Merge mark system

This closes #169. Thanks a lot to Github user Flurrywinde for
implementing this.

I did the modifications I requested after the last iteration to this
branch on top of what's in PR.

README.markdown

@@ -11,7 +11,7 @@ It is optimized to be quick and responsive.
 
 It comes with support for animations, slideshows, transparency, VIM-like key
 bindings, automated loading of new images as they appear, external image
-filters, image preloading, and much more.
+filters, marks, image preloading, and much more.
 
 pqiv started as a Python rewrite of qiv avoiding imlib, but evolved into a much
 more powerful tool. Today, pqiv stands for powerful quick image viewer.
@@ -33,6 +33,7 @@ Features
  * Comes with an interactive montage mode (a.k.a. "image grid")
  * Customizable key-bindings with support for VIM-like key sequences, action
    cycling and binding multiple actions to a single key
+ * Mark/unmark images and pipe the list of marked images to an external script
 
 Installation
 ------------
@@ -104,6 +105,7 @@ Contributors to pqiv 2.x are:
  * Chen Jonh L
  * Anton Älgmyr
  * Christian Garbs
+ * Kanon Kubose
 
 Contributors to pqiv ≤ 1.0 were:
 
@@ -184,6 +186,7 @@ pqiv 2.12 (dev)
  * Allow keybinding of special keys with shift modifier
  * Add `--auto-montage-mode` (Fixes #181)
  * Replace GTimeVal with GDateTime for glib 2.62 support
+ * Add an sxiv-like marks system
 
 pqiv 2.11
  * Added negate (color inversion) mode (bound to `n`, `--negate`)

pqiv.1

@@ -109,14 +109,17 @@ Bind the external \fICOMMAND\fR to key 1. You can use 2..9 to bind further
 commands. The \fBACTIONS\fR feature (see below) allows one to bind further keys to
 other commands. \fICOMMAND\fR is executed using the default shell processor.
 `$1' is substituted with the current file name. Unless \fICOMMAND\fR begins with
-`|', if `$1' is not present, the file name is appended to the command line.
+`|' or `-', if `$1' is not present, the file name is appended to the command line.
 .RS
 .PP
 If \fICOMMAND\fR begins with `>', its standard output is displayed in a popup window.
 .PP
 If \fICOMMAND\fR begins with `|', the current image is piped to its standard
 input, and its standard output is loaded as an image. This can be used to e.g.
 process images.
+.PP
+If \fICOMMAND\fR begins with `-', a list of currently marked images is piped to its
+standard input.
 .RE
 .\"
 .TP
@@ -417,6 +420,9 @@ Override a key binding. Remember to quote closing parenthesis inside the new
 definition by prepending a backslash. Useful in conjunction with
 \fBsend_keys(STRING)\fR to set up cyclic bindings.
 .TP
+.BR clear_marks()
+Clear all marks.
+.TP
 .BR command(STRING)
 Execute the given shell command. The syntax of the argument is the same as for
 the \fB\-\-command\-1\fR option.
@@ -636,6 +642,9 @@ window mode.
 .BR toggle_info_box()
 Toggle the visibility of the info box.
 .TP
+.BR toggle_mark()
+Toggle the current image's mark.
+.TP
 .BR toggle_negate_mode(INT)
 Toggle negate (color inversion) mode: 0 to toggle, 1 to enable, 2 to disable.
 .TP
@@ -670,6 +679,9 @@ Show a dialog with a list of all files for quick selection.
 Toggle \fImontage\fR mode, an interactive image selection mode. Use cursor keys
 or your mouse to select an image and Return to return to single image view. Use
 \fIg\fR to quickly navigate to a thumbnail.
+.IP o
+Toggle a mark on an image. Use \fIctrl-R\fR to reset all marks. Used in conjunction
+with commands starting with a \fI-\fR.
 .IP q
 Quit \fBpqiv\fR
 .IP r

pqiv.c

@@ -16,7 +16,8 @@
  *
  */
 
-#define _XOPEN_SOURCE 600
+#define _XOPEN_SOURCE 700
+#define _GNU_SOURCE
 
 #include "pqiv.h"
 #include "lib/config_parser.h"
@@ -546,6 +547,10 @@ static const struct default_key_bindings_struct {
 	{ DEFAULT, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_i                ), ACTION_TOGGLE_INFO_BOX                 , { 0   }},
 	{ DEFAULT, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_j                ), ACTION_JUMP_DIALOG                     , { 0   }},
 	{ DEFAULT, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_m                ), ACTION_MONTAGE_MODE_ENTER              , { 0   }},
+#ifndef CONFIGURED_WITHOUT_EXTERNAL_COMMANDS
+	{ DEFAULT, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_o                ), ACTION_TOGGLE_MARK                     , { 0   }},
+	{ DEFAULT, KEY_BINDING_VALUE(0 , GDK_CONTROL_MASK , GDK_KEY_o                ), ACTION_CLEAR_MARKS                     , { 0   }},
+#endif
 	{ DEFAULT, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_s                ), ACTION_TOGGLE_SLIDESHOW                , { 0   }},
 	{ DEFAULT, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_b                ), ACTION_TOGGLE_BACKGROUND_PATTERN       , { 0   }},
 	{ DEFAULT, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_n                ), ACTION_TOGGLE_NEGATE_MODE              , { 0   }},
@@ -598,6 +603,10 @@ static const struct default_key_bindings_struct {
 
