Google Cloud Messaging in Delphi XE5?

Question

I've got an android app that I am thinking about porting to Delphi but I can't see a way to interface with GCM. I am thinking I would possibly have to run the GCMBaseIntentService in java and interface with the delphi shared object?

Alternatively, I am looking for a way to do push notifications in a Delphi Xe5 android app.

Answer 1

You interface Java with Delphi using JNI. The JNI allows you to call in both directions: Java to Delphi or Delphi to Java. So you can extend your Delphi applications with Java classes.

For implementing what you want on Android, doing it in Java will be the easier path to follow, as some available examples do exactly what you have in mind. Just have a look:

• Implementing Push Notification / Google Cloud Messaging for Android
• Android* Client App Using Cloud-Based Alert Service
• Github Gist - GCMIntentService.java

To interface Java JNI and Delphi, you can follow detailed steps, thus allowing a smooth communication between front end and back end of your application.

If you decide to re-use some of the code, remember to give appropriate credit to the authors.

Answer 2

I got GCM working with Delphi and I made a sample component to take care of registering and receiving the GCM messages.

NOTE: This is just a rough test code, I'm not using it in any real application (yet). Please fell free to modify and improve, and if you find bugs, please post back.

Big thanks to Brian Long and his article on Android Services.

Get your GCM sender ID (it's your Project Number from gcm console) and your GCM API id (create a key for server application in GCM console), you'll need them (see the pictures at the bottom).

First of all, you need a modified classes.dex file. You can create this by running the bat file Java dir in the archive, or you can use the one that is already compiled by me (also included in the archive).

You have to ADD the new classes.dex to your Android Deployment and UNCHECK the embarcadero one:

Then, you need to edit your AndroidManifest.template.xml and add right after <%uses-permission%>:

<%uses-permission%> <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" /> 

and right after android:theme="%theme%">

    <receiver         android:name="com.ioan.delphi.GCMReceiver"         android:permission="com.google.android.c2dm.permission.SEND" >         <intent-filter>             <action android:name="com.google.android.c2dm.intent.RECEIVE" />             <category android:name="%package%" />         </intent-filter>     </receiver> 

In your application, declare the gcmnotification unit:

uses   gcmnotification; 

and then in your form declare a variable of the TGCMNotification type and a procedure that you will link to the TGCMNotification.OnReceiveGCMNotification event:

type   TForm8 = class(TForm)     //....   private     { Private declarations }   public     { Public declarations }     gcmn: TGCMNotification;     procedure OnNotification(Sender: TObject; ANotification: TGCMNotificationMessage);   end;   procedure TForm8.FormCreate(Sender: TObject); begin    gcmn := TGCMNotification.Create(self);    gcmn.OnReceiveGCMNotification := OnNotification; end; 

Put in the SenderID your GCM Project Number. To register you APP with GCM, call DoRegister:

procedure TForm8.Button1Click(Sender: TObject); begin   gcmn.SenderID := YOUR_GCM_SENDERID;   if gcmn.DoRegister then     Toast('Successfully registered with GCM.'); end; 

If the DoRegister returns true (successfully registered), gcmn.RegistrationID will have the unique ID you need for sending messages to this device.

And you'll receive messages in event procedure:

procedure TForm8.OnNotification(Sender: TObject;  ANotification: TGCMNotificationMessage); begin   Memo1.Lines.Add('Received: ' + ANotification.Body); end; 

.. and that's ALL you need it for Receiving. Cool, huh? :-)

To send, just use TIdHttp:

procedure TForm8.Button2Click(Sender: TObject); const   sendUrl = 'https://android.googleapis.com/gcm/send'; var   Params: TStringList;   AuthHeader: STring;   idHTTP: TIDHTTP;   SSLIOHandler: TIdSSLIOHandlerSocketOpenSSL; begin   idHTTP := TIDHTTP.Create(nil);   try     SslIOHandler := TIdSSLIOHandlerSocketOpenSSL.Create(nil);     idHTTP.IOHandler := SSLIOHandler;     idHTTP.HTTPOptions := [];     Params := TStringList.Create;     try       Params.Add('registration_id='+ gcmn.RegistrationID);       Params.Values['data.message'] := 'test: ' + FormatDateTime('yy-mm-dd hh:nn:ss', Now);       idHTTP.Request.Host := sendUrl;       AuthHeader := 'Authorization: key=' + YOUR_API_ID;       idHTTP.Request.CustomHeaders.Add(AuthHeader);       IdHTTP.Request.ContentType := 'application/x-www-form-urlencoded;charset=UTF-8';       Memo1.Lines.Add('Send result: ' + idHTTP.Post(sendUrl, Params));     finally       Params.Free;     end;   finally     FreeAndNil(idHTTP);   end; end; 

