From b2d45380967cb2f682c3edfa6288b3d412507d5d Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 4 Sep 2011 22:46:31 +0300
Subject: [PATCH] Use hashes to make button/axis indices in Hub predictable

---
 source/input/hub.cpp | 42 +++++++++++++++++++-----------------------
 source/input/hub.h   |  8 ++++----
 2 files changed, 23 insertions(+), 27 deletions(-)

diff --git a/source/input/hub.cpp b/source/input/hub.cpp
index cbf9f78..4a2d553 100644
--- a/source/input/hub.cpp
+++ b/source/input/hub.cpp
@@ -1,5 +1,7 @@
 #include <stdexcept>
 #include <sigc++/bind.h>
+#include <msp/core/hash.h>
+#include <msp/core/maputils.h>
 #include "hub.h"
 
 using namespace std;
@@ -12,49 +14,43 @@ Hub::Hub()
 	name = "Hub";
 }
 
-unsigned Hub::attach(Device &dev)
+void Hub::attach(Device &dev)
 {
-	unsigned index = devices.size();
-	devices.push_back(&dev);
-	dev.signal_button_press.connect(sigc::bind(sigc::mem_fun(this, &Hub::button_press), index));
-	dev.signal_button_release.connect(sigc::bind(sigc::mem_fun(this, &Hub::button_release), index));
-	dev.signal_axis_motion.connect(sigc::bind(sigc::mem_fun(this, &Hub::axis_motion), index));
-	return index;
+	unsigned tag = hash32(dev.get_name(), 20);
+	while(devices.count(tag))
+		++tag;
+
+	devices[tag] = &dev;
+	dev.signal_button_press.connect(sigc::bind(sigc::mem_fun(this, &Hub::button_press), tag));
+	dev.signal_button_release.connect(sigc::bind(sigc::mem_fun(this, &Hub::button_release), tag));
+	dev.signal_axis_motion.connect(sigc::bind(sigc::mem_fun(this, &Hub::axis_motion), tag));
 }
 
 std::string Hub::get_button_name(unsigned btn) const
 {
-	unsigned dev_index = btn>>12;
-	if(dev_index>=devices.size())
-		throw invalid_argument("Hub::get_button_name");
-
-	const Device &dev = *devices[dev_index];
+	const Device &dev = *get_item(devices, btn>>12);
 	return dev.get_name()+": "+dev.get_button_name(btn&0xFFF);
 }
 
 std::string Hub::get_axis_name(unsigned axis) const
 {
-	unsigned dev_index = axis>>12;
-	if(dev_index>=devices.size())
-		throw invalid_argument("Hub::get_axis_name");
-
-	const Device &dev = *devices[dev_index];
+	const Device &dev = *get_item(devices, axis>>12);
 	return dev.get_name()+": "+dev.get_axis_name(axis&0xFFF);
 }
 
-void Hub::button_press(unsigned btn, unsigned index)
+void Hub::button_press(unsigned btn, unsigned tag)
 {
-	set_button_state((index<<12) | (btn&0xFFF), true, true);
+	set_button_state((tag<<12) | (btn&0xFFF), true, true);
 }
 
-void Hub::button_release(unsigned btn, unsigned index)
+void Hub::button_release(unsigned btn, unsigned tag)
 {
-	set_button_state((index<<12) | (btn&0xFFF), false, true);
+	set_button_state((tag<<12) | (btn&0xFFF), false, true);
 }
 
-void Hub::axis_motion(unsigned axis, float value, float, unsigned index)
+void Hub::axis_motion(unsigned axis, float value, float, unsigned tag)
 {
-	set_axis_value((index<<12) | (axis&0xFFF), value, true);
+	set_axis_value((tag<<12) | (axis&0xFFF), value, true);
 }
 
 } // namespace Input
diff --git a/source/input/hub.h b/source/input/hub.h
index 8ec2fad..8d41bce 100644
--- a/source/input/hub.h
+++ b/source/input/hub.h
@@ -1,6 +1,7 @@
 #ifndef MSP_INPUT_INPUTHUB_H_
 #define MSP_INPUT_INPUTHUB_H_
 
+#include <map>
 #include "device.h"
 
 namespace Msp {
@@ -13,14 +14,13 @@ aggregate of them.  Button and axis numbers are mapped to unique values.
 class Hub: public Device
 {
 protected:
-	std::vector<Device *> devices;
+	std::map<unsigned, Device *> devices;
 
 public:
 	Hub();
 
-	/** Attaches an input device to the hub.  Returns the index of the device
-	within the hub. */
-	unsigned attach(Device &dev);
+	/// Attaches an input device to the hub.
+	void attach(Device &dev);
 
 	virtual std::string get_button_name(unsigned) const;
 	virtual std::string get_axis_name(unsigned) const;
-- 
2.45.2