ClarionX

Btrieve 6.15 is my Closest Friend

For those of you who love "Old School" Database drivers... Btrieve Rocks!

The core Btrieve 6.15 engine still exists inside Pervasive.SQL and its pretty much the same engine you would have known and loved since its release in 1995 for windows 95/NT.

It provides extremely efficient, high-speed ISAM data access that can’t be beat by any other access method.

The latest versions have relational capabilities (a SQL engine).

Btrieve stands the test of time. Why only now, 27/5/2008 am I considering moving my major application from btrieve 6.15 (circa 1995) to SQL Server Express Edition 2005.

Btrieve has served me faithfully for 13 years and will go on serving me. Its Gold!

Reading Base64 ...

This is the first article in an Internet Protocol/encoding Series...As developers we will at one time or another need to read base64 encoded data....heres my take...

Base64 is used to encode binary files in a text format suitable to be encapsulated in text documents. One interesting thing about base 64 is that it is one of the only data representation
schemes in modern use that doesn’t encrypt or compress the data. It just represents data
in a different form.

The solution to this problem was to create a data representation protocol that would allow
binary data to be encapsulated within another document. The defacto standard for doing
this is called base 64. In fact, some applications use base 64 as an encryption technique,
albeit a weak one. Basic authentication over the Internet encrypts the username-password
using base 64.

Here is a simple base64 decoder algorithm that has been very useful over the years...

base64decode PROCEDURE(STRING b64)

b64chars STRING('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/')

oString ANY

CODE

oString = '' !Dont use CLEAR it will cause a GPF on an ANY Variable

! Base64 strings especially those from emails can contain carriage returns and tabs these must be removed before decoding....

b64 = StringReplace(b64,CHR(9),'')
b64 = StringReplace(b64,CHR(10),'')
b64 = StringReplace(b64,CHR(13),'')

! Base64 strings are groups of four characters and need to be stepped through by 4....

LOOP i# = 1 TO LEN(CLIP(b64)) BY 4

!Create a 24 bit Number by bit shifting the four chars values by  6 bit segments...

BigNumber# = BSHIFT(INSTRING(b64[i#],b64chars,1,1)-1,18) + BSHIFT(INSTRING(b64[i#+1],b64chars,1,1)-1,12) + BSHIFT(INSTRING(b64[i#+2],b64chars,1,1)-1,6) + (INSTRING(b64[i#+3],b64chars,1,1)-1)

!Extract the original 3 ascii chars by bit shifting in the other direction by 8 bit segments...

Char1# = BAND(BSHIFT(BigNumber#,-16),11111111b)
Char2# = BAND(BSHIFT(BigNumber#,-8),11111111b)
Char3# = BAND(BigNumber#,11111111b)

!handle trailing padding characters thus...and translate the character values...
IF b64[i#+3] = '=' AND b64[i#+2] ~= '=' THEN
oString = oString & CHR(Char1#)&CHR(Char2#)
ELSIF b64[i#+3] = '=' AND b64[i#+2] = '=' THEN
oString = oString & CHR(Char1#)
ELSE
oString = oString & CHR(Char1#)&CHR(Char2#)&CHR(Char3#)
END
!repeat operation for each group of four base64 chars

END

RETURN CLIP(oString)

The result is the unencoded text or binary data....for more info on base64 like a encoding checkout RFC 3548...

Cheers Clarion ... My Old Friend...

When a customer rings you up, gives you a rap and asks you to send an invoice for November and mentions they don't mind paying a premium...if your using C#....that's a miracle...if your using Clarion....its probably because you have delivered a solid product ahead of time and under budget....

Here is to Clarion and its RAD philosophy....

How to :: Subclass Windows and do Icons in the System Tray!

Its simple to add code to your Clarion Application and you too can have icons in the System Tray. The concept is sound and simple to do in windows yourself! Microsoft has all the tools you need in their Windows API to help you extend your clarion apps by yourself...

Here is a starting point...

To place icons in the system tray Win API Shell Notify Icon Function does all the work for you - providing an interface to add, change and remove icons from the system tray. (See example code below for implementation)

If you want animated icons in the System Tray you will need to setup a timer event and change the icons to create the effect of animated gif.

If you want to capture mouse events on the icon you will need to subclass the windows event handlers of the parent clarion window. (See example code below for implementation)

Once subclassed you can intercept messages to the window and handle them appropriately....like left mouse clicks on the icon in the system tray. You can also handle windows shutdown grace fully! When windows shuts down it sends a system exit message to all applications running...You can then shutdown your application properly and avoid those Application is still active messages....(See example code below for implementation)

In further articles I will explain Balloon tips and other issues surrounding icons and windows services.