Next I'm going to post the units you need, just save them in the same place with your application (or just download the whole thing from HERE).

gcmnotification.pas

unit gcmnotification;  interface {$IFDEF ANDROID} uses   System.SysUtils,   System.Classes,   FMX.Helpers.Android,   Androidapi.JNI.PlayServices,   Androidapi.JNI.GraphicsContentViewText,   Androidapi.JNIBridge,   Androidapi.JNI.JavaTypes;  type   TGCMNotificationMessageKind = (nmMESSAGE_TYPE_MESSAGE, nmMESSAGE_TYPE_DELETED, nmMESSAGE_TYPE_SEND_ERROR);    { Discription of notification for Notification Center }   TGCMNotificationMessage = class (TPersistent)   private     FKind: TGCMNotificationMessageKind;     FSender: string;     FWhat: integer;     FBody: string;   protected     procedure AssignTo(Dest: TPersistent); override;   public     { Unique identificator for determenation notification in Notification list }     property Kind: TGCMNotificationMessageKind read FKind write FKind;     property Sender: string read FSender write FSender;     property What: integer read FWhat write FWhat;     property Body: string read FBody write FBody;     constructor Create;   end;    TOnReceiveGCMNotification = procedure (Sender: TObject; ANotification: TGCMNotificationMessage) of object;    TGCMNotification = class(TComponent)   strict private     { Private declarations }     FRegistrationID: string;     FSenderID: string;     FOnReceiveGCMNotification: TOnReceiveGCMNotification;     FReceiver: JBroadcastReceiver;     FAlreadyRegistered: boolean;     function CheckPlayServicesSupport: boolean;   protected     { Protected declarations }   public     { Public declarations }     constructor Create(AOwner: TComponent); override;     destructor Destroy; override;     function DoRegister: boolean;     function GetGCMInstance: JGoogleCloudMessaging;   published     { Published declarations }     property SenderID: string read FSenderID write FSenderID;     property RegistrationID: string read FRegistrationID write FRegistrationID;     property OnReceiveGCMNotification: TOnReceiveGCMNotification read FOnReceiveGCMNotification write FOnReceiveGCMNotification;   end;  {$ENDIF} implementation {$IFDEF ANDROID} uses   uGCMReceiver;   { TGCMNotification } function TGCMNotification.CheckPlayServicesSupport: boolean; var   resultCode: integer; begin   resultCode := TJGooglePlayServicesUtil.JavaClass.isGooglePlayServicesAvailable(SharedActivity);   result := (resultCode = TJConnectionResult.JavaClass.SUCCESS); end;  constructor TGCMNotification.Create(AOwner: TComponent); var   Filter: JIntentFilter; begin   inherited;   Filter := TJIntentFilter.Create;   FReceiver := TJGCMReceiver.Create(Self);   SharedActivity.registerReceiver(FReceiver, Filter);   FAlreadyRegistered := false; end;  destructor TGCMNotification.Destroy; begin   SharedActivity.unregisterReceiver(FReceiver);   FReceiver := nil;   inherited; end;  function TGCMNotification.DoRegister: boolean; var   p: TJavaObjectArray<JString>;   gcm: JGoogleCloudMessaging; begin   if FAlreadyRegistered then     result := true   else   begin     if CheckPlayServicesSupport then     begin       gcm := GetGCMInstance;       p := TJavaObjectArray<JString>.Create(1);       p.Items[0] := StringToJString(FSenderID);       FRegistrationID := JStringToString(gcm.register(p));       FAlreadyRegistered := (FRegistrationID <> '');       result := FAlreadyRegistered;     end     else       result := false;   end; end;  function TGCMNotification.GetGCMInstance: JGoogleCloudMessaging; begin   result := TJGoogleCloudMessaging.JavaClass.getInstance(SharedActivity.getApplicationContext); end;  { TGCMNotificationMessage }  procedure TGCMNotificationMessage.AssignTo(Dest: TPersistent); var   DestNotification: TGCMNotificationMessage; begin   if Dest is TGCMNotificationMessage then   begin     DestNotification := Dest as TGCMNotificationMessage;     DestNotification.Kind := Kind;     DestNotification.What := What;     DestNotification.Sender := Sender;     DestNotification.Body := Body;   end   else     inherited AssignTo(Dest); end;  constructor TGCMNotificationMessage.Create; begin   Body := ''; end; {$ENDIF} end. 

