Integrate new minicap along with a moderate rewrite. What's currently missing is recovering from socket death.

lib/units/device/plugins/screen/capture.js

@@ -0,0 +1,81 @@
+var util = require('util')
+
+var syrup = require('stf-syrup')
+var adbkit = require('adbkit')
+
+var logger = require('../../../../util/logger')
+var wire = require('../../../../wire')
+var wireutil = require('../../../../wire/util')
+
+/*jshint maxlen:90*/
+module.exports = syrup.serial()
+  .dependency(require('../../support/adb'))
+  .dependency(require('../../support/router'))
+  .dependency(require('../../support/push'))
+  .dependency(require('../../support/storage'))
+  .dependency(require('../../resources/minicap'))
+  .dependency(require('../display'))
+  .define(function(options, adb, router, push, storage, minicap, display) {
+    var log = logger.createLogger('device:plugins:screen:capture')
+    var plugin = Object.create(null)
+
+    function projectionFormat() {
+      return util.format(
+        '%dx%d@%dx%d/%d'
+      , display.width
+      , display.height
+      , display.width
+      , display.height
+      , display.rotation
+      )
+    }
+
+    plugin.capture = function() {
+      log.info('Capturing screenshot')
+
+      var file = util.format('/data/local/tmp/minicap_%d.jpg', Date.now())
+      return minicap.run(util.format('-P %s -s >%s', projectionFormat(), file))
+        .then(adbkit.util.readAll)
+        .then(function() {
+          return adb.stat(options.serial, file)
+        })
+        .then(function(stats) {
+          if (stats.size === 0) {
+            throw new Error('Empty screenshot; possibly secure screen?')
+          }
+
+          return adb.pull(options.serial, file)
+            .then(function(transfer) {
+              return storage.store('image', transfer, {
+                filename: util.format('%s.jpg', options.serial)
+              , contentType: 'image/jpeg'
+              , knownLength: stats.size
+              })
+            })
+        })
+        .finally(function() {
+          return adb.shell(options.serial, ['rm', '-f', file])
+            .then(adbkit.util.readAll)
+        })
+    }
+
+    router.on(wire.ScreenCaptureMessage, function(channel) {
+      var reply = wireutil.reply(options.serial)
+      plugin.capture()
+        .then(function(file) {
+          push.send([
+            channel
+          , reply.okay('success', file)
+          ])
+        })
+        .catch(function(err) {
+          log.error('Screen capture failed', err.stack)
+          push.send([
+            channel
+          , reply.fail(err.message)
+          ])
+        })
+    })
+
+    return plugin
+  })