From fdc860613546a4c0f5194e0f5508d0d23c76b244 Mon Sep 17 00:00:00 2001
From: sekelsenmat <sekelsenmat@lazarus-ide.org>
Date: Thu, 29 Dec 2011 00:24:15 +0000
Subject: [PATCH] Adds Accelerometer stopping in Android (and to the general
 structure) and starts implementing SMS sending

git-svn-id: trunk@34486 -
---
 .../androidlcl/android/AndroidManifest.xml    |  1 +
 .../src/com/pascal/lcltest/LCLActivity.java   | 20 +++++
 examples/androidlcl/secondform.lfm            | 77 +++++++++++++++----
 examples/androidlcl/secondform.pas            | 62 ++++++++++++---
 lcl/include/intfbaselcl.inc                   |  5 ++
 lcl/include/lclintf.inc                       |  5 ++
 lcl/include/lclintfh.inc                      |  1 +
 lcl/interfaces/customdrawn/customdrawnint.pas |  6 ++
 .../customdrawnlclintf_android.inc            | 23 +++++-
 .../customdrawn/customdrawnlclintf_cocoa.inc  |  5 ++
 .../customdrawn/customdrawnlclintf_win.inc    |  5 ++
 .../customdrawn/customdrawnlclintf_x11.inc    |  5 ++
 .../customdrawn/customdrawnlclintfh.inc       |  1 +
 .../customdrawn/customdrawnobject_android.inc |  6 ++
 lcl/lazdeviceapis.pas                         | 20 +++--
 15 files changed, 210 insertions(+), 32 deletions(-)

diff --git a/examples/androidlcl/android/AndroidManifest.xml b/examples/androidlcl/android/AndroidManifest.xml
index 636ee0160d..ac54a82c73 100644
--- a/examples/androidlcl/android/AndroidManifest.xml
+++ b/examples/androidlcl/android/AndroidManifest.xml
@@ -4,6 +4,7 @@
       android:versionCode="1"
       android:versionName="1.0">
     <uses-permission android:name="android.permission.VIBRATE" />
+    <uses-permission android:name="android.permission.SEND_SMS" />
     <supports-screens android:smallScreens="true" android:normalScreens="true" android:largeScreens="true" android:anyDensity="true" />
     <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="8" />
     <application android:label="@string/app_name" 
diff --git a/examples/androidlcl/android/src/com/pascal/lcltest/LCLActivity.java b/examples/androidlcl/android/src/com/pascal/lcltest/LCLActivity.java
index 22fd67fb97..71a6e00085 100755
--- a/examples/androidlcl/android/src/com/pascal/lcltest/LCLActivity.java
+++ b/examples/androidlcl/android/src/com/pascal/lcltest/LCLActivity.java
@@ -13,6 +13,7 @@ import android.hardware.Sensor;
 import android.hardware.SensorEvent;
 import android.hardware.SensorEventListener;
 import android.hardware.SensorManager;
+import android.telephony.SmsManager;
 
 public class LCLActivity extends Activity implements SensorEventListener
 {
@@ -342,6 +343,22 @@ public class LCLActivity extends Activity implements SensorEventListener
     localSensorManager.unregisterListener(this);
   };
 
+  // input: String lcldestination, String lcltext (Body)
+  public void LCLDoSendMessage()
+  {
+    if (lclkind == 1)
+    {
+      PendingIntent pi = PendingIntent.getActivity(this, 0,
+        new Intent(this, Object.class), 0);
+      SmsManager sms = SmsManager.getDefault();
+      sms.sendTextMessage(lcldestination, null, lcltext, pi, null);
+    }
+  };
+
+  public void LCLDoRequestPositionInfo()
+  {
+  }
+
   // -------------------------------------------
   // Fields exported to the Pascal side for easier data communication
   // -------------------------------------------
@@ -377,6 +394,9 @@ public class LCLActivity extends Activity implements SensorEventListener
   public int lclformheight;
   public int lclscreenwidth;
   public int lclscreenheight;
+  // for LazDeviceAPIs
+  public String lcldestination;
+  public int lclkind;
 
