tklistbox.c

linux系统下的音频通信

 *
 *----------------------------------------------------------------------
 */

static void
ListboxComputeGeometry(listPtr, fontChanged, maxIsStale, updateGrid)
    Listbox *listPtr;		/* Listbox whose geometry is to be
				 * recomputed. */
    int fontChanged;		/* Non-zero means the font may have changed
				 * so per-element width information also
				 * has to be computed. */
    int maxIsStale;		/* Non-zero means the "maxWidth" field may
				 * no longer be up-to-date and must
				 * be recomputed.  If fontChanged is 1 then
				 * this must be 1. */
    int updateGrid;		/* Non-zero means call Tk_SetGrid or
				 * Tk_UnsetGrid to update gridding for
				 * the window. */
{
    register Element *elPtr;
    int width, height, pixelWidth, pixelHeight;
    Tk_FontMetrics fm;

    if (fontChanged  || maxIsStale) {
	listPtr->xScrollUnit = Tk_TextWidth(listPtr->tkfont, "0", 1);
	if (listPtr->xScrollUnit == 0) {
	    listPtr->xScrollUnit = 1;
	}
	listPtr->maxWidth = 0;
	for (elPtr = listPtr->firstPtr; elPtr != NULL; elPtr = elPtr->nextPtr) {
	    if (fontChanged) {
		elPtr->pixelWidth = Tk_TextWidth(listPtr->tkfont,
			elPtr->text, elPtr->textLength);
		elPtr->lBearing = 0;
	    }
	    if (elPtr->pixelWidth > listPtr->maxWidth) {
		listPtr->maxWidth = elPtr->pixelWidth;
	    }
	}
    }

    Tk_GetFontMetrics(listPtr->tkfont, &fm);
    listPtr->lineHeight = fm.linespace + 1 + 2*listPtr->selBorderWidth;
    width = listPtr->width;
    if (width <= 0) {
	width = (listPtr->maxWidth + listPtr->xScrollUnit - 1)
		/listPtr->xScrollUnit;
	if (width < 1) {
	    width = 1;
	}
    }
    pixelWidth = width*listPtr->xScrollUnit + 2*listPtr->inset
	    + 2*listPtr->selBorderWidth;
    height = listPtr->height;
    if (listPtr->height <= 0) {
	height = listPtr->numElements;
	if (height < 1) {
	    height = 1;
	}
    }
    pixelHeight = height*listPtr->lineHeight + 2*listPtr->inset;
    Tk_GeometryRequest(listPtr->tkwin, pixelWidth, pixelHeight);
    Tk_SetInternalBorder(listPtr->tkwin, listPtr->inset);
    if (updateGrid) {
	if (listPtr->setGrid) {
	    Tk_SetGrid(listPtr->tkwin, width, height, listPtr->xScrollUnit,
		    listPtr->lineHeight);
	} else {
	    Tk_UnsetGrid(listPtr->tkwin);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * InsertEls --
 *
 *	Add new elements to a listbox widget.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	New information gets added to listPtr;  it will be redisplayed
 *	soon, but not immediately.
 *
 *----------------------------------------------------------------------
 */

static void
InsertEls(listPtr, index, argc, argv)
    register Listbox *listPtr;	/* Listbox that is to get the new
				 * elements. */
    int index;			/* Add the new elements before this
				 * element. */
    int argc;			/* Number of new elements to add. */
    char **argv;		/* New elements (one per entry). */
{
    register Element *prevPtr, *newPtr;
    int length, i, oldMaxWidth;

    /*
     * Find the element before which the new ones will be inserted.
     */

    if (index <= 0) {
	index = 0;
    }
    if (index > listPtr->numElements) {
	index = listPtr->numElements;
    }
    if (index == 0) {
	prevPtr = NULL;
    } else if (index == listPtr->numElements) {
          prevPtr = listPtr->lastPtr;
    } else {
	for (prevPtr = listPtr->firstPtr, i = index - 1; i > 0; i--) {
	    prevPtr = prevPtr->nextPtr;
	}
    }

