tkcanvtext.c

linux系统下的音频通信

	if (textInfoPtr->selectFirst > textInfoPtr->selectLast) {
	    textInfoPtr->selItemPtr = NULL;
	}
	if ((textInfoPtr->anchorItemPtr == itemPtr)
		&& (textInfoPtr->selectAnchor > first)) {
	    textInfoPtr->selectAnchor -= count;
	    if (textInfoPtr->selectAnchor < first) {
		textInfoPtr->selectAnchor = first;
	    }
	}
    }
    if (textPtr->insertPos > first) {
	textPtr->insertPos -= count;
	if (textPtr->insertPos < first) {
	    textPtr->insertPos = first;
	}
    }
    ComputeTextBbox(canvas, textPtr);
    return;
}

/*
 *--------------------------------------------------------------
 *
 * TextToPoint --
 *
 *	Computes the distance from a given point to a given
 *	text item, in canvas units.
 *
 * Results:
 *	The return value is 0 if the point whose x and y coordinates
 *	are pointPtr[0] and pointPtr[1] is inside the text item.  If
 *	the point isn't inside the text item then the return value
 *	is the distance from the point to the text item.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

static double
TextToPoint(canvas, itemPtr, pointPtr)
    Tk_Canvas canvas;		/* Canvas containing itemPtr. */
    Tk_Item *itemPtr;		/* Item to check against point. */
    double *pointPtr;		/* Pointer to x and y coordinates. */
{
    TextItem *textPtr;

    textPtr = (TextItem *) itemPtr;
    return (double) Tk_DistanceToTextLayout(textPtr->textLayout,
	    (int) pointPtr[0] - textPtr->leftEdge,
	    (int) pointPtr[1] - textPtr->header.y1);
}

/*
 *--------------------------------------------------------------
 *
 * TextToArea --
 *
 *	This procedure is called to determine whether an item
 *	lies entirely inside, entirely outside, or overlapping
 *	a given rectangle.
 *
 * Results:
 *	-1 is returned if the item is entirely outside the area
 *	given by rectPtr, 0 if it overlaps, and 1 if it is entirely
 *	inside the given area.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

static int
TextToArea(canvas, itemPtr, rectPtr)
    Tk_Canvas canvas;		/* Canvas containing itemPtr. */
    Tk_Item *itemPtr;		/* Item to check against rectangle. */
    double *rectPtr;		/* Pointer to array of four coordinates
				 * (x1, y1, x2, y2) describing rectangular
				 * area.  */
{
    TextItem *textPtr;

    textPtr = (TextItem *) itemPtr;
    return Tk_IntersectTextLayout(textPtr->textLayout,
	    (int) (rectPtr[0] + 0.5) - textPtr->leftEdge,
	    (int) (rectPtr[1] + 0.5) - textPtr->header.y1,
	    (int) (rectPtr[2] - rectPtr[0] + 0.5),
	    (int) (rectPtr[3] - rectPtr[1] + 0.5));
}

/*
 *--------------------------------------------------------------
 *
 * ScaleText --
 *
 *	This procedure is invoked to rescale a text item.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Scales the position of the text, but not the size
 *	of the font for the text.
 *
 *--------------------------------------------------------------
 */

	/* ARGSUSED */
static void
ScaleText(canvas, itemPtr, originX, originY, scaleX, scaleY)
    Tk_Canvas canvas;			/* Canvas containing rectangle. */
    Tk_Item *itemPtr;			/* Rectangle to be scaled. */
    double originX, originY;		/* Origin about which to scale rect. */
    double scaleX;			/* Amount to scale in X direction. */
    double scaleY;			/* Amount to scale in Y direction. */
{
    TextItem *textPtr = (TextItem *) itemPtr;

    textPtr->x = originX + scaleX*(textPtr->x - originX);
    textPtr->y = originY + scaleY*(textPtr->y - originY);
    ComputeTextBbox(canvas, textPtr);
    return;
}

/*
 *--------------------------------------------------------------
 *
 * TranslateText --
 *
 *	This procedure is called to move a text item by a
 *	given amount.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The position of the text item is offset by (xDelta, yDelta),
 *	and the bounding box is updated in the generic part of the
 *	item structure.
 *
 *--------------------------------------------------------------
 */

static void
TranslateText(canvas, itemPtr, deltaX, deltaY)
    Tk_Canvas canvas;			/* Canvas containing item. */
    Tk_Item *itemPtr;			/* Item that is being moved. */
    double deltaX, deltaY;		/* Amount by which item is to be
					 * moved. */
{
    TextItem *textPtr = (TextItem *) itemPtr;

    textPtr->x += deltaX;
    textPtr->y += deltaY;
    ComputeTextBbox(canvas, textPtr);
}