   static
   {
diff --git a/examples/androidlcl/secondform.lfm b/examples/androidlcl/secondform.lfm
index 8098ffce86..da50c1c391 100644
--- a/examples/androidlcl/secondform.lfm
+++ b/examples/androidlcl/secondform.lfm
@@ -16,20 +16,20 @@ object Form2: TForm2
     OnClick = Button1Click
     TabOrder = 0
   end
-  object Edit1: TEdit
-    Left = 12
+  object textDest: TEdit
+    Left = 8
     Height = 25
-    Top = 32
+    Top = 56
     Width = 80
-    OnExit = Edit1Exit
-    OnKeyDown = Edit1KeyDown
-    OnKeyUp = Edit1KeyUp
-    OnUTF8KeyPress = Edit1UTF8KeyPress
+    OnExit = textDestExit
+    OnKeyDown = textDestKeyDown
+    OnKeyUp = textDestKeyUp
+    OnUTF8KeyPress = textDestUTF8KeyPress
     TabOrder = 1
-    Text = 'Edit1'
+    Text = 'textDest'
   end
   object Image1: TImage
-    Left = 96
+    Left = 102
     Height = 138
     Top = 32
     Width = 210
@@ -1783,13 +1783,13 @@ object Form2: TForm2
       2E202E202E202E202E202E20227D3B0A
     }
   end
-  object Button2: TButton
+  object btnStartAccel: TButton
     Left = 8
     Height = 25
     Top = 194
-    Width = 304
-    Caption = 'Read Accelerometer'
-    OnClick = Button2Click
+    Width = 112
+    Caption = 'Read Accel.'
+    OnClick = btnStartAccelClick
     TabOrder = 2
   end
   object labelSensorData: TLabel
@@ -1800,4 +1800,55 @@ object Form2: TForm2
     Caption = 'Sensor Data'
     ParentColor = False
   end
+  object btnStopAccel: TButton
+    Left = 128
+    Height = 25
+    Top = 194
+    Width = 91
+    Caption = 'Stop Accel.'
+    OnClick = btnStopAccelClick
+    TabOrder = 3
+  end
+  object btnGetPos: TButton
+    Left = 224
+    Height = 25
+    Top = 194
+    Width = 88
+    Caption = 'Get Position'
+    OnClick = btnGetPosClick
+    TabOrder = 4
+  end
+  object Label1: TLabel
+    Left = 10
+    Height = 18
+    Top = 88
+    Width = 63
+    Caption = 'SMS Text:'
+    ParentColor = False
+  end
+  object textBody: TEdit
+    Left = 8
+    Height = 25
+    Top = 104
+    Width = 80
+    TabOrder = 5
+    Text = 'textBody'
+  end
+  object btnSendSMS: TButton
+    Left = 8
+    Height = 25
+    Top = 136
+    Width = 75
+    Caption = 'Send SMS'
+    OnClick = btnSendSMSClick
+    TabOrder = 6
+  end
+  object Label2: TLabel
+    Left = 8
+    Height = 18
+    Top = 32
+    Width = 53
+    Caption = 'Number'
+    ParentColor = False
+  end
 end
diff --git a/examples/androidlcl/secondform.pas b/examples/androidlcl/secondform.pas
index a20f5920f1..db71597996 100644
--- a/examples/androidlcl/secondform.pas
+++ b/examples/androidlcl/secondform.pas
@@ -14,21 +14,31 @@ type
 
   TForm2 = class(TForm)
     Button1: TButton;
-    Button2: TButton;
-    Edit1: TEdit;
+    btnStartAccel: TButton;
+    btnStopAccel: TButton;
+    btnGetPos: TButton;
+    btnSendSMS: TButton;
+    textDest: TEdit;
+    textBody: TEdit;
     Image1: TImage;
+    Label1: TLabel;
+    Label2: TLabel;
     labelSensorData: TLabel;
+    procedure btnSendSMSClick(Sender: TObject);
     procedure Button1Click(Sender: TObject);
-    procedure Button2Click(Sender: TObject);
-    procedure Edit1Exit(Sender: TObject);
-    procedure Edit1KeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
-    procedure Edit1KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
-    procedure Edit1UTF8KeyPress(Sender: TObject; var UTF8Key: TUTF8Char);
+    procedure btnStartAccelClick(Sender: TObject);
+    procedure btnStopAccelClick(Sender: TObject);
+    procedure btnGetPosClick(Sender: TObject);
+    procedure textDestExit(Sender: TObject);
+    procedure textDestKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
+    procedure textDestKeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
+    procedure textDestUTF8KeyPress(Sender: TObject; var UTF8Key: TUTF8Char);
   private
     { private declarations }
   public
     { public declarations }
     procedure HandleAccelerometerChanged(Sender: TObject);
+    procedure HandlePositionRetrieved(Sender: TObject);
   end; 
 
 var
@@ -45,29 +55,50 @@ begin
   Hide;
 end;
 
