Stability fixes

Fixes various crashes, by (a) disabling the stats gathering thread and
(b) only trying to open a USB device if it identifies itself as a MIDI
keyboard. Disabling stats gathering should improve responsiveness and
improve battery consumption as well.

The crash in the stats gathering thread was a race on destruction, where
the audio thread set the stats_ringbuffer to NULL, but the Java thread
continued to try to read from it. This could be made more robust.

android/AndroidManifest.xml

@@ -2,8 +2,8 @@
 <manifest
     xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.levien.synthesizer"
-    android:versionCode="3"
-    android:versionName="0.91">
+    android:versionCode="4"
+    android:versionName="0.92">
   <uses-sdk android:minSdkVersion="9" 
       android:targetSdkVersion="17"
       /> <!-- 9 = Gingerbread -->

android/src/com/levien/synthesizer/android/ui/PianoActivity2.java

@@ -35,7 +35,6 @@ import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.util.Log;
-import android.view.Menu;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.WindowManager;
@@ -123,6 +122,9 @@ public class PianoActivity2 extends Activity {
       tryConnectUsb();
     }
 
+    final boolean doStats = false;
+
+    if (doStats) {
       jitterStats_ = new JitterStats();
       jitterStats_.setNominalCb(params.bufferSize / (double)params.sampleRate);
       statusHandler_ = new Handler();
@@ -140,6 +142,7 @@ public class PianoActivity2 extends Activity {
         }
       };
       statusRunnable_.run();
+    }
 
     // Create burst of load -- test code to be removed. Ultimately we'll
     // be able to get this kind of functionality by hooking up the sequencer
@@ -229,21 +232,31 @@ public class PianoActivity2 extends Activity {
     UsbManager usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
     HashMap<String, UsbDevice> deviceList = usbManager.getDeviceList();
     TextView label = (TextView)findViewById(R.id.status);
-    if (!deviceList.isEmpty()) {
-      UsbDevice device = deviceList.values().iterator().next();
+    Log.i("synth", "USB device count=" + deviceList.size());
+    for (UsbDevice device : deviceList.values()) {
       //label.setText("ic:" + device.getInterfaceCount());
+      Log.i("synth", "usb name=" + device.toString() + " #if=" + device.getInterfaceCount());
+      if (device.getInterfaceCount() < 2) {
+        continue;
+      }
       UsbInterface usbIf = device.getInterface(1);
+      if (usbIf.getInterfaceClass() != 1 || usbIf.getInterfaceSubclass() != 3) {
+        continue;
+      }
       UsbDeviceConnection connection = usbManager.openDevice(device);
       if (connection != null) {
         connection.claimInterface(usbIf, true);
         UsbEndpoint endpoint = getInputEndpoint(usbIf);
         //label.setText(endpoint.toString());
+        Log.i("synth", "MIDI keyboard detected, starting USB thread");
         startUsbThread(connection, endpoint);
       } else {
         if (label != null) {
+          Log.i("synth", "error opening USB MIDI device");
           label.setText("error opening device");
         }
       }
+      break;
     }
   }
 

android/src/com/levien/synthesizer/android/widgets/piano/PianoView.java

@@ -24,6 +24,7 @@ import android.content.res.TypedArray;
 import android.graphics.Canvas;
 import android.graphics.Rect;
 import android.util.AttributeSet;
+import android.util.Log;
 import android.view.MotionEvent;
 import android.view.View;
 
@@ -230,6 +231,7 @@ public class PianoView extends View {
   public boolean onTouchEvent(MotionEvent event) {
     int action = event.getAction();
     int actionCode = action & MotionEvent.ACTION_MASK;
+    //Log.i("synth", "actionCode = " + actionCode);
     boolean redraw = false;
     if (actionCode == MotionEvent.ACTION_DOWN) {
       int pointerId = event.getPointerId(0);
@@ -238,6 +240,8 @@ public class PianoView extends View {
         int y = (int)event.getY();
         float pressure = event.getPressure();
         redraw |= onTouchDown(pointerId, x, y, pressure);
+      } else {
+        Log.i("synth", "Discarded ACTION_DOWN pointerId=" + pointerId);
       }
     } else if (actionCode == MotionEvent.ACTION_POINTER_DOWN) {
       int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK)
@@ -248,6 +252,8 @@ public class PianoView extends View {
         int y = (int)event.getY(pointerIndex);
         float pressure = event.getPressure(pointerIndex);
         redraw |= onTouchDown(pointerId, x, y, pressure);
+      } else {
+        Log.i("synth", "Discarded ACTION_POINTER_DOWN pointerId=" + pointerId);
       }
     } else if (actionCode == MotionEvent.ACTION_MOVE) {
       for (int pointerIndex = 0; pointerIndex < event.getPointerCount(); ++pointerIndex) {
@@ -277,7 +283,11 @@ public class PianoView extends View {
           }
         }
         if (!found) {
-          redraw |= onTouchUp(pointerId);
+          boolean thisRedraw = onTouchUp(pointerId);
+          if (thisRedraw) {
+            Log.i("synth", "ACTION_UP cleaned up pointerId=" + pointerId);
+          }
+          redraw |= thisRedraw;
         }
       }
     } else if (actionCode == MotionEvent.ACTION_POINTER_UP) {
@@ -296,7 +306,11 @@ public class PianoView extends View {
           }
         }
         if (!found) {
-          redraw |= onTouchUp(pointerId);
+          boolean thisRedraw = onTouchUp(pointerId);
+          if (thisRedraw) {
+            Log.i("synth", "ACTION_POINTER_UP cleaned up pointerId=" + pointerId);
+          }
+          redraw |= thisRedraw;
         }
       }
     } else {