I'm trying to create a small window manager (just for fun), but I'm having problems in handling windows created by Firefox (only with that application, other apps works fine)
The problem is, after I launch Firefox, and add my decoration, it seems to work fine, but if for example I try to click on the menu button, the (sub)window doesn't appear.
What seems to happen is that after the click, a ClientMessage event is fired with the following values:
Data: (null)
Data: _NET_WM_STATE_HIDDEN
Data: (null)
Data: (null)
Data: (null)
Now the problem is that I don't know how to show the window, which window.
I tried with:
XRaiseWindow
XMapWindow
I tried to get the transient window and show it
But without success. What I don't understand is that if this client message is generated by the menu subwindow or not.
How should I show a window that is in _NET_WM_STATE_HIDDEN?
Another strange problem is that after receiving the ClientMessage, I always receive 2 UnMapNotify Events.
I also have another question, if I want to show the "File, Edit" menù (in Firefox it appears, if I remember correctly, when you press the Alt button.
Maybe Firefox creates a tree of windows?
This is the loop where I handle the events:
while(1){
XNextEvent(display, &local_event);
switch(local_event.type){
case ConfigureNotify:
configure_notify_handler(local_event, display);
break;
case MotionNotify:
motion_handler(local_event, display);
break;
case CreateNotify:
cur_win = local_event.xcreatewindow.window;
char *window_name;
XFetchName(display, cur_win, &window_name);
printf("Window name: %s\n", window_name);
if(window_name!=NULL){
if(!strcmp(window_name, "Parent")){
printf("Adding borders\n");
XSetWindowBorderWidth(display, cur_win, BORDER_WIDTH);
}
XFree(window_name);
}
break;
case MapNotify:
map_notify_handler(local_event,display, infos);
break;
case UnmapNotify:
printf("UnMapNotify\n");
break;
case DestroyNotify:
printf("Destroy Event\n");
destroy_notify_handler(local_event,display);
break;
case ButtonPress:
printf("Event button pressed\n");
button_handler(local_event, display, infos);
break;
case KeyPress:
printf("Keyboard key pressed\n");
keyboard_handler(local_event, display);
break;
case ClientMessage:
printf("------------ClientMessage\n");
printf("\tMessage: %s\n", XGetAtomName(display,local_event.xclient.message_type));
printf("\tFormat: %d\n", local_event.xclient.format);
Atom *atoms = (Atom *)local_event.xclient.data.l;
int i =0;
for(i=0; i<=5; i++){
printf("\t\tData %d: %s\n", i, XGetAtomName(display, atoms[i]));
}
int nchild;
Window *child_windows;
Window parent_window;
Window root_window;
XQueryTree(display, local_event.xclient.window, &root_window, &parent_window, &child_windows, &nchild);
printf("\tNumber of childs: %d\n", nchild);
break;
}
Now in the clientmessage actually I'm just trying to see collect some information to understand what is happening. And what I can see from the code above, is that the window that raised the event contains one child (again: is that the menu? or not?)
The code for the MapNotify event, where I add the decoration is the following:
void map_notify_handler(XEvent local_event, Display* display, ScreenInfos infos){
printf("----------Map Notify\n");
XWindowAttributes win_attr;
char *child_name;
XGetWindowAttributes(display, local_event.xmap.window, &win_attr);
XFetchName(display, local_event.xmap.window, &child_name);
printf("\tAttributes: W: %d - H: %d - Name: %s - ID %lu\n", win_attr.width, win_attr.height, child_name, local_event.xmap.window);
Window trans = None;
XGetTransientForHint(display, local_event.xmap.window, &trans);
printf("\tIs transient: %ld\n", trans);
if(child_name!=NULL){
if(strcmp(child_name, "Parent") && local_event.xmap.override_redirect == False){
Window new_win = draw_window_with_name(display, RootWindow(display, infos.screen_num), "Parent", infos.screen_num,
win_attr.x, win_attr.y, win_attr.width, win_attr.height+DECORATION_HEIGHT, 0,
BlackPixel(display, infos.screen_num));
XMapWindow(display, new_win);
XReparentWindow(display,local_event.xmap.window, new_win,0, DECORATION_HEIGHT);
set_window_item(local_event.xmap.window, new_win);
XSelectInput(display, local_event.xmap.window, StructureNotifyMask);
printf("\tParent window id: %lu\n", new_win);
put_text(display, new_win, child_name, "9x15", 10, 10, BlackPixel(display,infos.screen_num), WhitePixel(display, infos.screen_num));
}
}
XFree(child_name);
}
Now can someone help me with these problems? Unfortunately I already googled many times, but without success.
