/*
* 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) 1994-1997 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* RCS: @(#) $Id: tkClipboard.c,v 1.20 2008/07/23 23:24:23 nijtmans Exp $
*/
#include "tkInt.h"
#include "tkSelect.h"
/*
* Prototypes for functions used only in this file:
*/
static int ClipboardAppHandler(ClientData clientData,
int offset, char *buffer, int maxBytes);
static int ClipboardHandler(ClientData clientData,
int offset, char *buffer, int maxBytes);
static int ClipboardWindowHandler(ClientData clientData,
int offset, char *buffer, int maxBytes);
static void ClipboardLostSel(ClientData clientData);
static int ClipboardGetProc(ClientData clientData,
Tcl_Interp *interp, char *portion);
/*
*----------------------------------------------------------------------
*
* ClipboardHandler --
*
* This function 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 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 = clientData;
TkClipboardBuffer *cbPtr;
char *srcPtr, *destPtr;
size_t 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 (int)count;
}
/*
*----------------------------------------------------------------------
*
* ClipboardAppHandler --
*
* This function 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 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 = clientData;
size_t length;
const char *p;
p = dispPtr->clipboardAppPtr->winPtr->nameUid;
length = strlen(p);
length -= offset;
if (length <= 0) {
return 0;
}
if (length > (size_t) maxBytes) {
length = maxBytes;
}
strncpy(buffer, p, length);
return (int)length;
}
/*
*----------------------------------------------------------------------
*
* ClipboardWindowHandler --
*
* This function 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 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 function 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) /* Pointer to TkDisplay structure. */
{
TkDisplay *dispPtr = clientData;
dispPtr->clipboardActive = 0;
}
/*
*----------------------------------------------------------------------
*
* Tk_ClipboardClear --
*
* Take control of the clipboard and clear out the previous contents.
* This function must be invoked before any calls to Tk_ClipboardAppend.
*
* Results:
* A standard Tcl result. If an error occurs, an error message is left in
* the interp's 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_ClipboardAppend calls. This function 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(
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, 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_ClipboardAppend calls.
*
* Results:
* A standard Tcl result. If an error is returned, an error message is
* left in the interp's 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(
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, 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, 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), 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_ClipboardObjCmd --
*
* This function 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_ClipboardObjCmd(
ClientData clientData, /* Main window associated with interpreter. */
Tcl_Interp *interp, /* Current interpreter. */
int objc, /* Number of arguments. */
Tcl_Obj *const objv[]) /* Argument strings. */
{
Tk_Window tkwin = (Tk_Window) clientData;
char *path = NULL;
Atom selection;
static const char *optionStrings[] = { "append", "clear", "get", NULL };
enum options { CLIPBOARD_APPEND, CLIPBOARD_CLEAR, CLIPBOARD_GET };
int index, i;
if (objc < 2) {
Tcl_WrongNumArgs(interp, 1, objv, "option ?arg ...?");
return TCL_ERROR;
}
if (Tcl_GetIndexFromObj(interp, objv[1], optionStrings, "option", 0,
&index) != TCL_OK) {
return TCL_ERROR;
}
switch ((enum options) index) {
case CLIPBOARD_APPEND: {
Atom target, format;
char *targetName = NULL;
char *formatName = NULL;
char *string;
static const char *appendOptionStrings[] = {
"-displayof", "-format", "-type", NULL
};
enum appendOptions { APPEND_DISPLAYOF, APPEND_FORMAT, APPEND_TYPE };
int subIndex, length;
for (i = 2; i < objc - 1; i++) {
string = Tcl_GetStringFromObj(objv[i], &length);
if (string[0] != '-') {
break;
}
/*
* If the argument is "--", it signifies the end of arguments.
*/
if (string[1] == '-' && length == 2) {
i++;
break;
}
if (Tcl_GetIndexFromObj(interp, objv[i], appendOptionStrings,
"option", 0, &subIndex) != TCL_OK) {
return TCL_ERROR;
}
/*
* Increment i so that it points to the value for the flag instead
* of the flag itself.
