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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.51 by sf-exg, Sun Jun 10 19:01:03 2012 UTC vs.
Revision 1.68 by root, Sun Jul 1 21:47:07 2012 UTC

…		…
26	to be as simple as possible.	26	to be as simple as possible.
27		27
28	For example, to load an image and scale it to the window size, you would	28	For example, to load an image and scale it to the window size, you would
29	use:	29	use:
30		30
31	urxvt --background-expr 'scale load "/path/to/mybg.png"'	31	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
32		32
33	Or specified as a X resource:	33	Or specified as a X resource:
34		34
35	URxvt.background-expr: scale load "/path/to/mybg.png"	35	URxvt.background-expr: scale keep { load "/path/to/mybg.png" }
36		36
37	=head1 THEORY OF OPERATION	37	=head1 THEORY OF OPERATION
38		38
39	At startup, just before the window is mapped for the first time, the	39	At startup, just before the window is mapped for the first time, the
40	expression is evaluated and must yield an image. The image is then	40	expression is evaluated and must yield an image. The image is then
…		…
53	If any of the parameters that the expression relies on changes (when the	53	If any of the parameters that the expression relies on changes (when the
54	window is moved or resized, its position or size changes; when the root	54	window is moved or resized, its position or size changes; when the root
55	pixmap is replaced by another one the root background changes; or when the	55	pixmap is replaced by another one the root background changes; or when the
56	timer elapses), then the expression will be evaluated again.	56	timer elapses), then the expression will be evaluated again.
57		57
58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the	58	For example, an expression such as C<scale keep { load "$HOME/mybg.png"
59	image to the window size, so it relies on the window size and will	59	}> scales the image to the window size, so it relies on the window size
60	be reevaluated each time it is changed, but not when it moves for	60	and will be reevaluated each time it is changed, but not when it moves for
61	example. That ensures that the picture always fills the terminal, even	61	example. That ensures that the picture always fills the terminal, even
62	after its size changes.	62	after its size changes.
63		63
64	=head2 EXPRESSIONS	64	=head2 EXPRESSIONS
65		65
66	Expressions are normal Perl expressions, in fact, they are Perl blocks -	66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
67	which means you could use multiple lines and statements:	67	which means you could use multiple lines and statements:
68		68
		69	scale keep {
69	again 3600;	70	again 3600;
70	if (localtime now)[6]) {	71	if (localtime now)[6]) {
71	return scale load "$HOME/weekday.png";	72	return load "$HOME/weekday.png";
72	} else {	73	} else {
73	return scale load "$HOME/sunday.png";	74	return load "$HOME/sunday.png";
		75	}
74	}	76	}
75		77
76	This expression gets evaluated once per hour. It will set F<sunday.png> as	78	This 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
…		…
202		236
203	=back	237	=back
204		238
205	=cut	239	=cut
206		240
207	our %_IMGCACHE;	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.	272	If the image is already in memory (e.g. because another terminal instance
		273	uses it), then the in-memory copy us returned instead.
234		274
		275	=item load_uc $path
		276
		277	Load uncached - same as load, but does not cache the image, which means it
		278	is I<always> loaded from the filesystem again.
		279
235	=cut	280	=cut
		281
		282	sub load_uc($) {
		283	$self->new_img_from_file ($path)
		284	}
236		285
237	sub load($) {	286	sub load($) {
238	my ($path) = @_;	287	my ($path) = @_;
239		288
240	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	289	$_IMG_CACHE{$path} \|\| do {
		290	my $img = load_uc $path;
		291	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		292	$img
		293	}
241	}	294	}
242		295
243	=item root	296	=item root
244		297
245	Returns the root window pixmap, that is, hopefully, the background image	298	Returns the root window pixmap, that is, hopefully, the background image
246	of your screen. The image is set to extend mode.	299	of your screen.
247		300
248	This function makes your expression root sensitive, that means it will be	301	This function makes your expression root sensitive, that means it will be
249	reevaluated when the bg image changes.	302	reevaluated when the bg image changes.
