/* ------------- editbox.c ------------ */
#include "dflat.h"

#define EditBufLen(wnd) (isMultiLine(wnd) ? EDITLEN : ENTRYLEN)
#define SetLinePointer(wnd, ln) (wnd->CurrLine = ln)
#define isWhite(c)     ((c)==' '||(c)=='\n')
/* ---------- local prototypes ----------- */
static void SaveDeletedText(WINDOW, char *, int);
static void Forward(WINDOW);
static void Backward(WINDOW);
static void End(WINDOW);
static void Home(WINDOW);
static void Downward(WINDOW);
static void Upward(WINDOW);
static void StickEnd(WINDOW);
static void NextWord(WINDOW);
static void PrevWord(WINDOW);
static void ResetEditBox(WINDOW);
static void ModTextPointers(WINDOW, int, int);
/* -------- local variables -------- */
static int KeyBoardMarking, ButtonDown;
static int TextMarking;
static int ButtonX, ButtonY;
static int PrevY = -1;

/* ----------- CREATE_WINDOW Message ---------- */
static int CreateWindowMsg(WINDOW wnd)
{
    int rtn = BaseWndProc(EDITBOX, wnd, CREATE_WINDOW, 0, 0);
    wnd->MaxTextLength = MAXTEXTLEN+1;
    wnd->textlen = EditBufLen(wnd);
    wnd->InsertMode = TRUE;
    ResetEditBox(wnd);
    return rtn;
}
/* ----------- SETTEXT Message ---------- */
static int SetTextMsg(WINDOW wnd, PARAM p1)
{
    int rtn = FALSE;
    if (strlen((char *)p1) <= wnd->MaxTextLength)    {
        rtn = BaseWndProc(EDITBOX, wnd, SETTEXT, p1, 0);
        wnd->CurrLine = 0;
    }
    return rtn;
}
/* ----------- ADDTEXT Message ---------- */
static int AddTextMsg(WINDOW wnd, PARAM p1, PARAM p2)
{
    int rtn = FALSE;
    if (strlen((char *)p1)+wnd->textlen <= wnd->MaxTextLength) {
        rtn = BaseWndProc(EDITBOX, wnd, ADDTEXT, p1, p2);
        if (rtn != FALSE)    {
            if (!isMultiLine(wnd))    {
                wnd->CurrLine = 0;
                wnd->CurrCol = strlen((char *)p1);
                if (wnd->CurrCol >= ClientWidth(wnd))    {
                    wnd->wleft = wnd->CurrCol-ClientWidth(wnd);
                    wnd->CurrCol -= wnd->wleft;
                }
                wnd->BlkEndCol = wnd->CurrCol;
                SendMessage(wnd, KEYBOARD_CURSOR,
                                     WndCol, wnd->WndRow);
            }
        }
    }
    return rtn;
}
/* ----------- GETTEXT Message ---------- */
static int GetTextMsg(WINDOW wnd, PARAM p1, PARAM p2)
{
    char *cp1 = (char *)p1;
    char *cp2 = wnd->text;
    if (cp2 != NULL)    {
        while (p2-- && *cp2 && *cp2 != '\n')
            *cp1++ = *cp2++;
        *cp1 = '\0';
        return TRUE;
    }
    return FALSE;
}
/* ----------- SETTEXTLENGTH Message ---------- */
static int SetTextLengthMsg(WINDOW wnd, unsigned int len)
{
    if (++len < MAXTEXTLEN)    {
        wnd->MaxTextLength = len;
        if (len < wnd->textlen)    {
            if ((wnd->text=realloc(wnd->text, len+2)) != NULL) {
                wnd->textlen = len;
                *((wnd->text)+len) = '\0';
                *((wnd->text)+len+1) = '\0';
                BuildTextPointers(wnd);
            }
        }
        return TRUE;
    }
    return FALSE;
}
/* ----------- KEYBOARD_CURSOR Message ---------- */
static int KeyboardCursorMsg(WINDOW wnd, PARAM p1, PARAM p2)
{
    int rtn;
    wnd->CurrCol = (int)p1 + wnd->wleft;
    wnd->WndRow = (int)p2;
    wnd->CurrLine = (int)p2 + wnd->wtop;
    rtn = BaseWndProc(EDITBOX, wnd, KEYBOARD_CURSOR, p1, p2);
    if (wnd == inFocus && CharInView(wnd, (int)p1, (int)p2))
        SendMessage(NULL, SHOW_CURSOR, wnd->InsertMode, 0);
    else SendMessage(NULL, HIDE_CURSOR, 0, 0);
    return rtn;
}
/* ----------- SIZE Message ---------- */
int SizeMsg(WINDOW wnd, PARAM p1, PARAM p2)
{
    int rtn = BaseWndProc(EDITBOX, wnd, SIZE, p1, p2);
    if (WndCol > ClientWidth(wnd)-1)
        wnd->CurrCol = ClientWidth(wnd)-1 + wnd->wleft;
    if (wnd->WndRow > ClientHeight(wnd)-1)    {
        wnd->WndRow = ClientHeight(wnd)-1;
        SetLinePointer(wnd, wnd->WndRow+wnd->wtop);
    }
    SendMessage(wnd, KEYBOARD_CURSOR, WndCol, wnd->WndRow);
    return rtn;
}
/* ----------- SCROLL Message ---------- */
static int ScrollMsg(WINDOW wnd, PARAM p1)
{
    int rtn = FALSE;
    if (isMultiLine(wnd))    {
        rtn = BaseWndProc(EDITBOX,wnd,SCROLL,p1,0);
        if (rtn != FALSE)    {
            if (p1)    {
                /* -------- scrolling up --------- */
                if (wnd->WndRow == 0)    {
                    wnd->CurrLine++;
