ios - How to refresh the screen when I draw a line for realtime data -


in current swift program, 1 function display real time acceleration data on screen line. used class drawrect. result, acceleration figure can drawn, not real time everytime refresh (turn down app , reopen). know should use method such setneedsdisplay() redraw it. no use. maybe wrote in wrong way. here code:

import uikit  import coremotion  class draw: uiview, uiaccelerometerdelegate {       var motionmanager = cmmotionmanager()       override func drawrect(rect: cgrect) {           motionmanager.devicemotionupdateinterval = 0.1          var acc_x: double = 0.0          var temp_x: double = 0.0          var i: cgfloat = 0          var accline_x = uigraphicsgetcurrentcontext()          if(motionmanager.devicemotionavailable) {              var queue = nsoperationqueue.mainqueue()              motionmanager.startdevicemotionupdatestoqueue(queue, withhandler: {                 (devicemotion: cmdevicemotion!, error: nserror!) in                  temp_x = acc_x                  acc_x = devicemotion.useracceleration.x                  cgcontextsetlinewidth(accline_x, 2)                 cgcontextsetstrokecolorwithcolor(accline_x, uicolor.redcolor().cgcolor)                 cgcontextmovetopoint(accline_x, + 10, self.screenheight * 436 + cgfloat(temp_x * 100))                 cgcontextaddlinetopoint(accline_x, + 13, self.screenheight * 436 + cgfloat(acc_x * 100))                 cgcontextstrokepath(accline_x)                  = (i + 3) % 320             })          }     }    }

ok, here's rewritten code... important point here have isolate drawing code updates:

var acc_x : double = 0.0 var temp_x : double = 0.0 var i: cgfloat = 0  func startmonitoring() {      motionmanager.devicemotionupdateinterval = 0.1     if(motionmanager.devicemotionavailable) {          var queue = nsoperationqueue.mainqueue()          motionmanager.startdevicemotionupdatestoqueue(queue, withhandler: {             (devicemotion: cmdevicemotion!, error: nserror!) in              temp_x = acc_x             acc_x = devicemotion.useracceleration.x              // update things here             self.setneedsdisplay()         })      }  }  override func drawrect(rect: cgrect) {      var accline_x = uigraphicsgetcurrentcontext()      cgcontextsetlinewidth(accline_x, 2)     cgcontextsetstrokecolorwithcolor(accline_x, uicolor.redcolor().cgcolor)     cgcontextmovetopoint(accline_x, + 10, self.screenheight * 436 + cgfloat(temp_x * 100))     cgcontextaddlinetopoint(accline_x, + 13, self.screenheight * 436 + cgfloat(acc_x * 100))     cgcontextstrokepath(accline_x)      = (i + 3) % 320 }

please note did make sure call function "startmonitoring" should updates accelerometer, save couple of relevant variables (that using) , call setneedsdisplay. , @ point, drawrect called , use variables have saved correctly draw.


Comments

Post a Comment

Popular posts from this blog

node.js - Using Node without global install -

i'm working on few node & electron (atom shell) projects , i'm curious how them work without user having install node globally. i've seen few applications including node directory in project contains node.exe binary. how go setting node project use binary? edit: thought should add, i've searched everywhere answer this, unrelated results.
Read more

How to access a php class file from PHPFox framework into javascript code written in simple HTML file? -

i've website developed using phpfox v3.0.7 . now i'm trying implement 'sse(server sent events)' 1 of php files. reference i'm giving below necessary code part of file. file titled process.class.php , present @ location /var/www/module/notification/include/service/process.class.php present on server having ip http://34.124.40.142/ . <?php /** * [phpfox_header] */ header('content-type: text/event-stream'); header('cache-control: no-cache'); defined('phpfox') or exit('no dice!'); /** * * * @copyright [phpfox_copyright] * @author raymond benc * @package phpfox_service * @version $id: service.class.php 67 2009-01-20 11:32:45z raymond_benc $ */ class notification_service_process extends phpfox_service { /** * class constructor */ public function __construct() { $this->_stable = phpfox::gett('notification'); } public function add($...
Read more

java - Null response to php query in android, even though php works properly -

Image
table i'm trying retrieve above data using 2 php files below. want pass email parameter , return bets user = email. work fine when tested advanced rest client, problem not php. however, when try through android 2 java classes below, null pointer exception (logcat below) , json object returned null. i'm not sure error is, think i'm not passing parameter php , that's why it's producing null response. logcat 05-31 15:10:50.227 26074-26074/com.example.albert.betterapp e/androidruntime﹕ fatal exception: main process: com.example.albert.betterapp, pid: 26074 java.lang.runtimeexception: unable start activity componentinfo{com.example.albert.betterapp/com.example.albert.betterapp.displayallbets}: java.lang.nullpointerexception @ android.app.activitythread.performlaunchactivity(activitythread.java:2292) @ android.app.activitythread.handlelaunchactivity(activitythread.java:2350) @ android.app.activitythread.acce...
Read more