Notify applications when input devices change.

This change allows the InputManager to keep track of what input
devices are registered with the system and when they change.
It needs to do this so that it can properly clear its cache of
input device properties (especially the key map!) when changes
occur.

Added new API so that applications can register listeners for
input device changes.

Fixed a minor bug in EventHub where it didn't handle EPOLLHUP
properly so it would spam the log about unsupposed epoll events
until inotify noticed that the device was gone and removed it.

Change-Id: I937d8c601f7185d4299038bce6a2934fe4fdd2b3

1 files changed, 54 insertions, 14 deletions

diff --git a/core/java/com/android/internal/widget/PointerLocationView.java b/core/java/com/android/internal/widget/PointerLocationView.java
index 0524c25..1d6af90 100644
--- a/core/java/com/android/internal/widget/PointerLocationView.java
+++ b/core/java/com/android/internal/widget/PointerLocationView.java
@@ -21,6 +21,8 @@ import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.RectF;
 import android.graphics.Paint.FontMetricsInt;
+import android.hardware.input.InputManager;
+import android.hardware.input.InputManager.InputDeviceListener;
 import android.util.Log;
 import android.view.InputDevice;
 import android.view.KeyEvent;
@@ -32,7 +34,7 @@ import android.view.MotionEvent.PointerCoords;
 
 import java.util.ArrayList;
 
-public class PointerLocationView extends View {
+public class PointerLocationView extends View implements InputDeviceListener {
     private static final String TAG = "Pointer";
     
     public static class PointerState {
@@ -82,6 +84,8 @@ public class PointerLocationView extends View {
     private final int ESTIMATE_FUTURE_POINTS = 2;
     private final float ESTIMATE_INTERVAL = 0.02f;
 
+    private final InputManager mIm;
+
     private final ViewConfiguration mVC;
     private final Paint mTextPaint;
     private final Paint mTextBackgroundPaint;
@@ -108,6 +112,8 @@ public class PointerLocationView extends View {
         super(c);
         setFocusableInTouchMode(true);
 
+        mIm = (InputManager)c.getSystemService(Context.INPUT_SERVICE);
+
         mVC = ViewConfiguration.get(c);
         mTextPaint = new Paint();
         mTextPaint.setAntiAlias(true);
@@ -139,18 +145,6 @@ public class PointerLocationView extends View {
         mActivePointerId = 0;
         
         mVelocity = VelocityTracker.obtain();
-        
-        logInputDeviceCapabilities();
-    }
-    
-    private void logInputDeviceCapabilities() {
-        int[] deviceIds = InputDevice.getDeviceIds();
-        for (int i = 0; i < deviceIds.length; i++) {
-            InputDevice device = InputDevice.getDevice(deviceIds[i]);
-            if (device != null) {
-                Log.i(TAG, device.toString());
-            }
-        }
     }
 
     public void setPrintCoords(boolean state) {
@@ -631,7 +625,53 @@ public class PointerLocationView extends View {
         logMotionEvent("Trackball", event);
         return true;
     }
-    
+
+    @Override
+    protected void onAttachedToWindow() {
+        super.onAttachedToWindow();
+
+        mIm.registerInputDeviceListener(this, getHandler());
+        logInputDevices();
+    }
+
+    @Override
+    protected void onDetachedFromWindow() {
+        super.onDetachedFromWindow();
+
+        mIm.unregisterInputDeviceListener(this);
+    }
+
+    @Override
+    public void onInputDeviceAdded(int deviceId) {
+        logInputDeviceState(deviceId, "Device Added");
+    }
+
+    @Override
+    public void onInputDeviceChanged(int deviceId) {
+        logInputDeviceState(deviceId, "Device Changed");
+    }
+
+    @Override
+    public void onInputDeviceRemoved(int deviceId) {
+        logInputDeviceState(deviceId, "Device Removed");
+    }
+
+    private void logInputDevices() {
+        int[] deviceIds = InputDevice.getDeviceIds();
+        for (int i = 0; i < deviceIds.length; i++) {
+            logInputDeviceState(deviceIds[i], "Device Enumerated");
+        }
+    }
+
+    private void logInputDeviceState(int deviceId, String state) {
+        InputDevice device = mIm.getInputDevice(deviceId);
+        if (device != null) {
+            Log.i(TAG, state + ": " + device);
+        } else {
+            Log.i(TAG, state + ": " + deviceId);
+        }
+    }
+
     // HACK
     // A quick and dirty string builder implementation optimized for GC.
     // Using String.format causes the application grind to a halt when