[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 1.73 by sf-exg, Thu Jul 5 20:05:19 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	terminal 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 again
		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 COLOUR SPECIFICATIONS
142		163
143	As has been mentioned before, the expression might be evaluated multiple	164	Whenever an operator expects a "colour", then this can be specified in one
144	times. Each time the expression is reevaluated, a new cycle is said to	165	of two ways: Either as string with an X11 colour specification, such as:
145	have begun. Many operators cache their results till the next cycle.
146		166
147	For example, the C<load> operator keeps a copy of the image. If it is	167	"red" # named colour
148	asked to load the same image on the next cycle it will not load it again,	168	"#f00" # simple rgb
149	but return the cached copy.	169	"[50]red" # red with 50% alpha
		170	"TekHVC:300/50/50" # anything goes
150		171
151	This only works for one cycle though, so as long as you load the same	172	OR as an array reference with one, three or four components:
152	image every time, it will always be cached, but when you load a different
153	image, it will forget about the first one.
154		173
155	This allows you to either speed things up by keeping multiple images in	174	[0.5] # 50% gray, 100% alpha
156	memory, or conserve memory by loading images more often.	175	[0.5, 0, 0] # dark red, no green or blur, 100% alpha
		176	[0.5, 0, 0, 0.7] # same with explicit 70% alpha
157		177
158	For example, you can keep two images in memory and use a random one like	178	=head2 CACHING AND SENSITIVITY
159	this:
160		179
161	my $img1 = load "img1.png";	180	Since some operations (such as C<load> and C<blur>) can take a long time,
162	my $img2 = load "img2.png";	181	caching results can be very important for a smooth operation. Caching can
163	(0.5 > rand) ? $img1 : $img2	182	also be useful to reduce memory usage, though, for example, when an image
		183	is cached by C<load>, it could be shared by multiple terminal windows
		184	running inside urxvtd.
164		185
165	Since both images are "loaded" every time the expression is evaluated,	186	=head3 C<keep { ... }> caching
166	they are always kept in memory. Contrast this version:
167		187
168	my $path1 = "img1.png";	188	The most important way to cache expensive operations is to use C<keep {
169	my $path2 = "img2.png";	189	... }>. The C<keep> operator takes a block of multiple statements enclosed
170	load ((0.5 > rand) ? $path1 : $path2)	190	by C<{}> and keeps the return value in memory.
171		191
172	Here, a path is selected randomly, and load is only called for one image,	192	An expression can be "sensitive" to various external events, such as
173	so keeps only one image in memory. If, on the next evaluation, luck	193	scaling or moving the window, root background changes and timers. Simply
174	decides to use the other path, then it will have to load that image again.	194	using an expression (such as C<scale> without parameters) that depends on
		195	certain changing values (called "variables"), or using those variables
		196	directly, will make an expression sensitive to these events - for example,
		197	using C<scale> or C<TW> will make the expression sensitive to the terminal
		198	size, and thus to resizing events.
		199
		200	When such an event happens, C<keep> will automatically trigger a
		201	reevaluation of the whole expression with the new value of the expression.
		202
		203	C<keep> is most useful for expensive operations, such as C<blur>:
		204
		205	rootalign keep { blur 20, root }
		206
		207	This makes a blurred copy of the root background once, and on subsequent
		208	calls, just root-aligns it. Since C<blur> is usually quite slow and
		209	C<rootalign> is quite fast, this trades extra memory (for the cached
		210	blurred pixmap) with speed (blur only needs to be redone when root
		211	changes).
		212
		213	=head3 C<load> caching
		214
		215	The C<load> operator itself does not keep images in memory, but as long as
		216	the image is still in memory, C<load> will use the in-memory image instead
		217	of loading it freshly from disk.
