Extend the fullscreen command

Rather than just toggling the fullscreen modes, allow to set them
directly with:

    fullscreen enable|toggle [global]
    fullscreen disable

For compatibility, retain the previous command and its toggling behavior:

    fullscreen [global]

fixes #1120

testcases/i3-test.config

@@ -20,7 +20,7 @@ bindsym Mod1+h split h
 bindsym Mod1+v split v
 
 # Fullscreen (Mod1+f)
-bindsym Mod1+f fullscreen
+bindsym Mod1+f fullscreen toggle
 
 # Stacking (Mod1+s)
 bindsym Mod1+s layout stacking

testcases/t/100-fullscreen.t

@@ -255,4 +255,131 @@ $swindow = open_window({
 is(fullscreen_windows($tmp), 1, 'one fullscreen window on ws');
 is($x->input_focus, $swindow->id, 'fullscreen window focused');
 
+################################################################################
+# Verify that command ‘fullscreen enable’ works and is idempotent.
+################################################################################
+
+$tmp = fresh_workspace;
+
+$window = open_window;
+is($x->input_focus, $window->id, 'window focused');
+is(fullscreen_windows($tmp), 0, 'no fullscreen window on workspace');
+
+cmd 'fullscreen enable';
+is($x->input_focus, $window->id, 'window still focused');
+is(fullscreen_windows($tmp), 1, 'one fullscreen window on workspace');
+
+cmd 'fullscreen enable';
+is($x->input_focus, $window->id, 'window still focused');
+is(fullscreen_windows($tmp), 1, 'still one fullscreen window on workspace');
+
+$window->fullscreen(0);
+sync_with_i3;
+is(fullscreen_windows($tmp), 0, 'no fullscreen window on workspace');
+
+################################################################################
+# Verify that command ‘fullscreen enable global’ works and is idempotent.
+################################################################################
+
+$tmp = fresh_workspace;
+
+$window = open_window;
+is($x->input_focus, $window->id, 'window focused');
+is(fullscreen_windows($tmp), 0, 'no fullscreen window on workspace');
+
+cmd 'fullscreen enable global';
+is($x->input_focus, $window->id, 'window still focused');
+is(fullscreen_windows($tmp), 1, 'one fullscreen window on workspace');
+
+cmd 'fullscreen enable global';
+is($x->input_focus, $window->id, 'window still focused');
+is(fullscreen_windows($tmp), 1, 'still one fullscreen window on workspace');
+
+$window->fullscreen(0);
+sync_with_i3;
+is(fullscreen_windows($tmp), 0, 'no fullscreen window on workspace');
+
+################################################################################
+# Verify that command ‘fullscreen disable’ works and is idempotent.
+################################################################################
+
+$tmp = fresh_workspace;
+
+$window = open_window;
+is($x->input_focus, $window->id, 'window focused');
+is(fullscreen_windows($tmp), 0, 'no fullscreen window on workspace');
+
+$window->fullscreen(1);
+sync_with_i3;
+is(fullscreen_windows($tmp), 1, 'one fullscreen window on workspace');
+
+cmd 'fullscreen disable';
+is($x->input_focus, $window->id, 'window still focused');
+is(fullscreen_windows($tmp), 0, 'no fullscreen window on workspace');
+
+cmd 'fullscreen disable';
+is($x->input_focus, $window->id, 'window still focused');
+is(fullscreen_windows($tmp), 0, 'still no fullscreen window on workspace');
+
+################################################################################
+# Verify that command ‘fullscreen toggle’ works.
+################################################################################
+
+$tmp = fresh_workspace;
+
+$window = open_window;
+is(fullscreen_windows($tmp), 0, 'no fullscreen window on workspace');
+
+cmd 'fullscreen toggle';
+is($x->input_focus, $window->id, 'window still focused');
+is(fullscreen_windows($tmp), 1, 'one fullscreen window on workspace');
+
+cmd 'fullscreen toggle';
+is($x->input_focus, $window->id, 'window still focused');
+is(fullscreen_windows($tmp), 0, 'no fullscreen window on workspace');
+
+################################################################################
+# Verify that a window’s fullscreen is disabled when another one is enabled
+# on the same workspace. The new fullscreen window should be focused.
+################################################################################
+
+$tmp = fresh_workspace;
+
+$window = open_window;
+$other = open_window;
+
+is($x->input_focus, $other->id, 'other window focused');
+is(fullscreen_windows($tmp), 0, 'no fullscreen window on workspace');
+
+cmd 'fullscreen enable';
+is($x->input_focus, $other->id, 'other window focused');
+is(fullscreen_windows($tmp), 1, 'one fullscreen window on workspace');
+
+cmd '[id="' . $window->id . '"] fullscreen enable';
+is($x->input_focus, $window->id, 'window focused');
+is(fullscreen_windows($tmp), 1, 'one fullscreen window on workspace');
+
+################################################################################
+# Verify that when a global fullscreen is enabled the window is focused and
+# its workspace is selected, so that disabling the fullscreen keeps the window
+# focused and visible.
+################################################################################
+
+$tmp = fresh_workspace;
+
+$window = open_window;
+
+is($x->input_focus, $window->id, 'window focused');
+
+cmd 'workspace ' . get_unused_workspace;
+isnt($x->input_focus, $window->id, 'window not focused');
+isnt(focused_ws(), $tmp, 'workspace not selected');
+
+cmd '[id="' . $window->id . '"] fullscreen enable global';
+is($x->input_focus, $window->id, 'window focused');
+
+cmd 'fullscreen disable';
+is($x->input_focus, $window->id, 'window still focused');
+is(focused_ws(), $tmp, 'workspace selected');
+
 done_testing;