Touch Features in EWB

by Erick Engelke
January 13, 2024

In my last blog article I made a space invaders styled game. But it didn’t work on many tablets, because they use Touch events and I didn’t program that in.

So I wrote a simple program to test Touch events: test program

You can use it to see which events are generated on your tablet.

when you touch the screen, the message sent is TouchStart
if you tap the screen, the TouchStart is sent then a TouchEnd
if you drag across the screen, a TouchStart followed by TouchMove’s but no TouchEnd is sent
successive moves just add more TouchMoves, with no TouchStart or TouchEnd.

Here’s the simple source code:[source,]

unit touchgui;

interface

uses WebCore, WebUI, WebForms, WebCtrls, WebLabels;

type

   TForm1 = class(TForm)
      HTMLLabel1: THTMLLabel;
      procedure HTMLLabel1TouchCancel(Sender: TObject; ShiftKey: Boolean;
                                      CtrlKey: Boolean; AltKey: Boolean;
                                      X: Integer; Y: Integer);
      procedure HTMLLabel1TouchEnd(Sender: TObject; ShiftKey: Boolean;
                                   CtrlKey: Boolean; AltKey: Boolean;
                                   X: Integer; Y: Integer);
      procedure HTMLLabel1TouchMove(Sender: TObject; ShiftKey: Boolean;
                                    CtrlKey: Boolean; AltKey: Boolean;
                                    X: Integer; Y: Integer);
      procedure HTMLLabel1TouchStart(Sender: TObject; ShiftKey: Boolean;
                                     CtrlKey: Boolean; AltKey: Boolean;
                                     X: Integer; Y: Integer);
   private
      { Private declarations }
      procedure Label( s : string );
   public
      { Public declarations }
   end;

var
   Form1: TForm1;

implementation

procedure TForm1.Label( s : string );
begin
   HTMLLabel1.Content := s + '<br>' + htmlLabel1.Content;
end;
procedure TForm1.HTMLLabel1TouchCancel(Sender: TObject; ShiftKey: Boolean;
                                       CtrlKey: Boolean; AltKey: Boolean;
                                       X: Integer; Y: Integer);
begin
  label( 'Touch Cancel (x:'+IntToStr(x )+', y:' +inttostr( y )+')');

end;

procedure TForm1.HTMLLabel1TouchEnd(Sender: TObject; ShiftKey: Boolean;
                                    CtrlKey: Boolean; AltKey: Boolean;
                                    X: Integer; Y: Integer);
begin
  label( 'Touch End (x:'+IntToStr(x )+', y:' +inttostr( y )+')');

end;

procedure TForm1.HTMLLabel1TouchMove(Sender: TObject; ShiftKey: Boolean;
                                     CtrlKey: Boolean; AltKey: Boolean;
                                     X: Integer; Y: Integer);
begin
  label( 'Touch Move (x:'+IntToStr(x )+', y:' +inttostr( y )+')');

end;

procedure TForm1.HTMLLabel1TouchStart(Sender: TObject; ShiftKey: Boolean;
                                      CtrlKey: Boolean; AltKey: Boolean;
                                      X: Integer; Y: Integer);
begin
  label( 'Touch Start (x:'+IntToStr(x )+', y:' +inttostr( y )+')');

end;

end.