Android4Pascal

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Android robot.svg

This article applies to Android only.

See also: Multiplatform Programming Guide

Android4Pascal are the bindings which connect Pascal applications running as executables in Android with the Android Java APIs.

Download

Latest development version

Changelog:

  • Added a tool to automatically generate the bindings
  • Added many new APIs (don't remember all of them)

Version 0.3

Released June 2011

svn co https://p-tools.svn.sourceforge.net/svnroot/p-tools/systeminfo4android/ systeminfo4android

Changelog:

  • Added support for reading android.util.DisplayMetrics, Activity.getWindowManager, WindowManager.getDefaultDisplay, Display.getMetrics

Version 0.2

Released on March 2011

This version was distributed as an example project which can be obtained with the following svn command:

svn co https://p-tools.svn.sourceforge.net/svnroot/p-tools/turbochessclock4android/ -r 230 turbochessclock4android

Android API Hello World in Pascal

Here is an example Pascal application written for Android. It shows how to create controls, receive callback events and how to use the timer.

The full directory structure can be download with this svn command:

 svn co https://p-tools.svn.sourceforge.net/svnroot/p-tools/turbochessclock4android turbochessclock4android

Simple Android app.png

Here is the Pascal code from this example:

{
  A simple Chess Clock application
 
  Author: Felipe Monteiro de Carvalho - 2011
  License: Public Domain
}
program turbochessclock4android;
 
{$mode objfpc}{$H+}
 
uses
  Classes, SysUtils, androidpipescomm, androidview, javalang,
  androidapp, androidtimer, androidutil;
 
type
  TEventHandler = class
  public
    procedure HandleOnTimer(ASender: TObject);
    procedure buttonStartClickCallback(v: TView);
    procedure buttonMoveClickCallback(v: TView);
  end;
 
var
  layout: TLinearLayout;
  params: TLayoutParams;
  tv, black_label, white_label: TTextView;
  scroller: TScrollView;
  btn_move, btn_start: TButton;
  tp: TTimePicker;
  WhiteTimeCount: Integer = 0;
  BlackTimeCount: Integer = 0;
  MyTimer: TAndroidTimer;
  MyEventHandler: TEventHandler;
  IsWhitePlayerMove: Boolean = True;
 
procedure TEventHandler.buttonStartClickCallback(v: TView);
begin
  black_label.setVisibility(VISIBLE);
  white_label.setVisibility(VISIBLE);
  btn_move.setVisibility(VISIBLE);
  //
  WhiteTimeCount := tp.getCurrentHour() * 60 * 60 + tp.getCurrentMinute() * 60;
  BlackTimeCount := WhiteTimeCount;
  //
  MyTimer.removeCallbacks();
  MyTimer.postDelayed(100);
end;
 
procedure TEventHandler.buttonMoveClickCallback(v: TView);
begin
  IsWhitePlayerMove := not IsWhitePlayerMove;
end;
 
procedure TEventHandler.HandleOnTimer(ASender: TObject);
var
  lSeconds, lMinutes, lHours: Integer;
begin
  if IsWhitePlayerMove then
  begin
    lSeconds := WhiteTimeCount mod 60;
    lMinutes := (WhiteTimeCount mod (60 * 60)) div 60;
    lHours := WhiteTimeCount div (60 * 60);
    white_label.setText(Format('White %d:%d:%d', [lHours, lMinutes, lSeconds]));
    //
    if WhiteTimeCount = 0 then Exit;
    Dec(WhiteTimeCount);
  end
  else
  begin
    lSeconds := BlackTimeCount mod 60;
    lMinutes := (BlackTimeCount mod (60 * 60)) div 60;
    lHours := BlackTimeCount div (60 * 60);
    black_label.setText(Format('Black %d:%d:%d', [lHours, lMinutes, lSeconds]));
    //
    if BlackTimeCount = 0 then Exit;
    Dec(BlackTimeCount);
  end;
  //
  MyTimer.removeCallbacks();
  // Note that this has a low precision, but it enough for this simple app
  // A more precise app would keep another time count instead of just using Dec
  // at each timer call
  MyTimer.postDelayed(1000);
end;
 
begin
  // Here add any initialization.
  // Any initialization code will be run inside Activity.onCreate,
  // so keep it as short as possible!
  // It should mostly contain GUI initialization
  // User interface
  MyEventHandler := TEventHandler.Create;
 