To sum up, my issues are two:
1. How to show subwindows from Firefox
2. How to show the File, Edit menu.
UPDATE
I noticed something strange testing Firefox with xev to understand what events are fired in order to show an application. I saw that using Firefox in unity, and using Firefox in another window manger, the events fired are completely different. In Unity I have only:
ClientMessage
UnmapNotify
Instead using Firefox, for example with xfce4, the xevents generated are more:
VisiblityNotify (more than one)
Expose event (more than one)
But if I try to enable VisibilityChangeMask in my wm, I receive the following events:
ConfigureNotify
ClientMessage
MapNotify
2 UnMapNotify
UPDATE 2
I tried to read the XWMhints properties in the ClientMessage window (probably the menù window) and the values are:
For the flags 67 = InputHint, StateHint, WIndowGroupHint
For the initial state NormalState
UPDATE 3
I tried to look how another window manager works, and I was looking at the source code of calmwm. What is my understanding is that, when the ClientMessage event arrives, with a _NET_WM_STATE message, it updates these properties, and in the case of _NET_WM_STATE_HIDDEN it clears this property, and the result will be that the property will be deleted. So I tried to update my code to delete that property, but it's still not working. Anyway the relevant updated code in client_message_handler now looks like this:
Atom *atoms = (Atom *)local_event.xclient.data.l;
int i =0;
for(i=0; i<=5; i++){
printf("\t\tData %d: %s\n", i, XGetAtomName(display, atoms[i]));
if(i==1){
printf("\t Deleting Property: _NET_WM_STATE_HIDDEN \n");
XDeleteProperty(display, cur_window, atoms[i]);
}
}
It is only a test, and I'm sure that i=1 in my case is the _NET_WM_STATE_HIDDEN property.
Here a link to calmwm source code: https://github.com/chneukirchen/cwm/blob/linux/xevents.c
So I'm still stuck at that point.
UPDATE 4
Really I don't know if it helps, but I tried to read the window attributes in the MapNotify Event, and the window map_state is IsViewable (2).
UPDATE 5
I found a similar problem here in SO, using xlib with python: Xlib python: cannot map firefox menus
The solution suggests to use XSetInputFocus, i tried that on my XMapNotify handler:
XSetInputFocus(display, local_event.xmap.window, RevertToParent, CurrentTime);
But it still doesn't help, the firefox menu still doesn't appear!!
And i have the same problem with right-click.
UPDATE 6
Playing with xconfigurenotify event and unmap event i found that the:
Xconfigure request has 2 window fields: window and above, and when the
the xconfigurerequest.window value is the same of xunmap.window value.
And also that the xconfigurerequest.above is always changing, but xconfigurerequest.window is always the same in all events.
It seems that the xconfigurerequest.above is related to what menu i'm trying to open. For example:
if right-click on a page i get an id (always the same for every subsequent click)
if i right-clik on a tab, the above value is another one
and the same happen if i left-click the firefox main menu
Still don't know if that helps.
Really don't know
Anyone got any idea?
