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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.55 by root, Thu Jun 14 16:48:57 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 $colour
276		308
…		…
285	=cut	317	=cut
286		318
287	sub solid($;$$) {	319	sub solid($;$$) {
288	my $colour = pop;	320	my $colour = pop;
289		321
290	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	322	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
291	$img->fill ($colour);	323	$img->fill ($colour);
292	$img	324	$img
293	}	325	}
294		326
295	=item clone $img	327	=item clone $img
…		…
299		331
300	=cut	332	=cut
301		333
302	sub clone($) {	334	sub clone($) {
303	$_[0]->clone	335	$_[0]->clone
		336	}
		337
		338	=item merge $img ...
		339
		340	Takes any number of images and merges them together, creating a single
		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.
		346
		347	=cut
		348
		349	sub merge(@) {
		350	return $_[0] unless $#_;
		351
		352	# rather annoyingly clumsy, but optimisation is for another time
		353
		354	my $x0 = +1e9;
		355	my $y0 = +1e9;
		356	my $x1 = -1e9;
		357	my $y1 = -1e9;
		358
		359	for (@_) {
		360	my ($x, $y, $w, $h) = $_->geometry;
		361
		362	$x0 = $x if $x0 > $x;
		363	$y0 = $y if $y0 > $y;
		364
		365	$x += $w;
		366	$y += $h;
		367
		368	$x1 = $x if $x1 < $x;
		369	$y1 = $y if $y1 < $y;
		370	}
		371
		372	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		373	$base->repeat_mode ($_[0]->repeat_mode);
		374	$base->fill ([0, 0, 0, 0]);
		375
		376	$base->draw ($_)
		377	for @_;
		378
		379	$base
304	}	380	}
305		381
306	=head2 TILING MODES	382	=head2 TILING MODES
307		383
308	The following operators modify the tiling mode of an image, that is, the	384	The following operators modify the tiling mode of an image, that is, the
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406	Using these functions make your expression sensitive to window moves.	482	Using these functions make your expression sensitive to window moves.
407		483
408	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.
409		485
410	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
411	background.	487	background (that's exactly what C<rootalign> does btw.):
412		488
413	move -TX, -TY, load "mybg.png"	489	move -TX, -TY, keep { load "mybg.png" }
414		490
415	=item TW	491	=item TW
416		492
417	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
418	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
…		…
424	the window size to conserve memory.	500	the window size to conserve memory.
425		501
426	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
427	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.
428		504
429	clip move -TX, -TY, once { blur 5, root }	505	clip move -TX, -TY, keep { blur 5, root }
430		506
431	=cut	507	=cut
432		508
433	sub TX() { $new->{again}{position} = 1; $x }	509	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
434	sub TY() { $new->{again}{position} = 1; $y }	510	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
435	sub TW() { $new->{again}{size} = 1; $w }	511	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
436	sub TH() { $new->{again}{size} = 1; $h }	512	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
437		513
438	=item now	514	=item now
439		515
440	Returns the current time as (fractional) seconds since the epoch.	516	Returns the current time as (fractional) seconds since the epoch.
441		517
…		…
448	C<$seconds> seconds.	524	C<$seconds> seconds.
449		525
450	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
451	the hour pointer of a clock). Update this image every minute.	527	the hour pointer of a clock). Update this image every minute.
452		528
		529	again 60;
453	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" }
454		531
455	=item counter $seconds	532	=item counter $seconds
456		533
457	Like C<again>, but also returns an increasing counter value, starting at	534	Like C<again>, but also returns an increasing counter value, starting at
458	0, which might be useful for some simple animation effects.	535	0, which might be useful for some simple animation effects.
…		…
460	=cut	537	=cut
461		538
462	sub now() { urxvt::NOW }	539	sub now() { urxvt::NOW }
463		540
464	sub again($) {	541	sub again($) {
465	$new->{again}{time} = $_[0];	542	$frame->[FR_AGAIN]{time} = $_[0];
466	}	543	}
467		544
468	sub counter($) {	545	sub counter($) {
469	$new->{again}{time} = $_[0];	546	$frame->[FR_AGAIN]{time} = $_[0];
470	$self->{counter} + 0	547	$frame->[FR_STATE]{counter} + 0
471	}	548	}
472		549
473	=back	550	=back
474		551
475	=head2 SHAPE CHANGING OPERATORS	552	=head2 SHAPE CHANGING OPERATORS
…		…
495	assumed.	572	assumed.
496		573
497	Example: load an image, blur it, and clip it to the window size to save	574	Example: load an image, blur it, and clip it to the window size to save
498	memory.	575	memory.
499		576
500	clip blur 10, load "mybg.png"	577	clip keep { blur 10, load "mybg.png" }
501		578
502	=cut	579	=cut
503		580
504	sub clip($;$$;$$) {	581	sub clip($;$$;$$) {
505	my $img = pop;	582	my $img = pop;
…		…
599	the terminal window (or the box specified by C<$width> and C<$height> if	676	the terminal window (or the box specified by C<$width> and C<$height> if
600	given).	677	given).