                    StickEnd(wnd);
                }
                else
                    --wnd->WndRow;
            }
            else    {
                /* -------- scrolling down --------- */
                if (wnd->WndRow == ClientHeight(wnd)-1)    {
                    if (wnd->CurrLine > 0)
                        --wnd->CurrLine;
                    StickEnd(wnd);
                }
                else
                    wnd->WndRow++;
            }
            SendMessage(wnd,KEYBOARD_CURSOR,WndCol,wnd->WndRow);
        }
    }
    return rtn;
}
/* ----------- HORIZSCROLL Message ---------- */
static int HorizScrollMsg(WINDOW wnd, PARAM p1)
{
    int rtn = FALSE;
    char *currchar = CurrChar;
    if (!(p1 &&
            wnd->CurrCol == wnd->wleft && *currchar == '\n'))  {
        rtn = BaseWndProc(EDITBOX, wnd, HORIZSCROLL, p1, 0);
        if (rtn != FALSE)    {
            if (wnd->CurrCol < wnd->wleft)
                wnd->CurrCol++;
            else if (WndCol == ClientWidth(wnd))
                --wnd->CurrCol;
            SendMessage(wnd,KEYBOARD_CURSOR,WndCol,wnd->WndRow);
        }
    }
    return rtn;
}
/* ----------- SCROLLPAGE Message ---------- */
static int ScrollPageMsg(WINDOW wnd, PARAM p1)
{
    int rtn = FALSE;
    if (isMultiLine(wnd))    {
        rtn = BaseWndProc(EDITBOX, wnd, SCROLLPAGE, p1, 0);
        SetLinePointer(wnd, wnd->wtop+wnd->WndRow);
        StickEnd(wnd);
        SendMessage(wnd, KEYBOARD_CURSOR,WndCol, wnd->WndRow);
    }
    return rtn;
}
/* ----------- HORIZSCROLLPAGE Message ---------- */
static int HorizPageMsg(WINDOW wnd, PARAM p1)
{
    int rtn = BaseWndProc(EDITBOX, wnd, HORIZPAGE, p1, 0);
    if ((int) p1 == FALSE)    {
        if (wnd->CurrCol > wnd->wleft+ClientWidth(wnd)-1)
            wnd->CurrCol = wnd->wleft+ClientWidth(wnd)-1;
    }
    else if (wnd->CurrCol < wnd->wleft)
        wnd->CurrCol = wnd->wleft;
    SendMessage(wnd, KEYBOARD_CURSOR, WndCol, wnd->WndRow);
    return rtn;
}
/* ----- Extend the marked block to the new x,y position ---- */
static void ExtendBlock(WINDOW wnd, int x, int y)
{
    int bbl, bel;
    int ptop = min(wnd->BlkBegLine, wnd->BlkEndLine);
    int pbot = max(wnd->BlkBegLine, wnd->BlkEndLine);
    char *lp = TextLine(wnd, wnd->wtop+y);
    int len = (int) (strchr(lp, '\n') - lp);
    x = min(x, len-wnd->wleft);
    wnd->BlkEndCol = x+wnd->wleft;
    wnd->BlkEndLine = y+wnd->wtop;
    bbl = min(wnd->BlkBegLine, wnd->BlkEndLine);
    bel = max(wnd->BlkBegLine, wnd->BlkEndLine);
    while (ptop < bbl)    {
        WriteTextLine(wnd, NULL, ptop, FALSE);
        ptop++;
    }
    for (y = bbl; y <= bel; y++)
        WriteTextLine(wnd, NULL, y, FALSE);
    while (pbot > bel)    {
        WriteTextLine(wnd, NULL, pbot, FALSE);
        --pbot;
    }
}
/* ----------- LEFT_BUTTON Message ---------- */
static int LeftButtonMsg(WINDOW wnd, PARAM p1, PARAM p2)
{
    int MouseX = (int) p1 - GetClientLeft(wnd);
    int MouseY = (int) p2 - GetClientTop(wnd);
    RECT rc = ClientRect(wnd);
    char *lp;
    int len;
    if (KeyBoardMarking)
        return TRUE;
    if (WindowMoving || WindowSizing)
        return FALSE;
    if (isMultiLine(wnd))    {
        if (TextMarking)    {
            if (!InsideRect(p1, p2, rc))    {
                if ((int)p1 == GetLeft(wnd))
                    if (SendMessage(wnd, HORIZSCROLL, 0, 0))
                        ExtendBlock(wnd, MouseX-1, MouseY);
                if ((int)p1 == GetRight(wnd))
                    if (SendMessage(wnd, HORIZSCROLL, TRUE, 0))
                        ExtendBlock(wnd, MouseX+1, MouseY);
                if ((int)p2 == GetTop(wnd))
                    if (SendMessage(wnd, SCROLL, FALSE, 0))
                        ExtendBlock(wnd, MouseX, MouseY+1);
                if ((int)p2 == GetBottom(wnd))
                    if (SendMessage(wnd, SCROLL, TRUE, 0))
                        ExtendBlock(wnd, MouseX, MouseY-1);
                SendMessage(wnd, PAINT, 0, 0);
            }
            return TRUE;
        }
        if (!InsideRect(p1, p2, rc))
            return FALSE;
        if (TextBlockMarked(wnd))    {
            ClearTextBlock(wnd);
            SendMessage(wnd, PAINT, 0, 0);
        }
        if (wnd->wlines)    {
            if (MouseY > wnd->wlines-1)
                return TRUE;
            lp = TextLine(wnd, MouseY+wnd->wtop);