This question is ancient but for the benefit of anyone who stumbles across it looking for an answer to this, here's an edited (chopped to bits) sample of how I solved this based on the hints above:
while (event = xcb_poll_for_event(connection)) {
uint8_t actual_event = event->response_type & 127;
switch (actual_event) {
case XCB_MAP_NOTIFY: ;
xcb_map_notify_event_t *map_evt = (xcb_map_notify_event_t *)event;
if (map_evt->override_redirect) {
xcb_get_property_cookie_t cookie = xcb_icccm_get_wm_transient_for(connection, map_evt->window);
xcb_window_t transient_for = 0;
xcb_icccm_get_wm_transient_for_reply(connection, cookie, &transient_for, NULL);
if (transient_for) {
xcb_set_input_focus(connection, XCB_INPUT_FOCUS_POINTER_ROOT, transient_for, XCB_CURRENT_TIME);
}
xcb_flush(connection);
}
break;
case XCB_CLIENT_MESSAGE: ;
xcb_client_message_event_t *message_evt = (xcb_client_message_event_t *)event;
xcb_get_atom_name_cookie_t name_cookie = xcb_get_atom_name(connection, message_evt->type);
xcb_get_atom_name_reply_t *name_reply = xcb_get_atom_name_reply(connection, name_cookie, NULL);
int length = xcb_get_atom_name_name_length(name_reply);
char *atom_name = malloc(length + 1);
strncpy(atom_name, xcb_get_atom_name_name(name_reply), length);
atom_name[length] = '\0';
free(atom_name);
free(name_reply);
if (message_evt->type == ewmh->_NET_WM_STATE) {
xcb_atom_t atom = message_evt->data.data32[1];
unsigned int action = message_evt->data.data32[0];
xcb_get_atom_name_cookie_t name_cookie = xcb_get_atom_name(connection, atom);
xcb_get_atom_name_reply_t *name_reply = xcb_get_atom_name_reply(connection, name_cookie, NULL);
int length = xcb_get_atom_name_name_length(name_reply);
char *atom_name = malloc(length + 1);
strncpy(atom_name, xcb_get_atom_name_name(name_reply), length);
atom_name[length] = '\0';
if (action == XCB_EWMH_WM_STATE_REMOVE) {
if (atom == ewmh->_NET_WM_STATE_HIDDEN) {
xcb_delete_property(connection, message_evt->window, ewmh->_NET_WM_STATE_HIDDEN);
}
}
free(atom_name);
free(name_reply);
}
break;
}
}
By way of explanation, the important events to handle are MapNotify and ClientMessage because there's two main things that have to be taken care of, the window has to have its hidden state removed on request (the xcb_delete_property call) and the parent window of the transient has to gain input focus (the xcb_set_input_focus call; note that the window that the transient is a transient for gains focus, not the transient itself) or Firefox will immediately hide the transient again.
It also seems to be important for the transients to be stacked above their parent so a WM should respect the ConfigureRequest events.
PS Even if this is the accepted answer, the code of it is for xcb, if you need the code for xlib check my answer below, with the code adapted for xlib, it does cover only the MapNotify event
Use xtruss — an easy-to-use X protocol tracing program
Overview
Any programmer accustomed to writing programs on Linux or System V-type Unixes will have encountered the program variously known as strace or truss, which monitors another program and produces a detailed log of every system call the program makes – in other words, all the program's interactions with the OS kernel. This is often an invaluable debugging tool, and almost as good an educational one.
When it's a GUI program (or rather, the GUI-related behaviour of a program) that you want to understand or debug, though, the level of interaction with the OS kernel is rarely the most useful one. More helpfully, one would like to log all the program's interactions with the X server in the same way.
Programs already exist that will do this. I'm aware of Xmon and Xtrace. But they tend to require a lot of effort to set up: you have to run the program to establish a listening server, then manually arrange for the target program to contact that instead of the real server – including some fiddly work with xauth. Ideally, you'd like tracing a program's X operations to be just as easy as tracing its kernel system calls: you'd like to type a command as simple as strace program-name arguments, and have everything automatically handled for you.
Also, the output of those programs is less easy to read than I'd have liked – by which I largely mean it's less like strace than I'd like it to be. strace has the nice property of putting each system call and its return value on the same line of output, so that you can see at a glance what each response was a response to. X protocol monitors, however, tend to follow the structure of the X protocol faithfully, meaning that each request and response is printed with a sequence number, and you have to match the two up by eye.
So this page presents xtruss, my own contribution to the field of X protocol loggers. It has a command-line syntax similar to strace – in its default mode, you just prefix "xtruss" to the same command line you would have run anyway – and its output format is also more like strace, putting requests and responses on the same line of output where reasonably possible.
strace also supports the feature of attaching to an already-running process and tracing it from the middle of its run – handy when something goes wrong with a long-running process that you didn't know in advance you were going to need to trace. xtruss supports this same feature, by means of the X RECORD extension (provided your X server supports it, which modern X.Org ones do); so in that mode, you can identify a window with the mouse (similarly to standard programs like xwininfo and xkill), and xtruss will attach to the X client program that owns the window you specified, and begin tracing it.
Description
xtruss is a utility which logs everything that passes between the X server and one or more X client programs. In this it is similar to xmon(1), but intended to combine xmon's basic functionality with an interface much more similar to strace(1).
