archie/tk4.2/generic/tkClipboard.c

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/*
* tkClipboard.c --
*
* This file manages the clipboard for the Tk toolkit,
* maintaining a collection of data buffers that will be
* supplied on demand to requesting applications.
*
* Copyright (c) 1994 The Regents of the University of California.
* Copyright (c) 1994-1995 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* SCCS: @(#) tkClipboard.c 1.14 96/02/15 18:52:37
*/
#include "tkInt.h"
#include "tkPort.h"
#include "tkSelect.h"
/*
* Prototypes for procedures used only in this file:
*/
static int ClipboardAppHandler _ANSI_ARGS_((ClientData clientData,
int offset, char *buffer, int maxBytes));
static int ClipboardHandler _ANSI_ARGS_((ClientData clientData,
int offset, char *buffer, int maxBytes));
static int ClipboardWindowHandler _ANSI_ARGS_((
ClientData clientData, int offset, char *buffer,
int maxBytes));
static void ClipboardLostSel _ANSI_ARGS_((ClientData clientData));
/*
*----------------------------------------------------------------------
*
* ClipboardHandler --
*
* This procedure acts as selection handler for the
* clipboard manager. It extracts the required chunk of
* data from the buffer chain for a given selection target.
*
* Results:
* The return value is a count of the number of bytes
* actually stored at buffer.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static int
ClipboardHandler(clientData, offset, buffer, maxBytes)
ClientData clientData; /* Information about data to fetch. */
int offset; /* Return selection bytes starting at this
* offset. */
char *buffer; /* Place to store converted selection. */
int maxBytes; /* Maximum # of bytes to store at buffer. */
{
TkClipboardTarget *targetPtr = (TkClipboardTarget*) clientData;
TkClipboardBuffer *cbPtr;
char *srcPtr, *destPtr;
int count = 0;
int scanned = 0;
size_t length, freeCount;
/*
* Skip to buffer containing offset byte
*/
for (cbPtr = targetPtr->firstBufferPtr; ; cbPtr = cbPtr->nextPtr) {
if (cbPtr == NULL) {
return 0;
}
if (scanned + cbPtr->length > offset) {
break;
}
scanned += cbPtr->length;
}
/*
* Copy up to maxBytes or end of list, switching buffers as needed.
*/
freeCount = maxBytes;
srcPtr = cbPtr->buffer + (offset - scanned);
destPtr = buffer;
length = cbPtr->length - (offset - scanned);
while (1) {
if (length > freeCount) {
strncpy(destPtr, srcPtr, freeCount);
return maxBytes;
} else {
strncpy(destPtr, srcPtr, length);
destPtr += length;
count += length;
freeCount -= length;
}
cbPtr = cbPtr->nextPtr;
if (cbPtr == NULL) {
break;
}
srcPtr = cbPtr->buffer;
length = cbPtr->length;
}
return count;
}
/*
*----------------------------------------------------------------------
*
* ClipboardAppHandler --
*
* This procedure acts as selection handler for retrievals of type
* TK_APPLICATION. It returns the name of the application that
* owns the clipboard. Note: we can't use the default Tk
* selection handler for this selection type, because the clipboard
* window isn't a "real" window and doesn't have the necessary
* information.
*
* Results:
* The return value is a count of the number of bytes
* actually stored at buffer.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static int
ClipboardAppHandler(clientData, offset, buffer, maxBytes)
ClientData clientData; /* Pointer to TkDisplay structure. */
int offset; /* Return selection bytes starting at this
* offset. */
char *buffer; /* Place to store converted selection. */
int maxBytes; /* Maximum # of bytes to store at buffer. */
{
TkDisplay *dispPtr = (TkDisplay *) clientData;
size_t length;
char *p;
p = dispPtr->clipboardAppPtr->winPtr->nameUid;
length = strlen(p);
length -= offset;
if (length <= 0) {
return 0;
}
if (length > maxBytes) {
length = maxBytes;
}
strncpy(buffer, p, length);
return length;
}
/*
*----------------------------------------------------------------------
*
* ClipboardWindowHandler --
*
* This procedure acts as selection handler for retrievals of
* type TK_WINDOW. Since the clipboard doesn't correspond to
* any particular window, we just return ".". We can't use Tk's
* default handler for this selection type, because the clipboard
* window isn't a valid window.
