Example Text Editor For DBC/DBP - GameCreators Forum

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TDK

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Joined: 19th Nov 2002

Location: UK

Posted: 7th May 2006 20:38

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This program works OK, but is not a complete finished program. It was intended to be a very simple example to demonstrate how to make a simple text editor in DB Classic. (It also seems to work fine in DBP too).

It has been written simply to make it as easy to follow as possible, so it's not meant to be an exemplary example of optimized code.

Feel free to modify and use in your own programs as you wish.

Supports:

Text entry, Enter key, Backspace key, Cursor keys, Home key, End key.

Ctrl-S - Save surrent text file (overwrites if already exists)
Ctrl-L - Load text file (must know the name)
Ctrl-C - Clear current text
Ctrl-X - Exit

Current number of lines in the text file is displayed on the menu bar, along with the current row and column position of the cursor.

Note: You may have to alter the Sleep values if keypresses are repeated or not recorded when you type. In a more refined version, all the sleep commands would be replaced with a better timing function, but that's for you to do yourself...

Rem Example Text Editor Program For DB Classic
Rem By TDK_Man May 2006

Rem Note: INCOMPLETE PROGRAM TO DEMONSTRATE PRINCIPLE ONLY

Sync On: Sync Rate 0: CLS 0

SET WINDOW ON
SET WINDOW TITLE "Text Editor"
SET WINDOW SIZE 648,494: Rem Window slightly larger than the display (640x480)
Show Window
Rem The default 640x480 display gives us an area with 71 characters across and 30 characters down

Set Text Font "Courier",1
Set Text Size 16
Set Text Transparent

True = 1: False = 0
MaxLines = 100
Dim Lines$(MaxLines): Rem up to 100 lines, but we will have to handle scrolling manually
CursorX = 0: CursorY=0: Rem Initial cursor starting position
NumLines = 1: Rem New doc always has a min of 1 line - even if not used
LineOffset = 0 : Rem for scrolling the lines of text
CharWidth = 9
ScrnCharWidth = 71

Gosub UpdateMenu
Ink RGB(255,255,255),0
Set Cursor CursorX,CursorY
Text CursorX*CharWidth,CursorY*16,"_"

Do
  Rem ***************************
  Rem   Handle ASCII Keypresses
  Rem ***************************

KeyPressed = Asc(Inkey$())
  If KeyPressed > 31 And KeyPressed < 122
    Rem Handle all keypresses here
    Rem For example: 97 - 122 = a .. z      65 - 90 = A .. Z      48 - 57 = 0 .. 9
    BeforeCursor$ = Left$(Lines$(CursorY),CursorX)
    CurrentLineLen = Len(Lines$(CursorY))
    AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen-CursorX)
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    If CursorX < ScrnCharWidth-1
      Lines$(CursorY) = BeforeCursor$ + Chr$(KeyPressed) + AfterCursor$
      Inc CursorX
    Else
      Lines$(CursorY) = BeforeCursor$+Chr$(KeyPressed)
      CursorX = 0: Inc CursorY: Rem Drop to start of the next line
      Lines$(CursorY) = AfterCursor$
      Inc NumLines: Rem Just started a new line
    Endif

Rem Now to check if line exceeds max line length
    CurrentLineLen = Len(Lines$(CursorY))
    If CurrentLineLen > ScrnCharWidth
      AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen - ScrnCharWidth): Rem characters after right edge of window
      Lines$(CursorY) = Left$(Lines$(CursorY),ScrnCharWidth): Rem keep characters inside window
      Lines$(CursorY+1) = AfterCursor$ + Lines$(CursorY+1)
    Endif
    Gosub UpdateAllLines
    Gosub UpdateMenu
    Sleep 120
  Endif