250		303
251	=cut	304	=cut
252		305
253	sub root() {	306	sub root() {
254	$new->{rootpmap_sensitive} = 1;	307	$frame->[FR_AGAIN]{rootpmap} = 1;
255	die "root op not supported, exg, we need you";	308	$self->new_img_from_root
256	}	309	}
257		310
258	=item solid $colour	311	=item solid $colour
259		312
260	=item solid $width, $height, $colour	313	=item solid $width, $height, $colour
…		…
268	=cut	321	=cut
269		322
270	sub solid($;$$) {	323	sub solid($;$$) {
271	my $colour = pop;	324	my $colour = pop;
272		325
273	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	326	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
274	$img->fill ($colour);	327	$img->fill ($colour);
275	$img	328	$img
276	}	329	}
277		330
278	=item clone $img	331	=item clone $img
…		…
284		337
285	sub clone($) {	338	sub clone($) {
286	$_[0]->clone	339	$_[0]->clone
287	}	340	}
288		341
289	=back	342	=item merge $img ...
		343
		344	Takes any number of images and merges them together, creating a single
		345	image containing them all. The tiling mode of the first image is used as
		346	the tiling mode of the resulting image.
		347
		348	This function is called automatically when an expression returns multiple
		349	images.
		350
		351	=cut
		352
		353	sub merge(@) {
		354	return $_[0] unless $#_;
		355
		356	# rather annoyingly clumsy, but optimisation is for another time
		357
		358	my $x0 = +1e9;
		359	my $y0 = +1e9;
		360	my $x1 = -1e9;
		361	my $y1 = -1e9;
		362
		363	for (@_) {
		364	my ($x, $y, $w, $h) = $_->geometry;
		365
		366	$x0 = $x if $x0 > $x;
		367	$y0 = $y if $y0 > $y;
		368
		369	$x += $w;
		370	$y += $h;
		371
		372	$x1 = $x if $x1 < $x;
		373	$y1 = $y if $y1 < $y;
		374	}
		375
		376	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		377	$base->repeat_mode ($_[0]->repeat_mode);
		378	$base->fill ([0, 0, 0, 0]);
		379
		380	$base->draw ($_)
		381	for @_;
		382
		383	$base
		384	}
290		385
291	=head2 TILING MODES	386	=head2 TILING MODES
292		387
293	The following operators modify the tiling mode of an image, that is, the	388	The following operators modify the tiling mode of an image, that is, the
294	way that pixels outside the image area are painted when the image is used.	389	way that pixels outside the image area are painted when the image is used.
…		…
391	Using these functions make your expression sensitive to window moves.	486	Using these functions make your expression sensitive to window moves.
392		487
393	These functions are mainly useful to align images to the root window.	488	These functions are mainly useful to align images to the root window.
394		489
395	Example: load an image and align it so it looks as if anchored to the	490	Example: load an image and align it so it looks as if anchored to the
396	background.	491	background (that's exactly what C<rootalign> does btw.):
397		492
398	move -TX, -TY, load "mybg.png"	493	move -TX, -TY, keep { load "mybg.png" }
399		494
400	=item TW	495	=item TW
401		496
402	Return the width (C<TW>) and height (C<TH>) of the terminal window (the	497	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
403	terminal window is the full window by default, and the character area only	498	terminal window is the full window by default, and the character area only
…		…
409	the window size to conserve memory.	504	the window size to conserve memory.
410		505
411	Example: take the screen background, clip it to the window size, blur it a	506	Example: take the screen background, clip it to the window size, blur it a
412	bit, align it to the window position and use it as background.	507	bit, align it to the window position and use it as background.
413		508
414	clip move -TX, -TY, blur 5, root	509	clip move -TX, -TY, keep { blur 5, root }
415		510
416	=cut	511	=cut
417		512
418	sub TX() { $new->{position_sensitive} = 1; $x }	513	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
419	sub TY() { $new->{position_sensitive} = 1; $y }	514	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
420	sub TW() { $new->{size_sensitive} = 1; $w }	515	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
421	sub TH() { $new->{size_sensitive} = 1; $h }	516	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
422		517
423	=item now	518	=item now
424		519
425	Returns the current time as (fractional) seconds since the epoch.	520	Returns the current time as (fractional) seconds since the epoch.
426		521
…		…
433	C<$seconds> seconds.	528	C<$seconds> seconds.
434		529
435	Example: load some image and rotate it according to the time of day (as if it were	530	Example: load some image and rotate it according to the time of day (as if it were
436	the hour pointer of a clock). Update this image every minute.	531	the hour pointer of a clock). Update this image every minute.