            len = (int) (strchr(lp, '\n') - lp);
            MouseX = min(MouseX, len);
            if (MouseX < wnd->wleft)    {
                MouseX = 0;
                SendMessage(wnd, KEYBOARD, HOME, 0);
            }
            ButtonDown = TRUE;
            ButtonX = MouseX;
            ButtonY = MouseY;
        }
        else
            MouseX = MouseY = 0;
        wnd->WndRow = MouseY;
        SetLinePointer(wnd, MouseY+wnd->wtop);
    }
    if (isMultiLine(wnd) ||
        (!TextBlockMarked(wnd)
            && MouseX+wnd->wleft < strlen(wnd->text)))
        wnd->CurrCol = MouseX+wnd->wleft;
    SendMessage(wnd, KEYBOARD_CURSOR, WndCol, wnd->WndRow);
    return TRUE;
}
/* ----------- MOUSE_MOVED Message ---------- */
static int MouseMovedMsg(WINDOW wnd, PARAM p1, PARAM p2)
{
    int MouseX = (int) p1 - GetClientLeft(wnd);
    int MouseY = (int) p2 - GetClientTop(wnd);
    RECT rc = ClientRect(wnd);
    if (!InsideRect(p1, p2, rc))
        return FALSE;
    if (MouseY > wnd->wlines-1)
        return FALSE;
    if (ButtonDown)    {
        SetAnchor(wnd, ButtonX+wnd->wleft, ButtonY+wnd->wtop);
        TextMarking = TRUE;
        SendMessage(NULL,MOUSE_TRAVEL,
                (PARAM)&WindowRect(wnd),0);
        ButtonDown = FALSE;
    }
    if (TextMarking && !(WindowMoving || WindowSizing))    {
        ExtendBlock(wnd, MouseX, MouseY);
        return TRUE;
    }
    return FALSE;
}
static void StopMarking(WINDOW wnd)
{
    TextMarking = FALSE;
    if (wnd->BlkBegLine > wnd->BlkEndLine)    {
        swap(wnd->BlkBegLine, wnd->BlkEndLine);
        swap(wnd->BlkBegCol, wnd->BlkEndCol);
    }
    if (wnd->BlkBegLine == wnd->BlkEndLine &&
            wnd->BlkBegCol > wnd->BlkEndCol)
        swap(wnd->BlkBegCol, wnd->BlkEndCol);
}
/* ----------- BUTTON_RELEASED Message ---------- */
static int ButtonReleasedMsg(WINDOW wnd)
{
    if (isMultiLine(wnd))    {
        ButtonDown = FALSE;
        if (TextMarking && !(WindowMoving || WindowSizing))  {
            /* release the mouse ouside the edit box */
            SendMessage(NULL, MOUSE_TRAVEL, 0, 0);
            StopMarking(wnd);
            return TRUE;
        }
        else
            PrevY = -1;
    }
    return FALSE;
}
/* ---- Process text block keys for multiline text box ---- */
static void DoMultiLines(WINDOW wnd, int c, PARAM p2)
{
    if (isMultiLine(wnd))    {
        if ((int)p2 & (LEFTSHIFT | RIGHTSHIFT))    {
            int kx, ky;
            SendMessage(NULL, CURRENT_KEYBOARD_CURSOR,
                (PARAM) &kx, (PARAM) &ky);
            kx -= GetClientLeft(wnd);
            ky -= GetClientTop(wnd);
            switch (c)    {
                case HOME:
                case END:
                case CTRL_HOME:
                case CTRL_END:
                case PGUP:
                case PGDN:
                case CTRL_PGUP:
                case CTRL_PGDN:
                case UP:
                case DN:
                case FWD:
                case BS:
                case CTRL_FWD:
                case CTRL_BS:
                    if (!KeyBoardMarking)    {
                        if (TextBlockMarked(wnd))    {
                            ClearTextBlock(wnd);
                            SendMessage(wnd, PAINT, 0, 0);
                        }
                        KeyBoardMarking = TextMarking = TRUE;
                        SetAnchor(wnd, kx+wnd->wleft,
                                                ky+wnd->wtop);
                    }
                    break;
                default:
                    break;
            }
        }
    }
}
/* ---------- page/scroll keys ----------- */
static int DoScrolling(WINDOW wnd, int c, PARAM p2)
{
    switch (c)    {
        case PGUP:
        case PGDN:
            if (isMultiLine(wnd))
                BaseWndProc(EDITBOX, wnd, KEYBOARD, c, p2);
            break;
        case CTRL_PGUP:
        case CTRL_PGDN:
            BaseWndProc(EDITBOX, wnd, KEYBOARD, c, p2);
            break;
        case HOME:
            Home(wnd);
            break;
        case END:
            End(wnd);
            break;
        case CTRL_FWD:
            NextWord(wnd);
            break;
        case CTRL_BS:
            PrevWord(wnd);
            break;
        case CTRL_HOME:
            if (isMultiLine(wnd))    {
                SendMessage(wnd, SCROLLDOC, TRUE, 0);
