window_layouter: add dynamic screen handling

This commit adds dynamic switching in between different defined
screens via keyboard shortcuts, or by editing the rules file.
In the window_layouter package it defines per default ten screens,
reachable by pressing the screen key along with numbers 0-9.

Fix #3646

repos/gems/recipes/raw/motif_wm/layouter.config

@@ -2,8 +2,17 @@
 	<report rules="yes"/>
 
 	<rules>
-		<screen name="screen"/>
+		<screen name="screen_1"/>
-		<assign label_prefix="" target="screen" xpos="any" ypos="any"/>
+		<screen name="screen_2"/>
+		<screen name="screen_3"/>
+		<screen name="screen_4"/>
+		<screen name="screen_5"/>
+		<screen name="screen_6"/>
+		<screen name="screen_7"/>
+		<screen name="screen_8"/>
+		<screen name="screen_9"/>
+		<screen name="screen_0"/>
+		<assign label_prefix="" target="screen_1" xpos="any" ypos="any"/>
 	</rules>
 
 	<press key="KEY_SCREEN">
@@ -21,5 +30,15 @@
 			</press>
 		</press>
 		<press key="KEY_ENTER" action="toggle_fullscreen"/>
+		<press key="KEY_1"     action="screen" target="screen_1"/>
+		<press key="KEY_2"     action="screen" target="screen_2"/>
+		<press key="KEY_3"     action="screen" target="screen_3"/>
+		<press key="KEY_4"     action="screen" target="screen_4"/>
+		<press key="KEY_5"     action="screen" target="screen_5"/>
+		<press key="KEY_6"     action="screen" target="screen_6"/>
+		<press key="KEY_7"     action="screen" target="screen_7"/>
+		<press key="KEY_8"     action="screen" target="screen_8"/>
+		<press key="KEY_9"     action="screen" target="screen_9"/>
+		<press key="KEY_0"     action="screen" target="screen_0"/>
 	</press>
 </config>

repos/gems/recipes/raw/window_layouter/window_layouter.config

@@ -2,8 +2,17 @@
 	<report rules="yes"/>
 
 	<rules>
-		<screen name="screen"/>
+		<screen name="screen_1"/>
-		<assign label_prefix="" target="screen" xpos="any" ypos="any"/>
+		<screen name="screen_2"/>
+		<screen name="screen_3"/>
+		<screen name="screen_4"/>
+		<screen name="screen_5"/>
+		<screen name="screen_6"/>
+		<screen name="screen_7"/>
+		<screen name="screen_8"/>
+		<screen name="screen_9"/>
+		<screen name="screen_0"/>
+		<assign label_prefix="" target="screen_1" xpos="any" ypos="any"/>
 	</rules>
 
 	<press key="KEY_SCREEN">
@@ -21,5 +30,15 @@
 			</press>
 		</press>
 		<press key="KEY_ENTER" action="toggle_fullscreen"/>
+		<press key="KEY_1"     action="screen" target="screen_1"/>
+		<press key="KEY_2"     action="screen" target="screen_2"/>
+		<press key="KEY_3"     action="screen" target="screen_3"/>
+		<press key="KEY_4"     action="screen" target="screen_4"/>
+		<press key="KEY_5"     action="screen" target="screen_5"/>
+		<press key="KEY_6"     action="screen" target="screen_6"/>
+		<press key="KEY_7"     action="screen" target="screen_7"/>
+		<press key="KEY_8"     action="screen" target="screen_8"/>
+		<press key="KEY_9"     action="screen" target="screen_9"/>
+		<press key="KEY_0"     action="screen" target="screen_0"/>
 	</press>
 </config>

repos/gems/src/app/window_layouter/action.h

@@ -14,6 +14,8 @@
 #ifndef _ACTION_H_
 #define _ACTION_H_
 
+#include <target.h>
+
 namespace Window_layouter { class Action; }
 
 
@@ -46,11 +48,13 @@ class Window_layouter::Action
 			NEXT_TAB,
 			PREV_TAB,
 			TOOGLE_OVERLAY,
+			SCREEN,
 		};
 
 	private:
 
-		Type _type;
+		Type         _type;
+		Target::Name _target;
 
 		template <Genode::size_t N>
 		static Type _type_by_string(String<N> const &string)
@@ -59,6 +63,7 @@ class Window_layouter::Action
 			if (string == "prev_window")       return PREV_WINDOW;
 			if (string == "raise_window")      return RAISE_WINDOW;
 			if (string == "toggle_fullscreen") return TOGGLE_FULLSCREEN;
+			if (string == "screen")            return SCREEN;
 
 			Genode::warning("cannot convert \"", string, "\" to action type");
 			return NONE;
@@ -66,12 +71,14 @@ class Window_layouter::Action
 
 	public:
 
-		Action(Type type) : _type(type) { }
+		Action(Type type) : _type(type), _target() { }
 
 		template <Genode::size_t N>
-		Action(String<N> const &string) : _type(_type_by_string(string)) { }
+		Action(String<N> const &string, Target::Name const &arg)
+		: _type(_type_by_string(string)), _target(arg) { }
 