		218
		219	That means that this expression:
		220
		221	keep { load "$HOME/path..." }
		222
		223	Not only caches the image in memory, other terminal instances that try to
		224	C<load> it can reuse that in-memory copy.
175		225
176	=head1 REFERENCE	226	=head1 REFERENCE
177		227
178	=head2 COMMAND LINE SWITCHES	228	=head2 COMMAND LINE SWITCHES
179		229
…		…
203	=back	253	=back
204		254
205	=cut	255	=cut
206		256
207	our %_IMG_CACHE;	257	our %_IMG_CACHE;
208	our %_ONCE_CACHE;
209	our $HOME;	258	our $HOME;
210	our ($self, $old, $new);	259	our ($self, $frame);
211	our ($x, $y, $w, $h);	260	our ($x, $y, $w, $h);
212		261
213	# enforce at least this interval between updates	262	# enforce at least this interval between updates
214	our $MIN_INTERVAL = 6/59.951;	263	our $MIN_INTERVAL = 6/59.951;
215		264
216	{	265	{
217	package urxvt::bgdsl; # background language	266	package urxvt::bgdsl; # background language
		267
		268	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		269	sub FR_CACHE () { 1 } # cached values
		270	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		271	sub FR_STATE () { 3 } # watchers etc.
218		272
219	use List::Util qw(min max sum shuffle);	273	use List::Util qw(min max sum shuffle);
220		274
221	=head2 PROVIDERS/GENERATORS	275	=head2 PROVIDERS/GENERATORS
222		276
…		…
229	=item load $path	283	=item load $path
230		284
231	Loads the image at the given C<$path>. The image is set to plane tiling	285	Loads the image at the given C<$path>. The image is set to plane tiling
232	mode.	286	mode.
233		287
234	Loaded images will be cached for one cycle, and shared between temrinals	288	If the image is already in memory (e.g. because another terminal instance
235	running in the same process (e.g. in C<urxvtd>).	289	uses it), then the in-memory copy us returned instead.
236		290
237	=item load_uc $path	291	=item load_uc $path
238		292
239	Load uncached - same as load, but does not cache the image. This function	293	Load uncached - same as load, but does not cache the image, which means it
240	is most useufl if you want to optimise a background expression in some	294	is I<always> loaded from the filesystem again, even if another copy of it
241	way.	295	is in memory at the time.
242		296
243	=cut	297	=cut
244		298
245	sub load_uc($) {	299	sub load_uc($) {
		300	$self->new_img_from_file ($_[0])
		301	}
		302
		303	sub load($) {
246	my ($path) = @_;	304	my ($path) = @_;
247		305
248	$_IMG_CACHE{$path} \|\| do {	306	$_IMG_CACHE{$path} \|\| do {
249	my $img = $self->new_img_from_file ($path);	307	my $img = load_uc $path;
250	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);	308	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
251	$img	309	$img
252	}	310	}
253	}	311	}
254		312
255	sub load($) {
256	my ($path) = @_;
257
258	$new->{load}{$path} = $old->{load}{$path} \|\| load_uc $path;
259	}
260
261	=item root	313	=item root
262		314
263	Returns the root window pixmap, that is, hopefully, the background image	315	Returns the root window pixmap, that is, hopefully, the background image
264	of your screen. The image is set to extend mode.	316	of your screen.
265		317
266	This function makes your expression root sensitive, that means it will be	318	This function makes your expression root sensitive, that means it will be
267	reevaluated when the bg image changes.	319	reevaluated when the bg image changes.
268		320
269	=cut	321	=cut
270		322
271	sub root() {	323	sub root() {
272	$new->{rootpmap_sensitive} = 1;	324	$frame->[FR_AGAIN]{rootpmap} = 1;
273	$self->new_img_from_root	325	$self->new_img_from_root
274	}	326	}
275		327
276	=item solid $colour	328	=item solid $colour
277		329
…		…
286	=cut	338	=cut
287		339
288	sub solid($;$$) {	340	sub solid($;$$) {
289	my $colour = pop;	341	my $colour = pop;
290		342
291	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	343	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
292	$img->fill ($colour);	344	$img->fill ($colour);
293	$img	345	$img
294	}	346	}
295		347
296	=item clone $img	348	=item clone $img
…		…
300		352
301	=cut	353	=cut
302		354
303	sub clone($) {	355	sub clone($) {
304	$_[0]->clone	356	$_[0]->clone
		357	}
		358
		359	=item merge $img ...
