Implementing Internet Features

LEADTOOLS offers the following alternatives for Internet support:

To support your own input stream you can use the ActiveX with the methods described in Loading a Bitmap from Your Own Buffer.
For asynchronous loading through Microsoft Internet Explorer you can use the capabilities described in the remainder of this topic.

Loading a Bitmap over the Internet

The LEADTOOLS ActiveX is a net-aware ActiveX. This means you can support new image formats and image processing on your web pages by adding the LEADTOOLS ActiveX to your HTML code. For examples using HTML with Java and VB Script, refer to the EXAMPLES\OCX\INTERNET subdirectory.

Use the following elements to manage asynchronous loading of a bitmap from a local file or from an Internet URL. Note that these elements require version 3.01 of the Microsoft Internet Explorer, which is available from http://www.microsoft.com.

BitmapDataPath property

BitmapDataPathClosed event

ReadyStateChange event

ReadyState property

Use the AutoSetRects property and its related properties to simplify the display rectangles when loading an image from the Internet.

Note: When using the LEAD ActiveX control on a web page, you should set the OLEDropAllowed property to False (0) in the Unload Event. For example, in VBScript this is done as follows:

Sub Window_OnUnload
LEAD1.OLEDropAllowed = False
end Sub

Using the LTOCX.LIC file on the Internet

The LEADTOOLS ActiveX requires the correct license string in order to load properly. In a development environment, the string is made available to the ActiveX control when the LTOCX.LIC file is placed in the same directory as the ActiveX control. When creating an executable program, the development environment will extract the correct string from the ActiveX control and place it in the generated code. When the executable code is run, it provides the license string to the control. This allows the executable program to function properly without the LTOCX.LIC file.

Since you cannot redistribute the LTOCX.LIC file with HTML script, special handling is required for Internet web page development to insure proper operation. You can unlock support for certain LEADTOOLS features by including the keys in the .LIC file. Edit the LTOCX.LIC file and append at the end of a line, and on the same line, one or more pairs in the form |L_SUPPORT_xxx=key. The keys that you can specify are the same as the UnlockSupport method:

Using a Cabinet File

LEADTOOLS provides a cabinet file (LTOCXU.CAB) that packages the LEADTOOLS ActiveX, its dependent DLLs, and the required code-signing information. You can reference this cabinet file in the CODEBASE attribute of the <OBJECT> tag of your HTML code as shown in the following example:

The LTOCXU.CAB cabinet includes the following files:

LTOCXU.OCX
LTKRNU.DLL
LTDISU.DLL
LTEFXU.DLL
LTFILU.DLL
LTIMGUTLU.DLL
LTIMGCORU.DLL
LTIMGCLRU.DLL
LTIMGEFXU.DLL
LFCMPU.DLL
LFTIFU.DLL
LFFAXU.DLL

For information about these files, refer to Files To Be Included With Your Application.