{ TPoweredby Component

  Copyright (C)2014 Gordon Bamber minesadorada@charcodelvalle.com

  This library is free software; you can redistribute it and/or modify it
  under the terms of the GNU Library General Public License as published by
  the Free Software Foundation; either version 2 of the License, or (at your
  option) any later version.

  This program is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
  for more details.

  You should have received a copy of the GNU Library General Public License
  along with this library; if not, write to the Free Software Foundation,
  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
}
unit uPoweredby;

{$mode objfpc}{$H+}

interface

uses
  Classes, Controls, Dialogs, Forms, Graphics, LResources, SysUtils,
  ExtCtrls, InterfaceBase, LCLType,LCLVersion;

const
  C_VERSIONSTRING = '1.0.3.0';
  C_WIDGETSET_GTK = 'GTK widget set';
  C_WIDGETSET_GTK2 = 'GTK 2 widget set';
  C_WIDGETSET_GTK3 = 'GTK 3 widget set';
  C_WIDGETSET_WIN = 'Win32/Win64 widget set';
  C_WIDGETSET_WINCE = 'WinCE widget set';
  C_WIDGETSET_CARBON = 'Carbon widget set';
  C_WIDGETSET_QT = 'QT widget set';
  C_WIDGETSET_fpGUI = 'fpGUI widget set';
  C_WIDGETSET_COCOA = 'Cocoa widget set';
  C_WIDGETSET_CUSTOM = 'Custom drawn widget set';
  C_WIDGETSET_OTHER = 'Other gui';

type
  TPoweredby = class(TComponent)
  private
    { Private declarations }
    fPoweredByForm: TForm;
    fVersionString: string;
    fDelayMilliseconds: integer;
    fFadeInMilliseconds: integer;
    fShowOnlyOnce,fAlreadyShown:Boolean;
    // Used by Timer to close the PoweredBy form
    procedure ClosePoweredByForm(Sender: TObject);
    // Windows only!
    procedure FadeInPoweredBy(Sender: TObject);
    procedure SetDelayMilliSeconds(AValue: integer);
    function GetWidgetSetString: string;
    Function GetFPCTargetInfoString: String;
    Function GetInfoLCLVersion:String;
    Function GetInfoFPCVersion:String;
  protected
    { Protected declarations }
  public
    { Public declarations }
    // Call the method 'ShowPoweredByForm' to show the shaped window
    procedure ShowPoweredByForm;
    // Called when component is dropped onto a form
    constructor Create(AOwner: TComponent); override;
  published
    { Published declarations }
    // Minimum delay=1000msec; Maximum delay=10000msec.  Fade-in time is automatically adjusted
    property DelayMilliSecs: integer read fDelayMilliSeconds write SetDelayMilliSeconds default 1000;
    // Call the method 'ShowPoweredByForm' to show the shaped window
    property Version: string read fVersionString;
    // Reports the current WidgetSet
    property InfoWidgetSet: string read GetWidgetSetString;
    // Reports your current Environment
    property InfoFPCTarget:String read GetFPCTargetInfoString;
    // Reports your current Environment
    property InfoFPCVersion:String read GetInfoFPCVersion;
    // Reports your current Environment
    property InfoLCLVersion:String read GetInfoLCLVersion;
    // Useful if you have ShowPoweredByForm in your TForm.Activate() method
    property ShowOnlyOnce:boolean read fShowOnlyOnce write fShowOnlyOnce default false;
  end;

procedure Register;

implementation

procedure Register;
begin
  {$I upoweredby_icon.lrs}
  RegisterComponents('Additional', [TPoweredby]);
end;

constructor TPoweredby.Create(AOwner: TComponent);
  // Initialise private vars
begin
  inherited Create(AOwner);
  fVersionString := C_VERSIONSTRING;
  fDelayMilliseconds := 1000;
  fFadeInMilliseconds := 20;
  fAlreadyShown:=False;
  fShowOnlyOnce:=False;
end;
Function TPoweredby.GetInfoLCLVersion:String;
begin
  result:=lcl_version;
end;
Function TPoweredby.GetInfoFPCVersion:String;
begin
  Result:={$I %FPCVERSION%};
end;
Function TPoweredby.GetFPCTargetInfoString: String;
begin
  Result := {$I %FPCTARGETCPU%}+' - '+{$I %FPCTARGETOS%};
end;

function priv_GetWidgetSetString: string;
  // This code cannot be a method of TPoweredBy
begin
  case WidgetSet.LCLPlatform of
    lpGtk: Result := C_WIDGETSET_GTK;
    lpGtk2: Result := C_WIDGETSET_GTK2;
    lpWin32: Result := C_WIDGETSET_WIN;
    lpWinCE: Result := C_WIDGETSET_WINCE;
    lpCarbon: Result := C_WIDGETSET_CARBON;
    lpCocoa: Result := C_WIDGETSET_COCOA;
    lpQT: Result := C_WIDGETSET_QT;
    lpfpGUI: Result := C_WIDGETSET_fpGUI;
    // When were these first included in InterfaceBase?
    {$IFDEF FPC_FULLVERSION>24200}
    lpGtk3: Result := C_WIDGETSET_GTK3;
    lpCustomDrawn: Result := C_WIDGETSET_CUSTOM;
    {$ENDIF}
    else
      Result := C_WIDGETSET_OTHER;
  end;
end;