		360
		361	Takes any number of images and merges them together, creating a single
		362	image containing them all. The tiling mode of the first image is used as
		363	the tiling mode of the resulting image.
		364
		365	This function is called automatically when an expression returns multiple
		366	images.
		367
		368	=cut
		369
		370	sub merge(@) {
		371	return $_[0] unless $#_;
		372
		373	# rather annoyingly clumsy, but optimisation is for another time
		374
		375	my $x0 = +1e9;
		376	my $y0 = +1e9;
		377	my $x1 = -1e9;
		378	my $y1 = -1e9;
		379
		380	for (@_) {
		381	my ($x, $y, $w, $h) = $_->geometry;
		382
		383	$x0 = $x if $x0 > $x;
		384	$y0 = $y if $y0 > $y;
		385
		386	$x += $w;
		387	$y += $h;
		388
		389	$x1 = $x if $x1 < $x;
		390	$y1 = $y if $y1 < $y;
		391	}
		392
		393	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		394	$base->repeat_mode ($_[0]->repeat_mode);
		395	$base->fill ([0, 0, 0, 0]);
		396
		397	$base->draw ($_)
		398	for @_;
		399
		400	$base
305	}	401	}
306		402
307	=head2 TILING MODES	403	=head2 TILING MODES
308		404
309	The following operators modify the tiling mode of an image, that is, the	405	The following operators modify the tiling mode of an image, that is, the
…		…
407	Using these functions make your expression sensitive to window moves.	503	Using these functions make your expression sensitive to window moves.
408		504
409	These functions are mainly useful to align images to the root window.	505	These functions are mainly useful to align images to the root window.
410		506
411	Example: load an image and align it so it looks as if anchored to the	507	Example: load an image and align it so it looks as if anchored to the
412	background.	508	background (that's exactly what C<rootalign> does btw.):
413		509
414	move -TX, -TY, load "mybg.png"	510	move -TX, -TY, keep { load "mybg.png" }
415		511
416	=item TW	512	=item TW
417		513
418	Return the width (C<TW>) and height (C<TH>) of the terminal window (the	514	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	515	terminal window is the full window by default, and the character area only
…		…
425	the window size to conserve memory.	521	the window size to conserve memory.
426		522
427	Example: take the screen background, clip it to the window size, blur it a	523	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.	524	bit, align it to the window position and use it as background.
429		525
430	clip move -TX, -TY, blur 5, root	526	clip move -TX, -TY, keep { blur 5, root }
431		527
432	=cut	528	=cut
433		529
434	sub TX() { $new->{position_sensitive} = 1; $x }	530	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
435	sub TY() { $new->{position_sensitive} = 1; $y }	531	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
436	sub TW() { $new->{size_sensitive} = 1; $w }	532	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
437	sub TH() { $new->{size_sensitive} = 1; $h }	533	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
438		534
439	=item now	535	=item now
440		536
441	Returns the current time as (fractional) seconds since the epoch.	537	Returns the current time as (fractional) seconds since the epoch.
442		538
…		…
449	C<$seconds> seconds.	545	C<$seconds> seconds.
450		546
451	Example: load some image and rotate it according to the time of day (as if it were	547	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.	548	the hour pointer of a clock). Update this image every minute.
453		549
		550	again 60;
454	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	551	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
455		552
456	=item counter $seconds	553	=item counter $seconds
457		554
458	Like C<again>, but also returns an increasing counter value, starting at	555	Like C<again>, but also returns an increasing counter value, starting at
459	0, which might be useful for some simple animation effects.	556	0, which might be useful for some simple animation effects.
…		…
461	=cut	558	=cut
462		559
463	sub now() { urxvt::NOW }	560	sub now() { urxvt::NOW }
464		561
465	sub again($) {	562	sub again($) {
466	$new->{again} = $_[0];	563	$frame->[FR_AGAIN]{time} = $_[0];
467	}	564	}
468		565
469	sub counter($) {	566	sub counter($) {
470	$new->{again} = $_[0];	567	$frame->[FR_AGAIN]{time} = $_[0];
471	$self->{counter} + 0	568	$frame->[FR_STATE]{counter} + 0
472	}	569	}
473		570
474	=back	571	=back
475		572
476	=head2 SHAPE CHANGING OPERATORS	573	=head2 SHAPE CHANGING OPERATORS
…		…
496	assumed.	593	assumed.