*
* Results:
* The return value is 1, the number of non-null bytes stored
* at buffer.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static int
ClipboardWindowHandler(clientData, offset, buffer, maxBytes)
ClientData clientData; /* Not used. */
int offset; /* Return selection bytes starting at this
* offset. */
char *buffer; /* Place to store converted selection. */
int maxBytes; /* Maximum # of bytes to store at buffer. */
{
buffer[0] = '.';
buffer[1] = 0;
return 1;
}
/*
*----------------------------------------------------------------------
*
* ClipboardLostSel --
*
* This procedure is invoked whenever clipboard ownership is
* claimed by another window. It just sets a flag so that we
* know the clipboard was taken away.
*
* Results:
* None.
*
* Side effects:
* The clipboard is marked as inactive.
*
*----------------------------------------------------------------------
*/
static void
ClipboardLostSel(clientData)
ClientData clientData; /* Pointer to TkDisplay structure. */
{
TkDisplay *dispPtr = (TkDisplay*) clientData;
dispPtr->clipboardActive = 0;
}
/*
*----------------------------------------------------------------------
*
* Tk_ClipboardClear --
*
* Take control of the clipboard and clear out the previous
* contents. This procedure must be invoked before any
* calls to Tk_AppendToClipboard.
*
* Results:
* A standard Tcl result. If an error occurs, an error message is
* left in interp->result.
*
* Side effects:
* From now on, requests for the CLIPBOARD selection will be
* directed to the clipboard manager routines associated with
* clipWindow for the display of tkwin. In order to guarantee
* atomicity, no event handling should occur between
* Tk_ClipboardClear and the following Tk_AppendToClipboard
* calls. This procedure may cause a user-defined LostSel command
* to be invoked when the CLIPBOARD is claimed, so any calling
* function should be reentrant at the point Tk_ClipboardClear is
* invoked.
*
*----------------------------------------------------------------------
*/
int
Tk_ClipboardClear(interp, tkwin)
Tcl_Interp *interp; /* Interpreter to use for error reporting. */
Tk_Window tkwin; /* Window in application that is clearing
* clipboard; identifies application and
* display. */
{
TkWindow *winPtr = (TkWindow *) tkwin;
TkDisplay *dispPtr = winPtr->dispPtr;
TkClipboardTarget *targetPtr, *nextTargetPtr;
TkClipboardBuffer *cbPtr, *nextCbPtr;
if (dispPtr->clipWindow == NULL) {
int result;
result = TkClipInit(interp, dispPtr);
if (result != TCL_OK) {
return result;
}
}
/*
* Discard any existing clipboard data and delete the selection
* handler(s) associated with that data.
*/
for (targetPtr = dispPtr->clipTargetPtr; targetPtr != NULL;
targetPtr = nextTargetPtr) {
for (cbPtr = targetPtr->firstBufferPtr; cbPtr != NULL;
cbPtr = nextCbPtr) {
ckfree(cbPtr->buffer);
nextCbPtr = cbPtr->nextPtr;
ckfree((char *) cbPtr);
}
nextTargetPtr = targetPtr->nextPtr;
Tk_DeleteSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,
targetPtr->type);
ckfree((char *) targetPtr);
}
dispPtr->clipTargetPtr = NULL;
/*
* Reclaim the clipboard selection if we lost it.
*/
if (!dispPtr->clipboardActive) {
Tk_OwnSelection(dispPtr->clipWindow, dispPtr->clipboardAtom,
ClipboardLostSel, (ClientData) dispPtr);
dispPtr->clipboardActive = 1;
}
dispPtr->clipboardAppPtr = winPtr->mainPtr;
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Tk_ClipboardAppend --
*
* Append a buffer of data to the clipboard. The first buffer of
* a given type determines the format for that type. Any successive
* appends to that type must have the same format or an error will
* be returned. Tk_ClipboardClear must be called before a sequence
* of Tk_ClipboardAppend calls can be issued. In order to guarantee
* atomicity, no event handling should occur between Tk_ClipboardClear
* and the following Tk_AppendToClipboard calls.
*
* Results:
* A standard Tcl result. If an error is returned, an error message
* is left in interp->result.
*
* Side effects:
* The specified buffer will be copied onto the end of the clipboard.
* The clipboard maintains a list of buffers which will be used to
* supply the data for a selection get request. The first time a given
* type is appended, Tk_ClipboardAppend will register a selection
* handler of the appropriate type.