  // Prepares the UI of the program
  layout := TLinearLayout.Create;
  params := TLayoutParams.Create(androidview.FILL_PARENT, androidview.FILL_PARENT);
  layout.setLayoutParams(params);
  params.Free;
  layout.setOrientation(androidview.VERTICAL);
 
  // Game UI
 
  black_label := TTextView.Create;
  black_label.setText('Black time:');
  black_label.setVisibility(GONE);
  black_label.setTextSize(COMPLEX_UNIT_PX, 40);
  layout.addView(black_label);
 
  white_label := TTextView.Create;
  white_label.setText('White time:');
  white_label.setVisibility(GONE);
  white_label.setTextSize(COMPLEX_UNIT_PX, 40);
  layout.addView(white_label);
 
  btn_move := TButton.Create;
  btn_move.setText('Move finished!');
  btn_move.setOnClickListener(@MyEventHandler.buttonMoveClickCallback);
  btn_move.setVisibility(GONE);
  layout.addView(btn_move);
 
  // Config UI
 
  tv := TTextView.Create;
  tv.setText('Please select how much to give to the players and press "Start Game":');
  layout.addView(tv);
 
  tp := TTimePicker.Create;
  tp.setIs24HourView(True);
  tp.setCurrentHour(0);
  tp.setCurrentMinute(30);
  layout.addView(tp);
 
  btn_start := TButton.Create;
  btn_start.setText('Start game!');
  btn_start.setOnClickListener(@MyEventHandler.buttonStartClickCallback);
  layout.addView(btn_start);
 
  // And also allow the user to scroll the UI if it is larger then the screen width
  // Scrolling takes place only horizontally
 
  scroller := TScrollView.Create;
  scroller.addView(layout);
 
  Activity.setContentView(scroller);
 
  MyTimer := TAndroidTimer.Create;
  MyTimer.OnTimer := @MyEventHandler.HandleOnTimer;
 
  // Now tell Java that the initialization has finished
  vAndroidPipesComm.onCreateFinished();
  // Here you can add any other initialization,
  // specially non-GUI code
 
  // Now we block our execution waiting for callbacks from Java
  vAndroidPipesComm.MessageLoop();
end.
Compiling the example project in Linux

1> Get a working arm-linux cross-compiler which generates ARMv5 eabi with softfloat (as many phones like HTC Wildfire have no FPU)

To do this one can download an unofficial build of FPC 2.5.1 from here:

http://sourceforge.net/projects/p-tools/files/Free%20Pascal%20for%20ARM/ Compiled for ARMv5 eabi with softfloat.

Or an older FPC 2.4.2

http://members.yline.com/~tom_at_work/fpc-2.4.2.UNOFFICIAL.arm-linux.tar Compiled for ARMv5 eabi with softfloat.

Or build your own. There are instructions here: Setup_Cross_Compile_For_ARM

2> Install the Android SDK. Instructions here: Android_Interface/Using_the_Android_SDK,_Emulator_and_Phones#Using_the_Android_SDK

3> Install ant, for example in Mandriva Linux:

 urpmi ant

4> Open the project turbochessclock/turbochessclock4android.lpi in Lazarus and build it

5> Build the APK file in debug mode

 ant debug

6> Connect your phone and make sure you can connect to it via ADB. More info here: Android_Interface/Using_the_Android_SDK,_Emulator_and_Phones#Recognition_of_devices_under_Linux

7> Install the APK file in your phone via ADB or whatever other method you prefer:

 ../android-sdk-linux_x86/tools/adb install android/bin/TurboChessClock4Android-debug.apk

If the package is already installed you need need to do this instead:

 ../android-sdk-linux_x86/tools/adb uninstall com.pascal.turbochessclock
 ../android-sdk-linux_x86/tools/adb install android/bin/TurboChessClock4Android-debug.apk

Version 0.1

Released on January 2011

This version was distributed as an example project which can be obtained with the following svn command:

svn co https://p-tools.svn.sourceforge.net/svnroot/PascalNotes4Android/ -r 230 PascalNotes4Android

See also