601		678
602	Example: load an image and center it.	679	Example: load an image and center it.
603		680
604	center pad load "mybg.png"	681	center keep { pad load "mybg.png" }
605		682
606	=item rootalign $img	683	=item rootalign $img
607		684
608	Moves the image so that it appears glued to the screen as opposed to the	685	Moves the image so that it appears glued to the screen as opposed to the
609	window. This gives the illusion of a larger area behind the window. It is	686	window. This gives the illusion of a larger area behind the window. It is
610	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	687	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
611	top left of the screen.	688	top left of the screen.
612		689
613	Example: load a background image, put it in mirror mode and root align it.	690	Example: load a background image, put it in mirror mode and root align it.
614		691
615	rootalign mirror load "mybg.png"	692	rootalign keep { mirror load "mybg.png" }
616		693
617	Example: take the screen background and align it, giving the illusion of	694	Example: take the screen background and align it, giving the illusion of
618	transparency as long as the window isn't in front of other windows.	695	transparency as long as the window isn't in front of other windows.
619		696
620	rootalign root	697	rootalign root
…		…
645		722
646	sub rootalign($) {	723	sub rootalign($) {
647	move -TX, -TY, $_[0]	724	move -TX, -TY, $_[0]
648	}	725	}
649		726
650	=item rotate $center_x, $center_y, $degrees	727	=item rotate $center_x, $center_y, $degrees, $img
651		728
652	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	729	Rotates the image clockwise by C<$degrees> degrees, around the point at
653	pointer at C<$center_x> and C<$center_y> (specified as factor of image	730	C<$center_x> and C<$center_y> (specified as factor of image width/height).
654	width/height).
655		731
656	#TODO# new width, height, maybe more operators?
657
658	Example: rotate the image by 90 degrees	732	Example: rotate the image by 90 degrees around it's center.
		733
		734	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
659		735
660	=cut	736	=cut
661		737
662	sub rotate($$$$) {	738	sub rotate($$$$) {
663	my $img = pop;	739	my $img = pop;
664	$img->rotate (	740	$img->rotate (
665	$_[0] * $img->w,	741	$_[0] * ($img->w + $img->x),
666	$_[1] * $img->h,	742	$_[1] * ($img->h + $img->y),
667	$_[2] * (3.14159265 / 180),	743	$_[2] * (3.14159265 / 180),
668	)	744	)
669	}	745	}
670		746
671	=back	747	=back
…		…
673	=head2 COLOUR MODIFICATIONS	749	=head2 COLOUR MODIFICATIONS
674		750
675	The following operators change the pixels of the image.	751	The following operators change the pixels of the image.
676		752
677	=over 4	753	=over 4
		754
		755	=item tint $color, $img
		756
		757	Tints the image in the given colour.
		758
		759	Example: tint the image red.
		760
		761	tint "red", load "rgb.png"
		762
		763	Example: the same, but specify the colour by component.
		764
		765	tint [1, 0, 0], load "rgb.png"
		766
		767	=cut
		768
		769	sub tint($$) {
		770	$_[1]->tint ($_[0])
		771	}
678		772
679	=item contrast $factor, $img	773	=item contrast $factor, $img
680		774
681	=item contrast $r, $g, $b, $img	775	=item contrast $r, $g, $b, $img
682		776
…		…
761		855
762	=back	856	=back
763		857
764	=head2 OTHER STUFF	858	=head2 OTHER STUFF
765		859
766	Anything that didn't fit any of the other categories, even after appliyng	860	Anything that didn't fit any of the other categories, even after applying
767	force and closing our eyes.	861	force and closing our eyes.
768		862
769	=over 4	863	=over 4
770		864
771	=item once { ... }	865	=item keep { ... }
772		866
773	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
774	statements enclosed by braces.	868	statements enclosed by braces.
775		869
776	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
777	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
778	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.
779		875
780	This can be extremely useful to avoid redoign the same slow operations	876	This can be extremely useful to avoid redoing slow operations - for
781	again and again- for example, if your background expression takes the root	877	example, if your background expression takes the root background, blurs it
782	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
783	root background on every window move or resize.	879	window move or resize.
784		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
785	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
786	once:	887	once, while the C<rootalign> is still done each time the window moves.
787		888
788	rootlign once { blur 10, root }	889	rootlign keep { blur 10, root }
789		890
790	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,
791	case the root background changes: Right now, all once blocks forget that	892	in case the root background changes: If expression inside the block
792	they ahve been executed before each time the root background changes (if	893	is sensitive to some event (root background changes, window geometry
793	the expression is sensitive to that) or when C<once_again> is called.	894	changes), then it will be reevaluated automatically as needed.
