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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.50 by root, Sun Jun 10 17:31:53 2012 UTC vs.
Revision 1.65 by sf-exg, Wed Jun 20 18:18:14 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 it's 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 expression is evaluated once per hour. It will set F<sunday.png> as
77	background on Sundays, and F<weekday.png> on all other days.	79	background on Sundays, and F<weekday.png> on all other days.
78		80
79	Fortunately, we expect that most expressions will be much simpler, with	81	Fortunately, we expect that most expressions will be much simpler, with
80	little Perl knowledge needed.	82	little Perl knowledge needed.
81		83
…		…
115	horizontal and vertical dimensions. For example, this halves the image	117	horizontal and vertical dimensions. For example, this halves the image
116	width and doubles the image height:	118	width and doubles the image height:
117		119
118	scale 0.5, 2, load "$HOME/mypic.png"	120	scale 0.5, 2, load "$HOME/mypic.png"
119		121
120	Other effects than scalign are also readily available, for exmaple, you can	122	IF you try out these expressions, you might suffer from sluggishness,
121	tile the image to fill the whole window, instead of resizing it:	123	because each time the terminal is resized, it again loads the PNG image
		124	and scales it. Scaling is usually fast, but loading the image can be quite
		125	time consuming. This is where C<keep> comes in handy:
122		126
		127	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		128
		129	The C<keep> operator executes all the statements inside the braces only
		130	once, or when it thinks the outcome might change. In other cases it
		131	returns the last value computed by the brace block.
		132
		133	This means that the C<load> is only executed once, which makes it much
		134	faster, but also means that more memory is being used, because the loaded
		135	image must be kept in memory at all times. In this expression, the
		136	trade-off is likely worth it.
		137
		138	But back to effects: Other effects than scaling are also readily
		139	available, for example, you can tile the image to fill the whole window,
		140	instead of resizing it:
		141
123	tile load "$HOME/mypic.png"	142	tile keep { load "$HOME/mypic.png" }
124		143
125	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	144	In fact, images returned by C<load> are in C<tile> mode by default, so the
126	is kind of superfluous.	145	C<tile> operator is kind of superfluous.
127		146
128	Another common effect is to mirror the image, so that the same edges touch:	147	Another common effect is to mirror the image, so that the same edges
		148	touch:
129		149
130	mirror load "$HOME/mypic.png"	150	mirror keep { load "$HOME/mypic.png" }
131		151
132	This is also a typical background expression:	152	Another common background expression is:
133		153
134	rootalign root	154	rootalign root
135		155
136	It first takes a snapshot of the screen background image, and then	156	This one first takes a snapshot of the screen background image, and then
137	moves it to the upper left corner of the screen - the result is	157	moves it to the upper left corner of the screen (as opposed to the upper
138	pseudo-transparency, as the image seems to be static while the window is	158	left corner of the terminal window)- the result is pseudo-transparency:
139	moved around.	159	the image seems to be static while the window is moved around.
140		160
141	=head2 CYCLES AND CACHING	161	=head2 CACHING AND SENSITIVITY
142		162
143	As has been mentioned before, the expression might be evaluated multiple	163	Since some operations (such as C<load> and C<blur>) can take a long time,
144	times. Each time the expression is reevaluated, a new cycle is said to	164	caching results can be very important for a smooth operation. Caching can
145	have begun. Many operators cache their results till the next cycle.	165	also be useful to reduce memory usage, though, for example, when an image
		166	is cached by C<load>, it could be shared by multiple terminal windows
		167	running inside urxvtd.
146		168
147	For example, the C<load> operator keeps a copy of the image. If it is	169	=head3 C<keep { ... }> caching
148	asked to load the same image on the next cycle it will not load it again,
149	but return the cached copy.
150		170
151	This only works for one cycle though, so as long as you load the same	171	The most important way to cache expensive operations is to use C<keep {
152	image every time, it will always be cached, but when you load a different	172	... }>. The C<keep> operator takes a block of multiple statements enclosed
153	image, it will forget about the first one.	173	by C<{}> and keeps the return value in memory.
154		174
155	This allows you to either speed things up by keeping multiple images in	175	An expression can be "sensitive" to various external events, such as
156	memory, or comserve memory by loading images more often.	176	scaling or moving the window, root background changes and timers. Simply
		177	using an expression (such as C<scale> without parameters) that depend on
		178	certain changing values (called "variables"), or using those variables
		179	directly, will make an expression sensitive to these events - for example,
		180	using C<scale> or C<TW> will make the expression sensitive to the terminal
		181	size, and thus to resizing events.
