Add 'previewoptions' option

At the moment only allows tweaking delay for graphics preview.

Thanks to Joshua Jensch (a.k.a., patroclos).

See vifm#481 (comment)

ChangeLog

@@ -17,6 +17,9 @@
 	Added a and A view mode keys that switch to next and previous viewer of
 	current file correspondingly.  Thanks to j-xella.
 
+	Added 'previewoptions' option to allow tweaking delay for graphics
+	preview.  Thanks to Joshua Jensch (a.k.a., patroclos).
+
 	Made :VifmCs of the plugin fail when 'termguicolors' produces a 24-bit color
 	value.  Thanks to AtomToast.
 

THANKS

@@ -103,6 +103,7 @@ John Shea (coachshea)
 Jose Riha (jose1711)
 Joseph LP (ootput)
 Josh Wainwright (joshaw)
+Joshua Jensch (patroclos)
 jsmith51 (metal.lunchbox)
 kalterfive
 kangshugang

data/man/vifm.1

@@ -1,4 +1,4 @@
-.TH VIFM 1 "December 4, 2020" "vifm 0.11"
+.TH VIFM 1 "December 6, 2020" "vifm 0.11"
 .\" ---------------------------------------------------------------------------
 .SH NAME
 .\" ---------------------------------------------------------------------------
@@ -4245,6 +4245,21 @@ scope: local
 .br
 Minimal number of characters for line number field.
 .TP
+.BI "'previewoptions'"
+type: string list
+.br
+default: "graphicsdelay:50000"
+.br
+
+Tweaks how previewing is done (in quick view, miller view's column and
+view mode).
+
+  item                default  meaning
+  graphicsdelay:num   0        delay before drawing graphics (microseconds)
+
+graphicsdelay is needed if terminal requires some timeout before it can
+draw graphics (otherwise it gets lost).
+.TP
 .BI "'previewprg'"
 type: string
 .br

data/vim/doc/app/vifm-app.txt

@@ -1,4 +1,4 @@
-*vifm-app.txt*    For Vifm version 0.11  Last change: 2020 Dec 4
+*vifm-app.txt*    For Vifm version 0.11  Last change: 2020 Dec 6
 
  Email for bugs and suggestions: <[email protected]>
 
@@ -3559,6 +3559,22 @@ scope: local
 
 Minimal number of characters for line number field.
 
+                                               *vifm-'previewoptions'*
+previewoptions
+type: string list
+default: "graphicsdelay:50000"
+
+Tweaks how previewing is done (in quick view, miller view's column and
+view mode).
+
+    item                default  meaning ~
+    graphicsdelay:num   0        delay before drawing graphics (microseconds)
+
+graphicsdelay is needed if terminal requires some timeout before it can
+draw graphics (otherwise it gets lost).
+
+Default value is used when item is missing from the option.
+
                                                *vifm-'previewprg'*
 previewprg
 type: string

data/vim/syntax/vifm.vim

@@ -1,6 +1,6 @@
 " vifm syntax file
 " Maintainer:  xaizek <[email protected]>
-" Last Change: October 6, 2020
+" Last Change: December 6, 2020
 " Inspired By: Vim syntax file by Dr. Charles E. Campbell, Jr.
 
 if exists('b:current_syntax')
@@ -141,13 +141,14 @@ syntax keyword vifmOption contained aproposprg autochpos caseoptions cdpath cd
 		\ followlinks fusehome gdefault grepprg histcursor history hi hlsearch hls
 		\ iec ignorecase ic iooptions incsearch is laststatus lines locateprg ls
 		\ lsoptions lsview mediaprg milleroptions millerview mintimeoutlen number nu
-		\ numberwidth nuw previewprg quickview relativenumber rnu rulerformat ruf
-		\ runexec scrollbind scb scrolloff sessionoptions ssop so sort sortgroups
-		\ sortorder sortnumbers shell sh shellflagcmd shcf shortmess shm showtabline
-		\ stal sizefmt slowfs smartcase scs statusline stl suggestoptions syncregs
-		\ syscalls tablabel tabprefix tabscope tabstop tabsuffix timefmt timeoutlen
-		\ title tm trash trashdir ts tuioptions to undolevels ul vicmd viewcolumns
-		\ vifminfo vimhelp vixcmd wildmenu wmnu wildstyle wordchars wrap wrapscan ws
+		\ numberwidth nuw previewoptions previewprg quickview relativenumber rnu
+		\ rulerformat ruf runexec scrollbind scb scrolloff sessionoptions ssop so
+		\ sort sortgroups sortorder sortnumbers shell sh shellflagcmd shcf shortmess
+		\ shm showtabline stal sizefmt slowfs smartcase scs statusline stl
+		\ suggestoptions syncregs syscalls tablabel tabprefix tabscope tabstop
+		\ tabsuffix timefmt timeoutlen title tm trash trashdir ts tuioptions to
+		\ undolevels ul vicmd viewcolumns vifminfo vimhelp vixcmd wildmenu wmnu
+		\ wildstyle wordchars wrap wrapscan ws
 