437		532
		533	again 60;
438	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	534	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
439		535
440	=item counter $seconds	536	=item counter $seconds
441		537
442	Like C<again>, but also returns an increasing counter value, starting at	538	Like C<again>, but also returns an increasing counter value, starting at
443	0, which might be useful for some simple animation effects.	539	0, which might be useful for some simple animation effects.
…		…
445	=cut	541	=cut
446		542
447	sub now() { urxvt::NOW }	543	sub now() { urxvt::NOW }
448		544
449	sub again($) {	545	sub again($) {
450	$new->{again} = $_[0];	546	$frame->[FR_AGAIN]{time} = $_[0];
451	}	547	}
452		548
453	sub counter($) {	549	sub counter($) {
454	$new->{again} = $_[0];	550	$frame->[FR_AGAIN]{time} = $_[0];
455	$self->{counter} + 0	551	$frame->[FR_STATE]{counter} + 0
456	}	552	}
457		553
458	=back	554	=back
459		555
460	=head2 SHAPE CHANGING OPERATORS	556	=head2 SHAPE CHANGING OPERATORS
…		…
480	assumed.	576	assumed.
481		577
482	Example: load an image, blur it, and clip it to the window size to save	578	Example: load an image, blur it, and clip it to the window size to save
483	memory.	579	memory.
484		580
485	clip blur 10, load "mybg.png"	581	clip keep { blur 10, load "mybg.png" }
486		582
487	=cut	583	=cut
488		584
489	sub clip($;$$;$$) {	585	sub clip($;$$;$$) {
490	my $img = pop;	586	my $img = pop;
…		…
584	the terminal window (or the box specified by C<$width> and C<$height> if	680	the terminal window (or the box specified by C<$width> and C<$height> if
585	given).	681	given).
586		682
587	Example: load an image and center it.	683	Example: load an image and center it.
588		684
589	center pad load "mybg.png"	685	center keep { pad load "mybg.png" }
590		686
591	=item rootalign $img	687	=item rootalign $img
592		688
593	Moves the image so that it appears glued to the screen as opposed to the	689	Moves the image so that it appears glued to the screen as opposed to the
594	window. This gives the illusion of a larger area behind the window. It is	690	window. This gives the illusion of a larger area behind the window. It is
595	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	691	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
596	top left of the screen.	692	top left of the screen.
597		693
598	Example: load a background image, put it in mirror mode and root align it.	694	Example: load a background image, put it in mirror mode and root align it.
599		695
600	rootalign mirror load "mybg.png"	696	rootalign keep { mirror load "mybg.png" }
601		697
602	Example: take the screen background and align it, giving the illusion of	698	Example: take the screen background and align it, giving the illusion of
603	transparency as long as the window isn't in front of other windows.	699	transparency as long as the window isn't in front of other windows.
604		700
605	rootalign root	701	rootalign root
…		…
630		726
631	sub rootalign($) {	727	sub rootalign($) {
632	move -TX, -TY, $_[0]	728	move -TX, -TY, $_[0]
633	}	729	}
634		730
		731	=item rotate $center_x, $center_y, $degrees, $img
		732
		733	Rotates the image clockwise by C<$degrees> degrees, around the point at
		734	C<$center_x> and C<$center_y> (specified as factor of image width/height).
		735
		736	Example: rotate the image by 90 degrees around it's center.
		737
		738	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
		739
		740	=cut
		741
		742	sub rotate($$$$) {
		743	my $img = pop;
		744	$img->rotate (
		745	$_[0] * ($img->w + $img->x),
		746	$_[1] * ($img->h + $img->y),
		747	$_[2] * (3.14159265 / 180),
		748	)
		749	}
		750
635	=back	751	=back
636		752
637	=head2 COLOUR MODIFICATIONS	753	=head2 COLOUR MODIFICATIONS
638		754
639	The following operators change the pixels of the image.	755	The following operators change the pixels of the image.
…		…
721	sub blur($$;$) {	837	sub blur($$;$) {
722	my $img = pop;	838	my $img = pop;
723	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	839	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
724	}	840	}
725		841
726	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
727
728	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
729	pointer at C<$center_x> and C<$center_y> (specified as factor of image
730	width/height), generating a new image with width C<$new_width> and height
731	C<$new_height>.
732
733	#TODO# new width, height, maybe more operators?
