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	<P>
	<DT></DT>
	<DD><B>8. </B>Now compile and run the program. Type an URL in the combo box and press
	Enter. If you typed in a valid URL, the page will load in the HTML control.
	<P>
</DL>

<P>Wow! A Web browser in 15 minutes! Notice that the browser acts like any other
Web browser...well, sort of. You need to add a lot of functionality, but it's a start.</P>


<BLOCKQUOTE>
	<P>
<HR>
<strong>NOTE:</strong> If you are fortunate enough to have a full-time Internet connection,
	your new browser will work immediately. If you are using dial-up networking with
	auto dial enabled, the dialer will start automatically and connect to your Internet
	service provider (ISP). If you don't have dial-up networking installed, you have
	to connect to the Internet manually before running the program. 
<HR>


</BLOCKQUOTE>

<H3></H3>
<H3><A NAME="Heading5"></A>Adding a Progress Indicator</H3>
<P>You now have a good start on your Web browser. One of the features you are missing
is some status information on each page as it loads. What you'll do is add a routine
that updates the status bar as a page loads. You make use of the THTML control's
OnUpdateRetrieval and OnEndRetrieval events to obtain periodic status updates. You
will use the GetBytesTotal and GetBytesDone methods to calculate a percentage and
then display the percentage loaded in the status bar. Ready?</P>

<DL>
	<DT></DT>
	<DD><B>1. </B>Click on the HTML control on your form. Generate an event handler for
	the OnUpdateRetrieval event. Add code to the event handler so that it looks like
	this:
	<P>
</DL>



<BLOCKQUOTE>
	<PRE>procedure TWebMain.HTMLUpdateRetrieval(Sender: TObject);
var
  Total   : Integer;
  Done    : Integer;
  Percent : Integer;
begin
  Total := HTML.RetrieveBytesTotal;
  Done  := HTML.RetrieveBytesDone;
  if (Total = 0) or (Done = 0) then
    Percent := 0
  else
    Percent := ((Done * 100) div Total);
  StatusBar.SimpleText := Format(
    `Getting Document: %d%% of %dK', [Percent, Total div 1024]);
end;</PRE>

</BLOCKQUOTE>

<PRE></PRE>

<DL>
	<DT></DT>
	<DD><B>2. </B>Now generate an event handler for the OnEndRetrieval event. Type this
	code in the event handler:
	<P>
</DL>



<BLOCKQUOTE>
	<PRE>StatusBar.SimpleText := `Done';</PRE>

</BLOCKQUOTE>

<PRE></PRE>
<P>Take a closer look at the code in step 1. There isn't very much to it. The GetBytesTotal
method tells you how many bytes are in the document or the embedded object currently
being loaded (objects include images). The GetBytesDone method gives the number of
bytes that have been retrieved for the page or object up to this point. From there
it's a simple matter to calculate the percentage of the object that has been retrieved.
Finally, you format a string with the information obtained from the HTML control
and send it to the status bar. The code in step 2 simply updates the status bar after
the entire document has been loaded.</P>
<P>Run the program again and watch what happens when you load a page. The status
bar shows the percentage loaded for the page and for any embedded objects.</P>
<P>
<H3><A NAME="Heading6"></A>Some Finishing Touches</H3>
<P>Now for some finishing touches. First, you'll add some buttons beneath the URL
combo box. (For a peek at the finished product, see Figure BD.2.) Here goes:</P>

<DL>
	<DT></DT>
	<DD><B>1. </B>Place a button on the panel beneath the URL combo box. Make its Name
	property GoBtn and change its Caption to Go!.
	<P>
	<DT></DT>
	<DD><B>2. </B>Generate an event handler for the OnClick event for the new button.
	Enter the following code in the event handler:
	<P>
</DL>



<BLOCKQUOTE>
	<PRE>URLComboBoxClick(Self);</PRE>

</BLOCKQUOTE>

<PRE></PRE>

<DL>
	<DT></DT>
	<DD><B>3. </B>Place another button on the panel, just to the right of the first button.
	Change the Name to StopBtn and the Caption to Stop.
	<P>
	<DT></DT>
	<DD><B>4. </B>Generate an event handler for the OnClick event for this button and
	type the following code in the event handler:
	<P>
</DL>



<BLOCKQUOTE>
	<P>HTML.Cancel(0);</P>
	<P>
	<PRE>StatusBar.SimpleText := `Done';</PRE>