function TPoweredby.GetWidgetSetString: string;
begin
  Result := priv_GetWidgetSetString;
end;

procedure TPoweredby.SetDelayMilliSeconds(AValue: integer);
begin
  if ((fDelayMilliSeconds <> AValue) and (AValue > 0) and (AValue < 11000)) then
  begin
    fDelayMilliseconds := AValue;
    fFadeInMilliseconds := (AValue div 1000) * 20;
  end;

end;

procedure TPoweredby.ClosePoweredByForm(Sender: TObject);
// Called by Timer event in ShowPoweredByForm to close Modal window
// Also the image OnClick event
begin
  fPoweredByForm.Close;
end;

procedure TPoweredby.FadeInPoweredBy(Sender: TObject);
// Use Alphablend property of TForm
begin
  if (fPoweredByForm.AlphaBlendValue < 245) then
    fPoweredByForm.AlphaBlendValue := fPoweredByForm.AlphaBlendValue + 10;
end;

function CanShowRoundedGraphic: boolean;
{
Check the current WidgetSet, and add to the list that can show the rounded graphic
Choices are:
  lpGtk,
  lpGtk2,
  lpGtk3,
  lpWin32,
  lpWinCE,
  lpCarbon,
  lpQT,
  lpfpGUI,
  lpNoGUI,
  lpCocoa,
  lpCustomDrawn
  }
begin
  case WidgetSet.LCLPlatform of
    lpWin32, lpQT: Result := True;
    else
      Result := False;
  end;
end;

procedure TPoweredby.ShowPoweredByForm;

// Graphics are in masks.lrs
// 1 ) Constructs a new TForm with an image control
// 2 ) Uses the 'SetShape' method of the form canvas to create a transparent mask
// 3 ) Paints the Timage over it with a color image
// 4 ) Sets a timer to fade it in using the Alphablend property
// 5 ) Sets another timer to close the form

// Note: Windows can fade in a shaped transparent screen
// But some widgetsets (GTK,Carbon) cannot
var
  img_Background: TImage;
  MyBitmap: TBitMap;
  DelayTimer: TTimer;
  FadeInTimer: TTImer;
begin
  // Respect the ShowOnlyOnce property setting
  If ((fShowOnlyOnce=TRUE) AND (fAlreadyShown=TRUE)) then Exit;

  // Try..Finally so we can be sure resources are Freed
  try
    try
      // Create controls
      fPoweredByForm := TForm.Create(nil);
      fPoweredByForm.AlphaBlend := True;
      fPoweredByForm.AlphaBlendValue := 0;
      img_background := TImage.Create(fPoweredByForm);
      // Bitmap mask - Load from resource
      MyBitmap := TBitMap.Create;
      MyBitmap.LoadFromLazarusResource('powered_by_mask');
      // Delay Timer
      Delaytimer := TTimer.Create(fPoweredByForm);
      delaytimer.Interval := fDelayMilliseconds;
      delaytimer.OnTimer := @ClosePoweredByForm;

      FadeInTimer := TTimer.Create(fPoweredByForm);
      FadeInTimer.Interval := fFadeInMilliseconds;
      FadeInTimer.OnTimer := @FadeInPoweredBy;

      // BackGround image - load from resource
      with img_background do
      begin
        Align := alClient;
        Stretch := True;
        Parent := fPoweredByForm;
        if CanShowRoundedGraphic then
          Picture.LoadFromLazarusResource('win_powered_by')
        else
          Picture.LoadFromLazarusResource('powered_by');
        OnClick := @ClosePoweredByForm;
        SendToBack;
      end;
      // Set form properties
      with fPoweredByForm do
      begin
        position := poScreenCenter;
        borderstyle := bsnone;
        formstyle := fsSystemStayOnTop;
        OnClick := @ClosePoweredByForm;
        color := clBlack;
        Height := MyBitmap.Height;
        Width := MyBitMap.Width;
        if CanShowRoundedGraphic then
        begin
          MyBitMap.Transparent := True;
          MyBitMap.TransparentColor := clBlack;
          Canvas.Draw(0, 0, MyBitMap);
          // raises Floating Point Error in linux GTK (!??)
          SetShape(MyBitMap);
        end
        else
        begin
          // If square graphic, then adjust form size
             height:=img_background.Picture.Height;
             width:=img_background.picture.width;
        end;
        // Now show the completed form
        delaytimer.Enabled := True;
        FadeInTimer.Enabled := True;
        Application.ProcessMessages;
        ShowModal; // Closed via the Timer event or a user click
        fAlreadyShown:=TRUE;
      end;
    except
      On E: Exception do
        raise Exception.CreateFmt('%s Error: %s', [Name, Exception.ClassName]);
    end;
  finally
    FreeAndNil(img_background);
    FreeAndNil(MyBitMap);
    FreeAndNil(delayTimer);
    FreeAndNil(FadeInTimer);
    FreeAndNil(fPoweredByForm);
  end;
end;

initialization
  // Load graphics as lazarus resources into the component
{$I graphics.lrs}

end.