 	{ MONTAGE, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_Return           ), ACTION_MONTAGE_MODE_RETURN_PROCEED     , { 0   }},
 	{ MONTAGE, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_Escape           ), ACTION_MONTAGE_MODE_RETURN_CANCEL      , { 0   }},
+#ifndef CONFIGURED_WITHOUT_EXTERNAL_COMMANDS
+	{ MONTAGE, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_o                ), ACTION_TOGGLE_MARK                     , { 0   }},
+	{ MONTAGE, KEY_BINDING_VALUE(0 , GDK_CONTROL_MASK , GDK_KEY_o                ), ACTION_CLEAR_MARKS                     , { 0   }},
+#endif
 	{ MONTAGE, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_m                ), ACTION_MONTAGE_MODE_RETURN_CANCEL      , { 0   }},
 	{ MONTAGE, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_f                ), ACTION_TOGGLE_FULLSCREEN               , { 0   }},
 	{ MONTAGE, KEY_BINDING_VALUE(0 , 0                , GDK_KEY_g                ), ACTION_MONTAGE_MODE_FOLLOW             , { .pcharptr = (char*)montage_mode_default_keys }},
@@ -711,6 +720,8 @@ const struct pqiv_action_descriptor {
 	{ "move_window", PARAMETER_2SHORT },
 	{ "toggle_background_pattern", PARAMETER_INT },
 	{ "toggle_negate_mode", PARAMETER_INT },
+	{ "toggle_mark", PARAMETER_NONE },
+	{ "clear_marks", PARAMETER_NONE },
 	{ NULL, 0 }
 };
 /* }}} */
@@ -792,6 +803,11 @@ void queue_action(pqiv_action_t action_id, pqiv_action_parameter_t parameter);
 gboolean montage_window_get_move_cursor_target(int, int, int, int*, int*, int*, BOSNode **);
 void montage_window_move_cursor(int, int, int);
 #endif
+#ifndef CONFIGURED_WITHOUT_EXTERNAL_COMMANDS
+void toggle_mark();
+void clear_marks();
+GString *get_all_marked();
+#endif
 // }}}
 /* Helper functions {{{ */
 gboolean strv_contains(const gchar * const *strv, const gchar *str) {
@@ -3558,6 +3574,45 @@ void apply_external_image_filter(gchar *external_filter) {/*{{{*/
 		// Reminder: Do not free the others, they are string constants
 		g_free(argv[2]);
 	}
+	else if(external_filter[0] == '-') {
+		GString *marklist = get_all_marked();
+		argv[2] = external_filter + 1;
+		GPid child_pid;
+		gint child_stdin;
+		if(!g_spawn_async_with_pipes(NULL, argv, NULL,
+			G_SPAWN_DO_NOT_REAP_CHILD,
+			NULL, NULL, &child_pid, &child_stdin, NULL, NULL, &error_pointer)
+		) {
+			g_printerr("Failed execute external command `%s': %s\n", argv[2], error_pointer->message);
+			g_clear_error(&error_pointer);
+		}
+		else {
+			if(write(child_stdin, marklist->str, marklist->len) == -1) {
+				g_printerr("Failed writing to stdin of %s\n", argv[2]);
+			}
+			close(child_stdin);
+			gint status = 0;  // When left uninitialized, external command reports exiting due to signal 95 (exit statuses have been 233, 201, 217). Why?
+			#ifdef _WIN32
+				WaitForSingleObject(child_pid, INFINITE);
+				DWORD exit_code = 0;
+				GetExitCodeProcess(child_pid, &exit_code);
+				status = (gint)exit_code;
+			#else
+				waitpid(child_pid, &status, 0);
+			#endif
+			g_spawn_close_pid(child_pid);
+
+			if (!WIFEXITED(status)) {
+				if (WIFSIGNALED(status)) {
+					g_printerr("External command exited due to signal %d (exit status: %d)\n", WTERMSIG(status), WEXITSTATUS(status));
+				}
+				else {
+					g_printerr("External command failed with exit status %d\n", WEXITSTATUS(status));
+				}
+			}
+		}
+		g_string_free(marklist, TRUE);
+	}
 	else if(external_filter[0] == '|') {
 		// Pipe image into program, read image from its stdout
 		argv[2] = external_filter + 1;
@@ -4249,12 +4304,13 @@ void update_info_text(const gchar *action) {/*{{{*/
 