157		182
158	For example, you can keep two images in memory and use a random one like	183	When such an event happens, C<keep> will automatically trigger a
159	this:	184	reevaluation of the whole expression with the new value of the expression.
160		185
161	my $img1 = load "img1.png";	186	C<keep> is most useful for expensive operations, such as C<blur>:
162	my $img2 = load "img2.png";
163	(0.5 > rand) ? $img1 : $img2
164		187
165	Since both images are "loaded" every time the expression is evaluated,	188	rootalign once { blur 20, root }
166	they are always kept in memory. Contrast this version:
167		189
168	my $path1 = "img1.png";	190	This makes a blurred copy of the root background once, and on subsequent
169	my $path2 = "img2.png";	191	calls, just root-aligns it. Since C<blur> is usually quite slow and
170	load ((0.5 > rand) ? $path1 : $path2)	192	C<rootalign> is quite fast, this trades extra memory (for the cached
		193	blurred pixmap) with speed (blur only needs to be redone when root
		194	changes).
171		195
172	Here, a path is selected randomly, and load is only called for one image,	196	=head3 C<load> caching
173	so keeps only one image in memory. If, on the next evaluation, luck	197
174	decides to use the other path, then it will have to load that image again.	198	The C<load> operator itself does not keep images in memory, but as long as
		199	the image is still in memory, C<load> will use the in-memory image instead
		200	of loading it freshly from disk.
		201
		202	That means that this expression:
		203
		204	keep { load "$HOME/path..." }
		205
		206	Not only caches the image in memory, other terminal instances that try to
		207	C<load> it can reuse that in-memory copy.
175		208
176	=head1 REFERENCE	209	=head1 REFERENCE
177		210
178	=head2 COMMAND LINE SWITCHES	211	=head2 COMMAND LINE SWITCHES
179		212
…		…
191	Specifying this flag changes the behaviour, so that the image only	224	Specifying this flag changes the behaviour, so that the image only
192	replaces the background of the character area.	225	replaces the background of the character area.
193		226
194	=item --background-interval seconds	227	=item --background-interval seconds
195		228
196	Since some operations in the underlying XRender extension can effetively	229	Since some operations in the underlying XRender extension can effectively
197	freeze your X-server for prolonged time, this extension enforces a minimum	230	freeze your X-server for prolonged time, this extension enforces a minimum
198	time between updates, which is normally about 0.1 seconds.	231	time between updates, which is normally about 0.1 seconds.
199		232
200	If you want to do updates more often, you can decrease this safety	233	If you want to do updates more often, you can decrease this safety
201	interval with this switch.	234	interval with this switch.
202		235
203	=back	236	=back
204		237
205	=cut	238	=cut
206		239
207	our %_IMGCACHE;	240	our %_IMG_CACHE;
208	our $HOME;	241	our $HOME;
209	our ($self, $old, $new);	242	our ($self, $frame);
210	our ($x, $y, $w, $h);	243	our ($x, $y, $w, $h);
211		244
212	# enforce at least this interval between updates	245	# enforce at least this interval between updates
213	our $MIN_INTERVAL = 6/59.951;	246	our $MIN_INTERVAL = 6/59.951;
214		247
215	{	248	{
216	package urxvt::bgdsl; # background language	249	package urxvt::bgdsl; # background language
		250
		251	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		252	sub FR_CACHE () { 1 } # cached values
		253	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		254	sub FR_STATE () { 3 } # watchers etc.
217		255
218	use List::Util qw(min max sum shuffle);	256	use List::Util qw(min max sum shuffle);
219		257
220	=head2 PROVIDERS/GENERATORS	258	=head2 PROVIDERS/GENERATORS
221		259
…		…
228	=item load $path	266	=item load $path
229		267
230	Loads the image at the given C<$path>. The image is set to plane tiling	268	Loads the image at the given C<$path>. The image is set to plane tiling
231	mode.	269	mode.
232		270
233	Loaded images will be cached for one cycle.	271	If the image is already in memory (e.g. because another terminal instance
		272	uses it), then the in-memory copy us returned instead.
234		273
		274	=item load_uc $path
		275
		276	Load uncached - same as load, but does not cache the image, which means it
		277	is I<always> loaded from the filesystem again.