497		594
498	Example: load an image, blur it, and clip it to the window size to save	595	Example: load an image, blur it, and clip it to the window size to save
499	memory.	596	memory.
500		597
501	clip blur 10, load "mybg.png"	598	clip keep { blur 10, load "mybg.png" }
502		599
503	=cut	600	=cut
504		601
505	sub clip($;$$;$$) {	602	sub clip($;$$;$$) {
506	my $img = pop;	603	my $img = pop;
…		…
600	the terminal window (or the box specified by C<$width> and C<$height> if	697	the terminal window (or the box specified by C<$width> and C<$height> if
601	given).	698	given).
602		699
603	Example: load an image and center it.	700	Example: load an image and center it.
604		701
605	center pad load "mybg.png"	702	center keep { pad load "mybg.png" }
606		703
607	=item rootalign $img	704	=item rootalign $img
608		705
609	Moves the image so that it appears glued to the screen as opposed to the	706	Moves the image so that it appears glued to the screen as opposed to the
610	window. This gives the illusion of a larger area behind the window. It is	707	window. This gives the illusion of a larger area behind the window. It is
611	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	708	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
612	top left of the screen.	709	top left of the screen.
613		710
614	Example: load a background image, put it in mirror mode and root align it.	711	Example: load a background image, put it in mirror mode and root align it.
615		712
616	rootalign mirror load "mybg.png"	713	rootalign keep { mirror load "mybg.png" }
617		714
618	Example: take the screen background and align it, giving the illusion of	715	Example: take the screen background and align it, giving the illusion of
619	transparency as long as the window isn't in front of other windows.	716	transparency as long as the window isn't in front of other windows.
620		717
621	rootalign root	718	rootalign root
…		…
646		743
647	sub rootalign($) {	744	sub rootalign($) {
648	move -TX, -TY, $_[0]	745	move -TX, -TY, $_[0]
649	}	746	}
650		747
651	=item rotate $center_x, $center_y, $degrees	748	=item rotate $center_x, $center_y, $degrees, $img
652		749
653	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	750	Rotates the image clockwise by C<$degrees> degrees, around the point at
654	pointer at C<$center_x> and C<$center_y> (specified as factor of image	751	C<$center_x> and C<$center_y> (specified as factor of image width/height).
655	width/height).
656		752
657	#TODO# new width, height, maybe more operators?
658
659	Example: rotate the image by 90 degrees	753	Example: rotate the image by 90 degrees around it's center.
		754
		755	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
660		756
661	=cut	757	=cut
662		758
663	sub rotate($$$$) {	759	sub rotate($$$$) {
664	my $img = pop;	760	my $img = pop;
665	$img->rotate (	761	$img->rotate (
666	$_[0] * $img->w,	762	$_[0] * ($img->w + $img->x),
667	$_[1] * $img->h,	763	$_[1] * ($img->h + $img->y),
668	$_[2] * (3.14159265 / 180),	764	$_[2] * (3.14159265 / 180),
669	)	765	)
670	}	766	}
671		767
672	=back	768	=back
…		…
674	=head2 COLOUR MODIFICATIONS	770	=head2 COLOUR MODIFICATIONS
675		771
676	The following operators change the pixels of the image.	772	The following operators change the pixels of the image.
677		773
678	=over 4	774	=over 4
		775
		776	=item tint $color, $img
		777
		778	Tints the image in the given colour.
		779
		780	Example: tint the image red.
		781
		782	tint "red", load "rgb.png"
		783
		784	Example: the same, but specify the colour by component.
		785
		786	tint [1, 0, 0], load "rgb.png"
		787
		788	=cut
		789
		790	sub tint($$) {
		791	$_[1]->tint ($_[0])
		792	}
679		793
680	=item contrast $factor, $img	794	=item contrast $factor, $img
681		795
682	=item contrast $r, $g, $b, $img	796	=item contrast $r, $g, $b, $img
683		797
…		…
762		876
763	=back	877	=back
764		878
765	=head2 OTHER STUFF	879	=head2 OTHER STUFF
766		880
767	Anything that didn't fit any of the other categories, even after appliyng	881	Anything that didn't fit any of the other categories, even after applying
768	force and closing our eyes.	882	force and closing our eyes.