</BLOCKQUOTE>

<PRE></PRE>

<DL>
	<DT></DT>
	<DD><B>5. </B>Place a third button on the panel to the right of the other two buttons.
	Change the Name property to ReloadBtn. Change the Caption property to Reload.
	<P>
	<DT></DT>
	<DD><B>6. </B>Create an event handler for the OnClick event for this button and enter
	the same code as in step 2:
	<P>
</DL>



<BLOCKQUOTE>
	<PRE>URLComboBoxClick(Self);</PRE>

</BLOCKQUOTE>

<PRE></PRE>

<DL>
	<DT></DT>
	<DD><B>7. </B>Place a fourth (and final) button on the panel. Change the Name to
	SourceBtn and change the Caption to View Source.
	<P>
	<DT></DT>
	<DD><B>8. </B>Create an event handler for the OnClick event and enter this code:
	<P>
</DL>



<BLOCKQUOTE>
	<PRE>HTML.ViewSource := not HTML.ViewSource;
if HTML.ViewSource then
  SourceBtn.Caption := `View Document'
else
  SourceBtn.Caption := `View Source';</PRE>

</BLOCKQUOTE>

<PRE></PRE>
<P>Your form should now look like the one shown in Figure BD.2.</P>
<P><A HREF="javascript:popUp('28672202.gif')"><B>FIGURE BD.2.</B></A><B> </B><I>The
EZ Web Browser with buttons in place.</I></P>
<P>These steps introduce a couple of new THTML elements. The Cancel method stops
the process of loading a document. The ViewSource property is used to toggle between
viewing the document as HTML source or as a regular HTML document.</P>
<P>Now run the program again. Check out the new buttons and see what they do. In
particular, give the View Source button a try.</P>
<P>Okay, you're almost done with your Web browser. Let's add a couple of more features.
You are going to respond to two more events of the THTML control in order to provide
more status information.</P>

<DL>
	<DT></DT>
	<DD><B>1. </B>Generate an event handler for THTML's OnDoRequestDoc event. Type this
	code in the event handler:
	<P>
</DL>



<BLOCKQUOTE>
	<PRE>StatusBar.SimpleText := `Connecting to ` + URL + `...';</PRE>

</BLOCKQUOTE>

<PRE></PRE>

<DL>
	<DT></DT>
	<DD><B>2. </B>Now create an event handler for the OnBeginRetrieval event. When the
	event handler appears, type this code:
	<P>
</DL>



<BLOCKQUOTE>
	<PRE>StatusBar.SimpleText := `Connected...';
URLComboBox.Items.Insert(0, URLComboBox.Text);</PRE>