uGCMReceiver.pas

unit uGCMReceiver;  interface {$IFDEF ANDROID} uses   FMX.Types,   Androidapi.JNIBridge,   Androidapi.JNI.GraphicsContentViewText,   gcmnotification;  type   JGCMReceiverClass = interface(JBroadcastReceiverClass)   ['{9D967671-9CD8-483A-98C8-161071CE7B64}']     {Methods}   end;    [JavaSignature('com/ioan/delphi/GCMReceiver')]   JGCMReceiver = interface(JBroadcastReceiver)   ['{4B30D537-5221-4451-893D-7916ED11CE1F}']     {Methods}   end;     TJGCMReceiver = class(TJavaGenericImport<JGCMReceiverClass, JGCMReceiver>)   private     FOwningComponent: TGCMNotification;   protected     constructor _Create(AOwner: TGCMNotification);   public     class function Create(AOwner: TGCMNotification): JGCMReceiver;     procedure OnReceive(Context: JContext; ReceivedIntent: JIntent);   end; {$ENDIF} implementation {$IFDEF ANDROID} uses   System.Classes,   System.SysUtils,   FMX.Helpers.Android,   Androidapi.NativeActivity,   Androidapi.JNI,   Androidapi.JNI.JavaTypes,   Androidapi.JNI.Os,   Androidapi.JNI.PlayServices;  {$REGION 'JNI setup code and callback'} var   GCMReceiver: TJGCMReceiver;   ARNContext: JContext;   ARNReceivedIntent: JIntent;  procedure GCMReceiverOnReceiveThreadSwitcher; begin   Log.d('+gcmReceiverOnReceiveThreadSwitcher');   Log.d('Thread: Main: %.8x, Current: %.8x, Java:%.8d (%2:.8x)',     [MainThreadID, TThread.CurrentThread.ThreadID,     TJThread.JavaClass.CurrentThread.getId]);   GCMReceiver.OnReceive(ARNContext,ARNReceivedIntent );   Log.d('-gcmReceiverOnReceiveThreadSwitcher'); end;  //This is called from the Java activity's onReceiveNative() method procedure GCMReceiverOnReceiveNative(PEnv: PJNIEnv; This: JNIObject; JNIContext, JNIReceivedIntent: JNIObject); cdecl; begin   Log.d('+gcmReceiverOnReceiveNative');   Log.d('Thread: Main: %.8x, Current: %.8x, Java:%.8d (%2:.8x)',     [MainThreadID, TThread.CurrentThread.ThreadID,     TJThread.JavaClass.CurrentThread.getId]);   ARNContext := TJContext.Wrap(JNIContext);   ARNReceivedIntent := TJIntent.Wrap(JNIReceivedIntent);   Log.d('Calling Synchronize');   TThread.Synchronize(nil, GCMReceiverOnReceiveThreadSwitcher);   Log.d('Synchronize is over');   Log.d('-gcmReceiverOnReceiveNative'); end;  procedure RegisterDelphiNativeMethods; var   PEnv: PJNIEnv;   ReceiverClass: JNIClass;   NativeMethod: JNINativeMethod; begin   Log.d('Starting the GCMReceiver JNI stuff');    PEnv := TJNIResolver.GetJNIEnv;    Log.d('Registering interop methods');    NativeMethod.Name := 'gcmReceiverOnReceiveNative';   NativeMethod.Signature := '(Landroid/content/Context;Landroid/content/Intent;)V';   NativeMethod.FnPtr := @GCMReceiverOnReceiveNative;    ReceiverClass := TJNIResolver.GetJavaClassID('com.ioan.delphi.GCMReceiver');    PEnv^.RegisterNatives(PEnv, ReceiverClass, @NativeMethod, 1);    PEnv^.DeleteLocalRef(PEnv, ReceiverClass); end; {$ENDREGION}  { TActivityReceiver }  constructor TJGCMReceiver._Create(AOwner: TGCMNotification); begin   inherited;   FOwningComponent := AOwner;   Log.d('TJGCMReceiver._Create constructor'); end;  class function TJGCMReceiver.Create(AOwner: TGCMNotification): JGCMReceiver; begin   Log.d('TJGCMReceiver.Create class function');   Result := inherited Create;   GCMReceiver := TJGCMReceiver._Create(AOwner); end;  procedure TJGCMReceiver.OnReceive(Context: JContext;  ReceivedIntent: JIntent); var   extras: JBundle;   gcm: JGoogleCloudMessaging;   messageType: JString;   noti: TGCMNotificationMessage; begin   if Assigned(FOwningComponent.OnReceiveGCMNotification) then   begin     noti := TGCMNotificationMessage.Create;     try       Log.d('Received a message!');       extras := ReceivedIntent.getExtras();       gcm := FOwningComponent.GetGCMInstance;       // The getMessageType() intent parameter must be the intent you received       // in your BroadcastReceiver.       messageType := gcm.getMessageType(ReceivedIntent);       if not extras.isEmpty() then       begin           {*            * Filter messages based on message type. Since it is likely that GCM will be            * extended in the future with new message types, just ignore any message types you're            * not interested in, or that you don't recognize.            *}           if TJGoogleCloudMessaging.JavaClass.MESSAGE_TYPE_SEND_ERROR.equals(messageType) then           begin             // It's an error.             noti.Kind := TGCMNotificationMessageKind.nmMESSAGE_TYPE_SEND_ERROR;             FOwningComponent.OnReceiveGCMNotification(Self, noti);           end           else           if TJGoogleCloudMessaging.JavaClass.MESSAGE_TYPE_DELETED.equals(messageType) then           begin             // Deleted messages on the server.             noti.Kind := TGCMNotificationMessageKind.nmMESSAGE_TYPE_DELETED;             FOwningComponent.OnReceiveGCMNotification(Self, noti);           end           else           if TJGoogleCloudMessaging.JavaClass.MESSAGE_TYPE_MESSAGE.equals(messageType) then           begin             // It's a regular GCM message, do some work.             noti.Kind := TGCMNotificationMessageKind.nmMESSAGE_TYPE_MESSAGE;             noti.Sender := JStringToString(extras.getString(StringToJString('sender')));             noti.What := StrToIntDef(JStringToString(extras.getString(StringToJString('what'))), 0);             noti.Body := JStringToString(extras.getString(StringToJString('message')));             FOwningComponent.OnReceiveGCMNotification(Self, noti);           end;       end;     finally       noti.Free;     end;   end; end;  initialization   RegisterDelphiNativeMethods {$ENDIF} end. 

