Make sure touch events arrive in correct order.

lib/roles/app.js

@@ -248,7 +248,8 @@ module.exports = function(options) {
         push.send([
           channel
         , wireutil.envelope(new Klass(
-            data.x
+            data.seq
+          , data.x
           , data.y
           ))
         ])

lib/roles/device/plugins/touch.js

@@ -7,6 +7,7 @@ var devutil = require('../../../util/devutil')
 var logger = require('../../../util/logger')
 var lifecycle = require('../../../util/lifecycle')
 var streamutil = require('../../../util/streamutil')
+var SeqQueue = require('../../../wire/seqqueue')
 
 module.exports = syrup.serial()
   .dependency(require('../support/adb'))
@@ -49,24 +50,35 @@ module.exports = syrup.serial()
 
     return openService()
       .then(function(monkey) {
+        var queue = new SeqQueue()
+
         router
           .on(wire.TouchDownMessage, function(channel, message) {
-            monkey.touchDownAsync(message.x, message.y)
-              .catch(function(err) {
-                log.error('touchDown failed', err.stack)
-              })
+            queue.push(message.seq, function() {
+              monkey.touchDownAsync(message.x, message.y)
+                .catch(function(err) {
+                  log.error('touchDown failed', err.stack)
+                })
+            })
           })
           .on(wire.TouchMoveMessage, function(channel, message) {
-            monkey.touchMoveAsync(message.x, message.y)
-              .catch(function(err) {
-                log.error('touchMove failed', err.stack)
-              })
+            queue.push(message.seq, function() {
+              monkey.touchMoveAsync(message.x, message.y)
+                .catch(function(err) {
+                  log.error('touchMove failed', err.stack)
+                })
+            })
           })
           .on(wire.TouchUpMessage, function(channel, message) {
-            monkey.touchUpAsync(message.x, message.y)
-              .catch(function(err) {
-                log.error('touchUp failed', err.stack)
-              })
+            queue.push(message.seq, function() {
+              monkey.touchUpAsync(message.x, message.y)
+                .catch(function(err) {
+                  log.error('touchUp failed', err.stack)
+                })
+            })
+
+            // Reset queue
+            queue = new SeqQueue()
           })
           .on(wire.TapMessage, function(channel, message) {
             monkey.tapAsync(message.x, message.y)

lib/wire/seqqueue.js

@@ -0,0 +1,26 @@
+function SeqQueue() {
+  this.queue = []
+  this.seq = 0
+}
+
+SeqQueue.prototype.push = function(seq, handler) {
+  this.queue[seq] = handler
+  this.maybeDequeue()
+}
+
+SeqQueue.prototype.done = function(seq, handler) {
+  this.queue[seq] = handler
+  this.maybeDequeue()
+}
+
+SeqQueue.prototype.maybeDequeue = function() {
+  var handler
+
+  while ((handler = this.queue[this.seq])) {
+    this.queue[this.seq] = void 0
+    handler()
+    this.seq += 1
+  }
+}
+
+module.exports = SeqQueue

lib/wire/wire.proto

@@ -214,18 +214,21 @@ message PhysicalIdentifyMessage {
 }
 
 message TouchDownMessage {
-  required uint32 x = 1;
-  required uint32 y = 2;
+  required uint32 seq = 1;
+  required uint32 x = 2;
+  required uint32 y = 3;
 }
 
 message TouchMoveMessage {
-  required uint32 x = 1;
-  required uint32 y = 2;
+  required uint32 seq = 1;
+  required uint32 x = 2;
+  required uint32 y = 3;
 }
 
 message TouchUpMessage {
-  required uint32 x = 1;
-  required uint32 y = 2;
+  required uint32 seq = 1;
+  required uint32 x = 2;
+  required uint32 y = 3;
 }
 
 message TapMessage {