 " Disabled boolean options
 syntax keyword vifmOption contained noautochpos nocf nochaselinks nodotfiles

src/cfg/config.c

@@ -192,6 +192,8 @@ cfg_init(void)
 
 	cfg.chase_links = 0;
 
+	cfg.graphics_delay = 50000;
+
 	cfg.timeout_len = 1000;
 	cfg.min_timeout_len = 150;
 

src/cfg/config.h

@@ -295,6 +295,8 @@ typedef struct config_t
 	 * link expanded). */
 	int chase_links;
 
+	int graphics_delay; /* Delay before redrawing graphics in microseconds. */
+
 	int timeout_len;     /* Maximum period on waiting for the input. */
 	int min_timeout_len; /* Minimum period on waiting for the input. */
 

src/cfg/info.c

@@ -2242,6 +2242,8 @@ store_global_options(JSON_Object *root)
 	append_dstr(options, format_str("rulerformat=%s",
 				escape_spaces(cfg.ruler_format)));
 	append_dstr(options, format_str("%srunexec", cfg.auto_execute ? "" : "no"));
+	append_dstr(options, format_str("previewoptions=%s",
+				escape_spaces(vle_opts_get("previewoptions", OPT_GLOBAL))));
 	append_dstr(options, format_str("%sscrollbind", cfg.scroll_bind ? "" : "no"));
 	append_dstr(options, format_str("scrolloff=%d", cfg.scroll_off));
 	append_dstr(options, format_str("shell=%s", escape_spaces(cfg.shell)));

src/modes/view.c

@@ -1112,7 +1112,7 @@ get_view_data(modview_info_t *vi, const char file_to_view[])
 	{
 		/* Wait a bit to let terminal emulator do actual refresh (at least some of
 		 * them need this). */
-		usleep(50000);
+		usleep(cfg.graphics_delay);
 	}
 
 	const char *error;

src/opt_handlers.c

@@ -92,6 +92,7 @@ static void init_lsoptions(optval_t *val);
 static void init_lsview(optval_t *val);
 static void init_milleroptions(optval_t *val);
 static void init_millerview(optval_t *val);
+static void init_previewoptions(optval_t *val);
 static void init_quickview(optval_t *val);
 static void init_shortmess(optval_t *val);
 static void init_sizefmt(optval_t *val);
@@ -147,6 +148,7 @@ static void mediaprg_handler(OPT_OP op, optval_t val);
 #endif
 static void mintimeoutlen_handler(OPT_OP op, optval_t val);
 static void scroll_line_down(view_t *view);
+static void previewoptions_handler(OPT_OP op, optval_t val);
 static void quickview_handler(OPT_OP op, optval_t val);
 static void rulerformat_handler(OPT_OP op, optval_t val);
 static void runexec_handler(OPT_OP op, optval_t val);
@@ -328,6 +330,11 @@ static const char *lsoptions_enum[][2] = {
 	{ "transposed", "fill grid by column instead of by line" },
 };
 
+/* Possible values of 'previewoptions'. */
+static const char *previewoptions_vals[][2] = {
+	{ "graphicsdelay:", "delay before drawing graphics" },
+};
+
 /* Possible values of 'suggestoptions'. */
 static const char *suggestoptions_vals[][2] = {
 	[BIT(SF_NORMAL)]      = { "normal",      "display in normal mode" },
@@ -701,6 +708,11 @@ options[] = {
 	  OPT_INT, 0, NULL, &mintimeoutlen_handler, NULL,
 	  { .ref.int_val = &cfg.min_timeout_len },
 	},
+	{ "previewoptions", "", "tweaks for how preview is done",
+	  OPT_STRLIST, ARRAY_LEN(previewoptions_vals), previewoptions_vals,
+		&previewoptions_handler, NULL,
+	  { .init = &init_previewoptions },
+	},
 	{ "quickview", "", "whether quick view is active",
 	  OPT_BOOL, 0, NULL, &quickview_handler, NULL,
 	  { .init = &init_quickview },
@@ -1158,6 +1170,20 @@ init_millerview(optval_t *val)
 	val->bool_val = curr_view->miller_view_g;
 }
 
+/* Initializes 'previewoptions' option from global state. */
+static void
+init_previewoptions(optval_t *val)
+{
+	static char buf[64];
+	buf[0] = '\0';
+
+	if(cfg.graphics_delay != 0)
+	{
+		snprintf(buf, sizeof(buf), "graphicsdelay:%d", cfg.graphics_delay);
+	}
+	val->str_val = buf;
+}
+
 /* Initializes 'quickview' option from global state. */
 static void
 init_quickview(optval_t *val)
@@ -2239,6 +2265,54 @@ scroll_line_down(view_t *view)
 	wresize(view->win, view->window_rows, view->window_cols);
 }
 