                wnd->CurrLine = 0;
                wnd->WndRow = 0;
            }
            Home(wnd);
            break;
        case CTRL_END:
			if (isMultiLine(wnd) &&
					wnd->WndRow+wnd->wtop+1 < wnd->wlines
						&& wnd->wlines > 0) {
                SendMessage(wnd, SCROLLDOC, FALSE, 0);
                SetLinePointer(wnd, wnd->wlines-1);
                wnd->WndRow =
                    min(ClientHeight(wnd)-1, wnd->wlines-1);
                Home(wnd);
            }
            End(wnd);
            break;
        case UP:
            if (isMultiLine(wnd))
                Upward(wnd);
            break;
        case DN:
            if (isMultiLine(wnd))
                Downward(wnd);
            break;
        case FWD:
            Forward(wnd);
            break;
        case BS:
            Backward(wnd);
            break;
        default:
            return FALSE;
    }
    if (!KeyBoardMarking && TextBlockMarked(wnd))    {
        ClearTextBlock(wnd);
        SendMessage(wnd, PAINT, 0, 0);
    }
    SendMessage(wnd, KEYBOARD_CURSOR, WndCol, wnd->WndRow);
    return TRUE;
}
/* -------------- Del key ---------------- */
static int DelKey(WINDOW wnd)
{
    char *currchar = CurrChar;
    int repaint = *currchar == '\n';
    if (TextBlockMarked(wnd))    {
        SendMessage(wnd, COMMAND, ID_DELETETEXT, 0);
        SendMessage(wnd, PAINT, 0, 0);
        return TRUE;
    }
    if (*(currchar+1) == '\0')
        return TRUE;
    strcpy(currchar, currchar+1);
    if (repaint)    {
        BuildTextPointers(wnd);
        SendMessage(wnd, PAINT, 0, 0);
    }
    else    {
        ModTextPointers(wnd, wnd->CurrLine+1, -1);
        WriteTextLine(wnd, NULL, wnd->WndRow+wnd->wtop, FALSE);
    }
    wnd->TextChanged = TRUE;
    return FALSE;
}
/* ------------ Tab key ------------ */
static int TabKey(WINDOW wnd, PARAM p2)
{
    if (isMultiLine(wnd))    {
        int insmd = wnd->InsertMode;
        do  {
            char *cc = CurrChar+1;
            if (!insmd && *cc == '\0')
                break;
            if (wnd->textlen == wnd->MaxTextLength)
                break;
            SendMessage(wnd,KEYBOARD,insmd ? ' ' : FWD,0);
        } while (wnd->CurrCol % cfg.Tabs);
        return TRUE;
    }
    PostMessage(GetParent(wnd), KEYBOARD, '\t', p2);
    return FALSE;
}
/* --------- All displayable typed keys ------------- */
static void KeyTyped(WINDOW wnd, int c)
{
    char *currchar = CurrChar;
    if ((c != '\n' && c < ' ') || (c & 0x1000))
        /* ---- not recognized by editor --- */
        return;
    if (!isMultiLine(wnd) && TextBlockMarked(wnd))    {
        ResetEditBox(wnd);
        currchar = CurrChar;
    }
    if (*currchar == '\0')    {
        /* ---- typing at end of text ---- */
        if (currchar == wnd->text+wnd->MaxTextLength)    {
            /* ---- typing at the end of maximum buffer ---- */
            beep();
            return;
        }
        /* --- insert a newline at end of text --- */
        *currchar = '\n';
        *(currchar+1) = '\0';
        BuildTextPointers(wnd);
    }
    /* --- displayable char or newline --- */
    if (c == '\n' || wnd->InsertMode ||    *currchar == '\n') {
        /* ------ inserting the keyed character ------ */
        if (wnd->text[wnd->textlen-1] != '\0')    {
            /* --- the current text buffer is full --- */
            if (wnd->textlen == wnd->MaxTextLength)    {
                /* --- text buffer is at maximum size --- */
                beep();
                return;
            }
            /* ---- increase the text buffer size ---- */
            wnd->textlen += GROWLENGTH;
            /* --- but not above maximum size --- */
            if (wnd->textlen > wnd->MaxTextLength)
                wnd->textlen = wnd->MaxTextLength;
            wnd->text = realloc(wnd->text, wnd->textlen+2);
            wnd->text[wnd->textlen-1] = '\0';
            currchar = CurrChar;
        }
        memmove(currchar+1, currchar, strlen(currchar)+1);
        ModTextPointers(wnd, wnd->CurrLine+1, 1);
        if (isMultiLine(wnd) && wnd->wlines > 1)
            wnd->textwidth = max(wnd->textwidth,
                (int) (TextLine(wnd, wnd->CurrLine+1)-
                TextLine(wnd, wnd->CurrLine)));
        else
            wnd->textwidth = max(wnd->textwidth,
                strlen(wnd->text));