*
*----------------------------------------------------------------------
*/
int
Tk_ClipboardAppend(interp, tkwin, type, format, buffer)
Tcl_Interp *interp; /* Used for error reporting. */
Tk_Window tkwin; /* Window that selects a display. */
Atom type; /* The desired conversion type for this
* clipboard item, e.g. STRING or LENGTH. */
Atom format; /* Format in which the selection
* information should be returned to
* the requestor. */
char* buffer; /* NULL terminated string containing the data
* to be added to the clipboard. */
{
TkWindow *winPtr = (TkWindow *) tkwin;
TkDisplay *dispPtr = winPtr->dispPtr;
TkClipboardTarget *targetPtr;
TkClipboardBuffer *cbPtr;
/*
* If this application doesn't already own the clipboard, clear
* the clipboard. If we don't own the clipboard selection, claim it.
*/
if (dispPtr->clipboardAppPtr != winPtr->mainPtr) {
Tk_ClipboardClear(interp, tkwin);
} else if (!dispPtr->clipboardActive) {
Tk_OwnSelection(dispPtr->clipWindow, dispPtr->clipboardAtom,
ClipboardLostSel, (ClientData) dispPtr);
dispPtr->clipboardActive = 1;
}
/*
* Check to see if the specified target is already present on the
* clipboard. If it isn't, we need to create a new target; otherwise,
* we just append the new buffer to the clipboard list.
*/
for (targetPtr = dispPtr->clipTargetPtr; targetPtr != NULL;
targetPtr = targetPtr->nextPtr) {
if (targetPtr->type == type)
break;
}
if (targetPtr == NULL) {
targetPtr = (TkClipboardTarget*) ckalloc(sizeof(TkClipboardTarget));
targetPtr->type = type;
targetPtr->format = format;
targetPtr->firstBufferPtr = targetPtr->lastBufferPtr = NULL;
targetPtr->nextPtr = dispPtr->clipTargetPtr;
dispPtr->clipTargetPtr = targetPtr;
Tk_CreateSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,
type, ClipboardHandler, (ClientData) targetPtr, format);
} else if (targetPtr->format != format) {
Tcl_AppendResult(interp, "format \"", Tk_GetAtomName(tkwin, format),
"\" does not match current format \"",
Tk_GetAtomName(tkwin, targetPtr->format),"\" for ",
Tk_GetAtomName(tkwin, type), (char *) NULL);
return TCL_ERROR;
}
/*
* Append a new buffer to the buffer chain.
*/
cbPtr = (TkClipboardBuffer*) ckalloc(sizeof(TkClipboardBuffer));
cbPtr->nextPtr = NULL;
if (targetPtr->lastBufferPtr != NULL) {
targetPtr->lastBufferPtr->nextPtr = cbPtr;
} else {
targetPtr->firstBufferPtr = cbPtr;
}
targetPtr->lastBufferPtr = cbPtr;
cbPtr->length = strlen(buffer);
cbPtr->buffer = (char *) ckalloc((unsigned) (cbPtr->length + 1));
strcpy(cbPtr->buffer, buffer);
TkSelUpdateClipboard((TkWindow*)(dispPtr->clipWindow), targetPtr);
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Tk_ClipboardCmd --
*
* This procedure is invoked to process the "clipboard" Tcl
* command. See the user documentation for details on what
* it does.
*
* Results:
* A standard Tcl result.
*
* Side effects:
* See the user documentation.