769		883
770	=over 4	884	=over 4
771		885
772	=item once { ... }	886	=item keep { ... }
773		887
774	This function takes a code block as argument, that is, one or more	888	This operator takes a code block as argument, that is, one or more
775	statements enclosed by braces.	889	statements enclosed by braces.
776		890
777	The trick is that this code block is only evaluated once - future calls	891	The trick is that this code block is only evaluated when the outcome
778	will simply return the original image (yes, it should only be used with	892	changes - on other calls the C<keep> simply returns the image it computed
779	images).	893	previously (yes, it should only be used with images). Or in other words,
		894	C<keep> I<caches> the result of the code block so it doesn't need to be
		895	computed again.
780		896
781	This can be extremely useful to avoid redoign the same slow operations	897	This can be extremely useful to avoid redoing slow operations - for
782	again and again- for example, if your background expression takes the root	898	example, if your background expression takes the root background, blurs it
783	background, blurs it and then root-aligns it it would have to blur the	899	and then root-aligns it it would have to blur the root background on every
784	root background on every window move or resize.	900	window move or resize.
785		901
		902	Another example is C<load>, which can be quite slow.
		903
		904	In fact, urxvt itself encloses the whole expression in some kind of
		905	C<keep> block so it only is reevaluated as required.
		906
786	Putting the blur into a C<once> block will make sure the blur is only done	907	Putting the blur into a C<keep> block will make sure the blur is only done
787	once:	908	once, while the C<rootalign> is still done each time the window moves.
788		909
789	rootlign once { blur 10, root }	910	rootalign keep { blur 10, root }
790		911
791	This leaves the question of how to force reevaluation of the block, in	912	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	913	in case the root background changes: If expression inside the block
793	they ahve been executed before each time the root background changes (if	914	is sensitive to some event (root background changes, window geometry
794	the expression is sensitive to that) or when C<once_again> is called.	915	changes), then it will be reevaluated automatically as needed.
795		916
796	=item once_again
797
798	Resets all C<once> block as if they had never been called, i.e. on the
799	next call they will be reevaluated again.
800
801	=cut	917	=cut
802		918
803	sub once(&) {	919	sub keep(&) {
804	$_ONCE_CACHE{$_[0]+0} \|\|= $_[0]()	920	my $id = $_[0]+0;
		921
		922	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		923
		924	unless ($frame->[FR_CACHE]) {
		925	$frame->[FR_CACHE] = [ $_[0]() ];
		926
		927	my $self = $self;
		928	my $frame = $frame;
		929	Scalar::Util::weaken $frame;
		930	$self->compile_frame ($frame, sub {
		931	# clear this frame cache, also for all parents
		932	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		933	undef $frame->[FR_CACHE];
		934	}
		935
		936	$self->recalculate;
		937	});
		938	};
		939
		940	# in scalar context we always return the first original result, which
		941	# is not quite how perl works.