        WriteTextLine(wnd, NULL,
            wnd->wtop+wnd->WndRow, FALSE);
    }
    /* ----- put the char in the buffer ----- */
    *currchar = c;
    wnd->TextChanged = TRUE;
    if (c == '\n')    {
        wnd->wleft = 0;
        BuildTextPointers(wnd);
        End(wnd);
        Forward(wnd);
        SendMessage(wnd, PAINT, 0, 0);
        return;
    }
    /* ---------- test end of window --------- */
    if (WndCol == ClientWidth(wnd)-1)    {
        int dif;
        char *cp = currchar;
        while (*cp != ' ' && cp != TextLine(wnd, wnd->CurrLine))
            --cp;
        if (!isMultiLine(wnd) ||
            cp == TextLine(wnd, wnd->CurrLine) ||
                !wnd->WordWrapMode)
            SendMessage(wnd, HORIZSCROLL, TRUE, 0);
        else    {
            dif = 0;
            if (c != ' ')    {
                dif = (int) (currchar - cp);
                wnd->CurrCol -= dif;
                SendMessage(wnd, KEYBOARD, DEL, 0);
                --dif;
            }
            SendMessage(wnd, KEYBOARD, '\r', 0);
            currchar = CurrChar;
            wnd->CurrCol = dif;
            if (c == ' ')
                return;
        }
    }
    /* ------ display the character ------ */
    SetStandardColor(wnd);
    PutWindowChar(wnd, c, WndCol, wnd->WndRow);
    /* ----- advance the pointers ------ */
    wnd->CurrCol++;
}
/* ------------ screen changing key strokes ------------- */
static int DoKeyStroke(WINDOW wnd, int c, PARAM p2)
{
    switch (c)    {
        case RUBOUT:
            Backward(wnd);
        case DEL:
            if (DelKey(wnd))
                return TRUE;
            break;
        case CTRL_FIVE:    /* same as Shift+Tab */
            if (!((int)p2 & (LEFTSHIFT | RIGHTSHIFT)))
                break;
        case '\t':
            if (TabKey(wnd, p2))
                return TRUE;
            break;
        case '\r':
            if (!isMultiLine(wnd))    {
                PostMessage(GetParent(wnd), KEYBOARD, c, p2);
                break;
            }
            c = '\n';
        default:
            if (TextBlockMarked(wnd))    {
                SendMessage(wnd, COMMAND, ID_DELETETEXT, 0);
                SendMessage(wnd, PAINT, 0, 0);
            }
            KeyTyped(wnd, c);
            break;
    }
    return FALSE;
}
/* ----------- KEYBOARD Message ---------- */
static int KeyboardMsg(WINDOW wnd, PARAM p1, PARAM p2)
{
    int c = (int) p1;
    if (WindowMoving || WindowSizing || ((int)p2 & ALTKEY))
        return FALSE;
    switch (c)    {
        /* --- these keys get processed by lower classes --- */
        case ESC:
        case F1:
        case F2:
        case F3:
        case F4:
        case F5:
        case F6:
        case F7:
        case F8:
        case F9:
        case F10:
        case INS:
        case SHIFT_INS:
        case SHIFT_DEL:
            return FALSE;
        /* --- these keys get processed here --- */
        case CTRL_FWD:
        case CTRL_BS:
        case CTRL_HOME:
        case CTRL_END:
        case CTRL_PGUP:
        case CTRL_PGDN:
            break;
        default:
            /* other ctrl keys get processed by lower classes */
            if ((int)p2 & CTRLKEY)
                return FALSE;
            /* --- all other keys get processed here --- */
            break;
    }
    DoMultiLines(wnd, c, p2);
    if (DoScrolling(wnd, c, p2))    {
        if (KeyBoardMarking)
            ExtendBlock(wnd, WndCol, wnd->WndRow);
    }
    else if (!TestAttribute(wnd, READONLY))    {
        DoKeyStroke(wnd, c, p2);
        SendMessage(wnd, KEYBOARD_CURSOR, WndCol, wnd->WndRow);
    }
    return TRUE;
}
/* ----------- SHIFT_CHANGED Message ---------- */
static void ShiftChangedMsg(WINDOW wnd, PARAM p1)
{
    if (!((int)p1 & (LEFTSHIFT | RIGHTSHIFT)) &&
                                   KeyBoardMarking)    {
        StopMarking(wnd);
        KeyBoardMarking = FALSE;
    }
}
/* ----------- ID_DELETETEXT Command ---------- */
static void DeleteTextCmd(WINDOW wnd)
{
    if (TextBlockMarked(wnd))    {
        char *bbl=TextLine(wnd,wnd->BlkBegLine)+wnd->BlkBegCol;
        char *bel=TextLine(wnd,wnd->BlkEndLine)+wnd->BlkEndCol;
        int len = (int) (bel - bbl);
        SaveDeletedText(wnd, bbl, len);
        wnd->TextChanged = TRUE;
        strcpy(bbl, bel);