-procedure TForm2.Button2Click(Sender: TObject);
+procedure TForm2.btnSendSMSClick(Sender: TObject);
+var
+  lMessage: TLazDeviceMessage;
+begin
+  lMessage := Messaging.CreateMessage();
+  lMessage.Body := textBody.Text;
+  lMessage.destinationAddress.Text := textDest.Text;
+  Messaging.SendMessage(lMessage);
+end;
+
+procedure TForm2.btnStartAccelClick(Sender: TObject);
 begin
   Accelerometer.OnSensorChanged := @HandleAccelerometerChanged;
   Accelerometer.StartReadingAccelerometerData();
 end;
 
-procedure TForm2.Edit1Exit(Sender: TObject);
+procedure TForm2.btnStopAccelClick(Sender: TObject);
+begin
+  Accelerometer.StopReadingAccelerometerData();
+end;
+
+procedure TForm2.btnGetPosClick(Sender: TObject);
+begin
+  PositionInfo.RequestPositionInfo([]);
+  PositionInfo.OnPositionRetrieved := @HandlePositionRetrieved;
+end;
+
+procedure TForm2.textDestExit(Sender: TObject);
 begin
   DebugLn('[Edit1Exit]');
 end;
 
-procedure TForm2.Edit1KeyDown(Sender: TObject; var Key: Word; Shift: TShiftState
+procedure TForm2.textDestKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState
   );
 begin
   DebugLn('[Edit1KeyDown] Key=' + DbgsVKCode(Key));
 end;
 
-procedure TForm2.Edit1KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
+procedure TForm2.textDestKeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
 begin
   DebugLn('[Edit1KeyUp] Key=' + DbgsVKCode(Key));
 end;
 
-procedure TForm2.Edit1UTF8KeyPress(Sender: TObject; var UTF8Key: TUTF8Char);
+procedure TForm2.textDestUTF8KeyPress(Sender: TObject; var UTF8Key: TUTF8Char);
 begin
   DebugLn('[Edit1UTF8KeyPress] Char=' + UTF8Key);
 end;
@@ -79,5 +110,12 @@ begin
   DebugLn(labelSensorData.Caption);
 end;
 
+procedure TForm2.HandlePositionRetrieved(Sender: TObject);
+begin
+  labelSensorData.Caption := Format('latitude=%f longitude=%f',
+    [PositionInfo.latitude, PositionInfo.longitude]);
+  DebugLn(labelSensorData.Caption);
+end;
+
 end.
 
diff --git a/lcl/include/intfbaselcl.inc b/lcl/include/intfbaselcl.inc
index 544c2ef1d2..b1f0b2f705 100644
--- a/lcl/include/intfbaselcl.inc
+++ b/lcl/include/intfbaselcl.inc
@@ -532,6 +532,11 @@ begin
 
 end;
 
+procedure TWidgetSet.LazDeviceAPIs_StopReadingAccelerometerData();
+begin
+
+end;
+
 function TWidgetSet.MoveWindowOrgEx(dc: hdc; dX,dY: Integer): boolean;
 var
   P: TPoint;
diff --git a/lcl/include/lclintf.inc b/lcl/include/lclintf.inc
index 464b8e758f..ed0cda1ae8 100644
--- a/lcl/include/lclintf.inc
+++ b/lcl/include/lclintf.inc
@@ -365,6 +365,11 @@ begin
   Widgetset.LazDeviceAPIs_StartReadingAccelerometerData();
 end;
 
+procedure LazDeviceAPIs_StopReadingAccelerometerData();
+begin
+  Widgetset.LazDeviceAPIs_StopReadingAccelerometerData();
+end;
+
 function MoveWindowOrgEx(dc: hdc; dX,dY: Integer): boolean;
 begin
   Result := WidgetSet.MoveWindowOrgEx(DC, dX, dY);
diff --git a/lcl/include/lclintfh.inc b/lcl/include/lclintfh.inc
index cbaf2c55eb..bd3369eb24 100644
--- a/lcl/include/lclintfh.inc
+++ b/lcl/include/lclintfh.inc
@@ -96,6 +96,7 @@ function IsDesignerDC(WindowHandle: HWND; DC: HDC): Boolean; {$IFDEF IF_BASE_MEM
 procedure LazDeviceAPIs_RequestPositionInfo(AMethod: TLazPositionMethod); {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
 procedure LazDeviceAPIs_SendMessage(AMsg: TLazDeviceMessage); {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
 procedure LazDeviceAPIs_StartReadingAccelerometerData(); {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
+procedure LazDeviceAPIs_StopReadingAccelerometerData(); {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
 