    /*
     * For each new element, create a record, initialize it, and link
     * it into the list of elements.
     */

    oldMaxWidth = listPtr->maxWidth;
    for (i = argc ; i > 0; i--, argv++, prevPtr = newPtr) {
	length = strlen(*argv);
	newPtr = (Element *) ckalloc(ElementSize(length));
	newPtr->textLength = length;
	strcpy(newPtr->text, *argv);
	newPtr->pixelWidth = Tk_TextWidth(listPtr->tkfont, newPtr->text,
		newPtr->textLength);
	newPtr->lBearing = 0;
	if (newPtr->pixelWidth > listPtr->maxWidth) {
	    listPtr->maxWidth = newPtr->pixelWidth;
	}
	newPtr->selected = 0;
	if (prevPtr == NULL) {
	    newPtr->nextPtr = listPtr->firstPtr;
	    listPtr->firstPtr = newPtr;
	} else {
	    newPtr->nextPtr = prevPtr->nextPtr;
	    prevPtr->nextPtr = newPtr;
	}
    }
    if ((prevPtr != NULL) && (prevPtr->nextPtr == NULL)) {
	listPtr->lastPtr = prevPtr;
    }
    listPtr->numElements += argc;

    /*
     * Update the selection and other indexes to account for the
     * renumbering that has just occurred.  Then arrange for the new
     * information to be displayed.
     */

    if (index <= listPtr->selectAnchor) {
	listPtr->selectAnchor += argc;
    }
    if (index < listPtr->topIndex) {
	listPtr->topIndex += argc;
    }
    if (index <= listPtr->active) {
	listPtr->active += argc;
	if ((listPtr->active >= listPtr->numElements)
		&& (listPtr->numElements > 0)) {
	    listPtr->active = listPtr->numElements-1;
	}
    }
    listPtr->flags |= UPDATE_V_SCROLLBAR;
    if (listPtr->maxWidth != oldMaxWidth) {
	listPtr->flags |= UPDATE_H_SCROLLBAR;
    }
    ListboxComputeGeometry(listPtr, 0, 0, 0);
    ListboxRedrawRange(listPtr, index, listPtr->numElements-1);
}

/*
 *----------------------------------------------------------------------
 *
 * DeleteEls --
 *
 *	Remove one or more elements from a listbox widget.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Memory gets freed, the listbox gets modified and (eventually)
 *	redisplayed.
 *
 *----------------------------------------------------------------------
 */

static void
DeleteEls(listPtr, first, last)
    register Listbox *listPtr;	/* Listbox widget to modify. */
    int first;			/* Index of first element to delete. */
    int last;			/* Index of last element to delete. */
{
    register Element *prevPtr, *elPtr;
    int count, i, widthChanged;

    /*
     * Adjust the range to fit within the existing elements of the
     * listbox, and make sure there's something to delete.
     */

    if (first < 0) {
	first = 0;
    }
    if (last >= listPtr->numElements) {
	last = listPtr->numElements-1;
    }
    count = last + 1 - first;
    if (count <= 0) {
	return;
    }

    /*
     * Find the element just before the ones to delete.
     */

    if (first == 0) {
	prevPtr = NULL;
    } else {
	for (i = first-1, prevPtr = listPtr->firstPtr; i > 0; i--) {
	    prevPtr = prevPtr->nextPtr;
	}
    }

    /*
     * Delete the requested number of elements.
     */

    widthChanged = 0;
    for (i = count; i > 0; i--) {
	if (prevPtr == NULL) {
	    elPtr = listPtr->firstPtr;
	    listPtr->firstPtr = elPtr->nextPtr;
	    if (listPtr->firstPtr == NULL) {
		listPtr->lastPtr = NULL;
	    }
	} else {
	    elPtr = prevPtr->nextPtr;
	    prevPtr->nextPtr = elPtr->nextPtr;
	    if (prevPtr->nextPtr == NULL) {
		listPtr->lastPtr = prevPtr;
	    }
	}
	if (elPtr->pixelWidth == listPtr->maxWidth) {
	    widthChanged = 1;
	}
	if (elPtr->selected) {
	    listPtr->numSelected -= 1;
	}
	ckfree((char *) elPtr);
    }
    listPtr->numElements -= count;

    /*
     * Update the selection and viewing information to reflect the change
     * in the element numbering, and redisplay to slide information up over
     * the elements that were deleted.
     */

    if (first <= listPtr->selectAnchor) {
	listPtr->selectAnchor -= count;
	if (listPtr->selectAnchor < first) {
	    listPtr->selectAnchor = first;
	}
    }
    if (first <= listPtr->topIndex) {
	listPtr->topIndex -= count;
	if (listPtr->topIndex < first) {
	    listPtr->topIndex = first;
	}
    }
    if (listPtr->topIndex > (listPtr->numElements - listPtr->fullLines)) {
	listPtr->topIndex = listPtr->numElements - listPtr->fullLines;
	if (listPtr->topIndex < 0) {
	    listPtr->topIndex = 0;
	}
    }
    if (listPtr->active > last) {
	listPtr->active -= count;
    } else if (listPtr->active >= first) {
	listPtr->active = first;
	if ((listPtr->active >= listPtr->numElements)
		&& (listPtr->numElements > 0)) {
	    listPtr->active = listPtr->numElements-1;
	}
    }
    listPtr->flags |= UPDATE_V_SCROLLBAR;
    ListboxComputeGeometry(listPtr, 0, widthChanged, 0);
    if (widthChanged) {
	listPtr->flags |= UPDATE_H_SCROLLBAR;
    }
    ListboxRedrawRange(listPtr, first, listPtr->numElements-1);
}