        wnd->CurrLine = TextLineNumber(wnd, bbl-wnd->BlkBegCol);
        wnd->CurrCol = wnd->BlkBegCol;
        wnd->WndRow = wnd->BlkBegLine - wnd->wtop;
        if (wnd->WndRow < 0)    {
            wnd->wtop = wnd->BlkBegLine;
            wnd->WndRow = 0;
        }
        SendMessage(wnd, KEYBOARD_CURSOR, WndCol, wnd->WndRow);
        ClearTextBlock(wnd);
        BuildTextPointers(wnd);
    }
}
/* ----------- ID_CLEAR Command ---------- */
static void ClearCmd(WINDOW wnd)
{
    if (TextBlockMarked(wnd))    {
        char *bbl=TextLine(wnd,wnd->BlkBegLine)+wnd->BlkBegCol;
        char *bel=TextLine(wnd,wnd->BlkEndLine)+wnd->BlkEndCol;
        int len = (int) (bel - bbl);
        SaveDeletedText(wnd, bbl, len);
        wnd->CurrLine = TextLineNumber(wnd, bbl);
        wnd->CurrCol = wnd->BlkBegCol;
        wnd->WndRow = wnd->BlkBegLine - wnd->wtop;
        if (wnd->WndRow < 0)    {
            wnd->WndRow = 0;
            wnd->wtop = wnd->BlkBegLine;
        }
        /* ------ change all text lines in block to \n ----- */
        while (bbl < bel)    {
            char *cp = strchr(bbl, '\n');
            if (cp > bel)
                cp = bel;
            strcpy(bbl, cp);
            bel -= (int) (cp - bbl);
            bbl++;
        }
        ClearTextBlock(wnd);
        BuildTextPointers(wnd);
        SendMessage(wnd, KEYBOARD_CURSOR, WndCol, wnd->WndRow);
        SendMessage(wnd, PAINT, 0, 0);
        wnd->TextChanged = TRUE;
    }
}
/* ----------- ID_UNDO Command ---------- */
static void UndoCmd(WINDOW wnd)
{
    if (wnd->DeletedText != NULL)    {
        PasteText(wnd, wnd->DeletedText, wnd->DeletedLength);
        free(wnd->DeletedText);
        wnd->DeletedText = NULL;
        wnd->DeletedLength = 0;
        SendMessage(wnd, PAINT, 0, 0);
    }
}
/* ----------- ID_PARAGRAPH Command ---------- */
static void ParagraphCmd(WINDOW wnd)
{
    int bc, ec, fl, el, Blocked;
    char *bl, *bbl, *bel, *bb;

    el = wnd->BlkEndLine;
    ec = wnd->BlkEndCol;
    if (!TextBlockMarked(wnd))    {
        Blocked = FALSE;
        /* ---- forming paragraph from cursor position --- */
        fl = wnd->wtop + wnd->WndRow;
        bbl = bel = bl = TextLine(wnd, wnd->CurrLine);
        if ((bc = wnd->CurrCol) >= ClientWidth(wnd))
            bc = 0;
        Home(wnd);
        /* ---- locate the end of the paragraph ---- */
        while (*bel)    {
            int blank = TRUE;
            char *bll = bel;
            /* --- blank line marks end of paragraph --- */
            while (*bel && *bel != '\n')    {
                if (*bel != ' ')
                    blank = FALSE;
                bel++;
            }
            if (blank)    {
                bel = bll;
                break;
            }
            if (*bel)
                bel++;
        }
        if (bel == bbl)    {
            SendMessage(wnd, KEYBOARD, DN, 0);
            return;
        }
        if (*bel == '\0')
            --bel;
        if (*bel == '\n')
            --bel;
    }
    else    {
        /* ---- forming paragraph from marked block --- */
        Blocked = TRUE;
        bbl = TextLine(wnd, wnd->BlkBegLine) + wnd->BlkBegCol;
        bel = TextLine(wnd, wnd->BlkEndLine) + wnd->BlkEndCol;
        fl = wnd->BlkBegLine;
        bc = wnd->CurrCol = wnd->BlkBegCol;
        wnd->CurrLine = fl;
        if (fl < wnd->wtop)
            wnd->wtop = fl;
        wnd->WndRow = fl - wnd->wtop;
        SendMessage(wnd, KEYBOARD, '\r', 0);
        el++, fl++;
        if (bc != 0)    {
            SendMessage(wnd, KEYBOARD, '\r', 0);
            el++, fl ++;
        }
        bc = 0;
        bl = TextLine(wnd, fl);
        wnd->CurrLine = fl;
        bbl = bl + bc;
        bel = TextLine(wnd, el) + ec;
    }
    /* --- change all newlines in block to spaces --- */
    while (CurrChar < bel)    {
        if (*CurrChar == '\n')    {
            *CurrChar = ' ';
            wnd->CurrLine++;
            wnd->CurrCol = 0;
        }
        else
            wnd->CurrCol++;
    }
    /* ---- insert newlines at new margin boundaries ---- */
    bb = bbl;
    while (bbl < bel)    {
        bbl++;
        if ((int)(bbl - bb) == ClientWidth(wnd)-1)    {
            while (*bbl != ' ' && bbl > bb)
                --bbl;
            if (*bbl != ' ')    {
                bbl = strchr(bbl, ' ');
                if (bbl == NULL || bbl >= bel)
