From 425d18e866354473ccbe80e43ce86cc8dc0f9c9f Mon Sep 17 00:00:00 2001
From: Christian Prochaska <christian.prochaska@genode-labs.com>
Date: Tue, 28 Nov 2017 18:23:23 +0100
Subject: [PATCH] pointer: strip the last label element when matching labels

Issue #2585
---
 repos/os/run/pointer.run                |  8 ++++----
 repos/os/src/app/pointer/README         | 12 ++++++++----
 repos/os/src/app/pointer/main.cc        |  8 ++++++--
 repos/os/src/app/pointer/rom_registry.h |  9 ++++++++-
 repos/ports/run/vbox_win.inc            |  2 +-
 repos/ports/run/virtualbox.run          |  4 ++--
 6 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/repos/os/run/pointer.run b/repos/os/run/pointer.run
index 517a90057..25fbfa23f 100644
--- a/repos/os/run/pointer.run
+++ b/repos/os/run/pointer.run
@@ -119,7 +119,7 @@ set config {
 			<service name="CPU">    <parent/> </service>
 			<service name="LOG">    <parent/> </service>
 			<service name="Report" label="shape">
-				<child name="pointer" label="test-label-arrow -> testnit"/>
+				<child name="pointer" label="test-label-arrow -> shape"/>
 			</service>
 		</route>
 	</start>
@@ -133,7 +133,7 @@ set config {
 			<service name="CPU">    <parent/> </service>
 			<service name="LOG">    <parent/> </service>
 			<service name="Report" label="shape">
-				<child name="pointer" label="test-label-blade -> testnit"/>
+				<child name="pointer" label="test-label-blade -> shape"/>
 			</service>
 		</route>
 	</start>
@@ -147,7 +147,7 @@ set config {
 			<service name="CPU">    <parent/> </service>
 			<service name="LOG">    <parent/> </service>
 			<service name="Report" label="shape">
-				<child name="pointer" label="test-label-bladex -> testnit"/>
+				<child name="pointer" label="test-label-bladex -> shape"/>
 			</service>
 		</route>
 	</start>
@@ -183,7 +183,7 @@ set config {
 			<service name="ROM" label="smiley.config">
 				<child name="shape-smiley-config"/> </service>
 			<service name="Report" label="shape">
-				<child name="pointer" label="test-label-smiley -> testnit"/>
+				<child name="pointer" label="test-label-smiley -> shape"/>
 			</service>
 			<service name="ROM"> <parent/> </service>
 			<service name="CPU"> <parent/> </service>
diff --git a/repos/os/src/app/pointer/README b/repos/os/src/app/pointer/README
index 34359f41e..ad669e52d 100644
--- a/repos/os/src/app/pointer/README
+++ b/repos/os/src/app/pointer/README
@@ -20,16 +20,20 @@ with report session label rewriting:
 ! 		<service name="CPU">    <parent/> </service>
 ! 		<service name="LOG">    <parent/> </service>
 ! 		<service name="Report" label="shape">
-! 			<child name="pointer" label="test-label-arrow -> testnit"/>
+! 			<child name="pointer" label="test-label-arrow -> shape"/>
 ! 		</service>
 ! 	</route>
 ! </start>
 
 In the example above, which is from 'pointer.run', the 'shape-arrow' component
 reports an arrow shape with the label "shape". By rewriting the label of the
-report, the shape will be drawn for the 'test-label-arrow' component, which
-is reported by Nitpicker with the label 'test-label-arror -> testnit' when
-hovered.
+report, the shape will be drawn for the 'test-label-arrow' component when
+its Nitpicker view is hovered.
+
+Technically, the 'pointer' component compares the hovered label, which is
+'test-label-arrow -> testnit' in this case, with the shape report label after
+stripping the last element of each label, so the remaining label prefix
+'test-label-arrow' is the actual match criteria.
 