		278
235	=cut	279	=cut
		280
		281	sub load_uc($) {
		282	$self->new_img_from_file ($path)
		283	}
236		284
237	sub load($) {	285	sub load($) {
238	my ($path) = @_;	286	my ($path) = @_;
239		287
240	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	288	$_IMG_CACHE{$path} \|\| do {
		289	my $img = load_uc $path;
		290	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		291	$img
		292	}
241	}	293	}
242		294
243	=item root	295	=item root
244		296
245	Returns the root window pixmap, that is, hopefully, the background image	297	Returns the root window pixmap, that is, hopefully, the background image
246	of your screen. The image is set to extend mode.	298	of your screen.
247		299
248	This function makes your expression root sensitive, that means it will be	300	This function makes your expression root sensitive, that means it will be
249	reevaluated when the bg image changes.	301	reevaluated when the bg image changes.
250		302
251	=cut	303	=cut
252		304
253	sub root() {	305	sub root() {
254	$new->{rootpmap_sensitive} = 1;	306	$frame->[FR_AGAIN]{rootpmap} = 1;
255	die "root op not supported, exg, we need you";	307	$self->new_img_from_root
256	}	308	}
257		309
258	=item solid $colour	310	=item solid $colour
259		311
260	=item solid $width, $height, $colour	312	=item solid $width, $height, $colour
…		…
268	=cut	320	=cut
269		321
270	sub solid($;$$) {	322	sub solid($;$$) {
271	my $colour = pop;	323	my $colour = pop;
272		324
273	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	325	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
274	$img->fill ($colour);	326	$img->fill ($colour);
275	$img	327	$img
276	}	328	}
277		329
278	=item clone $img	330	=item clone $img
…		…
284		336
285	sub clone($) {	337	sub clone($) {
286	$_[0]->clone	338	$_[0]->clone
287	}	339	}
288		340
289	=back	341	=item merge $img ...
		342
		343	Takes any number of images and merges them together, creating a single
		344	image containing them all. The tiling mode of the first image is used as
		345	the tiling mode of the resulting image.
		346
		347	This function is called automatically when an expression returns multiple
		348	images.
		349
		350	=cut
		351
		352	sub merge(@) {
		353	return $_[0] unless $#_;
		354
		355	# rather annoyingly clumsy, but optimisation is for another time
		356
		357	my $x0 = +1e9;
		358	my $y0 = +1e9;
		359	my $x1 = -1e9;
		360	my $y1 = -1e9;
		361
		362	for (@_) {
		363	my ($x, $y, $w, $h) = $_->geometry;
		364
		365	$x0 = $x if $x0 > $x;
		366	$y0 = $y if $y0 > $y;
		367
		368	$x += $w;
		369	$y += $h;
		370
		371	$x1 = $x if $x1 < $x;
		372	$y1 = $y if $y1 < $y;
		373	}
		374
		375	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		376	$base->repeat_mode ($_[0]->repeat_mode);
		377	$base->fill ([0, 0, 0, 0]);
		378
		379	$base->draw ($_)
		380	for @_;
		381
		382	$base
		383	}
290		384
291	=head2 TILING MODES	385	=head2 TILING MODES
292		386
293	The following operators modify the tiling mode of an image, that is, the	387	The following operators modify the tiling mode of an image, that is, the
294	way that pixels outside the image area are painted when the image is used.	388	way that pixels outside the image area are painted when the image is used.
…		…
324	become transparent. This mode is most useful when you want to place an	418	become transparent. This mode is most useful when you want to place an
325	image over another image or the background colour while leaving all	419	image over another image or the background colour while leaving all
326	background pixels outside the image unchanged.	420	background pixels outside the image unchanged.
327		421
328	Example: load an image and display it in the upper left corner. The rest	422	Example: load an image and display it in the upper left corner. The rest
329	of the space is left "empty" (transparent or wahtever your compisotr does	423	of the space is left "empty" (transparent or whatever your compositor does
330	in alpha mode, else background colour).	424	in alpha mode, else background colour).
331		425
332	pad load "mybg.png"	426	pad load "mybg.png"
333		427
334	=item extend $img	428	=item extend $img
335		429
336	Extends the image over the whole plane, using the closest pixel in the	430	Extends the image over the whole plane, using the closest pixel in the
337	area outside the image. This mode is mostly useful when you more complex	431	area outside the image. This mode is mostly useful when you use more complex
338	filtering operations and want the pixels outside the image to have the	432	filtering operations and want the pixels outside the image to have the
339	same values as the pixels near the edge.	433	same values as the pixels near the edge.
340		434
341	Example: just for curiosity, how does this pixel extension stuff work?	435	Example: just for curiosity, how does this pixel extension stuff work?