/*
 *--------------------------------------------------------------
 *
 * GetTextIndex --
 *
 *	Parse an index into a text item and return either its value
 *	or an error.
 *
 * Results:
 *	A standard Tcl result.  If all went well, then *indexPtr is
 *	filled in with the index (into itemPtr) corresponding to
 *	string.  Otherwise an error message is left in
 *	interp->result.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

static int
GetTextIndex(interp, canvas, itemPtr, string, indexPtr)
    Tcl_Interp *interp;		/* Used for error reporting. */
    Tk_Canvas canvas;		/* Canvas containing item. */
    Tk_Item *itemPtr;		/* Item for which the index is being
				 * specified. */
    char *string;		/* Specification of a particular character
				 * in itemPtr's text. */
    int *indexPtr;		/* Where to store converted index. */
{
    TextItem *textPtr = (TextItem *) itemPtr;
    size_t length;
    int c;
    TkCanvas *canvasPtr = (TkCanvas *) canvas;
    Tk_CanvasTextInfo *textInfoPtr = textPtr->textInfoPtr;

    c = string[0];
    length = strlen(string);

    if ((c == 'e') && (strncmp(string, "end", length) == 0)) {
	*indexPtr = textPtr->numChars;
    } else if ((c == 'i') && (strncmp(string, "insert", length) == 0)) {
	*indexPtr = textPtr->insertPos;
    } else if ((c == 's') && (strncmp(string, "sel.first", length) == 0)
	    && (length >= 5)) {
	if (textInfoPtr->selItemPtr != itemPtr) {
	    interp->result = "selection isn't in item";
	    return TCL_ERROR;
	}
	*indexPtr = textInfoPtr->selectFirst;
    } else if ((c == 's') && (strncmp(string, "sel.last", length) == 0)
	    && (length >= 5)) {
	if (textInfoPtr->selItemPtr != itemPtr) {
	    interp->result = "selection isn't in item";
	    return TCL_ERROR;
	}
	*indexPtr = textInfoPtr->selectLast;
    } else if (c == '@') {
	int x, y;
	double tmp;
	char *end, *p;

	p = string+1;
	tmp = strtod(p, &end);
	if ((end == p) || (*end != ',')) {
	    goto badIndex;
	}
	x = (int) ((tmp < 0) ? tmp - 0.5 : tmp + 0.5);
	p = end+1;
	tmp = strtod(p, &end);
	if ((end == p) || (*end != 0)) {
	    goto badIndex;
	}
	y = (int) ((tmp < 0) ? tmp - 0.5 : tmp + 0.5);
	*indexPtr = Tk_PointToChar(textPtr->textLayout,
		x + canvasPtr->scrollX1 - textPtr->leftEdge,
		y + canvasPtr->scrollY1 - textPtr->header.y1);
    } else if (Tcl_GetInt(interp, string, indexPtr) == TCL_OK) {
	if (*indexPtr < 0){
	    *indexPtr = 0;
	} else if (*indexPtr > textPtr->numChars) {
	    *indexPtr = textPtr->numChars;
	}
    } else {
	/*
	 * Some of the paths here leave messages in interp->result,
	 * so we have to clear it out before storing our own message.
	 */

	badIndex:
	Tcl_SetResult(interp, (char *) NULL, TCL_STATIC);
	Tcl_AppendResult(interp, "bad index \"", string, "\"",
		(char *) NULL);
	return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * SetTextCursor --
 *
 *	Set the position of the insertion cursor in this item.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The cursor position will change.
 *
 *--------------------------------------------------------------
 */

	/* ARGSUSED */
static void
SetTextCursor(canvas, itemPtr, index)
    Tk_Canvas canvas;			/* Record describing canvas widget. */
    Tk_Item *itemPtr;			/* Text item in which cursor position
					 * is to be set. */
    int index;				/* Index of character just before which
					 * cursor is to be positioned. */
{
    TextItem *textPtr = (TextItem *) itemPtr;

    if (index < 0) {
	textPtr->insertPos = 0;
    } else  if (index > textPtr->numChars) {
	textPtr->insertPos = textPtr->numChars;
    } else {
	textPtr->insertPos = index;
    }
}

