How Android realizes the Candid Camera feature (phone shutdown still takes photos) tutorial

Android Candid Camera function/Phone shutdown can take photos

The effect is as follows:

In fact, the camera and the record to achieve the same way, are used to WindowManager to draw the principle of small desktop controls. Then I will not say more ...

First, we need a surfaceview:

<?xmlversion= "1.0" encoding= "Utf-8"?> <linearlayout   xmlns:android= "http://schemas.android.com/apk/res/android"    android:id= "@+id/small_window_layout"   android:layout_width= "1dip"   android:layout_height= "1dip"   >   <framelayout     android:id= "@+id/percent"     android:layout_width= "Fill_parent"     android:layout_height= "Fill_parent"     android:gravity= "center"     /> </LinearLayout>

Second, then the operation is to produce this small control:

Publicphotowindowsmallview (Context context) { Super (context); WindowManager = (WindowManager) context.getsystemservice (Context.window_service); Layoutinflater.from (context). Inflate (R.layout.float_window_small,this); View view = Findviewbyid (r.id.small_window_layout); Viewwidth = View.getlayoutparams (). width; Viewheight = View.getlayoutparams (). Height; Surfaceview Percentview = (surfaceview) Findviewbyid (r.id.percent); Percentview.settext (Mywindowmanager.getusedpercentvalue (context)); } /** * The parameter of the small suspension window is passed in to update the position of the small suspension window. * * @param params small suspension window parameters */ Publicvoidsetparams (Windowmanager.layoutparams params) { Mparams = params; }

Third, the desktop control has, the following of course is to use WindowManager added to the desktop:

/** * Create a small suspension window. The initial position is the right middle position of the screen. * * @param context must be the context of the application. */ Publicvoidcreatesmallwindow (Context context) { Mcontext = context; WindowManager WindowManager = Getwindowmanager (context); Intscreenwidth = Windowmanager.getdefaultdisplay (). GetWidth (); Intscreenheight = Windowmanager.getdefaultdisplay (). GetHeight (); if (Smallwindow ==null) { Smallwindow =newphotowindowsmallview (context); if (Smallwindowparams ==null) { Smallwindowparams =newlayoutparams (); Smallwindowparams.type = Layoutparams.type_phone; Smallwindowparams.format = pixelformat.rgba_8888; Smallwindowparams.flags = Layoutparams.flag_not_touch_modal | layoutparams.flag_not_focusable; smallwindowparams.gravity = Gravity.left | Gravity.top; Smallwindowparams.width = Photowindowsmallview.viewwidth; Smallwindowparams.height = Photowindowsmallview.viewheight; Smallwindowparams.x = ScreenWidth; Smallwindowparams.y = SCREENHEIGHT/2; } Smallwindow.setparams (Smallwindowparams); Windowmanager.addview (Smallwindow, smallwindowparams); Msurfaceview = (framelayout) Smallwindow.findviewbyid (r.id.percent); } } /** * Remove the small suspension window from the screen. * * @param context must be the context of the application. */ Publicvoidremovesmallwindow (Context context) { if (Smallwindow!=null) { WindowManager WindowManager = Getwindowmanager (context); Windowmanager.removeview (Smallwindow); Smallwindow =null; } }

Four, this time we need to have the surfaceview, then, how to operate in the background? It's natural to think of service.

To perform the operation of a desktop control in a service:

@Override  publicintonstartcommand (Intent intent,intflags,intstartid) { div>    mywindowmanager =newmyphotowindowmanager ();    createwindow ();    returnsuper.onstartcommand (Intent, flags, Startid);       @Override  publicvoidonde Stroy () {    super.ondestroy ();        privatevoidcreatewindow () {    //The current interface is the desktop and no suspension window is displayed, create a floating window.    mywindowmanager.removesmallwindow (Getapplicationcontext ());    mywindowmanager.createsmallwindow (Getapplicationcontext ());

V. Bind service in activity and take photos

privateclassmyserviceconnimplementsserviceconnection { @Override publicvoidonserviceconnected (componentname name, IBinder service) { TODO auto-generated Method Stub Binder = (photowindowservice.myservicebinder) service; if (Isvedio) { Binder.startcarema (); }else{ Binder.stopcarema (); } } @Override publicvoidonservicedisconnected (componentname name) { TODO auto-generated Method Stub } }

Control the beginning and end of the Mywindowmanager in the service

Publicclassmyservicebinderextendsbinder { Publicvoidstartcarema () { Mywindowmanager.startcarema (); } Publicvoidstopcarema () { Mywindowmanager.stopcarema (); } }

Open or terminate photo operation at Myphotowindowmanager

Publicvoidstartcarema () { ITT = Inittimetotakepic.getinstance (Mcontext); Itt.initview (Msurfaceview); Itt.start (); } Publicvoidstopcarema () { if (ITT!=null) Itt.releasecarema (); }