		942	wantarray
		943	? @{ $frame->[FR_CACHE] }
		944	: $frame->[FR_CACHE][0]
		945	}
		946
		947	# sub keep_clear() {
		948	# delete $self->{frame_cache};
805	}	949	# }
806
807	sub once_again() {
808	%_ONCE_CACHE = ();
809	}
810		950
811	=back	951	=back
812		952
813	=cut	953	=cut
814		954
815	}	955	}
816		956
817	sub parse_expr {	957	sub parse_expr {
818	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	958	my $expr = eval
		959	"sub {\n"
		960	. "package urxvt::bgdsl;\n"
		961	. "#line 0 'background expression'\n"
		962	. "$_[0]\n"
		963	. "}";
819	die if $@;	964	die if $@;
820	$expr	965	$expr
821	}	966	}
822		967
823	# compiles a parsed expression	968	# compiles a parsed expression
824	sub set_expr {	969	sub set_expr {
825	my ($self, $expr) = @_;	970	my ($self, $expr) = @_;
826		971
		972	$self->{root} = [];
827	$self->{expr} = $expr;	973	$self->{expr} = $expr;
828	$self->recalculate;	974	$self->recalculate;
		975	}
		976
		977	# takes a hash of sensitivity indicators and installs watchers
		978	sub compile_frame {
		979	my ($self, $frame, $cb) = @_;
		980
		981	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		982	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		983
		984	# don't keep stuff alive
		985	Scalar::Util::weaken $state;
		986
		987	if ($again->{nested}) {
		988	$state->{nested} = 1;
		989	} else {
		990	delete $state->{nested};
		991	}
		992
		993	if (my $interval = $again->{time}) {
		994	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		995	if $state->{time}[0] != $interval;
		996
		997	# callback might have changed, although we could just rule that out
		998	$state->{time}[1]->cb (sub {
		999	++$state->{counter};
		1000	$cb->();
		1001	});
		1002	} else {
		1003	delete $state->{time};
		1004	}
		1005
		1006	if ($again->{position}) {
		1007	$state->{position} = $self->on (position_change => $cb);
		1008	} else {
		1009	delete $state->{position};
		1010	}
		1011
		1012	if ($again->{size}) {
		1013	$state->{size} = $self->on (size_change => $cb);
		1014	} else {
		1015	delete $state->{size};
		1016	}
		1017
		1018	if ($again->{rootpmap}) {
		1019	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		1020	} else {
		1021	delete $state->{rootpmap};
		1022	}
829	}	1023	}
830		1024
831	# evaluate the current bg expression	1025	# evaluate the current bg expression
832	sub recalculate {	1026	sub recalculate {
833	my ($arg_self) = @_;	1027	my ($arg_self) = @_;
…		…
843		1037
844	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1038	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
845		1039
846	# set environment to evaluate user expression	1040	# set environment to evaluate user expression
847		1041
848	local $self = $arg_self;	1042	local $self = $arg_self;
849
850	local $HOME = $ENV{HOME};	1043	local $HOME = $ENV{HOME};
851	local $old = $self->{state};	1044	local $frame = [];
852	local $new = my $state = $self->{state} = {};
853		1045
854	($x, $y, $w, $h) =
855	$self->background_geometry ($self->{border});	1046	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
856		1047
857	# evaluate user expression	1048	# evaluate user expression
858		1049
859	my $img = eval { $self->{expr}->() };	1050	my @img = eval { $self->{expr}->() };
860	warn $@ if $@;#d#	1051	die $@ if $@;
861	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";	1052	die "background-expr did not return anything.\n" unless @img;
		1053	die "background-expr: expected image(s), got something else.\n"
		1054	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
862		1055
863	$state->{size_sensitive} = 1	1056	my $img = urxvt::bgdsl::merge @img;
		1057
		1058	$frame->[FR_AGAIN]{size} = 1
864	if $img->repeat_mode != urxvt::RepeatNormal;	1059	if $img->repeat_mode != urxvt::RepeatNormal;
865		1060
866	# if the expression is sensitive to external events, prepare reevaluation then	1061	# if the expression is sensitive to external events, prepare reevaluation then
867		1062	$self->compile_frame ($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	$self->disable ("rootpmap_change");
900	}
901		1063
902	# clear stuff we no longer need	1064	# clear stuff we no longer need
903		1065
904	%$old = ();	1066	# unless (%{ $frame->[FR_STATE] }) {
905
906	unless ($repeat) {
907	delete $self->{state};	1067	# delete $self->{state};
908	delete $self->{expr};	1068	# delete $self->{expr};
909	}	1069	# }
910		1070
911	# set background pixmap	1071	# set background pixmap
912		1072
913	$self->set_background ($img, $self->{border});	1073	$self->set_background ($img, $self->{border});
914	$self->scr_recolour (0);	1074	$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 1.73 by sf-exg, Thu Jul 5 20:05:19 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 1.73 by sf-exg, Thu Jul 5 20:05:19 2012 UTC