clipper.c

This source code has been tested under OpenWindows 2.0, Sun s X11/NeWS server. For Xlib programs th

/***********************************************************************
**                                                                    **
**  clipper.c                                                         **
**                                                                    **
**  Text Editor -- Clipboard Interface Module                         **
**                                                                    **
***********************************************************************/


#include <stdio.h>
#include <Xm/Text.h>
#include <Xm/CutPaste.h>
#include <X11/Xatom.h>

#include "textedit.h"


/***********************************************************************
**                                                                    **
**               F O R W A R D   D E F I N I T I O N S                **
**                                                                    **
***********************************************************************/

static	char	*GetTextSelection();
static	void	RplTextSelection();



/***********************************************************************
**                                                                    **
**                    L O C A L   V A R I A B L E S                   **
**                                                                    **
***********************************************************************/

static	XmString    prog_name;		/* Name of application	      */
static	Display	    *clip_disp;		/* Our display connection     */
static	Window	    clip_win;		/* Window associated with cpy */
static	char	    *data_type;		/* String for XA_STRING       */



/***********************************************************************
**                                                                    **
**  InitClipper()                                                     **
**                                                                    **
**  This function creates some module-static variables, which hold    **
**  identification information needed by all clipboard calls.         **
**                                                                    **
***********************************************************************/

void InitClipper()
{
    prog_name = XmStringCreate( "TextEdit", XmSTRING_DEFAULT_CHARSET );
    clip_disp = XtDisplay( appshell );
    clip_win  = None;
    data_type = XGetAtomName( clip_disp, XA_STRING );
}



/***********************************************************************
**                                                                    **
**  ClipCut( time )                                                   **
**                                                                    **
**  Called from the Edit/Cut menu item, this function copies the      **
**  current work window selection to the clipboard, then deletes      **
**  it. To perform the copy, it calls ClipCopy().                     **
**                                                                    **
**  The "time" parameter comes from the invoking event, and is used   **
**  by the selection mechanism.                                       **
**                                                                    **
***********************************************************************/

void ClipCut( time )
    Time	time;
{
    ClipCopy( time );
    RplTextSelection( "" );
}



/***********************************************************************
**                                                                    **
**  ClipCopy( time )                                                  **
**                                                                    **
**  Called from the Edit/Cut menu item, this function copies the      **
**  current work window selection to the clipboard. It is also        **
**  called by the function ClipCut, to localize clipboard access.     **
**                                                                    **
**  The "time" parameter comes from the invoking event, and is used   **
**  by the selection mechanism.                                       **
**                                                                    **
***********************************************************************/

void ClipCopy( time )
    Time	time;
{
    char	*txtsel;
    int		txtlen;
    int		clipstat;
    long	clip_id;
    int		tries;

    
    if (clip_win == None)
        clip_win = XtWindow( appshell );


    txtsel = GetTextSelection();
    txtlen = strlen( txtsel ) + 1;

    tries = 0;
    do
    	clipstat = XmClipboardStartCopy( clip_disp, clip_win, prog_name, 
                                         time, NULL, NULL, &clip_id );
    while ((clipstat != ClipboardSuccess) && (tries++ < 8));

    if (tries == 8)
	{
	/* Display alert here */
	XtFree( txtsel );
	return;
	}

    XmClipboardCopy( clip_disp, clip_win, clip_id, data_type, 
		     txtsel, txtlen, 0, NULL );
    clipstat = XmClipboardEndCopy( clip_disp, clip_win, clip_id );

    XtFree( txtsel );
}



/***********************************************************************
**                                                                    **
**  ClipPaste( time )                                                 **
**                                                                    **
**  Called from the Edit/Paste menu item, this function copies the    **
**  contents of the clipboard into the work window, at the current    **
**  insertion point. If there is a current selection, it is replaced  **
**  or not, depending on the contents of "pendingDelete".             **
**                                                                    **
**  The "time" parameter comes from the invoking event, and is used   **
**  by the selection mechanism.                                       **
**                                                                    **
***********************************************************************/

void ClipPaste( time )
    Time	time;
{
    int		clipstat;
    long	data_len;
    long	real_len;
    char	*databuf;
    long	text_pos;
    int		tries;

    
    if (clip_win == None)
        clip_win = XtWindow( appshell );


    tries = 0;
    do
	clipstat = XmClipboardLock( clip_disp, clip_win );
    while ((clipstat == ClipboardLocked) && (tries++ < 8));

    if (tries == 8)
	{
	/* Display alert here */
	XmClipboardUnlock( clip_disp, clip_win, TRUE );
	return;
	}

    clipstat = XmClipboardInquireLength( clip_disp, clip_win, 
                                         data_type, &data_len );
    if (clipstat == ClipboardNoData)
	return;

    databuf = XtMalloc( data_len+1 );

    XmClipboardStartRetrieve( clip_disp, clip_win, time );
    clipstat = XmClipboardRetrieve( clip_disp, clip_win, data_type, databuf, 
				    data_len, &real_len, NULL );
    databuf[data_len] = '\0';

    RplTextSelection( databuf );
    XtFree( databuf );
}



/***********************************************************************
**                                                                    **
**  GetTextSelection()                                                **
**                                                                    **
**  This function retrieves the current text selection -- or NULL,    **
**  if there is no selection.                                         **
**                                                                    **
***********************************************************************/

static char *GetTextSelection()
{
    return( XmTextGetSelection(textwin) );
}



/***********************************************************************
**                                                                    **
**  RplTextSelection( newtext )                                       **
**                                                                    **
**  This function replaces the current text selection with newtext.   **
**  If there is no selection, newtext is inserted at the current      **
**  insertion point.                                                  **
**                                                                    **
***********************************************************************/

static void RplTextSelection( newtext )
    char	*newtext;
{
    Boolean	stest,
		pendel;
    int		insertion,
		sel_start,
		sel_end;


    XtSetArg( arglist[0], XmNcursorPosition, &insertion );
    XtSetArg( arglist[1], XmNpendingDelete, &pendel );
    XtGetValues( textwin, arglist, 2 );

    stest = XmTextGetSelectionPosition( textwin, &sel_start, &sel_end );
    if (!stest || !pendel)
        sel_end = sel_start = insertion;

    XmTextReplace( textwin, sel_start, sel_end, newtext );
}