 function MoveWindowOrgEx(dc : hdc; dX,dY : Integer): boolean; {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
 
diff --git a/lcl/interfaces/customdrawn/customdrawnint.pas b/lcl/interfaces/customdrawn/customdrawnint.pas
index 2a56ef6d3e..c797507add 100644
--- a/lcl/interfaces/customdrawn/customdrawnint.pas
+++ b/lcl/interfaces/customdrawn/customdrawnint.pas
@@ -297,6 +297,9 @@ var
   javaField_lclformheight: JfieldID=nil;
   javaField_lclscreenwidth: JfieldID=nil;
   javaField_lclscreenheight: JfieldID=nil;
+  // For LazDeviceAPIs
+  javaField_lcldestination: JfieldID=nil;
+  javaField_lclkind: JfieldID=nil;
 
   // Methods of our Activity
   javaMethod_LCLDoGetTextBounds: jmethodid = nil;
@@ -308,6 +311,9 @@ var
   javaMethod_LCLDoHideVirtualKeyboard: jmethodid = nil;
   javaMethod_LCLDoShowVirtualKeyboard: jmethodid = nil;
   javaMethod_LCLDoStartReadingAccelerometer: jmethodid = nil;
+  javaMethod_LCLDoStopReadingAccelerometer: jmethodid = nil;
+  javaMethod_LCLDoSendMessage: jmethodid = nil;
+  javaMethod_LCLDoRequestPositionInfo: jmethodid = nil;
 
   // This is utilized to store the information such as invalidate requests in events
   eventResult: jint;
diff --git a/lcl/interfaces/customdrawn/customdrawnlclintf_android.inc b/lcl/interfaces/customdrawn/customdrawnlclintf_android.inc
index e65fe38a37..27add832ff 100644
--- a/lcl/interfaces/customdrawn/customdrawnlclintf_android.inc
+++ b/lcl/interfaces/customdrawn/customdrawnlclintf_android.inc
@@ -165,12 +165,25 @@ end;
 
 procedure TCDWidgetSet.LazDeviceAPIs_RequestPositionInfo(AMethod: TLazPositionMethod);
 begin
-
 end;
 
 procedure TCDWidgetSet.LazDeviceAPIs_SendMessage(AMsg: TLazDeviceMessage);
+var
+  lJavaString: jstring;
+  lStr: String;
 begin
-
+  // Prepare the input
+  // String fields
+  lStr := AMsg.Body;
+  lJavaString :=javaEnvRef^^.NewStringUTF(javaEnvRef, PChar(lStr));
+  javaEnvRef^^.SetObjectField(javaEnvRef, javaActivityObject, JavaField_lcltext, lJavaString);
+  lStr := AMsg.destinationAddress.Text;
+  lJavaString :=javaEnvRef^^.NewStringUTF(javaEnvRef, PChar(lStr));
+  javaEnvRef^^.SetObjectField(javaEnvRef, javaActivityObject, JavaField_lcldestination, lJavaString);
+  // Message type
+  javaEnvRef^^.SetIntField(javaEnvRef, javaActivityObject, JavaField_lclkind, 1);
+  // Call the method
+  javaEnvRef^^.CallVoidMethod(javaEnvRef, javaActivityObject, javaMethod_LCLDoSendMessage);
 end;
 
 procedure TCDWidgetSet.LazDeviceAPIs_StartReadingAccelerometerData();
@@ -179,6 +192,12 @@ begin
   javaEnvRef^^.CallVoidMethod(javaEnvRef, javaActivityObject, javaMethod_LCLDoStartReadingAccelerometer);
 end;
 