                    break;
            }
            *bbl = '\n';
            bb = bbl+1;
        }
    }
    ec = (int)(bel - bb);
    BuildTextPointers(wnd);
    if (Blocked)    {
        /* ---- position cursor at end of new paragraph ---- */
        if (el < wnd->wtop ||
                wnd->wtop + ClientHeight(wnd) < el)
            wnd->wtop = el-ClientHeight(wnd);
        if (wnd->wtop < 0)
            wnd->wtop = 0;
        wnd->WndRow = el - wnd->wtop;
        wnd->CurrLine = el;
        wnd->CurrCol = ec;
        SendMessage(wnd, KEYBOARD, '\r', 0);
        SendMessage(wnd, KEYBOARD, '\r', 0);
    }
    else    {
        /* --- put cursor back at beginning --- */
        wnd->CurrLine = TextLineNumber(wnd, bl);
        wnd->CurrCol = bc;
        if (fl < wnd->wtop)
            wnd->wtop = fl;
        wnd->WndRow = fl - wnd->wtop;
    }
    SendMessage(wnd, PAINT, 0, 0);
    SendMessage(wnd, KEYBOARD_CURSOR, WndCol, wnd->WndRow);
    wnd->TextChanged = TRUE;
    BuildTextPointers(wnd);
}
/* ----------- COMMAND Message ---------- */
static int CommandMsg(WINDOW wnd, PARAM p1)
{
    switch ((int)p1)    {
        case ID_DELETETEXT:
            DeleteTextCmd(wnd);
            return TRUE;
        case ID_CLEAR:
            ClearCmd(wnd);
            return TRUE;
        case ID_UNDO:
            UndoCmd(wnd);
            return TRUE;
        case ID_PARAGRAPH:
            ParagraphCmd(wnd);
            return TRUE;
        default:
            break;
    }
    return FALSE;
}
/* ---------- CLOSE_WINDOW Message ----------- */
static void CloseWindowMsg(WINDOW wnd)
{
    SendMessage(NULL, HIDE_CURSOR, 0, 0);
    if (wnd->DeletedText != NULL)
        free(wnd->DeletedText);
}
/* ------- Window processing module for EDITBOX class ------ */
int EditBoxProc(WINDOW wnd, MESSAGE msg, PARAM p1, PARAM p2)
{
    int rtn;
    switch (msg)    {
        case CREATE_WINDOW:
            return CreateWindowMsg(wnd);
        case ADDTEXT:
            return AddTextMsg(wnd, p1, p2);
        case SETTEXT:
            return SetTextMsg(wnd, p1);
        case CLEARTEXT:
            ResetEditBox(wnd);
            break;
        case GETTEXT:
            return GetTextMsg(wnd, p1, p2);
        case SETTEXTLENGTH:
            return SetTextLengthMsg(wnd, (unsigned) p1);
        case KEYBOARD_CURSOR:
            return KeyboardCursorMsg(wnd, p1, p2);
        case SETFOCUS:
        case PAINT:
        case MOVE:
            rtn = BaseWndProc(EDITBOX, wnd, msg, p1, p2);
            SendMessage(wnd,KEYBOARD_CURSOR,WndCol,wnd->WndRow);
            return rtn;
        case SIZE:
            return SizeMsg(wnd, p1, p2);
        case SCROLL:
            return ScrollMsg(wnd, p1);
        case HORIZSCROLL:
            return HorizScrollMsg(wnd, p1);
        case SCROLLPAGE:
            return ScrollPageMsg(wnd, p1);
        case HORIZPAGE:
            return HorizPageMsg(wnd, p1);
        case LEFT_BUTTON:
            if (LeftButtonMsg(wnd, p1, p2))
                return TRUE;
            break;
        case MOUSE_MOVED:
            if (MouseMovedMsg(wnd, p1, p2))
                return TRUE;
            break;
        case BUTTON_RELEASED:
            if (ButtonReleasedMsg(wnd))
                return TRUE;
            break;
        case KEYBOARD:
            if (KeyboardMsg(wnd, p1, p2))
                return TRUE;
            break;
        case SHIFT_CHANGED:
            ShiftChangedMsg(wnd, p1);
            break;
        case COMMAND:
            if (CommandMsg(wnd, p1))
                return TRUE;
            break;
        case CLOSE_WINDOW:
            CloseWindowMsg(wnd);
            break;
        default:
            break;
    }
    return BaseWndProc(EDITBOX, wnd, msg, p1, p2);
}
/* ------ save deleted text for the Undo command ------ */
static void SaveDeletedText(WINDOW wnd, char *bbl, int len)
{
    wnd->DeletedLength = len;
    if ((wnd->DeletedText=realloc(wnd->DeletedText,len))!=NULL)
        memmove(wnd->DeletedText, bbl, len);
}
/* ---- cursor right key: right one character position ---- */
static void Forward(WINDOW wnd)
{
    char *cc = CurrChar+1;
    if (*cc == '\0')
        return;
    if (*CurrChar == '\n')    {
        Home(wnd);
        Downward(wnd);
    }
    else    {
        wnd->CurrCol++;
        if (WndCol == ClientWidth(wnd))
            SendMessage(wnd, HORIZSCROLL, TRUE, 0);
