Create Lazarus share library in android
lazarus / 43-Android

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aradeonas · 2015-11-11 16:44

Hi,

How can I make a share library (.so) in Lazarus that do a simple task
like sum two number and can be used in android?
Any one has an example or tutorial?

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Jurassic Pork · 2015-11-11 22:38

hello,
i don't know if the following code works under android but it works
under ubuntu :  

example
1 - create the shared library
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i library
mySumlib; {$mode objfpc}{$H+} uses  Classes; function mySum(int1,int2
:integer): integer; cdecl;begin    result := int1 + int2
;end; exports  mySum;end. compile :  a .so is created.
create a project to use the shared lib (my example use statically load
library but you can use also l library dynamically load).
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
tst_Sharedlib; {$mode objfpc}{$H+} uses  Classes,sysutils; function
mySum(int1,int2: integer): integer; external 'mysumlib'; begin 
writeln('sharedlib test');  writeln('the result of 323 + 593 is : ' +
inttoStr(mySum(323,593)));end. don't forget the option :
Compiler Options /Compilation and Linking

Enable setting: "Pass options to linker with "-k", delimiter is space"
with this option   :  -R ./    to indicate where is the library
(path).
Compile and run
result   : 
Quotesharedlib test
the result of 323 + 593 is : 916

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balazsszekely · 2015-11-12 09:36

In case you want to load it dynamically:Code: Pascal
 [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i uses
dynlibs, LCLType; type  TmySum = function(Int1, Int2: Integer):
Integer; cdecl; var  LibHandle: TLibHandle = NilHandle;  mySum: TmySum
= nil;  function Load(const ALibName, AFuncName: string):
Boolean;var FarProc: TFarProc;begin  Result := False;  LibHandle :=
LoadLibrary(ALibName);  if LibHandle <> NilHandle then  begin   
FarProc := GetProcedureAddress(LibHandle, AFuncName);    if FarProc <>
nil then    begin      MySum := TMySum(FarProc);      Result := mySum
<> nil;    end;  end;end;                  function UnLoad:
Boolean;begin  Result := True;  if LibHandle <> NilHandle then  begin 
  Result := UnloadLibrary(LibHandle);    if Result then    begin     
LibHandle := NilHandle;      mySum := nil;   end;  end;end;
Usage:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
var LibName: string;begin  LibName := ExtractFilePath(ParamStr(0)) +
'mySumlib.' + SharedSuffix; //you can change the path if necessary  if
Load(LibName, 'mySum') then    ShowMessage(IntToStr(mySum(3, 4))); 
UnLoad;end;

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jmpessoa · 2015-11-13 00:09

Hello aradeonas!

Here is a simple and complete  "Lamw: Lazarus Android Wizard"  NoGUI
project...

ref.:  https://od.lk/f/Ml8xMDUyNjY3NDlf

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aradeonas · 2015-11-13 10:23

Hi jmpessoa and thanks.

Sadly I cant download it,can you upload this here?

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jmpessoa · 2015-11-13 14:28

Sorry....

See Attachment ....

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aradeonas · 2015-11-13 17:07

Thanks.
But one problem is that I cant make the app in Lazarus and I just want
to write some stuff in a share library and use it in the Java Android
project.

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jmpessoa · 2015-11-13 18:16

Yes, is just about! You can learn from my project. Folder  ..\jni

1. From "*.lpi"  cross-compile settings... 

[change according to your system and "build"  to get the ".so" --> 
..\libs\armeabi ]

2. From "*.lpr"  JNI pascal side

3. From "*.java"  how to call/use your lib

NOTE:  you need a Lazarus prepared to cross-compile...

For windows there is  "Laz4Android":

ref:  http://sourceforge.net/projects/laz4android/files/?source=navbar

FPC: 3.0.0 rc2 (win32/arm-android/i386-android/jvm-android)
Lazarus:1.4.4
Android NDK: r10e (arm-linux-androideabi-4.9 + x86-4.9)