Smart Mobile currently ships with a rather spartan number of custom controls. Originally we were aiming at a rather minimal RTL and only the basic iOS widgets, this is how C# does it when it comes to iOS development. While we have the rounded iphone menu in the IDE, what is missing is a more versatile menu. Both Android and iOS devices have scrollable list menus that are flat and designed to cover the iphone’s entire horizontal width. You can then move around it with one finger, and when you touch a single item without scrolling – that is considered a “click”.

In this little article I’m going to create this list control to demonstrate how easy it is.

Roll your own

First, let’s start with the baseclasses. We are going to keep it very simple, reducing the list to only two classes: one representing a list item – and another representing the actual list.

Since iPhone lists have the capacity to include sub-controls, we are not going to cheat and wrap UL / LI tags, but use fully functional TW3CustomControls as list items. This will give us the freedom to not only style our list items – but to add buttons and whatever we want to each element.

So let’s start by defining a couple of classes:

  type

  (* Generic ancestor *)
  TLSTCustomMenuItem = Class(TW3CustomControl);

  (* Array type *)
  TLSTMenuItems = Array of TLSTCustomMenuItem;

  (* Menu item *)
  TLSTMenuItem = Class(TLSTCustomMenuItem)
  private
    FCaption: String;
    procedure setCaption(Const Value:String);
  protected
    procedure InitializeObject; override;
  public
    property  Caption:String read FCaption write setCaption;
  end;

  (* selection event *)
  TMenuItemSelectedEvent = procedure (Sender:TObject;Const aItem:TLSTCustomMenuItem);

  (* Our menu *)
  TLSTMenu = Class(TW3ScrollControl)
  private
    FItems:       TLSTMenuItems;
    FLastY:       Integer;
    FSelected:    TLSTMenuItem;
    FOnSelected:  TMenuItemSelectedEvent;
    procedure     HandleTouchBegins(Sender:TObject;Info:TW3TouchData);
    procedure     HandleTouchEnds(Sender:TObject;Info:TW3TouchData);
  protected
    procedure     HandleItemTapped(Const aItem:TLSTMenuItem);
    procedure     InitializeObject; override;
    procedure     FinalizeObject; override;
    procedure     ReSize;override;
  public
    property      OnItemSelected:TMenuItemSelectedEvent read FOnSelected write FOnSelected;
    property      Items:TLSTMenuItems read FItems;
    function      Add(Const aItem:TLSTCustomMenuItem):TLSTCustomMenuItem;overload;
    function      Add:TLSTMenuItem;overload;
  end;

The FItems array is basically a list of the child items. This is actually a bit overkill, since TW3Component already support parent/child management – but it’s Friday so I just used an array to keep track of things.

Ok, let’s move on a bit and look at the implementation for our item:

  //###########################################################################
  // TLSTMenuItem
  //###########################################################################

  procedure TLSTMenuItem.InitializeObject;
  begin
    inherited;
    Self.Color:=clWhite;
    Self.Height:=32;
  end;

  procedure TLSTMenuItem.setCaption(Const Value:String);
  begin
    FCaption:=Value;
    innerHTML:=Value;
  end;

This is a fairly simple setup. We give our item a default color of white, and set the height of the listitem to 22 pixels. The setcaption() is actually one you should look out for. As you can see i use the innerHTML property to set the caption. This is fine for this example – but it will kill all child controls (!). For a proper title, create a child TW3Label and position it by overriding the resize() method.

Ok, let’s look at the main scrolling control. The actual scrolling behavior is inherited from TW3ScrollControl which is a minimalistic, touch based scrollbox. Unlike the Delphi scrollbox – the smart version contains a sub-control called “content” which is what is actually moved.

This means that when we populate our listbox, we have to create our list-items with “content” as parent. Ok, let’s have a look:

  //###########################################################################
  // TLSTMenu
  //###########################################################################

  procedure TLSTMenu.InitializeObject;
  begin
    inherited;
    FItems.SetLength(0);
  end;

  procedure TLSTMenu.FinalizeObject;
  begin
    FItems.Clear;
    inherited;
  end;

  procedure TLSTMenu.HandleTouchBegins(Sender:TObject;Info:TW3TouchData);
  begin
    (* remember current scroll position *)
    if (sender<>NIL)
    and (sender is TLSTMenuItem) then
    begin
      FLastY:=Content.Top;
      FSelected:=TLSTMenuItem(sender);
    end else
    begin
      FLastY:=-1;
      FSelected:=NIL;
    end;
  end;

  procedure TLSTMenu.HandleTouchEnds(Sender:TObject;Info:TW3TouchData);
  begin
    (* No scrolling but touched? Its a tap *)
    if Content.Top=FLastY then
    begin
      if (FSelected<>NIL) then
      begin
        if (FSelected=sender) then
        begin
          HandleItemTapped(FSelected);
          FLastY:=-1;
          FSelected:=NIL;
        end;
      end;
    end;
  end;

  procedure TLSTMenu.HandleItemTapped(Const aItem:TLSTMenuItem);
  begin
    if assigned(FOnSelected) then
    FOnSelected(self,aItem);
  end;

  function TLSTMenu.Add:TLSTMenuItem;
  begin
    result:=TLSTMenuItem(Add(TLSTMenuItem.Create(Content)));
    result.OnTouchBegin:=HandleTouchBegins;
    result.OnTouchEnd:=HandleTouchEnds;
  end;

  function TLSTMenu.Add(Const aItem:TLSTCustomMenuItem):TLSTCustomMenuItem;
  begin
    if aItem<>NIL then
    begin
      if FItems.IndexOf(aItem)<0 then
      begin
        BeginUpdate;
        FItems.Add(aItem);
        EndUpdate;
        content.LayoutChildren;
      end;
    end;
    result:=aItem;
  end;

  procedure TLSTMenu.ReSize;
  var
    mItem:  TLSTCustomMenuItem;
    mSize:  Integer;
    x:  Integer;
    dy: Integer;
  begin
    inherited;
    for x:=0 to FItems.Length-1 do
    begin
      mItem:=FItems[x];
      if mItem.visible then
      inc(mSize,mItem.height);
    end;
    Content.Height:=mSize;

    dy:=0;
    for x:=0 to FItems.Length-1 do
    begin
      mItem:=FItems[x];
      if mItem.visible then
      begin
        mItem.SetBounds(0,dy,width,mItem.Height);
        inc(dy,mItem.Height);
      end;
    end;
  end;

Everything here should be fairly straight forward. We hook the onTouchBegins and onTouchEnd events on all our list items. Why? Because we have to solve a little problem. Since our list is scrollable, that means we have to somehow distinguish between a scroll swipe (up or down) and an actual tap. To achieve this we set down a simple law: If the Y position of the list is in both events, then we consider that a tap (or selection). If you have moved your finger on the other hand, then the tap is ignored.

The final procedure, namely resize, does two things: first, it calculates the total height of all the list items and size the content control accordingly. Then it loops through and positions the child elements.

Styling

Ok, with the behavior out of the way – we just need to add one final piece: namely styling. So double-click on the project CSS file and add the following:

.TLSTMenuItem {
  -webkit-user-select: auto;
  background: #FFFFFF;
  border-bottom: solid 1px #9A9A9A;

    font-family: "Helvetica Neue", Helvetica, sans-serif;
    font-size: 17px;
    color: #888888;

}

Let’s give the control a test-drive, so we add the unit to our mainform’s uses clause, create an instance, and add some items:

unit Form1;

interface

uses
  w3system, w3graphics, w3ctrls, w3components, w3forms, w3fonts,
  w3borders, w3application, unit1;

type
  TForm1=class(TW3form)
  private
    { Private methods }
    {$I 'Form1:intf'}
    FMenu:  TLSTMenu;
    procedure HandleItemSelected(Sender:TObject;Const aItem:TLSTCustomMenuItem);
  protected
    { Protected methods }
    procedure InitializeObject; override;
    procedure FinalizeObject; override;
    procedure StyleTagObject; reintroduce; virtual;
    procedure Resize; override;
  end;

implementation

//############################################################################
// TForm1
//############################################################################

procedure TForm1.InitializeObject;
var
  x:  Integer;
begin
  inherited;
  {$I 'Form1:impl'}
  W3HeaderControl1.Title.Caption:='Form header';
  w3HeaderControl1.BackButton.Visible:=False;

  FMenu:=TLSTMenu.Create(self);
  FMenu.Color:=clWhite;
  FMenu.StyleClass:='TPDFMenu';
  FMenu.Content.height:=120;
  FMenu.Content.color:=clGreen;
  FMenu.OnItemSelected:=HandleItemSelected;