Here is the modified AndroidManifest.template.xml

<?xml version="1.0" encoding="utf-8"?> <!-- BEGIN_INCLUDE(manifest) --> <manifest xmlns:android="http://schemas.android.com/apk/res/android"         package="%package%"         android:versionCode="%versionCode%"         android:versionName="%versionName%">      <!-- This is the platform API where NativeActivity was introduced. -->     <uses-sdk android:minSdkVersion="%minSdkVersion%" /> <%uses-permission%>     <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />      <application android:persistent="%persistent%"          android:restoreAnyVersion="%restoreAnyVersion%"          android:label="%label%"          android:installLocation="%installLocation%"          android:debuggable="%debuggable%"          android:largeHeap="%largeHeap%"         android:icon="%icon%"         android:theme="%theme%">         <receiver             android:name="com.ioan.delphi.GCMReceiver"             android:permission="com.google.android.c2dm.permission.SEND" >             <intent-filter>                 <action android:name="com.google.android.c2dm.intent.RECEIVE" />                 <category android:name="%package%" />             </intent-filter>         </receiver>         <!-- Our activity is a subclass of the built-in NativeActivity framework class.              This will take care of integrating with our NDK code. -->         <activity android:name="com.embarcadero.firemonkey.FMXNativeActivity"                 android:label="%activityLabel%"                 android:configChanges="orientation|keyboardHidden">             <!-- Tell NativeActivity the name of our .so -->             <meta-data android:name="android.app.lib_name"                 android:value="%libNameValue%" />             <intent-filter>                   <action android:name="android.intent.action.MAIN" />                 <category android:name="android.intent.category.LAUNCHER" />             </intent-filter>          </activity>         <receiver android:name="com.embarcadero.firemonkey.notifications.FMXNotificationAlarm" />     </application> </manifest>    <!-- END_INCLUDE(manifest) --> 