*
*----------------------------------------------------------------------
*/
int
Tk_ClipboardCmd(clientData, interp, argc, argv)
ClientData clientData; /* Main window associated with
* interpreter. */
Tcl_Interp *interp; /* Current interpreter. */
int argc; /* Number of arguments. */
char **argv; /* Argument strings. */
{
Tk_Window tkwin = (Tk_Window) clientData;
char *path = NULL;
size_t length;
int count;
char c;
char **args;
if (argc < 2) {
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" option ?arg arg ...?\"", (char *) NULL);
return TCL_ERROR;
}
c = argv[1][0];
length = strlen(argv[1]);
if ((c == 'a') && (strncmp(argv[1], "append", length) == 0)) {
Atom target, format;
char *targetName = NULL;
char *formatName = NULL;
for (count = argc-2, args = argv+2; count > 1; count -= 2, args += 2) {
if (args[0][0] != '-') {
break;
}
c = args[0][1];
length = strlen(args[0]);
if ((c == '-') && (length == 2)) {
args++;
count--;
break;
}
if ((c == 'd') && (strncmp(args[0], "-displayof", length) == 0)) {
path = args[1];
} else if ((c == 'f')
&& (strncmp(args[0], "-format", length) == 0)) {
formatName = args[1];
} else if ((c == 't')
&& (strncmp(args[0], "-type", length) == 0)) {
targetName = args[1];
} else {
Tcl_AppendResult(interp, "unknown option \"", args[0],
"\"", (char *) NULL);
return TCL_ERROR;
}
}
if (count != 1) {
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" append ?options? data\"", (char *) NULL);
return TCL_ERROR;
}
if (path != NULL) {
tkwin = Tk_NameToWindow(interp, path, tkwin);
}
if (tkwin == NULL) {
return TCL_ERROR;
}
if (targetName != NULL) {
target = Tk_InternAtom(tkwin, targetName);
} else {
target = XA_STRING;
}
if (formatName != NULL) {
format = Tk_InternAtom(tkwin, formatName);
} else {
format = XA_STRING;
}
return Tk_ClipboardAppend(interp, tkwin, target, format, args[0]);
} else if ((c == 'c') && (strncmp(argv[1], "clear", length) == 0)) {
for (count = argc-2, args = argv+2; count > 0; count -= 2, args += 2) {
if (args[0][0] != '-') {
break;
}
if (count < 2) {
Tcl_AppendResult(interp, "value for \"", *args,
"\" missing", (char *) NULL);
return TCL_ERROR;
}
c = args[0][1];
length = strlen(args[0]);
if ((c == 'd') && (strncmp(args[0], "-displayof", length) == 0)) {
path = args[1];
} else {
Tcl_AppendResult(interp, "unknown option \"", args[0],
"\"", (char *) NULL);
return TCL_ERROR;
}
}
if (count > 0) {
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" clear ?options?\"", (char *) NULL);
return TCL_ERROR;
}
if (path != NULL) {
tkwin = Tk_NameToWindow(interp, path, tkwin);
}
if (tkwin == NULL) {
return TCL_ERROR;
}
return Tk_ClipboardClear(interp, tkwin);
} else {
sprintf(interp->result,
"bad option \"%.50s\": must be clear or append",
argv[1]);
return TCL_ERROR;
}
}
/*
*----------------------------------------------------------------------
*
* TkClipInit --
*
* This procedure is called to initialize the window for claiming
* clipboard ownership and for receiving selection get results. This
* function is called from tkSelect.c as well as tkClipboard.c.
*
* Results:
* The result is a standard Tcl return value, which is normally TCL_OK.
* If an error occurs then an error message is left in interp->result
* and TCL_ERROR is returned.
*
* Side effects:
* Sets up the clipWindow and related data structures.
*
*----------------------------------------------------------------------
*/
int
TkClipInit(interp, dispPtr)
Tcl_Interp *interp; /* Interpreter to use for error
* reporting. */
register TkDisplay *dispPtr;/* Display to initialize. */
{
XSetWindowAttributes atts;
dispPtr->clipTargetPtr = NULL;
dispPtr->clipboardActive = 0;
dispPtr->clipboardAppPtr = NULL;
/*
* Create the window used for clipboard ownership and selection retrieval,
* and set up an event handler for it.
*/
dispPtr->clipWindow = Tk_CreateWindow(interp, (Tk_Window) NULL,
"_clip", DisplayString(dispPtr->display));
if (dispPtr->clipWindow == NULL) {
return TCL_ERROR;
}
atts.override_redirect = True;
Tk_ChangeWindowAttributes(dispPtr->clipWindow, CWOverrideRedirect, &atts);
Tk_MakeWindowExist(dispPtr->clipWindow);
if (dispPtr->multipleAtom == None) {
/*
* Need to invoke selection initialization to make sure that
* atoms we depend on below are defined.
*/
TkSelInit(dispPtr->clipWindow);
}
/*
* Create selection handlers for types TK_APPLICATION and TK_WINDOW
* on this window. Can't use the default handlers for these types
* because this isn't a full-fledged window.
*/
Tk_CreateSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,
dispPtr->applicationAtom, ClipboardAppHandler,
(ClientData) dispPtr, XA_STRING);
Tk_CreateSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,
dispPtr->windowAtom, ClipboardWindowHandler,
(ClientData) dispPtr, XA_STRING);
return TCL_OK;
}