  FMenu.BeginUpdate;
  try
    for x:=1 to 20 do
    FMenu.Add.Caption:='List item #' + IntToStr(x);
  finally
    FMenu.EndUpdate;
  end;
end;

procedure TForm1.FinalizeObject;
begin
  FMenu.free;
  inherited;
end;

procedure TForm1.HandleItemSelected(Sender:TObject;Const aItem:TLSTCustomMenuItem);
begin
  self.W3HeaderControl1.Title.Caption:=aItem.innerText;
end;

procedure TForm1.Resize;
var
  dy: Integer;
begin
  dy:=W3HeaderControl1.top + W3HeaderControl1.height + 2;
  FMenu.SetBounds(0,dy,width,height-dy);
  inherited;
end;

procedure TForm1.StyleTagObject;
begin
  //Custom styling
end;

end.

As you can see from the code, we catch the touch events and change the title of a header control we added to the form. This makes it quite easy to see what you are doing.

Scroll list galore

You can download the project file here (zip archive) and play with it!

It’s been a while since I have written anything in the developers log, so I thought it would be nice to share two new avenues of the web marked that can benefit from smart mobile studio. In fact, I’m scheduled for a meeting with a Norwegian publisher regarding our upcoming command-line compiler. There is a huge demand for template based projects in the multimedia scene (where only the content is changed but the code remains the same).

Adobe PDF embedding of javascript

Fairly simple coding, but good revenue

If you own an IPad and have children you will no doubt have noticed how much attention children give to iPad games, books and media. I have a 5 year old daughter that have no interest what so ever in computers, PlayStation or the sorts – but the moment she sat down with the iPad all that changed. I don’t know how many interactive books we have bought for her since we got the iPad but it’s quite a few. So where computers and digital gadgets used to be the domain of a predominantly male group in society – the ability to touch and interact with the devices is changing all that.

One of the latest advances in rich media (or should we say: interactive books that includes media) is not simply that they use javascript -but that the latest additions by Adobe to their PDF format is pretty much tailor made for iBooks and Amazon’s reader. But someone has to program the effects and movements of images using javascript (Adobe actually started adding javascript support 10 years ago, but hardly anyone have noticed that is not in the publishing business).

This is perfect for smart mobile studio which is capable of producing advanced yet compact apps that makes full use of hardware acceleration and all the latest web technologies. So if you’re into graphics and know smart – then this is absolutely knowledge publishers will be interested in. You wont believe some of the prices these publishers pay just for some javascript animations (I was gobsmacked by it). And with smart you can compete not only in terms of code complexity, but also in time to deliver.

Games and multimedia

Dune II, Amiga classic

Javascript games is becoming more and more popular. I really had to see it for myself to believe it, but kids today don’t grow up with or care about Amiga’s or commodore 64’s – they grow up with the browser. My 9 year old son loves to play online games but to my surprise, he is more interested in either retro games (super mario, sonic etc. in an emulator) or javascript games. He occasionally plays a game of FIFA on the PlayStation 3, but his generation prefers to play javascript games.

A good javascript game that can run in any webkit browser (we also support FireFox) can go a long way. Since smart compiles to javascript it can be played on all operative systems (linux, mac, windows, whatever has a modern browser, even my TV runs smart apps) and reach all mobile phones and pads at the same time. With a dedicated server and a REST API you could do a lot of cool stuff.

And one of our advantages that the others dont have, is quite frankly classes. Take something simple like hardware accelerated graphics. Sounds easy yeah? Well actually it’s not, at least not when you are hacking away in a javascript notepad editor, having not only to code the game – but also create the OOP layer as well (or use a framework that mimic these things). Most javascript developers end up with canvas games, because mixing pixel graphics with other elements is — well, let’s just say it quickly turns into a mess after 10.000 lines of javascript.

I invented the term ‘Object-Oriented’, and I can tell you I did not have C++ in mind.
-Source: Alan Kay. Creator of Smalltalk.

Since smart comes with a full implementation of sprite3d, reverse engineered in object pascal — creating responsive and blistering fast javascript games is really not that hard. And we have the benefit of classes, so our monsters can inherit things like behavior, animations and so on. For us coming from delphi we take that for granted, but it’s actually not something we should take for granted – because in a lot of languages you are expected to type quite a bit of code before you even see a pixel on screen.

Had I not been busy with the first smart update, I would probably be coding a Dune II clone right now.