Like xmon, xtruss in its default mode works by setting up a proxy X server, waiting for connections to that, and forwarding them on to the real X server. However, unlike xmon, you don't have to deal with any of that by hand: there's no need to start the trace utility in one terminal and manually attach processes to it from another, unless you really want to (in which case the -P option will do that). The principal mode of use is just to type xtruss followed by the command line of your X program; xtruss will automatically take care of adjusting the new program's environment to point at its proxy server, and (also unlike xmon) it will also take care of X authorisation automatically.
As an alternative mode of use, you can also attach xtruss to an already-running X application, if you didn't realise you were going to want to trace it until it had already been started. This mode requires cooperation from the X server – specifically, it can't work unless the server supports the RECORD protocol extension – but since modern X.Org servers do provide that, it's often useful.
Ok, i'm going to answer my own question after only 4.5 years and half.
I'm going to revise Mr Lightning Bolt answer, and adapt it for XLIB, keeping focused on what he said about the Transient window. The answer probably will not be complete, but at least with that code snippet, now i'm able to open firefox menus.
I will accept his question, since he proposed the correct solution.
As lightning bolt pointed the key is the MapNotify Event,so the window manager should accept that kind of events, and when it is generated it should:
grab any transient window with XGetTransientWindowForHint
if any transient window is found, we need then to set input focus to it using XSetInputFocus.
The complete code, in your MapNotifyHandler, should looks like:
Window trans = None;
XGetTransientForHint(display, local_event.xmap.window, &trans);
if(trans != None){
XSetInputFocus(display, trans, RevertToParent, CurrentTime);
}
I currently have an application which uses the activities/places and an AsyncDataProvider.
Right now, everytime the activity loads up - it uses the request factory to retrieve the data (currently not a lot but will get very large coming up here soon) and passes it to the View to update the DataGrid. Before it is updated it is filtered based on a search box.
Right now - I have implemented updating the DataGrid as follows: (this code isn't the prettiest)
private void updateData() {
final AsyncDataProvider<EquipmentTypeProxy> provider = new AsyncDataProvider<EquipmentTypeProxy>() {
#Override
protected void onRangeChanged(HasData<EquipmentTypeProxy> display) {
int start = display.getVisibleRange().getStart();
int end = start + display.getVisibleRange().getLength();
final List<EquipmentTypeProxy> subList = getSubList(start, end);
end = (end >= subList.size()) ? subList.size() : end;
if (subList.size() < DATAGRID_PAGE_SIZE) {
updateRowCount(subList.size(), true);
} else {
updateRowCount(data.size(), true);
}
updateRowData(start, subList);
}
private List<EquipmentTypeProxy> getSubList(int start, int end) {
final List<EquipmentTypeProxy> filteredEquipment;
if (searchString == null || searchString.equals("")) {
if (data.isEmpty() == false && data.size() > (end - start)) {
filteredEquipment = data.subList(start, end);
} else {
filteredEquipment = data;
}
} else {
filteredEquipment = new ArrayList<EquipmentTypeProxy>();
for (final EquipmentTypeProxy equipmentType : data) {
if (equipmentType.getName().contains(searchString)) {
filteredEquipment.add(equipmentType);
}
}
}
return filteredEquipment;
}
};
provider.addDataDisplay(dataGrid);
}
Ultimately - what I would like to do is only load up the necessary data at first (the default page size in this application is 25).
Unfortunately, to my current understanding, with Google App Engine there is no order to any of the Id's (one entry has an ID of 3 the next has an entry of 4203).
What I'm wondering, what is the best way to go about retrieving a subset of data from Google App Engine when using Objectify?
I was looking into using Offset and limit but another stack overflow post (http://stackoverflow.com/questions/9726232/achieve-good-paging-using-objectify) basically said this is inefficient.
The best information I've found is the following link (http://stackoverflow.com/questions/7027202/objectify-paging-with-cursors). The answer here says to use Cursors but also says this is inefficient. I'm also using Request Factory so I will have to store the Cursor in my user Session (if that is incorrect please let me know).
Currently since there isn't likely to be a lot of data (maybe 200 rows total for the next few months) I am just pulling back the entire set to the client as a temporary hack - I know this is the worst way to do it but would like to get input to the best way to do it before wasting my time implementing another hack solution. I am worried currently as it seems every single post i've read on doing this makes it seem like there's not really a solid way to do this.