Rem ***** Backspace Key *****
  If KeyPressed = 8
    If CursorX > 0
      CurrentLineLen = Len(Lines$(CursorY))
      If CursorX = CurrentLineLen
        Rem Currently at the end of the line
        Lines$(CursorY) = Left$(Lines$(CursorY),CurrentLineLen-1)
      Else
        Rem Currently somewhere in the middle of the line
        BeforeCursor$ = Left$(Lines$(CursorY),CursorX-1)
        AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen-CursorX)
        Lines$(CursorY) = BeforeCursor$ + AfterCursor$
      Endif
      Dec CursorX
    Else
      Rem At left edge of screen
      If Len(Lines$(CursorY))=0
        For N = CursorY To NumLines-2
          Lines$(N) = Lines$(N+1)
        Next N
        Dec NumLines
        Dec CursorY: CurrentLineLen = Len(Lines$(CursorY))
        If CursorX < CurrentLineLen Then CursorX = CurrentLineLen
      Else
        Rem There are characters after cursor
        AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen-CursorX)
        For N = CursorY To NumLines-2
          Lines$(N) = Lines$(N+1)
        Next N
        Dec NumLines
        Dec CursorY: CurrentLineLen = Len(Lines$(CursorY))
        If CursorX < CurrentLineLen Then CursorX = CurrentLineLen
        Lines$(CursorY) = Lines$(CursorY)+AfterCursor$
        Rem Check new line length
        CurrentLineLen = Len(Lines$(CursorY))
        If CurrentLineLen > ScrnCharWidth
          AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen - ScrnCharWidth): Rem characters after right edge of window
          Lines$(CursorY) = Left$(Lines$(CursorY),ScrnCharWidth): Rem keep characters inside window
          Lines$(CursorY+1) = AfterCursor$ + Lines$(CursorY+1)
        Endif
      Endif
    Endif
    Gosub UpdateAllLines
    Gosub UpdateMenu
    Sleep 140
  Endif

Rem *******************************
  Rem   Handle NON-ASCII Keypresses
  Rem *******************************

Rem ***** Return Key *****
  If Returnkey()=1
    Rem Drop to next line
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    CurrentLineLen = Len(Lines$(CursorY))
    BeforeCursor$ = Left$(Lines$(CursorY),CursorX)
    AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen-CursorX)
    Rem Shuffle All Following Lines Down One (Will lose very last line but unlikely to be used)
    For N = MaxLines-1 To CursorY+1 Step -1
      Lines$(N) = Lines$(N-1)
    Next N
    Lines$(CursorY) = BeforeCursor$: Rem Set current line to text before cursor
    Lines$(CursorY+1) = AfterCursor$: Rem Set following line to text after cursor
    CursorX = 0: Inc CursorY: Rem New cursor position
    Inc NumLines: Rem We just added a new line
    Ink 0,0: Text CursorX*CharWidth,(CursorY+1)*16,"_"
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
    Gosub UpdateAllLines
    Gosub UpdateMenu
    rem Gosub UpdateStatus
    Sleep 140
  Endif

Rem ***** Home Key ***** 199
  If Scancode() = 199
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    CursorX = 0
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
  Endif

Rem ***** End Key ***** 207
  If Scancode() = 207
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    CursorX =  Len(Lines$(CursorY))
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
  Endif

Rem ***** Cursor Keys *****
  If Upkey()=1 And CursorY > 0: Rem Move Cursor Up
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    Dec CursorY: CurrentLineLen = Len(Lines$(CursorY))
    If CursorX > CurrentLineLen Then CursorX = CurrentLineLen
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
    Gosub UpdateMenu
    Sleep 60
  Endif
  If Downkey()=1 And CursorY < 28 And CursorY+1 < NumLines: Rem Move Cursor Down
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    Inc CursorY: CurrentLineLen = Len(Lines$(CursorY))
    If CursorX > CurrentLineLen Then CursorX = CurrentLineLen
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
    Gosub UpdateMenu
    Sleep 60
  Endif
  If Leftkey()=1 And CursorX > 0: Rem Move Cursor Left
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    Dec CursorX
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
    Gosub UpdateMenu
    Sleep 30
  Endif
  If Rightkey()=1: Rem Move Cursor Right
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    CurrentLineLen = Len(Lines$(CursorY))
    If CursorX < ScrnCharWidth and CursorX < CurrentLineLen
      Inc CursorX
    Else
      If NumLines > CursorY+1
        Inc CursorY: CursorX=0: Rem New position at start of next line
      Endif
    Endif
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
    Gosub UpdateMenu
    Sleep 30
  Endif