+procedure TCDWidgetSet.LazDeviceAPIs_StopReadingAccelerometerData();
+begin
+  // Call the method
+  javaEnvRef^^.CallVoidMethod(javaEnvRef, javaActivityObject, javaMethod_LCLDoStopReadingAccelerometer);
+end;
+
 function TCDWidgetSet.PromptUser(const DialogCaption : string;
                     const DialogMessage : string;
                           DialogType    : LongInt;
diff --git a/lcl/interfaces/customdrawn/customdrawnlclintf_cocoa.inc b/lcl/interfaces/customdrawn/customdrawnlclintf_cocoa.inc
index 0e256a4c8d..43db984fab 100644
--- a/lcl/interfaces/customdrawn/customdrawnlclintf_cocoa.inc
+++ b/lcl/interfaces/customdrawn/customdrawnlclintf_cocoa.inc
@@ -128,6 +128,11 @@ begin
 
 end;
 
+procedure TCDWidgetSet.LazDeviceAPIs_StopReadingAccelerometerData();
+begin
+
+end;
+
 {------------------------------------------------------------------------------
   Function: PromptUser
   Params:
diff --git a/lcl/interfaces/customdrawn/customdrawnlclintf_win.inc b/lcl/interfaces/customdrawn/customdrawnlclintf_win.inc
index ddab0a56ba..b198da3c69 100644
--- a/lcl/interfaces/customdrawn/customdrawnlclintf_win.inc
+++ b/lcl/interfaces/customdrawn/customdrawnlclintf_win.inc
@@ -129,6 +129,11 @@ begin
 
 end;
 
+procedure TCDWidgetSet.LazDeviceAPIs_StopReadingAccelerometerData();
+begin
+
+end;
+
 {------------------------------------------------------------------------------
   Function: PromptUser
   Params:
diff --git a/lcl/interfaces/customdrawn/customdrawnlclintf_x11.inc b/lcl/interfaces/customdrawn/customdrawnlclintf_x11.inc
index 2a5ab2d9cc..a50b4fe926 100644
--- a/lcl/interfaces/customdrawn/customdrawnlclintf_x11.inc
+++ b/lcl/interfaces/customdrawn/customdrawnlclintf_x11.inc
@@ -129,6 +129,11 @@ begin
 
 end;
 
+procedure TCDWidgetSet.LazDeviceAPIs_StopReadingAccelerometerData();
+begin
+
+end;
+
 {------------------------------------------------------------------------------
   Function: PromptUser
   Params:
diff --git a/lcl/interfaces/customdrawn/customdrawnlclintfh.inc b/lcl/interfaces/customdrawn/customdrawnlclintfh.inc
index c2823d105a..ecbb6a083a 100644
--- a/lcl/interfaces/customdrawn/customdrawnlclintfh.inc
+++ b/lcl/interfaces/customdrawn/customdrawnlclintfh.inc
@@ -59,6 +59,7 @@ function IsDesignerDC(WindowHandle: HWND; DC: HDC): Boolean; override;*)
 procedure LazDeviceAPIs_RequestPositionInfo(AMethod: TLazPositionMethod); override;
 procedure LazDeviceAPIs_SendMessage(AMsg: TLazDeviceMessage); override;
 procedure LazDeviceAPIs_StartReadingAccelerometerData(); override;
+procedure LazDeviceAPIs_StopReadingAccelerometerData(); override;
 
 function PromptUser(const DialogCaption : string;
                     const DialogMessage : string;
diff --git a/lcl/interfaces/customdrawn/customdrawnobject_android.inc b/lcl/interfaces/customdrawn/customdrawnobject_android.inc
index 99b9a72b5e..02139e41bd 100644
--- a/lcl/interfaces/customdrawn/customdrawnobject_android.inc
+++ b/lcl/interfaces/customdrawn/customdrawnobject_android.inc
@@ -375,6 +375,9 @@ begin
   javaField_lclformheight := javaEnvRef^^.GetFieldID(javaEnvRef, javaActivityClass, 'lclformheight', 'I');
   javaField_lclscreenwidth := javaEnvRef^^.GetFieldID(javaEnvRef, javaActivityClass, 'lclscreenwidth', 'I');
   javaField_lclscreenheight := javaEnvRef^^.GetFieldID(javaEnvRef, javaActivityClass, 'lclscreenheight', 'I');
+  // For LazDeviceAPIs
+  javaField_lcldestination := javaEnvRef^^.GetFieldID(javaEnvRef, javaActivityClass, 'lcldestination', 'Ljava/lang/String;');
+  javaField_lclkind := javaEnvRef^^.GetFieldID(javaEnvRef, javaActivityClass, 'lclkind', 'I');
   //
   if not assigned(JavaField_lcltext) then
   begin
@@ -392,6 +395,9 @@ begin
   javaMethod_LCLDoHideVirtualKeyboard := javaEnvRef^^.GetMethodID(javaEnvRef, javaActivityClass, 'LCLDoHideVirtualKeyboard', '()V');
   javaMethod_LCLDoShowVirtualKeyboard := javaEnvRef^^.GetMethodID(javaEnvRef, javaActivityClass, 'LCLDoShowVirtualKeyboard', '()V');
   javaMethod_LCLDoStartReadingAccelerometer := javaEnvRef^^.GetMethodID(javaEnvRef, javaActivityClass, 'LCLDoStartReadingAccelerometer', '()V');
+  javaMethod_LCLDoStopReadingAccelerometer := javaEnvRef^^.GetMethodID(javaEnvRef, javaActivityClass, 'LCLDoStopReadingAccelerometer', '()V');
+  javaMethod_LCLDoSendMessage := javaEnvRef^^.GetMethodID(javaEnvRef, javaActivityClass, 'LCLDoSendMessage', '()V');
+  javaMethod_LCLDoRequestPositionInfo := javaEnvRef^^.GetMethodID(javaEnvRef, javaActivityClass, 'LCLDoRequestPositionInfo', '()V');
 