And the full source for the test application (it will send and receive a GCM message):

unit testgcmmain;  interface  uses   System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,   FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs,   FMX.StdCtrls, FMX.Layouts, FMX.Memo, IdBaseComponent, IdComponent, IdTCPConnection,   IdTCPClient, IdHTTP, IdIOHandler, IdIOHandlerSocket, IdIOHandlerStack, IdSSL, IdSSLOpenSSL,   gcmnotification;  type   TForm8 = class(TForm)     Button1: TButton;     Memo1: TMemo;     Button2: TButton;     procedure Button1Click(Sender: TObject);     procedure FormCreate(Sender: TObject);     procedure FormDestroy(Sender: TObject);     procedure Button2Click(Sender: TObject);   private     { Private declarations }   public     { Public declarations }     gcmn: TGCMNotification;     procedure OnNotification(Sender: TObject; ANotification: TGCMNotificationMessage);   end;  const   YOUR_GCM_SENDERID = '1234567890';   YOUR_API_ID = 'abc1234567890';  var   Form8: TForm8;  implementation  {$R *.fmx}  procedure TForm8.FormCreate(Sender: TObject); begin    gcmn := TGCMNotification.Create(self);    gcmn.OnReceiveGCMNotification := OnNotification; end;  procedure TForm8.FormDestroy(Sender: TObject); begin   FreeAndNil(gcmn); end;  procedure TForm8.Button1Click(Sender: TObject); begin   // register with the GCM    gcmn.SenderID := YOUR_GCM_SENDERID;   if gcmn.DoRegister then     Memo1.Lines.Add('Successfully registered with GCM.'); end;  procedure TForm8.OnNotification(Sender: TObject;  ANotification: TGCMNotificationMessage); begin   // you just received a message!   if ANotification.Kind = TGCMNotificationMessageKind.nmMESSAGE_TYPE_MESSAGE then     Memo1.Lines.Add('Received: ' + ANotification.Body); end;  // send a message procedure TForm8.Button2Click(Sender: TObject); const   sendUrl = 'https://android.googleapis.com/gcm/send'; var   Params: TStringList;   AuthHeader: STring;   idHTTP: TIDHTTP;   SSLIOHandler: TIdSSLIOHandlerSocketOpenSSL; begin   idHTTP := TIDHTTP.Create(nil);   try     SslIOHandler := TIdSSLIOHandlerSocketOpenSSL.Create(nil);     idHTTP.IOHandler := SSLIOHandler;     idHTTP.HTTPOptions := [];     Params := TStringList.Create;     try       Params.Add('registration_id='+ gcmn.RegistrationID);       // you can send the data with a payload, in my example the server will accept        // data.message = the message you want to send       // data.sender = some sender info       // data.what = an integer  (aka "message type")       // you can put any payload in the data, data.score, data.blabla...        // just make  sure you modify the code in my component to handle it        Params.Values['data.message'] := 'test: ' + FormatDateTime('yy-mm-dd hh:nn:ss', Now);       idHTTP.Request.Host := sendUrl;       AuthHeader := 'Authorization: key=' + YOUR_API_ID;       idHTTP.Request.CustomHeaders.Add(AuthHeader);       IdHTTP.Request.ContentType := 'application/x-www-form-urlencoded;charset=UTF-8';       Memo1.Lines.Add('Send result: ' + idHTTP.Post(sendUrl, Params));     finally       Params.Free;     end;   finally     FreeAndNil(idHTTP);   end; end;  end. 

The GCMReceiver.java that you need to compile and add it to the classes.dex is:

package com.ioan.delphi;  import android.content.BroadcastReceiver; import android.content.Intent; import android.content.Context; import android.util.Log;  public class GCMReceiver extends BroadcastReceiver {     static final String TAG = "GCMReceiver";      public native void gcmReceiverOnReceiveNative(Context context, Intent receivedIntent);      @Override     public void onReceive(Context context, Intent receivedIntent)     {         Log.d(TAG, "onReceive");         gcmReceiverOnReceiveNative(context, receivedIntent);     } } 

And HERE is the zip archive with the source.

If you have trouble making it work, it's probably something not configured right in you GCM console.

Here is what you need from you GCM console:

Project number (you use this when you register with GCM, place it into TGCMNotification.SenderID before calling DoRegister).

API ID you'll use this to send messages to the registered devices.