+/* Handles updates of the 'previewoptions' option. */
+static void
+previewoptions_handler(OPT_OP op, optval_t val)
+{
+	char *new_val = strdup(val.str_val);
+	char *part = new_val, *state = NULL;
+
+	int graphics_delay = 0;
+
+	while((part = split_and_get(part, ',', &state)) != NULL)
+	{
+		if(starts_with_lit(part, "graphicsdelay:"))
+		{
+			const char *const num = after_first(part, ':');
+			if(!read_int(num, &graphics_delay))
+			{
+				vle_tb_append_linef(vle_err,
+						"Failed to parse \"graphicsdelay\" value: %s", num);
+				break;
+			}
+			if(graphics_delay < 0)
+			{
+				vle_tb_append_linef(vle_err,
+						"\"graphicsdelay\" can't be negative, got: %s", num);
+				break;
+			}
+		}
+		else
+		{
+			break_at(part, ':');
+			vle_tb_append_linef(vle_err,
+					"Unknown key for 'previewoptions' option: %s", part);
+			break;
+		}
+	}
+	free(new_val);
+
+	if(part == NULL)
+	{
+		cfg.graphics_delay = graphics_delay;
+	}
+
+	/* In case of error, restore previous value, otherwise reload it anyway to
+	 * remove any duplicates. */
+	init_previewoptions(&val);
+	vle_opts_assign("previewoptions", val, OPT_GLOBAL);
+}
+
 /* Handles switch that controls visibility of quick view. */
 static void
 quickview_handler(OPT_OP op, optval_t val)

src/tags.c

@@ -85,6 +85,7 @@ const char *tags[] = {
 	"vifm-'number'",
 	"vifm-'numberwidth'",
 	"vifm-'nuw'",
+	"vifm-'previewoptions'",
 	"vifm-'previewprg'",
 	"vifm-'quickview'",
 	"vifm-'relativenumber'",

src/ui/quickview.c

@@ -328,7 +328,7 @@ view_file(const char path[], const preview_area_t *parea,
 	if(kind != VK_TEXTUAL)
 	{
 		cleanup_area(parea, curr_stats.preview.cleanup_cmd);
-		usleep(50000);
+		usleep(cfg.graphics_delay);
 	}
 	else
 	{

tests/misc/options.c

@@ -726,5 +726,33 @@ TEST(sessionoptions)
 	assert_int_equal(0, cfg.session_options);
 }
 
+TEST(previewoptions)
+{
+	assert_success(exec_commands("set previewoptions=graphicsdelay:12345", &lwin,
+				CIT_COMMAND));
+	assert_int_equal(12345, cfg.graphics_delay);
+
+	assert_failure(exec_commands("set previewoptions=graphicsdelay:inf", &lwin,
+				CIT_COMMAND));
+	assert_int_equal(12345, cfg.graphics_delay);
+	assert_string_equal("Failed to parse \"graphicsdelay\" value: inf",
+			vle_tb_get_data(vle_err));
+
+	assert_failure(exec_commands("set previewoptions=graphicsdelay:-12345", &lwin,
+				CIT_COMMAND));
+	assert_int_equal(12345, cfg.graphics_delay);
+	assert_string_equal("\"graphicsdelay\" can't be negative, got: -12345",
+			vle_tb_get_data(vle_err));
+
+	assert_failure(exec_commands("set previewoptions=graphicsdelay:145,wtf",
+				&lwin, CIT_COMMAND));
+	assert_int_equal(12345, cfg.graphics_delay);
+	assert_string_equal("Unknown key for 'previewoptions' option: wtf",
+			vle_tb_get_data(vle_err));
+
+	assert_success(exec_commands("set previewoptions=", &lwin, CIT_COMMAND));
+	assert_int_equal(0, cfg.graphics_delay);
+}
+
 /* vim: set tabstop=2 softtabstop=2 shiftwidth=2 noexpandtab cinoptions-=(0 : */
 /* vim: set cinoptions+=t0 filetype=c : */

tests/test-data/syntax-highlight/syntax.vifm

@@ -521,6 +521,7 @@ hi OddLine
 " "sessionoptions" and "ssop" should be highlighted as 'option'
 " "tabprefix" should be highlighted as 'option'
 " "tabsuffix" should be highlighted as 'option'
+" "previewoptions" should be highlighted as 'option'
 set dotfiles nodotfiles invdotfiles dotfiles!
 set caseoptions
 set sizefmt
@@ -539,6 +540,7 @@ set tablabel
 set sessionoptions ssop
 set tabprefix
 set tabsuffix
+set previewoptions
 
 " "term" should be highlighted as a function()
 echo term('cmd')