342		436
…		…
391	Using these functions make your expression sensitive to window moves.	485	Using these functions make your expression sensitive to window moves.
392		486
393	These functions are mainly useful to align images to the root window.	487	These functions are mainly useful to align images to the root window.
394		488
395	Example: load an image and align it so it looks as if anchored to the	489	Example: load an image and align it so it looks as if anchored to the
396	background.	490	background (that's exactly what C<rootalign> does btw.):
397		491
398	move -TX, -TY, load "mybg.png"	492	move -TX, -TY, keep { load "mybg.png" }
399		493
400	=item TW	494	=item TW
401		495
402	Return the width (C<TW>) and height (C<TH>) of the terminal window (the	496	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
403	terminal window is the full window by default, and the character area only	497	terminal window is the full window by default, and the character area only
…		…
409	the window size to conserve memory.	503	the window size to conserve memory.
410		504
411	Example: take the screen background, clip it to the window size, blur it a	505	Example: take the screen background, clip it to the window size, blur it a
412	bit, align it to the window position and use it as background.	506	bit, align it to the window position and use it as background.
413		507
414	clip move -TX, -TY, blur 5, root	508	clip move -TX, -TY, keep { blur 5, root }
415		509
416	=cut	510	=cut
417		511
418	sub TX() { $new->{position_sensitive} = 1; $x }	512	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
419	sub TY() { $new->{position_sensitive} = 1; $y }	513	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
420	sub TW() { $new->{size_sensitive} = 1; $w }	514	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
421	sub TH() { $new->{size_sensitive} = 1; $h }	515	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
422		516
423	=item now	517	=item now
424		518
425	Returns the current time as (fractional) seconds since the epoch.	519	Returns the current time as (fractional) seconds since the epoch.
426		520
…		…
433	C<$seconds> seconds.	527	C<$seconds> seconds.
434		528
435	Example: load some image and rotate it according to the time of day (as if it were	529	Example: load some image and rotate it according to the time of day (as if it were
436	the hour pointer of a clock). Update this image every minute.	530	the hour pointer of a clock). Update this image every minute.
437		531
		532	again 60;
438	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	533	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
439		534
440	=item counter $seconds	535	=item counter $seconds
441		536
442	Like C<again>, but also returns an increasing counter value, starting at	537	Like C<again>, but also returns an increasing counter value, starting at
443	0, which might be useful for some simple animation effects.	538	0, which might be useful for some simple animation effects.
…		…
445	=cut	540	=cut
446		541
447	sub now() { urxvt::NOW }	542	sub now() { urxvt::NOW }
448		543
449	sub again($) {	544	sub again($) {
450	$new->{again} = $_[0];	545	$frame->[FR_AGAIN]{time} = $_[0];
451	}	546	}
452		547
453	sub counter($) {	548	sub counter($) {
454	$new->{again} = $_[0];	549	$frame->[FR_AGAIN]{time} = $_[0];
455	$self->{counter} + 0	550	$frame->[FR_STATE]{counter} + 0
456	}	551	}
457		552
458	=back	553	=back
459		554
460	=head2 SHAPE CHANGING OPERATORS	555	=head2 SHAPE CHANGING OPERATORS
…		…
480	assumed.	575	assumed.
481		576
482	Example: load an image, blur it, and clip it to the window size to save	577	Example: load an image, blur it, and clip it to the window size to save
483	memory.	578	memory.
484		579
485	clip blur 10, load "mybg.png"	580	clip keep { blur 10, load "mybg.png" }
486		581
487	=cut	582	=cut
488		583
489	sub clip($;$$;$$) {	584	sub clip($;$$;$$) {
490	my $img = pop;	585	my $img = pop;
…		…
584	the terminal window (or the box specified by C<$width> and C<$height> if	679	the terminal window (or the box specified by C<$width> and C<$height> if
585	given).	680	given).
586		681
587	Example: load an image and center it.	682	Example: load an image and center it.
588		683
589	center pad load "mybg.png"	684	center keep { pad load "mybg.png" }
590		685
591	=item rootalign $img	686	=item rootalign $img
592		687
593	Moves the image so that it appears glued to the screen as opposed to the	688	Moves the image so that it appears glued to the screen as opposed to the
594	window. This gives the illusion of a larger area behind the window. It is	689	window. This gives the illusion of a larger area behind the window. It is
595	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	690	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
596	top left of the screen.	691	top left of the screen.
597		692
598	Example: load a background image, put it in mirror mode and root align it.	693	Example: load a background image, put it in mirror mode and root align it.