734
735	Example: rotate the image by 90 degrees
736
737	=cut
738
739	sub rotate($$$$$$) {
740	my $img = pop;
741	$img->rotate (
742	$_[0],
743	$_[1],
744	$_[2] * $img->w,
745	$_[3] * $img->h,
746	$_[4] * (3.14159265 / 180),
747	)
748	}
749
750	=back	842	=back
751		843
		844	=head2 OTHER STUFF
		845
		846	Anything that didn't fit any of the other categories, even after applying
		847	force and closing our eyes.
		848
		849	=over 4
		850
		851	=item keep { ... }
		852
		853	This operator takes a code block as argument, that is, one or more
		854	statements enclosed by braces.
		855
		856	The trick is that this code block is only evaluated when the outcome
		857	changes - on other calls the C<keep> simply returns the image it computed
		858	previously (yes, it should only be used with images). Or in other words,
		859	C<keep> I<caches> the result of the code block so it doesn't need to be
		860	computed again.
		861
		862	This can be extremely useful to avoid redoing slow operations - for
		863	example, if your background expression takes the root background, blurs it
		864	and then root-aligns it it would have to blur the root background on every
		865	window move or resize.
		866
		867	Another example is C<load>, which can be quite slow.
		868
		869	In fact, urxvt itself encloses the whole expression in some kind of
		870	C<keep> block so it only is reevaluated as required.
		871
		872	Putting the blur into a C<keep> block will make sure the blur is only done
		873	once, while the C<rootalign> is still done each time the window moves.
		874
		875	rootlign keep { blur 10, root }
		876
		877	This leaves the question of how to force reevaluation of the block,
		878	in case the root background changes: If expression inside the block
		879	is sensitive to some event (root background changes, window geometry
		880	changes), then it will be reevaluated automatically as needed.
		881
		882	=cut
		883
		884	sub keep(&) {
		885	my $id = $_[0]+0;
		886
		887	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		888
		889	unless ($frame->[FR_CACHE]) {
		890	$frame->[FR_CACHE] = [ $_[0]() ];
		891
		892	my $self = $self;
		893	my $frame = $frame;
		894	Scalar::Util::weaken $frame;
		895	$self->compile_frame ($frame, sub {
		896	# clear this frame cache, also for all parents
		897	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		898	undef $frame->[FR_CACHE];
		899	}
		900
		901	$self->recalculate;
		902	});
		903	};
		904
		905	# in scalar context we always return the first original result, which
		906	# is not quite how perl works.
		907	wantarray
		908	? @{ $frame->[FR_CACHE] }
		909	: $frame->[FR_CACHE][0]
		910	}
		911
		912	# sub keep_clear() {
		913	# delete $self->{frame_cache};
		914	# }
		915
		916	=back
		917
752	=cut	918	=cut
753		919
754	}	920	}
755		921
756	sub parse_expr {	922	sub parse_expr {
757	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	923	my $expr = eval
		924	"sub {\n"
		925	. "package urxvt::bgdsl;\n"
		926	. "#line 0 'background expression'\n"
		927	. "$_[0]\n"
		928	. "}";
758	die if $@;	929	die if $@;
759	$expr	930	$expr
760	}	931	}
761		932
762	# compiles a parsed expression	933	# compiles a parsed expression
763	sub set_expr {	934	sub set_expr {
764	my ($self, $expr) = @_;	935	my ($self, $expr) = @_;
765		936
		937	$self->{root} = [];
766	$self->{expr} = $expr;	938	$self->{expr} = $expr;
767	$self->recalculate;	939	$self->recalculate;
		940	}
		941
		942	# takes a hash of sensitivity indicators and installs watchers
		943	sub compile_frame {
		944	my ($self, $frame, $cb) = @_;
		945
		946	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		947	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		948
		949	# don't keep stuff alive
		950	Scalar::Util::weaken $state;
		951
		952	if ($again->{nested}) {
		953	$state->{nested} = 1;
		954	} else {
		955	delete $state->{nested};
		956	}
		957
		958	if (my $interval = $again->{time}) {
		959	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		960	if $state->{time}[0] != $interval;
		961