/*
 *--------------------------------------------------------------
 *
 * GetSelText --
 *
 *	This procedure is invoked to return the selected portion
 *	of a text item.  It is only called when this item has
 *	the selection.
 *
 * Results:
 *	The return value is the number of non-NULL bytes stored
 *	at buffer.  Buffer is filled (or partially filled) with a
 *	NULL-terminated string containing part or all of the selection,
 *	as given by offset and maxBytes.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

static int
GetSelText(canvas, itemPtr, offset, buffer, maxBytes)
    Tk_Canvas canvas;			/* Canvas containing selection. */
    Tk_Item *itemPtr;			/* Text item containing selection. */
    int offset;				/* Offset within selection of first
					 * character to be returned. */
    char *buffer;			/* Location in which to place
					 * selection. */
    int maxBytes;			/* Maximum number of bytes to place
					 * at buffer, not including terminating
					 * NULL character. */
{
    TextItem *textPtr = (TextItem *) itemPtr;
    int count;
    Tk_CanvasTextInfo *textInfoPtr = textPtr->textInfoPtr;

    count = textInfoPtr->selectLast + 1 - textInfoPtr->selectFirst - offset;
    if (textInfoPtr->selectLast == textPtr->numChars) {
	count -= 1;
    }
    if (count > maxBytes) {
	count = maxBytes;
    }
    if (count <= 0) {
	return 0;
    }
    strncpy(buffer, textPtr->text + textInfoPtr->selectFirst + offset,
	    (size_t) count);
    buffer[count] = '\0';
    return count;
}

/*
 *--------------------------------------------------------------
 *
 * TextToPostscript --
 *
 *	This procedure is called to generate Postscript for
 *	text items.
 *
 * Results:
 *	The return value is a standard Tcl result.  If an error
 *	occurs in generating Postscript then an error message is
 *	left in interp->result, replacing whatever used
 *	to be there.  If no error occurs, then Postscript for the
 *	item is appended to the result.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

static int
TextToPostscript(interp, canvas, itemPtr, prepass)
    Tcl_Interp *interp;			/* Leave Postscript or error message
					 * here. */
    Tk_Canvas canvas;			/* Information about overall canvas. */
    Tk_Item *itemPtr;			/* Item for which Postscript is
					 * wanted. */
    int prepass;			/* 1 means this is a prepass to
					 * collect font information;  0 means
					 * final Postscript is being created. */
{
    TextItem *textPtr = (TextItem *) itemPtr;
    int x, y;
    Tk_FontMetrics fm;
    char *justify;
    char buffer[500];

    if (textPtr->color == NULL) {
	return TCL_OK;
    }

    if (Tk_CanvasPsFont(interp, canvas, textPtr->tkfont) != TCL_OK) {
	return TCL_ERROR;
    }
    if (prepass != 0) {
	return TCL_OK;
    }
    if (Tk_CanvasPsColor(interp, canvas, textPtr->color) != TCL_OK) {
	return TCL_ERROR;
    }
    if (textPtr->stipple != None) {
	Tcl_AppendResult(interp, "/StippleText {\n    ",
		(char *) NULL);
	Tk_CanvasPsStipple(interp, canvas, textPtr->stipple);
	Tcl_AppendResult(interp, "} bind def\n", (char *) NULL);
    }

    sprintf(buffer, "%.15g %.15g [\n", textPtr->x,
	    Tk_CanvasPsY(canvas, textPtr->y));
    Tcl_AppendResult(interp, buffer, (char *) NULL);

    Tk_TextLayoutToPostscript(interp, textPtr->textLayout);

    x = 0;  y = 0;  justify = NULL;	/* lint. */
    switch (textPtr->anchor) {
	case TK_ANCHOR_NW:	x = 0; y = 0;	break;
	case TK_ANCHOR_N:	x = 1; y = 0;	break;
	case TK_ANCHOR_NE:	x = 2; y = 0;	break;
	case TK_ANCHOR_E:	x = 2; y = 1;	break;
	case TK_ANCHOR_SE:	x = 2; y = 2;	break;
	case TK_ANCHOR_S:	x = 1; y = 2;	break;
	case TK_ANCHOR_SW:	x = 0; y = 2;	break;
	case TK_ANCHOR_W:	x = 0; y = 1;	break;
	case TK_ANCHOR_CENTER:	x = 1; y = 1;	break;
    }
    switch (textPtr->justify) {
        case TK_JUSTIFY_LEFT:	justify = "0";	break;
	case TK_JUSTIFY_CENTER: justify = "0.5";break;
	case TK_JUSTIFY_RIGHT:  justify = "1";	break;
    }

    Tk_GetFontMetrics(textPtr->tkfont, &fm);
    sprintf(buffer, "] %d %g %g %s %s DrawText\n",
	    fm.linespace, x / -2.0, y / 2.0, justify,
	    ((textPtr->stipple == None) ? "false" : "true"));
    Tcl_AppendResult(interp, buffer, (char *) NULL);

    return TCL_OK;
}