</BLOCKQUOTE>

<PRE></PRE>
<P>In this sequence, step 1 makes use of the OnDoRequestDoc event, which is generated
when a document is requested. The URL parameter of the DoRequestDoc event handler
is the URL of the site to which you are connected. As long as the URL is provided,
you can use it to build a string to display in the status bar. Step 2 adds a little
more status information when the document actually starts to load. It also takes
the URL and adds it to the URL combo box's list. You need to make sure that you have
connected to a site before adding the URL to the list of visited sites.</P>
<P>Congratulations, you have finished (or nearly finished) your first Internet application.
Figure BD.3 shows the EZ Web Browser in operation.</P>
<P><A HREF="javascript:popUp('28672203.gif')"><B>FIGURE BD.3.</B></A><B> </B><I>The
finished EZ Web Browser displaying a page.</I></P>
<P>Hey, that's good work! There are some things that your Web browser doesn't do,
but it does a lot, so you can be proud. Stand back and admire your work. You can
take your new creation and add some new features of your own. One feature you might
want to add is a list of URLs that can be used to implement browse buttons (back
and next). You could also replace the standard buttons with a toolbar and add glyphs
to the toolbar's buttons. If you really want to add the ultimate touch, provide an
animation while the document is loading so that your users can tell when your browser
is doing something. You can do that most easily with a TImageList component, although
the TAnimate component would work, too.</P>
<P>The THTML control has several properties that I didn't cover. Most of these properties
have to do with user preferences such as background color, the color of links, the
color of visited links, the various fonts used for each heading size, and so on.
I'm not going to explain those properties because they are easy to figure out. For
the most part you can just accept the default values for these properties. If you
want to customize your browser further, though, you can certainly spend some time
reviewing the properties list for the THTML control.</P>
<P>Listing BD.1 lists the browser program's main unit.</P>
<P>
<H4>LISTING BD.1. WebBrwsU.pas.</H4>
<PRE>unit WebBrwsU;
interface
uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ExtCtrls, OleCtrls, NMHTML, ComCtrls;
type
  TWebMain = class(TForm)
    Panel1: TPanel;
    URLComboBox: TComboBox;
    StatusBar: TStatusBar;
    HTML: THTML;
    GoBtn: TButton;
    StopBtn: TButton;
    ReloadBtn: TButton;
    SourceBtn: TButton;
    procedure URLComboBoxClick(Sender: TObject);
    procedure URLComboBoxKeyPress(Sender: TObject; var Key: Char);
    procedure HTMLUpdateRetrieval(Sender: TObject);
    procedure HTMLEndRetrieval(Sender: TObject);
    procedure Gobtnclick(Sender: Tobject);
    procedure StopBtnClick(Sender: TObject);
    procedure ReloadBtnClick(Sender: TObject);
    procedure SourceBtnClick(Sender: TObject);
    procedure HTMLDoRequestDoc(Sender: TObject; const URL: WideString;
      Element: HTMLElement; DocInput: DocInput;
      var EnableDefault: WordBool);
    procedure HTMLBeginRetrieval(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
var
  WebMain: TWebMain;
implementation
{$R *.DFM}
procedure TWebMain.URLComboBoxClick(Sender: TObject);
begin
  if URLComboBox.Text &lt;&gt; `' then
    HTML.RequestDoc(URLComboBox.Text);
end;
procedure TWebMain.URLComboBoxKeyPress(Sender: TObject; var Key: Char);
begin
  if Key = Char(VK_RETURN) then begin
    Key := #0;
    if URLComboBox.Text = `' then
      Exit;
    URLComboBoxClick(Sender);
  end;
end;
procedure TWebMain.HTMLUpdateRetrieval(Sender: TObject); 
var
  Total   : Integer;
  Done    : Integer;
  Percent : Integer;
begin
  Total := HTML.RetrieveBytesTotal;
  Done  := HTML.RetrieveBytesDone;
  if (Total = 0) or (Done = 0) then
    Percent := 0
  else
    Percent := ((Done * 100) div Total);
  StatusBar.SimpleText := Format(
    `Getting Document: %d%% of %dK', [Percent, Total div 1024]);
end;
procedure TWebMain.HTMLEndRetrieval(Sender: TObject);
begin
  StatusBar.SimpleText := `Done';
end;
procedure TWebMain.GoBtnClick(Sender: TObject);
begin
  URLComboBoxClick(Self);
end;
procedure TWebMain.StopBtnClick(Sender: TObject);
begin
  HTML.Cancel(0);
  StatusBar.SimpleText := `Done';
end;
procedure TWebMain.ReloadBtnClick(Sender: TObject);
begin
  URLComboBoxClick(Self);
end;
procedure TWebMain.SourceBtnClick(Sender: TObject);
begin
  HTML.ViewSource := not HTML.ViewSource;
  if HTML.ViewSource then
    SourceBtn.Caption := `View Document'
  else
    SourceBtn.Caption := `View Source';
end;
procedure TWebMain.HTMLDoRequestDoc(Sender: TObject; const URL: WideString;
  Element: HTMLElement; DocInput: DocInput; var EnableDefault: WordBool);
begin
  StatusBar.SimpleText := `Connecting to ` + URL + `...';
end;
procedure TWebMain.HTMLBeginRetrieval(Sender: TObject);
begin
  StatusBar.SimpleText := `Connected...';
  URLComboBox.Items.Insert(0, URLComboBox.Text);
end;
</PRE>
<PRE>end.</PRE>
<P>
<H2><A NAME="Heading7"></A>Using Internet Explorer as an ActiveX Control</H2>
<P>If you have Microsoft Internet Explorer installed on your system, you can use
it as an ActiveX control. The first thing you need to do is import the control into
Delphi's Component palette. After that, you can place it on a form just as you would
any control. First, let me show you how to import Internet Explorer. (I showed you
how to import ActiveX controls on Day 15, &quot;COM and ActiveX,&quot; but it doesn't
hurt to review.) Here are the steps:</P>

<DL>