FiveTech Support Forums

Hello All,

I use bKeyDown and bKeyChar but I cant trap the UP and DOWN arrow keys..

No problem If using mouse to navigate but if UP,DOWN keys are pressed?

Regards,
Fraxzi

frose wrote:Fraxzi,

modifying the METHOD KeyDown() in xbrowse.prg works for me. For example I wanted to trap the key VK_TAB:

Code (fw): Select all Collapse

CASE nKey == VK_TAB
      My_Tab()

Fraxzi,

You will have to subclass xbrowse and create a new keyDown() method.

James

Thanks James,

Do you have a sample I can start with?

Fraxzi

James Bott wrote:

Code (fw): Select all Collapse

#include "fivewin.ch"
#include "vkey.ch"

CLASS MyBrowse from TXBrowse
   method KeyDown()
endclass

Method KeyDown( nKey, nFlags ) CLASS MyBrowse

  do case
     case nKey == VK_UP
        // do whatever
     case nKey == VK_DOWN
        // do whatever
  enddo

return super:keyDown( nKey, nFlags )

with the above, can I alter the Method Keydown() on an already created object TXBrowse?

James,

thank you very much for this tip, how to use inheritance and subtyping, polymorphism or overriding. How easy OOP can be

James Bott wrote:Fraxzi,

with the above, can I alter the Method Keydown() on an already created object TXBrowse?

Well, you have to use MyBrowse instead of TXBrowse, but other than the way you call it:

Instead of:

oBrw:= TXBrowse():new( oWnd )

You use:

oBrw:= MyBrowse():new( oWnd )

The syntax is exactly the same as TXBrowse (because everything else is TXBrowse code). So the only code you need to change is the above line.

You may want to read the Introduction to Object Oriented Programming articles on my website for a better understanding of OOP and subclassing.

http://www.gointellitech.com/program.htm

Regards,
James

...
   REDEFINE XBROWSE oBrw ID 1023 OF oDlg;
                  AUTOSORT UPDATE AUTOCOLS FASTEDIT LINES CELL;
                  ARRAY { {'Test'} };
                  CLASS MyxBrowse()
...

CLASS MyxBrowse from TXBrowse
   METHOD KeyDown( nKey, nFlags )
ENDCLASS

METHOD KeyDown( nKey, nFlags ) CLASS MyxBrowse

  DO CASE
     CASE nKey == VK_UP
        // do whatever
          msginfo( 'Up Key' test )
     CASE nKey == VK_DOWN
        // do whatever
  ENDCASE

RETURN Super:KeyDown( nKey, nFlags )
...

Unfortunately the name of the original class is used inside various FWH sources and this prevents the full working inheritance.

EMG

Enrico Maria Giordano wrote:Unfortunately the name of the original class is used inside various FWH sources and this prevents the full working inheritance.

EMG

SET XBROWSE TO MyBrowse()

SetXBrowse( { || MyBrowse() }

Please search for the string "txbrowse" inside FWH source code.

EMG

Please search for the string "txbrowse" inside FWH source code.

Exactly. The problem are the ones in btnbmp.prg, database.prg and dialog.prg.

EMG