What i am also thinking about doing - currently my searching / page loading is lightning fast because all the data is already on the client side. I use a KeyUpEvent handler in the search box to filter the data - i don't think there is any way to keep this speed by making a call to the server - is there any accepted solution to this problem?
Thank you very much
Go with Cursors. They are as efficient as it gets - cursor stores the point where last query ended and continues from there. The answer you linked actually does not discuss efficiency of cursors vs offset. (there is a comment that is wrong)
You can use limit with Cursors - it does not affect efficiency.
Also, Cursors can be serialized via cursor.toWebSafeString() and sent to client via RPC. This way you do not need to save them in session. Actually you can also use them as fragment identifier (aka history token in GWT parlance) - this way a certain "page" of your result set can be bookmarked.
(Offset is "inefficient" because it actually loads, and charges you, for all entities upto offset+limit, bit it only returns limit entities)
OTOH, if you already know the query parameters when the page is loaded, then just do the query at page generation time, instead invoking it via RPC. Also, if you have a small set of data (<1000) you could just preload all entity IDs s part of page html.
I want to write an application that will automatically detect and fill the text field in the window shown below:
(assuming the data to be entered is in a file).
The question is how does my application find this text field?
I can do this job if I am able to find the location of the text field on the desktop through program.
Can someone help me understand possible ways for finding this text field?
I am using Windows Form application in C++.
Update:
I played with spy++.
I used spy++, to find the window handle. I did it by putting finder on the window I am interested in. Its giving handle in hex values: 00080086 (actually just for testing purpose I put the finder tool on Visual Studio new project page ). How do I interpret this Hex value into meaningful window name ?
See the below figure.
What is the next step to get to the text field " Enter name" under "name" field.
****Any sample code will be highly appreciated.**
I am open to any solution not necessarily how I am doing this.
One solution is to use the Microsoft UI Automation technology. It's shipped out-of-the-box with Windows since Vista. It's usable from .NET but also from C++ using COM.
Here is a short C++ console application example that displays the class name of the UI Automation Element currently at the middle of the desktop window, each second (you can have it run and see what it displays):
int _tmain(int argc, _TCHAR* argv[])
{
CoInitialize(NULL);
IUIAutomation *pAutomation; // requires Uiautomation.h
HRESULT hr = CoCreateInstance(__uuidof(CUIAutomation), NULL, CLSCTX_INPROC_SERVER, __uuidof(IUIAutomation), (LPVOID *)&pAutomation);
if (SUCCEEDED(hr))
{
RECT rc;
GetWindowRect(GetDesktopWindow(), &rc);
POINT center;
center.x = (rc.right - rc.left) / 2;
center.y = (rc.bottom - rc.top) / 2;
printf("center x:%i y:%i'\n", center.x, center.y);
do
{
IUIAutomationElement *pElement;
hr = pAutomation->ElementFromPoint(center, &pElement);
if (SUCCEEDED(hr))
{
BSTR str;
hr = pElement->get_CurrentClassName(&str);
if (SUCCEEDED(hr))
{
printf("element name:'%S'\n", str);
::SysFreeString(str);
}
pElement->Release();
}
Sleep(1000);
}
while(TRUE);
pAutomation->Release();
}
CoUninitialize();
return 0;
}
From this sample, what you can do is launch the application you want to automate and see if the sample detects it (it should).
You could also use the UISpy tool to display the full tree of what can be automated in your target app. You should see the windows and other elements (text field) of this target app and you should see the element displayed by the console application example.
From the pElement discovered in the sample, you can call FindFirst with the proper condition (class name, name, control type, etc...) to get to the text field. From this text field, you would use one of the UI Automation Patterns that should be available (probably TextPattern or ValuePattern) to get or set the text itself.
The cool thing is you can use the UISpy tool to check all this is possible before actually coding it.
You could enumerate windows and then find it.
For exploring application on your screenshot you could you Spy++ (spyxx.exe) that is distributed with visual studio. In you code, you clould use EnumWindows and EnumChildWindows to enumerates all window or all child windows to find one you need.
Although the answer given by Simon is accepted and is the best one, but still for future visitors I am providing this link which has more description for UI automation of windows applications. .
Also for automating a web application one may want to go to this link
I'm using the WPF WebBrowser to display online help inside an app (just a few small web pages). Some of those pages use cookies to display items only for the first few times the pages are viewed (it's a "Why not try X" type of thing).