    }
}
/* ----- stick the moving cursor to the end of the line ---- */
static void StickEnd(WINDOW wnd)
{
    char *cp = TextLine(wnd, wnd->CurrLine);
    char *cp1 = strchr(cp, '\n');
    int len = cp1 ? (int) (cp1 - cp) : 0;
    wnd->CurrCol = min(len, wnd->CurrCol);
    if (wnd->wleft > wnd->CurrCol)    {
        wnd->wleft = max(0, wnd->CurrCol - 4);
        SendMessage(wnd, PAINT, 0, 0);
    }
    else if (wnd->CurrCol-wnd->wleft >= ClientWidth(wnd))    {
        wnd->wleft = wnd->CurrCol - (ClientWidth(wnd)-1);
        SendMessage(wnd, PAINT, 0, 0);
    }
}
/* --------- cursor down key: down one line --------- */
static void Downward(WINDOW wnd)
{
    if (isMultiLine(wnd) &&
            wnd->WndRow+wnd->wtop+1 < wnd->wlines)  {
        wnd->CurrLine++;
        if (wnd->WndRow == ClientHeight(wnd)-1)
            SendMessage(wnd, SCROLL, TRUE, 0);
        wnd->WndRow++;
        StickEnd(wnd);
    }
}
/* -------- cursor up key: up one line ------------ */
static void Upward(WINDOW wnd)
{
    if (isMultiLine(wnd) && wnd->CurrLine != 0)    {
        if (wnd->CurrLine > 0)
            --wnd->CurrLine;
        if (wnd->WndRow == 0)
            SendMessage(wnd, SCROLL, FALSE, 0);
        --wnd->WndRow;
        StickEnd(wnd);
    }
}
/* ---- cursor left key: left one character position ---- */
static void Backward(WINDOW wnd)
{
    if (wnd->CurrCol)    {
        if (wnd->CurrCol-- <= wnd->wleft)
            if (wnd->wleft != 0)
                SendMessage(wnd, HORIZSCROLL, FALSE, 0);
    }
    else if (isMultiLine(wnd) && wnd->CurrLine != 0)    {
        Upward(wnd);
        End(wnd);
    }
}
/* -------- End key: to end of line ------- */
static void End(WINDOW wnd)
{
    while (*CurrChar && *CurrChar != '\n')
        ++wnd->CurrCol;
    if (WndCol >= ClientWidth(wnd))    {
        wnd->wleft = wnd->CurrCol - (ClientWidth(wnd)-1);
        SendMessage(wnd, PAINT, 0, 0);
    }
}
/* -------- Home key: to beginning of line ------- */
static void Home(WINDOW wnd)
{
    wnd->CurrCol = 0;
    if (wnd->wleft != 0)    {
        wnd->wleft = 0;
        SendMessage(wnd, PAINT, 0, 0);
    }
}
/* -- Ctrl+cursor right key: to beginning of next word -- */
static void NextWord(WINDOW wnd)
{
    int savetop = wnd->wtop;
    int saveleft = wnd->wleft;
    ClearVisible(wnd);
    while (!isWhite(*CurrChar))    {
        char *cc = CurrChar+1;
        if (*cc == '\0')
            break;
        Forward(wnd);
    }
    while (isWhite(*CurrChar))    {
        char *cc = CurrChar+1;
        if (*cc == '\0')
            break;
        Forward(wnd);
    }
    SetVisible(wnd);
    SendMessage(wnd, KEYBOARD_CURSOR, WndCol, wnd->WndRow);
    if (wnd->wtop != savetop || wnd->wleft != saveleft)
        SendMessage(wnd, PAINT, 0, 0);
}
/* -- Ctrl+cursor left key: to beginning of previous word -- */
static void PrevWord(WINDOW wnd)
{
    int savetop = wnd->wtop;
    int saveleft = wnd->wleft;
    ClearVisible(wnd);
    Backward(wnd);
    while (isWhite(*CurrChar))    {
        if (wnd->CurrLine == 0 && wnd->CurrCol == 0)
            break;
        Backward(wnd);
    }
    while (!isWhite(*CurrChar))    {
        if (wnd->CurrLine == 0 && wnd->CurrCol == 0)
            break;
        Backward(wnd);
    }
    if (isWhite(*CurrChar))
        Forward(wnd);
    SetVisible(wnd);
    if (wnd->wleft != saveleft)
        if (wnd->CurrCol >= saveleft)
            if (wnd->CurrCol - saveleft < ClientWidth(wnd))
                wnd->wleft = saveleft;
    SendMessage(wnd, KEYBOARD_CURSOR, WndCol, wnd->WndRow);
    if (wnd->wtop != savetop || wnd->wleft != saveleft)
        SendMessage(wnd, PAINT, 0, 0);
}
/* ----- reset the text attributes of an EDITBOX ------- */
static void ResetEditBox(WINDOW wnd)
{
    unsigned blen = EditBufLen(wnd)+2;
    wnd->text = realloc(wnd->text, blen);
    memset(wnd->text, 0, blen);
    wnd->wlines = 0;
    wnd->CurrLine = 0;
    wnd->CurrCol = 0;
    wnd->WndRow = 0;
    wnd->wleft = 0;
    wnd->wtop = 0;
    wnd->textwidth = 0;
    wnd->TextChanged = FALSE;
    ClearTextPointers(wnd);
    ClearTextBlock(wnd);
}
/* ----- modify text pointers from a specified position
                by a specified plus or minus amount ----- */
static void ModTextPointers(WINDOW wnd, int lineno, int var)
{
    while (lineno < wnd->wlines)
        *((wnd->TextPointers) + lineno++) += var;
}