599		694
600	rootalign mirror load "mybg.png"	695	rootalign keep { mirror load "mybg.png" }
601		696
602	Example: take the screen background and align it, giving the illusion of	697	Example: take the screen background and align it, giving the illusion of
603	transparency as long as the window isn't in front of other windows.	698	transparency as long as the window isn't in front of other windows.
604		699
605	rootalign root	700	rootalign root
…		…
630		725
631	sub rootalign($) {	726	sub rootalign($) {
632	move -TX, -TY, $_[0]	727	move -TX, -TY, $_[0]
633	}	728	}
634		729
		730	=item rotate $center_x, $center_y, $degrees, $img
		731
		732	Rotates the image clockwise by C<$degrees> degrees, around the point at
		733	C<$center_x> and C<$center_y> (specified as factor of image width/height).
		734
		735	Example: rotate the image by 90 degrees around it's center.
		736
		737	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
		738
		739	=cut
		740
		741	sub rotate($$$$) {
		742	my $img = pop;
		743	$img->rotate (
		744	$_[0] * ($img->w + $img->x),
		745	$_[1] * ($img->h + $img->y),
		746	$_[2] * (3.14159265 / 180),
		747	)
		748	}
		749
635	=back	750	=back
636		751
637	=head2 COLOUR MODIFICATIONS	752	=head2 COLOUR MODIFICATIONS
638		753
639	The following operators change the pixels of the image.	754	The following operators change the pixels of the image.
…		…
673		788
674	Values less than 0 reduce brightness, while values larger than 0 increase	789	Values less than 0 reduce brightness, while values larger than 0 increase
675	it. Useful range is from -1 to 1 - the former results in a black, the	790	it. Useful range is from -1 to 1 - the former results in a black, the
676	latter in a white picture.	791	latter in a white picture.
677		792
678	Due to idiosynchrasies in the underlying XRender extension, biases less	793	Due to idiosyncrasies in the underlying XRender extension, biases less
679	than zero can be I<very> slow.	794	than zero can be I<very> slow.
680		795
681	=cut	796	=cut
682		797
683	sub contrast($$;$$;$) {	798	sub contrast($$;$$;$) {
…		…
721	sub blur($$;$) {	836	sub blur($$;$) {
722	my $img = pop;	837	my $img = pop;
723	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	838	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
724	}	839	}
725		840
726	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
727
728	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
729	pointer at C<$center_x> and C<$center_y> (specified as factor of image
730	width/height), generating a new image with width C<$new_width> and height
731	C<$new_height>.
732
733	#TODO# new width, height, maybe more operators?
734
735	Example: rotate the image by 90 degrees
736
737	=cut
738
739	sub rotate($$$$$$) {
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	841	=back
751		842
		843	=head2 OTHER STUFF
		844
		845	Anything that didn't fit any of the other categories, even after applying
		846	force and closing our eyes.
		847
		848	=over 4
		849
		850	=item once { ... }
		851
		852	This function takes a code block as argument, that is, one or more
		853	statements enclosed by braces.
		854
		855	The trick is that this code block is only evaluated once - future calls
		856	will simply return the original image (yes, it should only be used with
		857	images).
		858
		859	This can be extremely useful to avoid redoing the same slow operations
		860	again and again- for example, if your background expression takes the root
		861	background, blurs it and then root-aligns it it would have to blur the
		862	root background on every window move or resize.
		863
		864	In fact, urxvt itself encloses the whole expression in some kind of
		865	C<once> block so it only is reevaluated as required.
		866
		867	Putting the blur into a C<once> block will make sure the blur is only done
		868	once:
		869
		870	rootlign once { blur 10, root }
		871
		872	This leaves the question of how to force reevaluation of the block,
		873	in case the root background changes: If expression inside the block
		874	is sensitive to some event (root background changes, window geometry
		875	changes), then it will be reevaluated automatically as needed.
		876
		877	=item once_again
		878
		879	Resets all C<once> block as if they had never been called, i.e. on the
		880	next call they will be reevaluated again.
		881
		882	=cut
		883
		884	sub once(&) {
		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 once_again() {
		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 1.50 by root, Sun Jun 10 17:31:53 2012 UTC vs. Revision 1.65 by sf-exg, Wed Jun 20 18:18:14 2012 UTC

Diff Legend

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.50 by root, Sun Jun 10 17:31:53 2012 UTC vs.
Revision 1.65 by sf-exg, Wed Jun 20 18:18:14 2012 UTC