[banshee] [Mtp] Better device detection

[Gabriel Burt <gburt src gnome org>]

commit 5ea36bbb9274f031a750d5554f8fd6a3afb4bb7e
Author: Alan McGovern <alan mcgovern gmail com>
Date:   Tue Jul 20 19:35:56 2010 +0100

    [Mtp] Better device detection
    
    Use libmtp's ability to detect devices without connecting to them to allow us
    to A) Connect to multiple MTP devices at the same time and B) Remove the need
    to attempt to match (broken) serial numbers to see if we should connect to a
    device or not.

 src/Libraries/Mtp/Mtp/MtpDevice.cs |   78 +++++++++++++++++++++++++++++++-----
 1 files changed, 67 insertions(+), 11 deletions(-)
---
diff --git a/src/Libraries/Mtp/Mtp/MtpDevice.cs b/src/Libraries/Mtp/Mtp/MtpDevice.cs
index 4ad350e..afaa97e 100644
--- a/src/Libraries/Mtp/Mtp/MtpDevice.cs
+++ b/src/Libraries/Mtp/Mtp/MtpDevice.cs
@@ -37,6 +37,15 @@ namespace Mtp
 
     public class MtpDevice : IDisposable
     {
+        internal static IntPtr Offset (IntPtr ptr, int offset)
+        {
+            if (IntPtr.Size == 8) {
+                return (IntPtr) (ptr.ToInt64 () + offset);
+            } else {
+                return (IntPtr) (ptr.ToInt32 () + offset);
+            }
+        }
+
         internal MtpDeviceHandle Handle;
         private MtpDeviceStruct device;
         private string name;
@@ -249,18 +258,32 @@ namespace Mtp
 
             return file_types;
         }
-        
-        public static List<MtpDevice> Detect ()
+
+        public static MtpDevice Connect (RawMtpDevice rawDevice)
         {
-            IntPtr ptr;
-            GetConnectedDevices(out ptr);
-            
-            List<MtpDevice> devices = new List<MtpDevice>();
-            while (ptr != IntPtr.Zero)
+            var raw = rawDevice.RawDevice;
+            IntPtr device = LIBMTP_Open_Raw_Device (ref raw);
+            if (device == IntPtr.Zero)
+                return null;
+            return new MtpDevice (new MtpDeviceHandle (device, true), (MtpDeviceStruct) Marshal.PtrToStructure (device, typeof (MtpDeviceStruct)));
+        }
+
+        public static List<RawMtpDevice> Detect ()
+        {
+            int count = 0;
+            IntPtr ptr = IntPtr.Zero;
+            Console.WriteLine ("Getting raw devices");
+            LIBMTP_Detect_Raw_Devices (ref ptr, ref count);
+            Console.WriteLine ("got raw devices");
+
+            List<RawMtpDevice> devices = new List<RawMtpDevice>();
+            Console.WriteLine ("Count is:{0}", count);
+            Console.WriteLine ("initial is: {0}", ptr);
+            for (int i = 0; i < count; i++)
             {
-                MtpDeviceStruct d = (MtpDeviceStruct)Marshal.PtrToStructure(ptr, typeof(MtpDeviceStruct));
-                devices.Add(new MtpDevice(ptr, true, d));
-                ptr = d.next;
+                IntPtr offset = Offset (ptr, i * Marshal.SizeOf (typeof (RawDeviceStruct)));
+                RawDeviceStruct d = (RawDeviceStruct)Marshal.PtrToStructure (offset, typeof(RawDeviceStruct));
+                devices.Add(new RawMtpDevice (d));
             }
             
             return devices;
@@ -395,7 +418,13 @@ namespace Mtp
         
         [DllImportAttribute("libmtp.dll")]
         private static extern ErrorCode LIBMTP_Get_Connected_Devices (out IntPtr list); //LIBMTP_mtpdevice_t **
-        
+
+        [DllImport ("libmtp.dll")]
+        private static extern ErrorCode LIBMTP_Detect_Raw_Devices (ref IntPtr list, ref int count); //LIBMTP_raw_device_t
+
+        [DllImport ("libmtp.dll")]
+        private static extern IntPtr LIBMTP_Open_Raw_Device (ref RawDeviceStruct rawdevice);
+
         // Deallocates the memory for the device
         [DllImportAttribute("libmtp.dll")]
         private static extern void LIBMTP_Release_Device (IntPtr device);
@@ -533,4 +562,31 @@ namespace Mtp
         public IntPtr cd; // void*
         public IntPtr next; // LIBMTP_mtpdevice_t*
     }
+
+    [StructLayout (LayoutKind.Sequential)]
+    internal struct RawDeviceStruct {
+        public DeviceEntry device_entry; /**< The device entry for this raw device */
+        public uint bus_location; /**< Location of the bus, if device available */
+        public byte devnum; /**< Device number on the bus, if device available */
+    }
+
+    public class RawMtpDevice {
+
+        public uint BusNumber {
+            get { return RawDevice.bus_location; }
+        }
+
+        public int DeviceNumber {
+            get { return RawDevice.devnum; }
+        }
+
+        internal RawDeviceStruct RawDevice {
+            get; private set;
+        }
+
+        internal RawMtpDevice (RawDeviceStruct device)
+        {
+            RawDevice = device;
+        }
+    }
 }