 		Type type() const { return _type; }
+		Target::Name target_name() const { return _target; }
 };
 
 #endif /* _ACTION_H_ */

repos/gems/src/app/window_layouter/key_sequence_tracker.h

@@ -179,7 +179,10 @@ class Window_layouter::Key_sequence_tracker
 			typedef String<32> Action;
 			Action action = node.attribute_value("action", Action());
 
-			func(Window_layouter::Action(action));
+			using Name = Window_layouter::Target::Name;
+			Name const target = node.attribute_value("target", Name());
+
+			func(Window_layouter::Action(action, target));
 		}
 
 	public:

repos/gems/src/app/window_layouter/main.cc

@@ -105,9 +105,6 @@ struct Window_layouter::Main : Operations,
 		_assign_list.for_each([&] (Assign &assign) {
 			_target_list.for_each([&] (Target const &target) {
 
-				if (target.name() != assign.target_name())
-					return;
-
 				assign.for_each_member([&] (Assign::Member &member) {
 
 					member.window.floating(assign.floating());
@@ -208,6 +205,11 @@ struct Window_layouter::Main : Operations,
 		_gen_resize_request();
 	}
 
+	void screen(Target::Name const & name) override
+	{
+		_gen_rules_with_frontmost_screen(name);
+	}
+
 	void drag(Window_id id, Window::Element element, Point clicked, Point curr) override
 	{
 		if (_drag_state == Drag_state::SETTLING)
@@ -356,7 +358,13 @@ struct Window_layouter::Main : Operations,
 	void _gen_window_layout();
 	void _gen_resize_request();
 	void _gen_focus();
-	void _gen_rules();
+	void _gen_rules_with_frontmost_screen(Target::Name const &);
+
+	void _gen_rules()
+	{
+		/* keep order of screens unmodified */
+		_gen_rules_with_frontmost_screen(Target::Name());
+	}
 
 	template <typename FN>
 	void _gen_rules_assignments(Xml_generator &, FN const &);
@@ -492,14 +500,14 @@ void Window_layouter::Main::_gen_rules_assignments(Xml_generator &xml, FN const
 }
 
 
-void Window_layouter::Main::_gen_rules()
+void Window_layouter::Main::_gen_rules_with_frontmost_screen(Target::Name const &screen)
 {
 	if (!_rules_reporter.constructed())
 		return;
 
 	_rules_reporter->generate([&] (Xml_generator &xml) {
 
-		_target_list.gen_screens(xml);
+		_target_list.gen_screens(xml, screen);
 
 		/*
 		 * Generate exact <assign> nodes for present windows.

repos/gems/src/app/window_layouter/operations.h

@@ -31,6 +31,7 @@ struct Window_layouter::Operations : Interface
 	virtual void to_front(Window_id) = 0;
 	virtual void drag(Window_id, Window::Element, Point clicked, Point curr) = 0;
 	virtual void finalize_drag(Window_id, Window::Element, Point clicked, Point final) = 0;
+	virtual void screen(Target::Name const &) = 0;
 };
 
 #endif /* _OPERATIONS_H_ */

repos/gems/src/app/window_layouter/target_list.h

@@ -219,13 +219,36 @@ class Window_layouter::Target_list
 
 		/**
 		 * Generate screen-layout definitions for the 'rules' report
+		 *
+		 * If a valid 'screen_name' is specified, move the referred screen in
+		 * front of all others.
 		 */
-		void gen_screens(Xml_generator &xml) const
+		void gen_screens(Xml_generator &xml, Target::Name const &screen_name) const
 		{
 			if (!_rules.constructed())
 				return;
 
 			_rules->xml().for_each_sub_node("screen", [&] (Xml_node screen) {
+				if (screen_name.valid()) {
+					Target::Name const name =
+						screen.attribute_value("name", Target::Name());
+
+					if (screen_name != name)
+						return;
+				}
+				screen.with_raw_node([&] (char const *start, size_t length) {
+					xml.append(start, length); });
+				xml.append("\n");
+			});
+
+			if (!screen_name.valid())
+				return;
+
+			_rules->xml().for_each_sub_node("screen", [&] (Xml_node screen) {
+				Target::Name const name = screen.attribute_value("name", Target::Name());
+				if (screen_name == name)
+					return;
+
 				screen.with_raw_node([&] (char const *start, size_t length) {
 					xml.append(start, length); });
 				xml.append("\n");

repos/gems/src/app/window_layouter/user_state.h

@@ -327,6 +327,10 @@ void Window_layouter::User_state::_handle_event(Input::Event const &e,
 				_operations.focus(_focused_window_id);
 				return;
 
+			case Action::SCREEN:
+				_operations.screen(action.target_name());
+				return;
+
 			default:
 				warning("action ", (int)action.type(), " unhanded");
 			}