794		895
795	=item once_again
796
797	Resets all C<once> block as if they had never been called, i.e. on the
798	next call they will be reevaluated again.
799
800	=cut	896	=cut
801		897
802	sub once(&) {	898	sub keep(&) {
803	my $once = $self->{once_cache}{$_[0]+0} \|\|= do {	899	my $id = $_[0]+0;
804	local $new->{again};	900
805	my @res = $_[0]();	901	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
806	[$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;
807	};	916	});
808
809	$new->{again} = {
810	%{ $new->{again} },
811	%{ $once->[0] }
812	};	917	};
813		918
814	# in scalar context we always return the first original result, which	919	# in scalar context we always return the first original result, which
815	# is not quite how perl works.	920	# is not quite how perl works.
816	wantarray	921	wantarray
817	? @{ $once->[1] }	922	? @{ $frame->[FR_CACHE] }
818	: $once->[1][0]	923	: $frame->[FR_CACHE][0]
		924	}
		925
		926	# sub keep_clear() {
		927	# delete $self->{frame_cache};
819	}	928	# }
820
821	sub once_again() {
822	delete $self->{once_cache};
823	}
824		929
825	=back	930	=back
826		931
827	=cut	932	=cut
828		933
829	}	934	}
830		935
831	sub parse_expr {	936	sub parse_expr {
832	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	. "}";
833	die if $@;	943	die if $@;
834	$expr	944	$expr
835	}	945	}
836		946
837	# compiles a parsed expression	947	# compiles a parsed expression
838	sub set_expr {	948	sub set_expr {
839	my ($self, $expr) = @_;	949	my ($self, $expr) = @_;
840		950
		951	$self->{root} = [];
841	$self->{expr} = $expr;	952	$self->{expr} = $expr;
842	$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 $state->{rootpmap};
		1001	}
843	}	1002	}
844		1003
845	# evaluate the current bg expression	1004	# evaluate the current bg expression
846	sub recalculate {	1005	sub recalculate {
847	my ($arg_self) = @_;	1006	my ($arg_self) = @_;
…		…
857		1016
858	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1017	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
859		1018
860	# set environment to evaluate user expression	1019	# set environment to evaluate user expression
861		1020
862	local $self = $arg_self;	1021	local $self = $arg_self;
863
864	local $HOME = $ENV{HOME};	1022	local $HOME = $ENV{HOME};
865	local $old = $self->{state};	1023	local $frame = [];
866	local $new = my $state = $self->{state} = {};
867		1024
868	($x, $y, $w, $h) =
869	$self->background_geometry ($self->{border});	1025	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
870		1026
871	# evaluate user expression	1027	# evaluate user expression
872		1028
873	my $img = eval { $self->{expr}->() };	1029	my @img = eval { $self->{expr}->() };
874	warn $@ if $@;#d#	1030	die $@ if $@;
875	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;
876		1039
877	# if the expression is sensitive to external events, prepare reevaluation then	1040	# if the expression is sensitive to external events, prepare reevaluation then
878		1041	$self->compile_frame ($frame, sub { $arg_self->recalculate });
879	my $again = delete $state->{again};
880
881	$again->{size} = 1
882	if $img->repeat_mode != urxvt::RepeatNormal;
883
884	if (my $again = $again->{time}) {
885	my $self = $self;
886	$state->{timer} = $again == $old->{again}
887	? $old->{timer}
888	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
889	++$self->{counter};
890	$self->recalculate
891	});
892	}
893
894	if ($again->{position}) {
895	$self->enable (position_change => sub { $_[0]->recalculate });
896	} else {
897	$self->disable ("position_change");
898	}
899
900	if ($again->{size}) {
901	$self->enable (size_change => sub { $_[0]->recalculate });
902	} else {
903	$self->disable ("size_change");
904	}
905
906	if ($again->{rootpmap}) {
907	$self->enable (rootpmap_change => sub {
908	delete $_[0]{once_cache}; # this will override once-block values from
909	$_[0]->recalculate;
910	});
911	} else {
912	$self->disable ("rootpmap_change");
913	}
914		1042
915	# clear stuff we no longer need	1043	# clear stuff we no longer need
916		1044
917	%$old = ();	1045	# unless (%{ $frame->[FR_STATE] }) {
918
919	unless (%$again) {
920	delete $self->{state};	1046	# delete $self->{state};
921	delete $self->{expr};	1047	# delete $self->{expr};
922	}	1048	# }
923		1049
924	# set background pixmap	1050	# set background pixmap
925		1051
926	$self->set_background ($img, $self->{border});	1052	$self->set_background ($img, $self->{border});
927	$self->scr_recolour (0);	1053	$self->scr_recolour (0);

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.55 by root, Thu Jun 14 16:48:57 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 1.55 by root, Thu Jun 14 16:48:57 2012 UTC vs.
Revision 1.70 by root, Mon Jul 2 01:35:37 2012 UTC