 	// Update info text
 	if(!option_hide_info_box) {
-		current_info_text = g_strdup_printf("%s (%dx%d) %03.2f%% [%d/%d]", display_name,
+		current_info_text = g_strdup_printf("%s (%dx%d) %03.2f%% [%d/%d]%s", display_name,
 			CURRENT_FILE->width,
 			CURRENT_FILE->height,
 			current_scale_level * 100.,
 			(unsigned int)(bostree_rank(current_file_node) + 1),
-			(unsigned int)(bostree_node_count(file_tree)));
+			(unsigned int)(bostree_node_count(file_tree)),
+			CURRENT_FILE->marked ? " [m]" : "");
 
 		if(action != NULL) {
 			gchar *old_info_text = current_info_text;
@@ -4789,6 +4845,21 @@ gboolean window_draw_thumbnail_montage(cairo_t *cr_arg) {/*{{{*/
 				cairo_stroke(cr_arg);
 			}
 
+			// Marks
+			if(thumb_file->marked) {
+				int markx = cairo_image_surface_get_width(thumb_file->thumbnail);
+				int marky = cairo_image_surface_get_height(thumb_file->thumbnail);
+				cairo_save(cr_arg);
+				cairo_rectangle(cr_arg, markx - 5, marky - 5, markx + 1, marky + 1);
+				cairo_set_source_rgb(cr_arg, 0, 0, 0);
+				cairo_set_line_width(cr_arg, 1);
+				cairo_stroke_preserve(cr_arg);
+				cairo_set_source_rgb(cr_arg, 1, 0, 1);
+				cairo_set_operator(cr_arg, CAIRO_OPERATOR_DIFFERENCE);
+				cairo_fill(cr_arg);
+				cairo_restore(cr_arg);
+			}
+
 			cairo_restore(cr_arg);
 		}
 		else if(top_left_id + draw_now == selection_rank) {
@@ -6567,6 +6638,15 @@ void action(pqiv_action_t action_id, pqiv_action_parameter_t parameter) {/*{{{*/
 			gtk_widget_queue_draw(GTK_WIDGET(main_window));
 			break;
 #endif // without montage
+#ifndef CONFIGURED_WITHOUT_EXTERNAL_COMMANDS
+		case ACTION_TOGGLE_MARK:
+			toggle_mark();
+			break;
+
+		case ACTION_CLEAR_MARKS:
+			clear_marks();
+			break;
+#endif // without external commands
 
 		default:
 			break;
@@ -8020,6 +8100,48 @@ gboolean inner_main(void *user_data) {/*{{{*/
 
 	return FALSE;
 }/*}}}*/
+
+/* Marks system functions {{{ */
+#ifndef CONFIGURED_WITHOUT_EXTERNAL_COMMANDS
+void clear_marks() {/*{{{*/
+	D_LOCK(file_tree);
+	for(BOSNode *iter = bostree_select(file_tree, 0); iter; iter = bostree_next_node(iter)) {
+		FILE(iter)->marked = FALSE;
+	}
+	D_UNLOCK(file_tree);
+	if(application_mode == DEFAULT) {
+		update_info_text("Cleared all marks");
+		info_text_queue_redraw();
+	}
+}/*}}}*/
+void toggle_mark() {/*{{{*/
+	if(application_mode == DEFAULT) {
+		FILE(current_file_node)->marked = !FILE(current_file_node)->marked;
+		update_info_text(NULL);
+		info_text_queue_redraw();
+	}
+	#ifndef CONFIGURED_WITHOUT_MONTAGE_MODE
+	else if(application_mode == MONTAGE) {
+		FILE(montage_window_control.selected_node)->marked = !FILE(montage_window_control.selected_node)->marked;
+	}
+	#endif
+}/*}}}*/
+GString *get_all_marked() {/*{{{*/
+	GString *result = g_string_new(NULL);
+
+	D_LOCK(file_tree);
+	for(BOSNode *iter = bostree_select(file_tree, 0); iter; iter = bostree_next_node(iter)) {
+		file_t *file = FILE(iter);
+		if(file->marked) {
+			g_string_append_printf(result, "%s\n", file->file_name);
+		}
+	}
+	D_UNLOCK(file_tree);
+	return result;
+}/*}}}*/
+#endif
+// }}}
+
 int main(int argc, char *argv[]) {
 	#ifdef DEBUG
 		#ifndef _WIN32
@@ -8127,5 +8249,4 @@ int main(int argc, char *argv[]) {
 
 	return 0;
 }
-
 // vim:noet ts=4 sw=4 tw=0 fdm=marker

pqiv.h

@@ -106,6 +106,11 @@ struct _file {
 
 	// File-type specific data, allocated and freed by the file type handlers
 	void *private;
+
+	// TRUE if file is marked
+#ifndef CONFIGURED_WITHOUT_EXTERNAL_COMMANDS
+	gboolean marked;
+#endif
 };
 // }}}
 // Definition of the built-in file types {{{
@@ -285,6 +290,8 @@ typedef enum {
 	ACTION_MOVE_WINDOW,
 	ACTION_TOGGLE_BACKGROUND_PATTERN,
 	ACTION_TOGGLE_NEGATE_MODE,
+	ACTION_TOGGLE_MARK,
+	ACTION_CLEAR_MARKS,
 } pqiv_action_t;
 
 typedef union {