Rem ***** Load (Ctrl-L) *****
  If KeyState(38) = 1 And Scancode() = 29
    Rem Load A File
    Set Text Opaque: Sync
    Ink RGB(0,100,0),0: Box 0,465,639,479
    Ink RGB(255,255,255),RGB(0,100,0)
    Set Cursor 0,29*16: Input " Please Enter A Filename To Load (No Extension Required): ";FName$
    Repeat
    Until ReturnKey()=0
    FName$=FName$+".TXT": Rem <<< Choose your own filename extension here
    If File Exist(FName$) = 1
      UnDim Lines$(MaxLines): Rem Erase current string array
      Dim Lines$(MaxLines): Rem Recreate array (empty)
      Open To Read 1,FName$
        Read String 1, Temp$: NumLines=Val(Temp$)
        For N = 0 To NumLines-1
          Read String 1, Lines$(N)
        Next N
      Close File 1
      CursorX = 0: CursorY = 0
    Else
      Ink RGB(0,100,0),0: Box 0,465,639,479
      Ink RGB(255,255,0),RGB(0,100,0)
      Text 0,464," Sorry - That File Does Not Exist!"
      Sleep 4000
    Endif
    Gosub UpdateAllLines
    Gosub UpdateMenu
    Set Text Transparent: Sync
  Endif

Rem ***** Save (Ctrl-S) *****
  If KeyState(31) = 1 And Scancode() = 29
    Rem Save A File
    Set Text Opaque: Sync
    Ink RGB(0,100,0),0: Box 0,465,639,479
    Ink RGB(255,255,255),RGB(0,100,0)
    Set Cursor 0,29*16: Input " Please Enter A Filename To Save (No Extension Required): ";FName$
    Repeat
    Until ReturnKey()=0
    FName$=FName$+".TXT": Rem <<< Choose your own filename extension here
    If File Exist(FName$) = 1 Then Delete File FName$
    Open To Write 1,FName$
      Write String 1, Str$(NumLines)
      For N = 0 To NumLines-1
        Write String 1, Lines$(N)
      Next N
    Close File 1
    Gosub UpdateAllLines
    Gosub UpdateMenu
    Set Text Transparent: Sync
  Endif

Rem ***** Clear (Ctrl-C) *****
  If KeyState(46) = 1 And Scancode() = 29
    Rem Clear File
    Set Text Opaque: Sync
    Ink RGB(0,100,0),0: Box 0,465,639,479
    Ink RGB(255,255,255),RGB(0,100,0)
    Repeat
    Until Scancode() = 0
    CursorX=0: CursorY=0
    UnDim Lines$(MaxLines): Rem Erase current string array
    Dim Lines$(MaxLines): Rem Recreate array (empty)
    Gosub UpdateAllLines
    Gosub UpdateMenu
    Set Text Transparent: Sync
  Endif

Rem ***** Exit (Ctrl-X) *****
  If KeyState(45) = 1 And Scancode() = 29
    Rem Exit
    UnDim Lines$(MaxLines): Rem Erase current string array
    End
  Endif

Sync
Loop

UpdateAllLines:
  Set Text Opaque: Sync
  Ink 0,0: Box 0,0,639,464
  Ink RGB(255,255,255),0
  For N = 0 To 28: Rem 28 Lines
    Text 0,N*16,Lines$(N+LineOffset): Rem Correct lines if scrolled
  Next N
  Set Text Transparent: Sync
  Text CursorX*CharWidth,CursorY*16,"_"
Return

UpdateMenu:
  Set Text Opaque: Sync
  Ink RGB(255,255,255),RGB(0,100,0)
  Text 0,464," Ctrl-S Save  Ctrl-L Load  Ctrl-C Clear  Ctrl-X Exit  L:"+Str$(NumLines)+"  CPos:"+Str$(CursorX+1)+"/"+Str$(CursorY+1)+"      ": Rem Bottom line reserved for menu commands
  Set Text Transparent: Sync
Return