 When configured with '<config shapes="yes" verbose="yes"/>', the 'pointer'
 component prints the labels of hovered Nitpicker sessions and received shape
diff --git a/repos/os/src/app/pointer/main.cc b/repos/os/src/app/pointer/main.cc
index 48eb640d6..0131d1b73 100644
--- a/repos/os/src/app/pointer/main.cc
+++ b/repos/os/src/app/pointer/main.cc
@@ -100,7 +100,7 @@ class Pointer::Main : public Rom::Reader
 
 		Report::Root _report_root { _env, _sliced_heap, _rom_registry, _verbose };
 
-		String _hovered_label;
+		Genode::Session_label _hovered_label;
 
 		Genode::Attached_ram_dataspace _texture_pixel_ds { _env.ram(), _env.rm(),
 		                                                   Pointer::MAX_WIDTH  *
@@ -293,7 +293,11 @@ void Pointer::Main::_handle_hover()
 	try {
 		Genode::Xml_node node(_hover_ds->local_addr<char>());
 
-		String hovered_label  = read_string_attribute(node, "label",  String());
+		Genode::Session_label hovered_label { read_string_attribute(node,
+		                                                            "label",
+		                                                            String()) };
+
+		hovered_label = hovered_label.prefix();
 
 		if (_verbose)
 			Genode::log("hovered_label: ", hovered_label);
diff --git a/repos/os/src/app/pointer/rom_registry.h b/repos/os/src/app/pointer/rom_registry.h
index 0ccc9a7b7..41e331dbd 100644
--- a/repos/os/src/app/pointer/rom_registry.h
+++ b/repos/os/src/app/pointer/rom_registry.h
@@ -68,11 +68,18 @@ struct Rom::Registry : Registry_for_reader, Registry_for_writer, Genode::Noncopy
 
 			/* module does not exist yet, create one */
 
+			Genode::Session_label session_label(name);
+
+			if (session_label.last_element() != "shape")
+				Genode::warning("received unexpected report with label '",
+				                session_label, "'");
+
 			/* XXX proper accounting for the used memory is missing */
 			/* XXX if we run out of memory, the server will abort */
 
 			Module * const module = new (&_md_alloc)
-				Module(_ram, _rm, name, _read_write_policy, _read_write_policy);
+				Module(_ram, _rm, session_label.prefix(), _read_write_policy,
+				       _read_write_policy);
 
 			_modules.insert(module);
 			return *module;
diff --git a/repos/ports/run/vbox_win.inc b/repos/ports/run/vbox_win.inc
index 9b7534f06..38d40594d 100644
--- a/repos/ports/run/vbox_win.inc
+++ b/repos/ports/run/vbox_win.inc
@@ -297,7 +297,7 @@ for { set i 1} { $i <= $use_vms } { incr i} {
 			<service name=\"Framebuffer\"> <child name=\"nit_fb${i}\" /> </service>
 			<service name=\"Input\"> <child name=\"nit_fb${i}\" /> </service>
 			<service name=\"Report\" label=\"shape\">
-				<child name=\"pointer\" label=\"nit_fb${i} -> \"/>
+				<child name=\"pointer\" label=\"nit_fb${i} -> shape\"/>
 			</service>"
 	append config_of_app {
 			<service name="Report"><child name="report_rom" /></service>
diff --git a/repos/ports/run/virtualbox.run b/repos/ports/run/virtualbox.run
index 856113820..b35bb4d52 100644
--- a/repos/ports/run/virtualbox.run
+++ b/repos/ports/run/virtualbox.run
@@ -244,7 +244,7 @@ append_if [expr $use_gui] config {
 		</config>
 		<route>
 			<service name="Nic"> <child name="nic_bridge"/> </service>
-			<service name="Report" label="shape"> <child name="pointer" label="nit_fb2 -> "/> </service>
+			<service name="Report" label="shape"> <child name="pointer" label="nit_fb2 -> shape"/> </service>
 			<service name="Report"> <child name="report_rom"/> </service>
 			<service name="Framebuffer"> <child name="nit_fb2" /> </service>
 			<service name="Input"> <child name="nit_fb2" /> </service>
@@ -277,7 +277,7 @@ append_if [expr $use_bridge] config {
 			<service name="Nic"> <child name="nic_bridge"/> </service>}
 
 append_if [expr $use_gui] config {
-			<service name="Report" label="shape"> <child name="pointer" label="nit_fb1 -> "/> </service>
+			<service name="Report" label="shape"> <child name="pointer" label="nit_fb1 -> shape"/> </service>
 			<service name="Report"> <child name="report_rom"/> </service>
 			<service name="Framebuffer"> <child name="nit_fb1" /> </service>
 			<service name="Input"> <child name="nit_fb1" /> </service>}