devices: return index from function adding / removing devices

This will be used to keep the model representing the device-list
up to date.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

2 files changed, 12 insertions, 5 deletions

diff --git a/core/device.cpp b/core/device.cpp
index 512d17d57..764531414 100644
--- a/core/device.cpp
+++ b/core/device.cpp
@@ -299,17 +299,24 @@ extern "C" void create_device_node(struct device_table *device_table, const char
 }
 
 /* Does not check for duplicates! */
-extern "C" void add_to_device_table(struct device_table *device_table, const struct device *dev)
+extern "C" int add_to_device_table(struct device_table *device_table, const struct device *dev)
 {
 	auto it = std::lower_bound(device_table->devices.begin(), device_table->devices.end(), *dev);
+	int idx = it - device_table->devices.begin();
 	device_table->devices.insert(it, *dev);
+	return idx;
 }
 
-extern "C" void remove_device(struct device_table *device_table, const struct device *dev)
+extern "C" int remove_device(struct device_table *device_table, const struct device *dev)
 {
 	auto it = std::lower_bound(device_table->devices.begin(), device_table->devices.end(), *dev);
-	if (it != device_table->devices.end() && same_device(*it, *dev))
+	if (it != device_table->devices.end() && same_device(*it, *dev)) {
+		int idx = it - device_table->devices.begin();
 		device_table->devices.erase(it);
+		return idx;
+	} else {
+		return -1;
+	}
 }
 
 extern "C" void clear_device_table(struct device_table *device_table)
diff --git a/core/device.h b/core/device.h
index 9c7fff31c..590609c45 100644
--- a/core/device.h
+++ b/core/device.h
@@ -29,8 +29,8 @@ extern bool device_used_by_selected_dive(const struct device *dev);
 
 extern const struct device *get_device_for_dc(const struct device_table *table, const struct divecomputer *dc);
 extern bool device_exists(const struct device_table *table, const struct device *dev);
-extern void add_to_device_table(struct device_table *table, const struct device *dev);
-extern void remove_device(struct device_table *table, const struct device *dev);
+extern int add_to_device_table(struct device_table *table, const struct device *dev); // returns index
+extern int remove_device(struct device_table *table, const struct device *dev); // returns index or -1 if not found
 
 // struct device accessors for C-code. The returned strings are not stable!
 const char *device_get_model(const struct device *dev);