/*
 *--------------------------------------------------------------
 *
 * ListboxEventProc --
 *
 *	This procedure is invoked by the Tk dispatcher for various
 *	events on listboxes.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	When the window gets deleted, internal structures get
 *	cleaned up.  When it gets exposed, it is redisplayed.
 *
 *--------------------------------------------------------------
 */

static void
ListboxEventProc(clientData, eventPtr)
    ClientData clientData;	/* Information about window. */
    XEvent *eventPtr;		/* Information about event. */
{
    Listbox *listPtr = (Listbox *) clientData;

    if (eventPtr->type == Expose) {
	ListboxRedrawRange(listPtr,
		NearestListboxElement(listPtr, eventPtr->xexpose.y),
		NearestListboxElement(listPtr, eventPtr->xexpose.y
		+ eventPtr->xexpose.height));
    } else if (eventPtr->type == DestroyNotify) {
	if (listPtr->tkwin != NULL) {
	    if (listPtr->setGrid) {
		Tk_UnsetGrid(listPtr->tkwin);
	    }
	    listPtr->tkwin = NULL;
	    Tcl_DeleteCommandFromToken(listPtr->interp, listPtr->widgetCmd);
	}
	if (listPtr->flags & REDRAW_PENDING) {
	    Tcl_CancelIdleCall(DisplayListbox, (ClientData) listPtr);
	}
	Tcl_EventuallyFree((ClientData) listPtr, DestroyListbox);
    } else if (eventPtr->type == ConfigureNotify) {
	int vertSpace;

	vertSpace = Tk_Height(listPtr->tkwin) - 2*listPtr->inset;
	listPtr->fullLines = vertSpace / listPtr->lineHeight;
	if ((listPtr->fullLines*listPtr->lineHeight) < vertSpace) {
	    listPtr->partialLine = 1;
	} else {
	    listPtr->partialLine = 0;
	}
	listPtr->flags |= UPDATE_V_SCROLLBAR|UPDATE_H_SCROLLBAR;
	ChangeListboxView(listPtr, listPtr->topIndex);
	ChangeListboxOffset(listPtr, listPtr->xOffset);

	/*
	 * Redraw the whole listbox.  It's hard to tell what needs
	 * to be redrawn (e.g. if the listbox has shrunk then we
	 * may only need to redraw the borders), so just redraw
	 * everything for safety.
	 */

	ListboxRedrawRange(listPtr, 0, listPtr->numElements-1);
    } else if (eventPtr->type == FocusIn) {
	if (eventPtr->xfocus.detail != NotifyInferior) {
	    listPtr->flags |= GOT_FOCUS;
	    ListboxRedrawRange(listPtr, 0, listPtr->numElements-1);
	}
    } else if (eventPtr->type == FocusOut) {
	if (eventPtr->xfocus.detail != NotifyInferior) {
	    listPtr->flags &= ~GOT_FOCUS;
	    ListboxRedrawRange(listPtr, 0, listPtr->numElements-1);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * ListboxCmdDeletedProc --
 *
 *	This procedure is invoked when a widget command is deleted.  If
 *	the widget isn't already in the process of being destroyed,
 *	this command destroys it.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The widget is destroyed.
 *
 *----------------------------------------------------------------------
 */

static void
ListboxCmdDeletedProc(clientData)
    ClientData clientData;	/* Pointer to widget record for widget. */
{
    Listbox *listPtr = (Listbox *) clientData;
    Tk_Window tkwin = listPtr->tkwin;

    /*
     * This procedure could be invoked either because the window was
     * destroyed and the command was then deleted (in which case tkwin
     * is NULL) or because the command was deleted, and then this procedure
     * destroys the widget.
     */

    if (tkwin != NULL) {
	if (listPtr->setGrid) {
	    Tk_UnsetGrid(listPtr->tkwin);
	}
	listPtr->tkwin = NULL;
	Tk_DestroyWindow(tkwin);
    }
}

/*
 *--------------------------------------------------------------
 *
 * GetListboxIndex --
 *
 *	Parse an index into a listbox and return either its value
 *	or an error.