However, for some reason the cookies don't seem to be working inside the WebBrowser control. They work fine in full IE as well as Firefox and Chrome (so the items correctly hide), but they never hide when viewed through the WPF WebBrowser control.
Is there something special about using cookies in the WPF WebBrowser control? It seems to be behaving as if all the cookies are only stored in memory, rather than being persisted on disk.
Here's one of those pages inside a browser (where the cookies work):
And here's the exact same page inside the app:
That additional content should only be visible for the first few times of using the software (i.e. it should be hidden after N views of that web page), but because I can't get cookies to work it's always visible.
Cookies handling in Internet Explorer (or hosted versions) is tied to the IE's own notion of "URL Security Zones", doc here: About URL security Zones
So, IE determines an url zone using various alogorithms applied to the url. Depending on the zone, your hosted browser may or may not support session or persistent cookies.
Strangely, when I create a small WPF sample, add the web browser to it and have navigate to this persistent cookie tester utiliy page: http://www.rbaworld.com/Security/Computers/Cookies/givecook.shtml, it works fine. Each time I launch the sample app, the counter is incremented fine, so not everyone can reproduce your problem. Well, that's the whole purpose of URL Security zones: it can vary by machine, by user, by Windows policy, etc...
The next question is: Can I change the zone you're running in? The short and easy answer is ... no because it's heavily tied to the security.
If you were hosting IE yourself, you could implement your own security zone handle as described here: Implementing a Custom Security Manager and a sample here: SAMPLE: Secumgr.exe Overrides Security Manager for WebBrowser Host but you're relying on WPF's webbrowser that does not allow any override... You can get to Reflector and copy all WPF private/internal code but that's a log of risky work!
The last thing you can try is to manipulate the standard Internet Security Manager. Here is some sample code that gives some hints. At least you should be able to determine the zone you're running in (MapUrltoZone) and change the cookie (TryAllowCookie). The problem with the standard manager is most of the times, it pops up dialog to the end-user allowing authorization... (security again!):
[ComImport, Guid("7b8a2d94-0ac9-11d1-896c-00c04Fb6bfc4")]
private class InternetSecurityManager
{
}
[ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("79eac9ee-baf9-11ce-8c82-00aa004ba90b")]
private interface IInternetSecurityManager
{
void Unused1();
void Unused2();
[PreserveSig]
int MapUrlToZone([In, MarshalAs(UnmanagedType.BStr)] string pwszUrl, out int pdwZone, [In] int dwFlags);
void Unused3();
[PreserveSig]
int ProcessUrlAction(string pwszUrl, int dwAction, ref int pPolicy, int cbPolicy, ref Guid pContext, int cbContext, int dwFlags, int dwReserved);
// left undefined
}
public static SecurityZone MapUrlToZone(Uri uri)
{
IInternetSecurityManager securityManager = (IInternetSecurityManager)new InternetSecurityManager();
int zoneId;
if (securityManager.MapUrlToZone(uri.ToString(), out zoneId, 0) < 0)
return SecurityZone.NoZone;
return (SecurityZone)zoneId;
}
private const int URLACTION_COOKIES = 0x00001A02;
private const int URLACTION_COOKIES_ENABLED = 0x00001A10;
private const int URLPOLICY_ALLOW = 0x00;
private const int URLPOLICY_DISALLOW = 0x03;
private const int PUAF_DEFAULT = 0x00000000;
public static bool TryAllowCookies(Uri uri)
{
IInternetSecurityManager securityManager = (IInternetSecurityManager)new InternetSecurityManager();
int policy = 0;
Guid context = Guid.Empty;
int hr = securityManager.ProcessUrlAction(uri.ToString(), URLACTION_COOKIES_ENABLED, ref policy, Marshal.SizeOf(policy), ref context, Marshal.SizeOf(context), PUAF_DEFAULT, 0);
return (hr == 0) && policy == URLPOLICY_ALLOW;
}
Good luck :)
The WebBrowser control won't allow this by default. For security reasons, you probably wouldn't want different applications from different developers/companies being able to access cookie info that another app created.
However, check out this answer How to delete Cookies from windows.form?
That pertains to deleting cookies through javascript, but you may be able to use a similar method in order to persist and create the site cookie each time the application is loaded.