+ Code Snippet

Rem Example Text Editor Program For DB Classic
Rem By TDK_Man May 2006

Rem Note: INCOMPLETE PROGRAM TO DEMONSTRATE PRINCIPLE ONLY

Sync On: Sync Rate 0: CLS 0

SET WINDOW ON
SET WINDOW TITLE "Text Editor"
SET WINDOW SIZE 648,494: Rem Window slightly larger than the display (640x480)
Show Window
Rem The default 640x480 display gives us an area with 71 characters across and 30 characters down

Set Text Font "Courier",1
Set Text Size 16
Set Text Transparent

True = 1: False = 0
MaxLines = 100
Dim Lines$(MaxLines): Rem up to 100 lines, but we will have to handle scrolling manually
CursorX = 0: CursorY=0: Rem Initial cursor starting position
NumLines = 1: Rem New doc always has a min of 1 line - even if not used
LineOffset = 0 : Rem for scrolling the lines of text
CharWidth = 9
ScrnCharWidth = 71

Gosub UpdateMenu
Ink RGB(255,255,255),0
Set Cursor CursorX,CursorY
Text CursorX*CharWidth,CursorY*16,"_"

Do
  Rem ***************************
  Rem   Handle ASCII Keypresses
  Rem ***************************

  KeyPressed = Asc(Inkey$())
  If KeyPressed > 31 And KeyPressed < 122
    Rem Handle all keypresses here
    Rem For example: 97 - 122 = a .. z      65 - 90 = A .. Z      48 - 57 = 0 .. 9
    BeforeCursor$ = Left$(Lines$(CursorY),CursorX)
    CurrentLineLen = Len(Lines$(CursorY))
    AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen-CursorX)
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    If CursorX < ScrnCharWidth-1
      Lines$(CursorY) = BeforeCursor$ + Chr$(KeyPressed) + AfterCursor$
      Inc CursorX
    Else
      Lines$(CursorY) = BeforeCursor$+Chr$(KeyPressed)
      CursorX = 0: Inc CursorY: Rem Drop to start of the next line
      Lines$(CursorY) = AfterCursor$
      Inc NumLines: Rem Just started a new line
    Endif

    Rem Now to check if line exceeds max line length
    CurrentLineLen = Len(Lines$(CursorY))
    If CurrentLineLen > ScrnCharWidth
      AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen - ScrnCharWidth): Rem characters after right edge of window
      Lines$(CursorY) = Left$(Lines$(CursorY),ScrnCharWidth): Rem keep characters inside window
      Lines$(CursorY+1) = AfterCursor$ + Lines$(CursorY+1)
    Endif
    Gosub UpdateAllLines
    Gosub UpdateMenu
    Sleep 120
  Endif

  Rem ***** Backspace Key *****
  If KeyPressed = 8
    If CursorX > 0
      CurrentLineLen = Len(Lines$(CursorY))
      If CursorX = CurrentLineLen
        Rem Currently at the end of the line
        Lines$(CursorY) = Left$(Lines$(CursorY),CurrentLineLen-1)
      Else
        Rem Currently somewhere in the middle of the line
        BeforeCursor$ = Left$(Lines$(CursorY),CursorX-1)
        AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen-CursorX)
        Lines$(CursorY) = BeforeCursor$ + AfterCursor$
      Endif
      Dec CursorX
    Else
      Rem At left edge of screen
      If Len(Lines$(CursorY))=0
        For N = CursorY To NumLines-2
          Lines$(N) = Lines$(N+1)
        Next N
        Dec NumLines
        Dec CursorY: CurrentLineLen = Len(Lines$(CursorY))
        If CursorX < CurrentLineLen Then CursorX = CurrentLineLen
      Else
        Rem There are characters after cursor
        AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen-CursorX)
        For N = CursorY To NumLines-2
          Lines$(N) = Lines$(N+1)
        Next N
        Dec NumLines
        Dec CursorY: CurrentLineLen = Len(Lines$(CursorY))
        If CursorX < CurrentLineLen Then CursorX = CurrentLineLen
        Lines$(CursorY) = Lines$(CursorY)+AfterCursor$
        Rem Check new line length
        CurrentLineLen = Len(Lines$(CursorY))
        If CurrentLineLen > ScrnCharWidth
          AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen - ScrnCharWidth): Rem characters after right edge of window
          Lines$(CursorY) = Left$(Lines$(CursorY),ScrnCharWidth): Rem keep characters inside window
          Lines$(CursorY+1) = AfterCursor$ + Lines$(CursorY+1)
        Endif
      Endif
    Endif
    Gosub UpdateAllLines
    Gosub UpdateMenu
    Sleep 140
  Endif