Learning through doing is an excellent way to become a better programmer but not necessarily a better developer. Having said that a good mix of both skill sets is essential. I believe that any experience a good or painful one helps us grow.

Here are some example pieces of code that I use in some of my personal applications at home.

Example Code: (Subclassing Windows Event handlers)

After opening window do the following....

SubClassWindows ROUTINE

SavedProc1 = Window{PROP:WndProc}

Window{PROP:WndProc} = ADDRESS(SubFunc1)

SavedProc2 = Window{PROP:ClientWndProc}

Window{PROP:ClientWndProc} = ADDRESS(SubFunc2)

DO SetupNID

Once subclassed you can intercept messages to the window and handle them appropriately....like left mouse clicks on the icon in the system tray. You can also handle windows shutdown grace fully!

Example Code: (Subclass WndProc)

Some code adapted from a clarionmag article some years ago.

SubFunc1 FUNCTION (hWnd,wMsg,wP,lP) ! Declare Procedure

WM_QUERYENDSESSION Equate(00011H)

WM_ENDSESSION Equate(00016H)

CODE ! Begin processed code

CASE wMsg

IF WM_QUERYENDSESSION

     RETURN(TRUE)

OF WM_ENDSESSION

     POST(EVENT:CloseWindow,,MainThread)

     RETURN(TRUE)

OF EVENT:NIM

CASE BAND(lP, 0FFFFh)

OF LOC:WM_LBUTTONUP ! Left mouse click

   POST(Event:NIM:MouseLeft,,MainThread)

OF LOC:WM_LBUTTONDBLCLK ! Left mouse double click

   POST(Event:NIM:MouseLeft2,,MainThread)

OF LOC:WM_RBUTTONDOWN ! Right mouse click - pressed

OF LOC:WM_RBUTTONUP ! Right mouse click - released

   POST(Event:NIM:MouseRight,,MainThread)

OF LOC:WM_RBUTTONDBLCLK ! Right mouse double click

   POST(Event:NIM:MouseRight2,,MainThread)

END

RETURN(0)

ELSE

! Pass the unhandled event and it's params on to the previous window procedure  in the chain

          RETURN(CallWindowProc(SavedProc1,hWnd,wMsg,wP,lP))

      END

Example Code:(Icons in the Tray)

Shell Notify Icon does all the work for you here!!!!

SetupNID ROUTINE

TrayCString = 'generic_ico'

NID:cbSize = SIZE(NotifyIconData)

NID:hWnd = Window{Prop:Handle}

NID:uID = 100

NID:uFlags = NIF_ICON + NIF_MESSAGE + NIF_TIP

NID:uCBmessage = Event:NIM

!your defined message to capture in the parent clarion window

NID:hIcon = LoadIcon(SYSTEM{PROP:APPINSTANCE},ADDRESS(TrayCString))

NID:ToolTip = CLIP(SVC:ToolTip) & CHR(0)

DO AddIconToTray

AddIconToTray ROUTINE

IF Shell_NotifyIcon(NIM_ADD, ADDRESS(NotifyIconData)) THEN

Icon change success fult

END

ChangeIconInTray ROUTINE

IF Shell_NotifyIcon(NIM_MODIFY, ADDRESS(NotifyIconData)) THEN

!Suceeded

ELSE

!Failed

END

RemoveIconFromTray ROUTINE

IF Shell_NotifyIcon(NIM_DELETE, ADDRESS(NotifyIconData)) THEN

Removed

END

A lot of this code would be easily adaptable to your own reusable class...enjoy learning...

Clarion 7....When?

Does anyone know when?

I am keen to get started on C7 but still no word of an Alpha...

Wasn't it supposed to be alpha this year??

Please anyone with any useful info about time lines please post a comment...

I have several large projects on the go and am trying to make some strategic decisions...

Mac OSX Viruses....

After numerous discussions with my colleagues about the validity of Apple's claim or at least users claim, that they were virus free and safe....I scanned the net and found and interesting article....demonstrating the detection of the first ever virus for Mac OSX....16/02/2006...by Sophos Engineers.

Feeling vindicated...I believe the proliferation of viruses on an operating system is a function of its popularity and share of the market place...In other words in the majority of cases not including script kiddies virus writers are skillful enough to tackle any OS platform...its just that more people use windows...

Sophos Article:

16 February 2006

First ever virus for Mac OS X discovered

OSX/Leap-A worm spreads via iChat instant messaging software

OSX/Leap-A uses an image of a JPEG icon to try and fool users.

