Implement 'all' matching criterion

This criterion matches all open windows, as a more readable (and
correct) version of the 'class=".*"' criterion (more correct because
it'll also match windows which don't have WM_CLASS set yet).

RELEASE-NOTES-next

@@ -41,6 +41,7 @@ option is enabled and only then sets a screenshot as background.
   • Add %machine placeholder (WM_CLIENT_MACHINE) to title_format
   • Allow multiple output names in 'move container|workspace to output'
   • Add 'move container|workspace to output next'
+  • Add 'all' window matching criterion
 
  ┌────────────────────────────┐
  │ Bugfixes                   │

docs/userguide

@@ -1959,12 +1959,17 @@ bindsym $mod+x [class="Firefox" window_role="About"] kill
 # enable floating mode and move container to workspace 4
 for_window [class="^evil-app$"] floating enable, move container to workspace 4
 
+# enable window icons for all windows with extra horizontal padding of 1px
+for_window [all] title_window_icon padding 1px
+
 # move all floating windows to the scratchpad
 bindsym $mod+x [floating] move scratchpad
 ------------------------------------
 
 The criteria which are currently implemented are:
 
+all::
+	Matches all windows. This criterion requires no value.
 class::
 	Compares the window class (the second part of WM_CLASS). Use the
 	special value +\_\_focused__+ to match all windows having the same window

include/data.h

@@ -530,6 +530,7 @@ struct Match {
            WM_FLOATING_USER,
            WM_FLOATING } window_mode;
     Con *con_id;
+    bool match_all_windows;
 
     /* Where the window looking for a match should be inserted:
      *

parser-specs/commands.spec

@@ -56,7 +56,7 @@ state CRITERIA:
   ctype = 'urgent'      -> CRITERION
   ctype = 'workspace'   -> CRITERION
   ctype = 'machine'     -> CRITERION
-  ctype = 'tiling', 'floating'
+  ctype = 'tiling', 'floating', 'all'
       -> call cmd_criteria_add($ctype, NULL); CRITERIA
   ']' -> call cmd_criteria_match_windows(); INITIAL
 

parser-specs/config.spec

@@ -200,7 +200,7 @@ state CRITERIA:
   ctype = 'machine'     -> CRITERION
   ctype = 'floating_from' -> CRITERION_FROM
   ctype = 'tiling_from'   -> CRITERION_FROM
-  ctype = 'tiling', 'floating'
+  ctype = 'tiling', 'floating', 'all'
       -> call cfg_criteria_add($ctype, NULL); CRITERIA
   ']'
       -> call cfg_criteria_pop_state()

src/match.c

@@ -53,7 +53,8 @@ bool match_is_empty(Match *match) {
             match->window_type == UINT32_MAX &&
             match->con_id == NULL &&
             match->dock == M_NODOCK &&
-            match->window_mode == WM_ANY);
+            match->window_mode == WM_ANY &&
+            match->match_all_windows == false);
 }
 
 /*
@@ -260,6 +261,10 @@ bool match_matches_window(Match *match, i3Window *window) {
         LOG("window_mode matches\n");
     }
 
+    /* NOTE: See the comment regarding 'all' in match_parse_property()
+     * for an explanation of why match_all_windows isn't explicitly
+     * checked. */
+
     return true;
 }
 
@@ -438,5 +443,16 @@ void match_parse_property(Match *match, const char *ctype, const char *cvalue) {
         return;
     }
 
+    /* match_matches_window() only checks negatively, so match_all_windows
+     * won't actually be used there, but that's OK because if no negative
+     * match is found (e.g. because of a more restrictive criterion) the
+     * return value of match_matches_window() is true.
+     * Setting it here only serves to cause match_is_empty() to return false,
+     * otherwise empty criteria rules apply, and that's not what we want. */
+    if (strcmp(ctype, "all") == 0) {
+        match->match_all_windows = true;
+        return;
+    }
+
     ELOG("Unknown criterion: %s\n", ctype);
 }

testcases/t/315-all-criterion.t

@@ -0,0 +1,90 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+#
+# Please read the following documents before working on tests:
+# • https://build.i3wm.org/docs/testsuite.html
+#   (or docs/testsuite)
+#
+# • https://build.i3wm.org/docs/lib-i3test.html
+#   (alternatively: perldoc ./testcases/lib/i3test.pm)
+#
+# • https://build.i3wm.org/docs/ipc.html
+#   (or docs/ipc)
+#
+# • http://onyxneon.com/books/modern_perl/modern_perl_a4.pdf
+#   (unless you are already familiar with Perl)
+#
+# Tests all kinds of matching methods
+#
+use i3test;
+
+my $tmp = fresh_workspace;
+
+ok(@{get_ws_content($tmp)} == 0, 'no containers yet');
+
+# Open a new window
+my $window = open_window;
+my $content = get_ws_content($tmp);
+ok(@{$content} == 1, 'window mapped');
+my $win = $content->[0];
+
+######################################################################
+# check that simple matching works.
+######################################################################
+cmd '[all] kill';
+
+sync_with_i3;
+
+is_num_children($tmp, 0, 'window killed');
+
+######################################################################
+# check that simple matching against multiple windows works.
+######################################################################
+
+$tmp = fresh_workspace;
+
+my $left = open_window;
+ok($left->mapped, 'left window mapped');
+
+my $right = open_window;
+ok($right->mapped, 'right window mapped');
+
+# two windows should be here
+is_num_children($tmp, 2, 'two windows opened');
+
+cmd '[all] kill';
+
+sync_with_i3;
+
+is_num_children($tmp, 0, 'two windows killed');
+
+######################################################################
+# check that multiple criteria work are checked with a logical AND,
+# not a logical OR (that is, matching is not cancelled after the first
+# criterion matches).
+######################################################################
+
+$tmp = fresh_workspace;
+
+my $left = open_window(name => 'left');
+ok($left->mapped, 'left window mapped');
+
+my $right = open_window(name => 'right');
+ok($right->mapped, 'right window mapped');
+
+# two windows should be here
+is_num_children($tmp, 2, 'two windows opened');
+
+cmd '[all title="left"] kill';
+
+sync_with_i3;
+
+is_num_children($tmp, 1, 'one window still there');
+
+cmd '[all] kill';
+
+sync_with_i3;
+
+is_num_children($tmp, 0, 'all windows killed');
+
+done_testing;