  Rem *******************************
  Rem   Handle NON-ASCII Keypresses
  Rem *******************************

  Rem ***** Return Key *****
  If Returnkey()=1
    Rem Drop to next line
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    CurrentLineLen = Len(Lines$(CursorY))
    BeforeCursor$ = Left$(Lines$(CursorY),CursorX)
    AfterCursor$ = Right$(Lines$(CursorY),CurrentLineLen-CursorX)
    Rem Shuffle All Following Lines Down One (Will lose very last line but unlikely to be used)
    For N = MaxLines-1 To CursorY+1 Step -1
      Lines$(N) = Lines$(N-1)
    Next N
    Lines$(CursorY) = BeforeCursor$: Rem Set current line to text before cursor
    Lines$(CursorY+1) = AfterCursor$: Rem Set following line to text after cursor
    CursorX = 0: Inc CursorY: Rem New cursor position
    Inc NumLines: Rem We just added a new line
    Ink 0,0: Text CursorX*CharWidth,(CursorY+1)*16,"_"
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
    Gosub UpdateAllLines
    Gosub UpdateMenu
    rem Gosub UpdateStatus
    Sleep 140
  Endif

  Rem ***** Home Key ***** 199
  If Scancode() = 199
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    CursorX = 0
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
  Endif

  Rem ***** End Key ***** 207
  If Scancode() = 207
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    CursorX =  Len(Lines$(CursorY))
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
  Endif

  Rem ***** Cursor Keys *****
  If Upkey()=1 And CursorY > 0: Rem Move Cursor Up
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    Dec CursorY: CurrentLineLen = Len(Lines$(CursorY))
    If CursorX > CurrentLineLen Then CursorX = CurrentLineLen
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
    Gosub UpdateMenu
    Sleep 60
  Endif
  If Downkey()=1 And CursorY < 28 And CursorY+1 < NumLines: Rem Move Cursor Down
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    Inc CursorY: CurrentLineLen = Len(Lines$(CursorY))
    If CursorX > CurrentLineLen Then CursorX = CurrentLineLen
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
    Gosub UpdateMenu
    Sleep 60
  Endif
  If Leftkey()=1 And CursorX > 0: Rem Move Cursor Left
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    Dec CursorX
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
    Gosub UpdateMenu
    Sleep 30
  Endif
  If Rightkey()=1: Rem Move Cursor Right
    Ink 0,0: Text CursorX*CharWidth,CursorY*16,"_"
    CurrentLineLen = Len(Lines$(CursorY))
    If CursorX < ScrnCharWidth and CursorX < CurrentLineLen
      Inc CursorX
    Else
      If NumLines > CursorY+1
        Inc CursorY: CursorX=0: Rem New position at start of next line
      Endif
    Endif
    Ink RGB(255,255,255),0: Text CursorX*CharWidth,CursorY*16,"_"
    Gosub UpdateMenu
    Sleep 30
  Endif

  Rem ***** Load (Ctrl-L) *****
  If KeyState(38) = 1 And Scancode() = 29
    Rem Load A File
    Set Text Opaque: Sync
    Ink RGB(0,100,0),0: Box 0,465,639,479
    Ink RGB(255,255,255),RGB(0,100,0)
    Set Cursor 0,29*16: Input " Please Enter A Filename To Load (No Extension Required): ";FName$
    Repeat
    Until ReturnKey()=0
    FName$=FName$+".TXT": Rem <<< Choose your own filename extension here
    If File Exist(FName$) = 1
      UnDim Lines$(MaxLines): Rem Erase current string array
      Dim Lines$(MaxLines): Rem Recreate array (empty)
      Open To Read 1,FName$
        Read String 1, Temp$: NumLines=Val(Temp$)
        For N = 0 To NumLines-1
          Read String 1, Lines$(N)
        Next N
      Close File 1
      CursorX = 0: CursorY = 0
    Else
      Ink RGB(0,100,0),0: Box 0,465,639,479
      Ink RGB(255,255,0),RGB(0,100,0)
      Text 0,464," Sorry - That File Does Not Exist!"
      Sleep 4000
    Endif
    Gosub UpdateAllLines
    Gosub UpdateMenu
    Set Text Transparent: Sync
  Endif