Experts at SophosLabs™, Sophos's global network of virus, spyware and spam analysis centers, have announced the discovery of the first virus for the Apple Mac OS X platform. The virus, named OSX/Leap-A (also known as OSX/Oompa-A) spreads via instant messaging systems....[more]

John

How to :: Subclass Windows and do Icons in the System Tray!

Its simple to add code to your Clarion Application and you too can have icons in the System Tray. The concept is sound and simple to do in windows yourself! Microsoft has all the tools you need in their Windows API to help you extend your clarion apps by yourself...

Here is a starting point...

To place icons in the system tray Win API Shell Notify Icon Function does all the work for you - providing an interface to add, change and remove icons from the system tray. (See example code below for implementation)

If you want animated icons in the System Tray you will need to setup a timer event and change the icons to create the effect of animated gif.

If you want to capture mouse events on the icon you will need to subclass the windows event handlers of the parent clarion window. (See example code below for implementation)

Once subclassed you can intercept messages to the window and handle them appropriately....like left mouse clicks on the icon in the system tray. You can also handle windows shutdown grace fully! When windows shuts down it sends a system exit message to all applications running...You can then shutdown your application properly and avoid those Application is still active messages....(See example code below for implementation)

In further articles I will explain Balloon tips and other issues surrounding icons and windows services.

Learning through doing is an excellent way to become a better programmer but not necessarily a better developer. Having said that a good mix of both skill sets is essential. I believe that any experience a good or painful one helps us grow.

Here are some example pieces of code that I use in some of my personal applications at home.

Example Code: (Subclassing Windows Event handlers)

After opening window do the following....

SubClassWindows ROUTINE

SavedProc1 = Window{PROP:WndProc}

Window{PROP:WndProc} = ADDRESS(SubFunc1)

SavedProc2 = Window{PROP:ClientWndProc}

Window{PROP:ClientWndProc} = ADDRESS(SubFunc2)

DO SetupNID

Once subclassed you can intercept messages to the window and handle them appropriately....like left mouse clicks on the icon in the system tray. You can also handle windows shutdown grace fully!

Example Code: (Subclass WndProc)

Some code adapted from a clarionmag article some years ago.

SubFunc1 FUNCTION (hWnd,wMsg,wP,lP) ! Declare Procedure

WM_QUERYENDSESSION Equate(00011H)

WM_ENDSESSION Equate(00016H)

CODE ! Begin processed code

CASE wMsg

IF WM_QUERYENDSESSION

     RETURN(TRUE)

OF WM_ENDSESSION

     POST(EVENT:CloseWindow,,MainThread)

     RETURN(TRUE)

OF EVENT:NIM

CASE BAND(lP, 0FFFFh)

OF LOC:WM_LBUTTONUP ! Left mouse click

   POST(Event:NIM:MouseLeft,,MainThread)

OF LOC:WM_LBUTTONDBLCLK ! Left mouse double click

   POST(Event:NIM:MouseLeft2,,MainThread)

OF LOC:WM_RBUTTONDOWN ! Right mouse click - pressed

OF LOC:WM_RBUTTONUP ! Right mouse click - released

   POST(Event:NIM:MouseRight,,MainThread)

OF LOC:WM_RBUTTONDBLCLK ! Right mouse double click

   POST(Event:NIM:MouseRight2,,MainThread)

END

RETURN(0)

ELSE

 ! Pass the unhandled event and it's params on to the previous window procedure  in the chain

          RETURN(CallWindowProc(SavedProc1,hWnd,wMsg,wP,lP))

      END

Example Code:(Icons in the Tray)

Shell Notify Icon does all the work for you here!!!!

SetupNID ROUTINE

TrayCString = 'generic_ico'

NID:cbSize = SIZE(NotifyIconData)

NID:hWnd = Window{Prop:Handle}

NID:uID = 100

NID:uFlags = NIF_ICON + NIF_MESSAGE + NIF_TIP

NID:uCBmessage = Event:NIM

!your defined message to capture in the parent clarion window

NID:hIcon = LoadIcon(SYSTEM{PROP:APPINSTANCE},ADDRESS(TrayCString))

NID:ToolTip = CLIP(SVC:ToolTip) & CHR(0)

DO AddIconToTray

AddIconToTray ROUTINE

IF Shell_NotifyIcon(NIM_ADD, ADDRESS(NotifyIconData)) THEN

Icon change success fult

END

ChangeIconInTray ROUTINE

IF Shell_NotifyIcon(NIM_MODIFY, ADDRESS(NotifyIconData)) THEN

!Suceeded

ELSE

!Failed

END

RemoveIconFromTray ROUTINE

IF Shell_NotifyIcon(NIM_DELETE, ADDRESS(NotifyIconData)) THEN

Removed

END

A lot of this code would be easily adaptable to your own reusable class...enjoy learning...