nit_focus component that implements click-to-focus

repos/os/recipes/src/nit_focus/content.mk

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+SRC_DIR = src/app/nit_focus
+include $(GENODE_DIR)/repos/base/recipes/src/content.inc

repos/os/recipes/src/nit_focus/hash

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+2017-11-19 8a4dfb6ff5019ef00c5428040243f05e936eb655

repos/os/recipes/src/nit_focus/used_apis

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+base
+os
+report_session

repos/os/src/app/nit_focus/README

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+The nit_focus component implements the input-focus policy for the nitpicker
+GUI server. It consumes nitpicker's 'clicked' report and, in turn, produces a
+'focus' report to be consumed by nitpicker.
+
+Focus changes are subjected to a configurable policy, which is selected via
+Genode's regular policy-selection mechanism based on the label of the clicked
+nitpicker client. The client is focused only if the policy has the attribute
+'focus' set to "yes".

repos/os/src/app/nit_focus/main.cc

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+/*
+ * \brief  Input-focus policy for the nitpicker GUI server
+ * \author Norman Feske
+ * \date   2017-11-19
+ */
+
+/*
+ * Copyright (C) 2017 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU Affero General Public License version 3.
+ */
+
+/* Genode includes */
+#include <base/component.h>
+#include <base/attached_rom_dataspace.h>
+#include <os/session_policy.h>
+#include <os/reporter.h>
+
+namespace Nit_focus {
+	using namespace Genode;
+	struct Main;
+}
+
+
+struct Nit_focus::Main
+{
+	Env &_env;
+
+	Attached_rom_dataspace _config_rom  { _env, "config" };
+	Attached_rom_dataspace _clicked_rom { _env, "clicked" };
+
+	Reporter _focus_reporter { _env, "focus" };
+
+	void _handle_update()
+	{
+		_clicked_rom.update();
+		_config_rom.update();
+
+		typedef String<160> Label;
+		Label const label = _clicked_rom.xml().attribute_value("label", Label());
+
+		try {
+			Session_policy const policy(label, _config_rom.xml());
+			if (policy.attribute_value("focus", true)) {
+				Reporter::Xml_generator xml(_focus_reporter, [&] () {
+					xml.attribute("label", label); });
+			}
+		}
+		catch (...) { /* don't change focus on policy mismatch */ }
+	}
+
+	Signal_handler<Main> _update_handler {
+		_env.ep(), *this, &Main::_handle_update };
+
+	Main(Env &env) : _env(env)
+	{
+		_clicked_rom.sigh(_update_handler);
+		_focus_reporter.enabled(true);
+		_handle_update();
+	}
+};
+
+
+void Component::construct(Genode::Env &env) { static Nit_focus::Main main(env); }

repos/os/src/app/nit_focus/target.mk

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+TARGET = nit_focus
+SRC_CC = main.cc
+LIBS   = base