		962	# callback might have changed, although we could just rule that out
		963	$state->{time}[1]->cb (sub {
		964	++$state->{counter};
		965	$cb->();
		966	});
		967	} else {
		968	delete $state->{time};
		969	}
		970
		971	if ($again->{position}) {
		972	$state->{position} = $self->on (position_change => $cb);
		973	} else {
		974	delete $state->{position};
		975	}
		976
		977	if ($again->{size}) {
		978	$state->{size} = $self->on (size_change => $cb);
		979	} else {
		980	delete $state->{size};
		981	}
		982
		983	if ($again->{rootpmap}) {
		984	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		985	} else {
		986	delete $state->{rootpmap};
		987	}
768	}	988	}
769		989
770	# evaluate the current bg expression	990	# evaluate the current bg expression
771	sub recalculate {	991	sub recalculate {
772	my ($arg_self) = @_;	992	my ($arg_self) = @_;
…		…
782		1002
783	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1003	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
784		1004
785	# set environment to evaluate user expression	1005	# set environment to evaluate user expression
786		1006
787	local $self = $arg_self;	1007	local $self = $arg_self;
788
789	local $HOME = $ENV{HOME};	1008	local $HOME = $ENV{HOME};
790	local $old = $self->{state};	1009	local $frame = [];
791	local $new = my $state = $self->{state} = {};
792		1010
793	($x, $y, $w, $h) =
794	$self->background_geometry ($self->{border});	1011	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
795		1012
796	# evaluate user expression	1013	# evaluate user expression
797		1014
798	my $img = eval { $self->{expr}->() };	1015	my @img = eval { $self->{expr}->() };
799	warn $@ if $@;#d#	1016	die $@ if $@;
800	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";	1017	die "background-expr did not return anything.\n" unless @img;
		1018	die "background-expr: expected image(s), got something else.\n"
		1019	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
801		1020
802	$state->{size_sensitive} = 1	1021	my $img = urxvt::bgdsl::merge @img;
		1022
		1023	$frame->[FR_AGAIN]{size} = 1
803	if $img->repeat_mode != urxvt::RepeatNormal;	1024	if $img->repeat_mode != urxvt::RepeatNormal;
804		1025
805	# if the expression is sensitive to external events, prepare reevaluation then	1026	# if the expression is sensitive to external events, prepare reevaluation then
806		1027	$self->compile_frame ($frame, sub { $arg_self->recalculate });
807	my $repeat;
808
809	if (my $again = $state->{again}) {
810	$repeat = 1;
811	my $self = $self;
812	$state->{timer} = $again == $old->{again}
813	? $old->{timer}
814	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
815	++$self->{counter};
816	$self->recalculate
817	});
818	}
819
820	if (delete $state->{position_sensitive}) {
821	$repeat = 1;
822	$self->enable (position_change => sub { $_[0]->recalculate });
823	} else {
824	$self->disable ("position_change");
825	}
826
827	if (delete $state->{size_sensitive}) {
828	$repeat = 1;
829	$self->enable (size_change => sub { $_[0]->recalculate });
830	} else {
831	$self->disable ("size_change");
832	}
833
834	if (delete $state->{rootpmap_sensitive}) {
835	$repeat = 1;
836	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
837	} else {
838	$self->disable ("rootpmap_change");
839	}
840		1028
841	# clear stuff we no longer need	1029	# clear stuff we no longer need
842		1030
843	%$old = ();	1031	# unless (%{ $frame->[FR_STATE] }) {
844
845	unless ($repeat) {
846	delete $self->{state};	1032	# delete $self->{state};
847	delete $self->{expr};	1033	# delete $self->{expr};
848	}	1034	# }
849		1035
850	# set background pixmap	1036	# set background pixmap
851		1037
852	$self->set_background ($img, $self->{border});	1038	$self->set_background ($img, $self->{border});
853	$self->scr_recolour (0);	1039	$self->scr_recolour (0);

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.51 by sf-exg, Sun Jun 10 19:01:03 2012 UTC vs. Revision 1.68 by root, Sun Jul 1 21:47:07 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.51 by sf-exg, Sun Jun 10 19:01:03 2012 UTC vs.
Revision 1.68 by root, Sun Jul 1 21:47:07 2012 UTC