window-rules: add fixedPosition property

...to address regression introduced by 57075ce and enables panel/desktop
clients which rely on window rules to remain in the same position when
the usable-area changes (normally because an exclusive layer-shell
clients is started/finished).

Also disallows interactive move/resize, for example by alt +
mouse-press.

Fixes: #1235

docs/labwc-config.5.scd

@@ -526,6 +526,12 @@ situation.
 *<windowRules><windowRule ignoreFocusRequest="">* [yes|no|default]
 	*ignoreFocusRequest* prevent window to activate itself.
 
+*<windowRules><windowRule fixedPosition="">* [yes|no|default]
+	*fixedPosition* disallows interactive move/resize and prevents
+	re-positioning in response to changes in reserved output space, which
+	can be caused by *<margin>* settings or exclusive layer-shell clients
+	such as panels.
+
 ## ENVIRONMENT VARIABLES
 
 *XCURSOR_THEME* and *XCURSOR_SIZE* are supported to set cursor theme

docs/rc.xml.all

@@ -442,6 +442,7 @@
       <windowRule title="pcmanfm-desktop*">
         <skipTaskbar>yes</skipTaskbar>
         <skipWindowSwitcher>yes</skipWindowSwitcher>
+	<fixedPosition>yes</fixedPosition>
         <action name="MoveTo" x="0" y="0" />
         <action name="ToggleAlwaysOnBottom"/>
       </windowRule>

include/window-rules.h

@@ -30,6 +30,7 @@ struct window_rule {
 	enum property skip_taskbar;
 	enum property skip_window_switcher;
 	enum property ignore_focus_request;
+	enum property fixed_position;
 
 	struct wl_list link; /* struct rcxml.window_rules */
 };

src/config/rcxml.c

@@ -159,6 +159,8 @@ fill_window_rule(char *nodename, char *content)
 		set_property(content, &current_window_rule->skip_window_switcher);
 	} else if (!strcasecmp(nodename, "ignoreFocusRequest")) {
 		set_property(content, &current_window_rule->ignore_focus_request);
+	} else if (!strcasecmp(nodename, "fixedPosition")) {
+		set_property(content, &current_window_rule->fixed_position);
 
 	/* Actions */
 	} else if (!strcmp(nodename, "name.action")) {

src/interactive.c

@@ -4,6 +4,7 @@
 #include "regions.h"
 #include "resize_indicator.h"
 #include "view.h"
+#include "window-rules.h"
 
 static int
 max_move_scale(double pos_cursor, double pos_current,
@@ -34,6 +35,10 @@ interactive_begin(struct view *view, enum input_mode mode, uint32_t edges)
 		return;
 	}
 
+	if (window_rules_get_property(view, "fixedPosition") == LAB_PROP_TRUE) {
+		return;
+	}
+
 	switch (mode) {
 	case LAB_INPUT_STATE_MOVE:
 		if (view->fullscreen) {

src/view.c

@@ -587,6 +587,10 @@ view_adjust_floating_geometry(struct view *view, struct wlr_box *geometry)
 		return false;
 	}
 
+	if (window_rules_get_property(view, "fixedPosition") == LAB_PROP_TRUE) {
+		return false;
+	}
+
 	bool adjusted = false;
 	/*
 	 * First check whether the view is onscreen. For now, "onscreen"

src/window-rules.c

@@ -128,6 +128,10 @@ window_rules_get_property(struct view *view, const char *property)
 					&& !strcasecmp(property, "ignoreFocusRequest")) {
 				return rule->ignore_focus_request;
 			}
+			if (rule->fixed_position
+					&& !strcasecmp(property, "fixedPosition")) {
+				return rule->fixed_position;
+			}
 		}
 	}
 	return LAB_PROP_UNSPECIFIED;