  Rem ***** Save (Ctrl-S) *****
  If KeyState(31) = 1 And Scancode() = 29
    Rem Save A File
    Set Text Opaque: Sync
    Ink RGB(0,100,0),0: Box 0,465,639,479
    Ink RGB(255,255,255),RGB(0,100,0)
    Set Cursor 0,29*16: Input " Please Enter A Filename To Save (No Extension Required): ";FName$
    Repeat
    Until ReturnKey()=0
    FName$=FName$+".TXT": Rem <<< Choose your own filename extension here
    If File Exist(FName$) = 1 Then Delete File FName$
    Open To Write 1,FName$
      Write String 1, Str$(NumLines)
      For N = 0 To NumLines-1
        Write String 1, Lines$(N)
      Next N
    Close File 1
    Gosub UpdateAllLines
    Gosub UpdateMenu
    Set Text Transparent: Sync
  Endif

  Rem ***** Clear (Ctrl-C) *****
  If KeyState(46) = 1 And Scancode() = 29
    Rem Clear File
    Set Text Opaque: Sync
    Ink RGB(0,100,0),0: Box 0,465,639,479
    Ink RGB(255,255,255),RGB(0,100,0)
    Repeat
    Until Scancode() = 0
    CursorX=0: CursorY=0
    UnDim Lines$(MaxLines): Rem Erase current string array
    Dim Lines$(MaxLines): Rem Recreate array (empty)
    Gosub UpdateAllLines
    Gosub UpdateMenu
    Set Text Transparent: Sync
  Endif

  Rem ***** Exit (Ctrl-X) *****
  If KeyState(45) = 1 And Scancode() = 29
    Rem Exit
    UnDim Lines$(MaxLines): Rem Erase current string array
    End
  Endif

  Sync
Loop

UpdateAllLines:
  Set Text Opaque: Sync
  Ink 0,0: Box 0,0,639,464
  Ink RGB(255,255,255),0
  For N = 0 To 28: Rem 28 Lines
    Text 0,N*16,Lines$(N+LineOffset): Rem Correct lines if scrolled
  Next N
  Set Text Transparent: Sync
  Text CursorX*CharWidth,CursorY*16,"_"
Return

UpdateMenu:
  Set Text Opaque: Sync
  Ink RGB(255,255,255),RGB(0,100,0)
  Text 0,464," Ctrl-S Save  Ctrl-L Load  Ctrl-C Clear  Ctrl-X Exit  L:"+Str$(NumLines)+"  CPos:"+Str$(CursorX+1)+"/"+Str$(CursorY+1)+"      ": Rem Bottom line reserved for menu commands
  Set Text Transparent: Sync
Return

TDK_Man

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dab

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Joined: 22nd Sep 2004

Location: Your Temp Folder!

Posted: 8th May 2006 00:05

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That's great. Works really well.

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Jack

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Joined: 4th Oct 2004

Location: [Germany]

Posted: 8th May 2006 00:15

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I found a bug: If you press backspace if nothing stands: crash!

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TDK

Retired Moderator

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Joined: 19th Nov 2002

Location: UK

Posted: 8th May 2006 01:13

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Quote: "I found a bug: If you press backspace if nothing stands: crash!"

Quite possible. It's just a part-working demo example to demonstrate how to do it.

A number of features need to be added - including error trapping. I didn't bother as I only really wanted to quickly demonstrate one method of how to make a text editor using string arrays.

Once the principle is understood, I assumed that people would use the method but with their own code - a bit more structured and optimised than mine, which was deliberatly kept simple to make it easier to follow.

TDK_Man

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Code Snippets / Example Text Editor For DBC/DBP