	879	=item once_again
797		880
798	Resets all C<once> block as if they had never been called, i.e. on the	881	Resets all C<once> block as if they had never been called, i.e. on the
799	next call they will be reevaluated again.	882	next call they will be reevaluated again.
800		883
801	=cut	884	=cut
802		885
803	sub once(&) {	886	sub once(&) {
804	$_ONCE_CACHE{$_[0]+0} \|\|= $_[0]()	887	my $id = $_[0]+0;
		888
		889	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		890
		891	unless ($frame->[FR_CACHE]) {
		892	$frame->[FR_CACHE] = [ $_[0]() ];
		893
		894	my $self = $self;
		895	my $frame = $frame;
		896	Scalar::Util::weaken $frame;
		897	$self->compile_frame ($frame, sub {
		898	# clear this frame cache, also for all parents
		899	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		900	undef $frame->[FR_CACHE];
		901	}
		902
		903	$self->recalculate;
		904	});
		905	};
		906
		907	# in scalar context we always return the first original result, which
		908	# is not quite how perl works.
		909	wantarray
		910	? @{ $frame->[FR_CACHE] }
		911	: $frame->[FR_CACHE][0]
805	}	912	}
806		913
807	sub once_again() {	914	sub once_again() {
808	%_ONCE_CACHE = ();	915	delete $self->{frame_cache};
809	}	916	}
810		917
811	=back	918	=back
812		919
813	=cut	920	=cut
814		921
815	}	922	}
816		923
817	sub parse_expr {	924	sub parse_expr {
818	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	925	my $expr = eval
		926	"sub {\n"
		927	. "package urxvt::bgdsl;\n"
		928	. "#line 0 'background expression'\n"
		929	. "$_[0]\n"
		930	. "}";
819	die if $@;	931	die if $@;
820	$expr	932	$expr
821	}	933	}
822		934
823	# compiles a parsed expression	935	# compiles a parsed expression
824	sub set_expr {	936	sub set_expr {
825	my ($self, $expr) = @_;	937	my ($self, $expr) = @_;
826		938
		939	$self->{root} = [];
827	$self->{expr} = $expr;	940	$self->{expr} = $expr;
828	$self->recalculate;	941	$self->recalculate;
		942	}
		943
		944	# takes a hash of sensitivity indicators and installs watchers
		945	sub compile_frame {
		946	my ($self, $frame, $cb) = @_;
		947
		948	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		949	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		950
		951	# don't keep stuff alive
		952	Scalar::Util::weaken $state;
		953
		954	if ($again->{nested}) {
		955	$state->{nested} = 1;
		956	} else {
		957	delete $state->{nested};
		958	}
		959
		960	if (my $interval = $again->{time}) {
		961	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		962	if $state->{time}[0] != $interval;
		963
		964	# callback might have changed, although we could just rule that out
		965	$state->{time}[1]->cb (sub {
		966	++$state->{counter};
		967	$cb->();
		968	});
		969	} else {
		970	delete $state->{time};
		971	}
		972
		973	if ($again->{position}) {
		974	$state->{position} = $self->on (position_change => $cb);
		975	} else {
		976	delete $state->{position};
		977	}
		978
		979	if ($again->{size}) {
		980	$state->{size} = $self->on (size_change => $cb);
		981	} else {
		982	delete $state->{size};
		983	}
		984
		985	if ($again->{rootpmap}) {
		986	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		987	} else {
		988	delete $state->{rootpmap};
		989	}
829	}	990	}
830		991
831	# evaluate the current bg expression	992	# evaluate the current bg expression
832	sub recalculate {	993	sub recalculate {
833	my ($arg_self) = @_;	994	my ($arg_self) = @_;
…		…
843		1004
844	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1005	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
845		1006
846	# set environment to evaluate user expression	1007	# set environment to evaluate user expression
847		1008
848	local $self = $arg_self;	1009	local $self = $arg_self;
849
850	local $HOME = $ENV{HOME};	1010	local $HOME = $ENV{HOME};
851	local $old = $self->{state};	1011	local $frame = [];
852	local $new = my $state = $self->{state} = {};
853		1012
854	($x, $y, $w, $h) =
855	$self->background_geometry ($self->{border});	1013	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
856		1014
857	# evaluate user expression	1015	# evaluate user expression
858		1016
859	my $img = eval { $self->{expr}->() };	1017	my @img = eval { $self->{expr}->() };
860	warn $@ if $@;#d#	1018	die $@ if $@;
861	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";	1019	die "background-expr did not return anything.\n" unless @img;
		1020	die "background-expr: expected image(s), got something else.\n"
		1021	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
862		1022
863	$state->{size_sensitive} = 1	1023	my $img = urxvt::bgdsl::merge @img;
		1024
		1025	$frame->[FR_AGAIN]{size} = 1
864	if $img->repeat_mode != urxvt::RepeatNormal;	1026	if $img->repeat_mode != urxvt::RepeatNormal;
865		1027
866	# if the expression is sensitive to external events, prepare reevaluation then	1028	# if the expression is sensitive to external events, prepare reevaluation then
867		1029	$self->compile_frame ($frame, sub { $arg_self->recalculate });
868	my $repeat;
869
870	if (my $again = $state->{again}) {
871	$repeat = 1;
872	my $self = $self;
873	$state->{timer} = $again == $old->{again}
874	? $old->{timer}
875	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
876	++$self->{counter};
877	$self->recalculate
878	});
879	}
880
881	if (delete $state->{position_sensitive}) {
882	$repeat = 1;
883	$self->enable (position_change => sub { $_[0]->recalculate });
884	} else {
885	$self->disable ("position_change");
886	}
887
888	if (delete $state->{size_sensitive}) {
889	$repeat = 1;
890	$self->enable (size_change => sub { $_[0]->recalculate });
891	} else {
892	$self->disable ("size_change");
893	}
894
895	if (delete $state->{rootpmap_sensitive}) {
896	$repeat = 1;
897	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
898	} else {
899	$self->disable ("rootpmap_change");
900	}
901		1030
902	# clear stuff we no longer need	1031	# clear stuff we no longer need
903		1032
904	%$old = ();	1033	# unless (%{ $frame->[FR_STATE] }) {
905
906	unless ($repeat) {
907	delete $self->{state};	1034	# delete $self->{state};
908	delete $self->{expr};	1035	# delete $self->{expr};
909	}	1036	# }
910		1037
911	# set background pixmap	1038	# set background pixmap
912		1039
913	$self->set_background ($img, $self->{border});	1040	$self->set_background ($img, $self->{border});
914	$self->scr_recolour (0);	1041	$self->scr_recolour (0);

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.54 by root, Thu Jun 14 16:22:20 2012 UTC vs. Revision 1.67 by sf-exg, Fri Jun 29 18:12:25 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.54 by root, Thu Jun 14 16:22:20 2012 UTC vs.
Revision 1.67 by sf-exg, Fri Jun 29 18:12:25 2012 UTC