   __android_log_write(ANDROID_LOG_INFO, 'lclapp', 'JNI_OnLoad finished');
   result:=JNI_VERSION_1_4;// 1_6 is another option
diff --git a/lcl/lazdeviceapis.pas b/lcl/lazdeviceapis.pas
index a1b10c0540..7d1614bb55 100644
--- a/lcl/lazdeviceapis.pas
+++ b/lcl/lazdeviceapis.pas
@@ -40,6 +40,7 @@ type
   TLazAccelerometer = class
   private
     FOnSensorChanged: TNotifyEvent;
+    FReadingStarted: Boolean;
   public
     // These fields store the last data read, to get fresh data use UpdateAccelerometerData;
     xaxis, yaxis, zaxis: Double; // in m/s^2
@@ -63,6 +64,8 @@ type
   public
     // Attempt to send the specified message.
     procedure SendMessage(AMsg: TLazDeviceMessage);
+    //
+    function CreateMessage: TLazDeviceMessage;
     // Called asynchronously when the message sending is finished
     property OnMessageSendingFinished: TOnMessageSendingFinished read FTOnMessageSendingFinished
       write FTOnMessageSendingFinished;
@@ -70,11 +73,9 @@ type
 
   // TLazPositionInfo
 
-  TOnPositionRetrieved = procedure of object;
-
   TLazPositionInfo = class
   private
-    FOnPositionRetrieved: TOnPositionRetrieved;
+    FOnPositionRetrieved: TNotifyEvent;
   public
     IsPositionDataAvailable: Boolean; // Indicates if position info was read in the life of this program
     // These fields hold the last position information read
@@ -87,7 +88,7 @@ type
     timeStamp: TDateTime; // The time when the location was established.
     procedure RequestPositionInfo(AMethod: TLazPositionMethod);
     // Called asynchronously when the position is read
-    property OnPositionRetrieved: TOnPositionRetrieved read FOnPositionRetrieved write FOnPositionRetrieved;
+    property OnPositionRetrieved: TNotifyEvent read FOnPositionRetrieved write FOnPositionRetrieved;
   end;
 
 var
@@ -101,12 +102,16 @@ implementation
 
 procedure TLazAccelerometer.StartReadingAccelerometerData;
 begin
+  if FReadingStarted then Exit;
   LCLIntf.LazDeviceAPIs_StartReadingAccelerometerData();
+  FReadingStarted := True;
 end;
 
 procedure TLazAccelerometer.StopReadingAccelerometerData;
 begin
-
+  if not FReadingStarted then Exit;
+  LCLIntf.LazDeviceAPIs_StopReadingAccelerometerData();
+  FReadingStarted := False;
 end;
 
 { TLazPositionInfo }
@@ -123,6 +128,11 @@ begin
   LCLIntf.LazDeviceAPIs_SendMessage(AMsg);
 end;
 
+function TLazMessaging.CreateMessage: TLazDeviceMessage;
+begin
+  Result := TLazDeviceMessage.Create;
+end;
+
 initialization
   Accelerometer := TLazAccelerometer.Create;
   Messaging := TLazMessaging.Create;