Viii. related processing of photographing in inittimetotakepic

Packagecom.ddv.www.candidphotodemo; Importandroid.annotation.TargetApi; importandroid.app.Activity; Importandroid.content.Context; Importandroid.content.Intent; Importandroid.content.pm.PackageManager; Importandroid.hardware.Camera; Importandroid.hardware.Camera.AutoFocusCallback; Importandroid.hardware.Camera.PictureCallback; Importandroid.os.Build; Importandroid.os.Handler; Importandroid.os.Message; Importandroid.widget.FrameLayout; Importjava.io.File; Importjava.io.FileOutputStream; /** * Set the timing camera function * * @author <p> * Create a timed photo task * Cameratype Camera * Resolutionstring Resolution * Tvsavelocation Save Address * Etextension Development Name * Camerastart, start shooting time * Cameranumber, shooting times * Camerastop shot Count */ Publicclassinittimetotakepic { Privatestaticinittimetotakepic minstance; Privatestaticintcameratype = 1; Context Mcontext; Staticframelayout Msurfaceviewframe; Privatestaticcamera Mcamera; Privatestaticcamerapreview Mpreview; Privatestaticstring resolutionstring = "1920x1080"; privatestaticstring SaveLocation = Apputils.getsdcardpath (); privatestaticstring extension = "JPG"; Privatestaticstring Camerastart = "1"; Privatestaticstring Cameranumber = "1"; Privatestaticstring camerastop = "10"; Privatestaticintnumber = 0; Privatestaticbooleanclearvoice =false; Privateintent Intent; Privateinittimetotakepic (Context context) { This.mcontext = context; } Publicsynchronizedstaticinittimetotakepic getinstance (Context context) { Minstance =null; Minstance =newinittimetotakepic (context); Returnminstance; } Publicvoidinitview (Framelayout surfaceviewframe) { Msurfaceviewframe = Surfaceviewframe; } /** * Start timed photo and upload function */ Handler Mhandler =newhandler () { @Override Publicvoidhandlemessage (Message msg) { Switch (msg.what) { CASE1: LOGUTILS.V ("Start taking pictures"); Initcarema (); Break CASE2: if (Mcamera ==null) { Releasecarema (); Number = 0; Mhandler.removecallbacksandmessages (NULL); }else{ if (number < integer.valueof (camerastop)) { Mcamera.autofocus (Newautofocuscallback () { @Override Publicvoidonautofocus (booleansuccess, Camera Camera) { Capturing pictures from camera LOGUTILS.V ("autofocus" + success); try{ Mcamera.takepicture (Null,null, mpicture); Mhandler.sendemptymessagedelayed (1, integer.valueof (cameranumber) *1000); }catch (Exception e) { Releasecarema (); Mhandler.removecallbacksandmessages (NULL); } } }); }else{ Releasecarema (); Number = 0; Mhandler.removecallbacksandmessages (NULL); } } Break } } }; Publicvoidstart () { Mhandler.sendemptymessagedelayed (1,1*1000); start the camera after//7s } Privatevoidinitcarema () { LOGUTILS.V ("Initcarema"); if (Mcamera ==null) { LOGUTILS.V ("Camera=null"); Mcamera = Getcamerainstance (); Mpreview =newcamerapreview (Mcontext, Mcamera); Msurfaceviewframe.removeallviews (); Msurfaceviewframe.addview (Mpreview); } LOGUTILS.V (Mcamera ==null?) Mcamera is null ': ' Mcamera is not null '); Mcamera.startpreview (); Mhandler.sendemptymessagedelayed (2, integer.valueof (Camerastart) *1000); Photos after//3s } /** * Detect whether the device exists camera hardware */ Privatebooleancheckcamerahardware (Context context) { if (Context.getpackagemanager (). Hassystemfeature ( Packagemanager.feature_camera)) { Exist Returntrue; }else{ does not exist Returnfalse; } } /** * Open a camera */ @TargetApi (build.version_codes. JELLY_BEAN_MR1) Publicstaticcamera getcamerainstance () { Camera c =null; try{ c = Camera.open (Cameratype); C.setdisplayorientation (90); Camera.parameters mparameters = C.getparameters (); Shutter Sound C.enableshuttersound (Clearvoice); You can use the picture size that you currently support, and then List<size> ms = Mparameters.getsupportedpicturesizes (); Mparameters.setpicturesize (Ms.get (0). Width, ms.get (0). height); Default maximum photo to take maximum clarity string[] xes = Resolutionstring.split ("x"); Logutils.i ("ms.get (0) .width==>" +ms.get (0). width); Logutils.i ("ms.get (0) .height==>" +ms.get (0). height); Logutils.i ("integer.valueof (Xes[0]) ==>" +integer.valueof (xes[0)); Logutils.i ("integer.valueof (xes[1]) ==>" +integer.valueof (xes[1)); Mparameters.setpicturesize (Integer.valueof (Xes[0]), integer.valueof (xes[1));//default maximum photo taking maximum resolution C.setparameters (mparameters); }catch (Exception e) { LOGUTILS.V ("Open camera failure failed"); } RETURNC; } Privatepicturecallback mpicture =newpicturecallback () { @Override Publicvoidonpicturetaken (byte[] data, Camera Camera) { Get the JPEG picture and save it on the SD card String path = SaveLocation; File DIRF =newfile (path); if (!dirf.exists ()) { Dirf.mkdirs (); } File picturefile =newfile (path + "/" + system.currenttimemillis () + ".") + extension);//Extension try{ FileOutputStream Fos =newfileoutputstream (picturefile); Fos.write (data); Fos.close (); LOGUTILS.V ("Save diagram Success"); number++; Intent =newintent (); Intent.setaction ("Camerafragment.start"); Intent.putextra ("number", number); Mcontext.sendbroadcast (Intent); }catch (Exception e) { LOGUTILS.V ("Save picture Failed"); E.printstacktrace (); } Releasecarema (); } }; Publicvoidreleasecarema () { if (Mcamera!=null) { Mcamera.stoppreview (); Mcamera.release (); Mcamera =null; } } }

Original link: http://blog.csdn.net/huangxiaoguo1/article/details/53666047