xref: /xsrc/external/mit/xterm/dist/testxmc.c

/* $XTermId: testxmc.c,v 1.45 2009/09/10 09:05:20 tom Exp $ */

/************************************************************

Copyright 1997-2006,2009 by Thomas E. Dickey

                        All Rights Reserved

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name(s) of the above copyright
holders shall not be used in advertising or otherwise to promote the
sale, use or other dealings in this Software without prior written
authorization.

********************************************************/

/*
 * This module provides test support for curses applications that must work
 * with terminals that have the xmc (magic cookie) glitch.  The xmc_glitch
 * resource denotes the number of spaces that are emitted when switching to or
 * from standout (reverse) mode.  Some terminals implement this by storing the
 * attribute controls in the character cell that is skipped.  So if the cell is
 * overwritten by text, then the attribute change in the cell is cancelled,
 * causing attributes to the left of the change to propagate.
 *
 * We implement the glitch by writing a character that won't be mistaken for
 * other normal characters (and mapping normal writes to that character to a
 * different one).
 *
 * Since xmc isn't normally part of xterm, we document it here rather than in
 * the man-page.  This module is driven by resources rather than by the
 * termcap/terminfo description to make it a little more flexible for testing
 * purposes.
 *
 * Resources:
 *
 * xmcGlitch (class XmcGlitch)
 *	When true, enables this extension.  The default is `0', which disables
 *	the module.  (termcap sg, terminfo xmc).
 *
 * xmcAttributes (class XmcAttributes)
 *	The attributes for which we'll generate a glitch, as a bitmask.
 *
 *		INVERSE		1
 *		UNDERLINE	2
 *		BOLD		4
 *		BLINK		8
 *
 *	The default is `1' (INVERSE).  Some terminals emit glitches for
 *	underline.  Just for completeness, we recognize all of the video
 *	attributes.
 *
 * xmcInline (class XmcInline)
 *	When true, limits the extent of an SGR change to the current line.
 *	The default is `false'.  (No termcap or terminfo equivalent, though
 *	there are comments in some entries relating to this issue).
 *
 * xmcMoveSGR (class XmcMoveSGR)
 *	When false, a cursor movement will leave a glitch when SGR's are
 *	active.  The default is `true'.  (termcap ms, terminfo msgr).
 *
 * TODO:
 *	When xmc is active, the terminfo max_attributes (ma) capability is
 *	assumed to be 1.
 *
 *	The xmcAttributes resource should also apply to alternate character
 *	sets and to color.
 */

#include <xterm.h>
#include <data.h>

#define MARK_ON(a)  (my_attrs & a) != 0 && (xw->flags & (whichone = CharOf(a))) == 0
#define MARK_OFF(a) (my_attrs & a) != 0 && (xw->flags & (whichone = CharOf(a))) != 0

void
Mark_XMC(XtermWidget xw, int param)
{
    static IChar *glitch;

    TScreen *screen = &(xw->screen);
    Bool found = False;
    Char my_attrs = CharOf(screen->xmc_attributes & XMC_FLAGS);
    Char whichone = 0;

    if (glitch == 0) {
	unsigned len = screen->xmc_glitch;
	glitch = TypeMallocN(IChar, len);
	while (len--)
	    glitch[len] = XMC_GLITCH;
    }
    switch (param) {
    case -1:			/* DEFAULT */
    case 0:			/* FALLTHRU */
	found = MARK_OFF((xw->flags & XMC_FLAGS));
	break;
    case 1:
	found = MARK_ON(BOLD);
	break;
    case 4:
	found = MARK_ON(UNDERLINE);
	break;
    case 5:
	found = MARK_ON(BLINK);
	break;
    case 7:
	found = MARK_ON(INVERSE);
	break;
    case 22:
	found = MARK_OFF(BOLD);
	break;
    case 24:
	found = MARK_OFF(UNDERLINE);
	break;
    case 25:
	found = MARK_OFF(BLINK);
	break;
    case 27:
	found = MARK_OFF(INVERSE);
	break;
    }

    /*
     * Write a glitch with the attributes temporarily set to the new(er)
     * ones.
     */
    if (found) {
	unsigned save = xw->flags;
	xw->flags ^= whichone;
	TRACE(("XMC Writing glitch (%d/%d) after SGR %d\n", my_attrs,
	       whichone, param));
	dotext(xw, '?', glitch, screen->xmc_glitch);
	xw->flags = save;
    }
}

/*
 * Force a glitch on cursor movement when we're in standout mode and not at the
 * end of a line.
 */
void
Jump_XMC(XtermWidget xw)
{
    TScreen *screen = &(xw->screen);
    if (!screen->move_sgr_ok
	&& screen->cur_col <= LineMaxCol(screen,
					 getLineData(screen, screen->cur_row))) {
	Mark_XMC(xw, -1);
    }
}

/*
 * After writing text to the screen, resolve mismatch between the current
 * location and any attributes that would have been set by preceding locations.
 */
void
Resolve_XMC(XtermWidget xw)
{
    TScreen *screen = &(xw->screen);
    LineData *ld;
    Bool changed = False;
    Char start;
    Char my_attrs = CharOf(screen->xmc_attributes & XMC_FLAGS);
    int row = screen->cur_row;
    int col = screen->cur_col;

    /* Find the preceding cell.
     */
    ld = getLineData(screen, row);
    if (ld->charData[col] != XMC_GLITCH) {
	if (col != 0) {
	    col--;
	} else if (!screen->xmc_inline && row != 0) {
	    ld = getLineData(screen, --row);
	    col = LineMaxCol(screen, ld);
	}
    }
    start = (ld->attribs[col] & my_attrs);

    /* Now propagate the starting state until we reach a cell which holds
     * a glitch.
     */
    for (;;) {
	if (col < LineMaxCol(screen, ld)) {
	    col++;
	} else if (!screen->xmc_inline && row < screen->max_row) {
	    col = 0;
	    ld = getLineData(screen, ++row);
	} else
	    break;
	if (ld->charData[col] == XMC_GLITCH)
	    break;
	if ((ld->attribs[col] & my_attrs) != start) {
	    ld->attribs[col] =
		CharOf(start | (ld->attribs[col] & ~my_attrs));
	    changed = True;
	}
    }

    TRACE(("XMC %s (%s:%d/%d) from %d,%d to %d,%d\n",
	   changed ? "Ripple" : "Nochange",
	   BtoS(xw->flags & my_attrs),
	   my_attrs, start,
	   screen->cur_row, screen->cur_col,
	   row, col));

    if (changed) {
	ScrnUpdate(xw, screen->cur_row, 0, row + 1 - screen->cur_row,
		   MaxCols(screen), True);
    }
}