*/
i++;
if (i >= objc) {
Tcl_AppendResult(interp, "value for \"", string,
"\" missing", NULL);
return TCL_ERROR;
}
switch ((enum appendOptions) subIndex) {
case APPEND_DISPLAYOF:
path = Tcl_GetString(objv[i]);
break;
case APPEND_FORMAT:
formatName = Tcl_GetString(objv[i]);
break;
case APPEND_TYPE:
targetName = Tcl_GetString(objv[i]);
break;
}
}
if (objc - i != 1) {
Tcl_WrongNumArgs(interp, 2, objv, "?-option value ...? data");
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,
Tcl_GetString(objv[i]));
}
case CLIPBOARD_CLEAR: {
static const char *clearOptionStrings[] = { "-displayof", NULL };
enum clearOptions { CLEAR_DISPLAYOF };
int subIndex;
if (objc != 2 && objc != 4) {
Tcl_WrongNumArgs(interp, 2, objv, "?-displayof window?");
return TCL_ERROR;
}
if (objc == 4) {
if (Tcl_GetIndexFromObj(interp, objv[2], clearOptionStrings,
"option", 0, &subIndex) != TCL_OK) {
return TCL_ERROR;
}
if ((enum clearOptions) subIndex == CLEAR_DISPLAYOF) {
path = Tcl_GetString(objv[3]);
}
}
if (path != NULL) {
tkwin = Tk_NameToWindow(interp, path, tkwin);
}
if (tkwin == NULL) {
return TCL_ERROR;
}
return Tk_ClipboardClear(interp, tkwin);
}
case CLIPBOARD_GET: {
Atom target;
char *targetName = NULL;
Tcl_DString selBytes;
int result;
char *string;
static const char *getOptionStrings[] = {
"-displayof", "-type", NULL
};
enum getOptions { APPEND_DISPLAYOF, APPEND_TYPE };
int subIndex;
for (i = 2; i < objc; i++) {
string = Tcl_GetString(objv[i]);
if (string[0] != '-') {
break;
}
if (Tcl_GetIndexFromObj(interp, objv[i], getOptionStrings,
"option", 0, &subIndex) != TCL_OK) {
return TCL_ERROR;
}
i++;
if (i >= objc) {
Tcl_AppendResult(interp, "value for \"", string,
"\" missing", NULL);
return TCL_ERROR;
}
switch ((enum getOptions) subIndex) {
case APPEND_DISPLAYOF:
path = Tcl_GetString(objv[i]);
break;
case APPEND_TYPE:
targetName = Tcl_GetString(objv[i]);
break;
}
}
if (path != NULL) {
tkwin = Tk_NameToWindow(interp, path, tkwin);
}
if (tkwin == NULL) {
return TCL_ERROR;
}
selection = Tk_InternAtom(tkwin, "CLIPBOARD");
if (objc - i > 1) {
Tcl_WrongNumArgs(interp, 2, objv, "?-option value ...?");
return TCL_ERROR;
} else if (objc - i == 1) {
target = Tk_InternAtom(tkwin, Tcl_GetString(objv[i]));
} else if (targetName != NULL) {
target = Tk_InternAtom(tkwin, targetName);
} else {
target = XA_STRING;
}
Tcl_DStringInit(&selBytes);
result = Tk_GetSelection(interp, tkwin, selection, target,
ClipboardGetProc, (ClientData) &selBytes);
if (result == TCL_OK) {
Tcl_DStringResult(interp, &selBytes);
} else {
Tcl_DStringFree(&selBytes);
}
return result;
}
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* TkClipInit --
*
* This function 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 the interp's
* result and TCL_ERROR is returned.
*
* Side effects:
* Sets up the clipWindow and related data structures.
*
*----------------------------------------------------------------------
*/
int
TkClipInit(
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, NULL, "_clip",
DisplayString(dispPtr->display));
if (dispPtr->clipWindow == NULL) {
return TCL_ERROR;
}
Tcl_Preserve(dispPtr->clipWindow);
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, dispPtr,XA_STRING);
Tk_CreateSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,
dispPtr->windowAtom, ClipboardWindowHandler, dispPtr, XA_STRING);
return TCL_OK;
}
/*
*--------------------------------------------------------------
*
* ClipboardGetProc --
*
* This function is invoked to process pieces of the selection as they
* arrive during "clipboard get" commands.
*
* Results:
* Always returns TCL_OK.
*
* Side effects:
* Bytes get appended to the dynamic string pointed to by the clientData
* argument.
*
*--------------------------------------------------------------
*/
/* ARGSUSED */
static int
ClipboardGetProc(
ClientData clientData, /* Dynamic string holding partially assembled
* selection. */
Tcl_Interp *interp, /* Interpreter used for error reporting (not
* used). */
char *portion) /* New information to be appended. */
{
Tcl_DStringAppend((Tcl_DString *) clientData, portion, -1);
return TCL_OK;
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/