I am following this tutorial here: http://www.sbin.org/doc/Xlib/chapt_16.html
Here is the image of the tutorial:
Here is my code: (it is in another thread from which I called XInitThreads - I know using threads and X is bad, I know I should be on the main thread, but just wondering if possible)
var ev = XEvent();
var rez_XMaskEvent = XMaskEvent(cachedXOpenDisplay(), ButtonPressMask | ButtonReleaseMask, ev.address());
console.log('rez_XMaskEvent:', rez_XMaskEvent);
console.log('ev:', ev);
ButtonPressMask is 4
ButtonReleaseMask is 8
So XMaskEvent is blocking, but whenever I press my mouse button it is not catching it. Shouldn't it unblock and get to the console.log line?
Do I need to run an event loop somehow in this thread?
Thanks
I'm not 100% sure here but I feel this could be your problem:
You probably can't do this from JavaScript without some extra precautions. JavaScript in the browser is single-threaded. That means you're holding a lock and no other JavaScript can run. Your problem is a) you're using threads and b) "If the event you requested is not in the queue, XMaskEvent flushes the output buffer and blocks until one is received." (see the man page)
That means XMaskEvent blocks since the button hasn't been pressed, yet. And your browser can't execute JavaScript anymore. If there is an event in the queue which would trigger some JavaScript, the browser will lock up.
Related
I have a problem waiting for an iframe to exist on page after entering a date range and I would rather not use sleep. I am using ruby/watir
I have tried solutions like this -
wait_until(10, "iFrame has not loaded") do
#browser.iframe(id: "dtl00_DP1_content").exists?
end
but this simply returns this error - Selenium::WebDriver::Error::NoSuchWindowError: no such window
So how do I wait for an iframe that does not yet exist please?
I am not sure whether you only want to wait for an Iframe, If you want to perform any operation on an element which is present in the iframe, then you could do as I mentioned in my comment.
#browser.iframe(name: "something").text_field(name: "username").set 'raja'
Or If you still wait for an iframe to appear, then write the following code
#browser.wait_until { #browser.iframe(id: "dtl00_DP1_content").exists? }
The above code waits for 30 seconds, but If you want to increase the time to wait, then write the following code, the following code would wait fo 50 seconds.
#browser.wait_until(timeout: 50) { #browser.iframe(id: "dtl00_DP1_content").exists? }
I am making an addon in Firefox, so I have a ChromeWorker - which is a privileged WebWorker. This is just a thread other then the mainthread.
In here I have no code but this (modified to make it look like not js-ctypes [which is the language for addons])
On startup I run this code, conn is a global variable:
conn = xcb_connect(null, null);
Then I run this in a 200ms interval:
evt = xcb_poll_for_event(conn);
console.log('evt:', evt);
if (!evt.isNull()) {
console.log('good got an event!!');
ostypes.API('free')(evt);
}
However evt is always null, I am never getting any events. My goal is to get all events on the system.
Anyone know what can cause something so simple to not work?
I have tried
xcb_change_window_attributes (conn, screens.data->root, XCB_CW_EVENT_MASK, values);
But this didn't fix it :(
The only way I can get it to work is by doing xcb_create_window xcb_map_window but then I get ONLY the events that happen in this created window.
You don't just magically get all events by opening a connection. There's only very few messages any client will receive, such as client messages, most others will only be sent to a client if it explicitly registered itself to receive them.
And yes, that means you have to register them on each and every window, which involves both crawling the tree and listening for windows being created, mapped, unmapped and destroyed and registering on them as well.
However, I would reconsider whether
My goal is to get all events on the system.
isn't an A-B problem. Why do you "need" all events? What do you actually want to do?
I have this code:
_myQueue = dispatch_queue_create("com.myapp", DISPATCH_QUEUE_SERIAL);
_mainQueue = dispatch_get_main_queue();
and lot of this block that require some seconds (or minutes)
dispatch_async(_myQueue,
^{
if(canRun){
dispatch_async(_mainQueue,^{/* updating interface here */});
// code here
}
});
My app have a "Stop" button to try stopping all job, and the BOOL "canRun" help me to execute all blocks w/o do nothing.....but always I have to wait the completition of each block until the queue come 0.
Is there any way to instantly "clean" the queue istead doing that?
The aim is to stop processes and to start over without closing and reopening the application.
This project works under ARC.
You can cancel them if you take a few extra steps to creat a dispatch_source object and keep a reference to it.
Review this for starters
https://developer.apple.com/library/mac/documentation/Performance/Reference/GCD_libdispatch_Ref/index.html
There are functions to pause, resume and cancel.
Both QWebFrame and QWebPage have void loadFinished(bool ok) signal which can be used to detect when a web page is completely loaded. The problem is when a web page has some content loaded asynchronously (ajax). How to know when the page is completely loaded in this case?
I haven't actually done this, but I think you may be able to achieve your solution using QNetworkAccessManager.
You can get the QNetworkAccessManager from your QWebPage using the networkAccessManager() function. QNetworkAccessManager has a signal finished ( QNetworkReply * reply ) which is fired whenever a file is requested by the QWebPage instance.
The finished signal gives you a QNetworkReply instance, from which you can get a copy of the original request made, in order to identify the request.
So, create a slot to attach to the finished signal, use the passed-in QNetworkReply's methods to figure out which file has just finished downloading and if it's your Ajax request, do whatever processing you need to do.
My only caveat is that I've never done this before, so I'm not 100% sure that it would work.
Another alternative might be to use QWebFrame's methods to insert objects into the page's object model and also insert some JavaScript which then notifies your object when the Ajax request is complete. This is a slightly hackier way of doing it, but should definitely work.
EDIT:
The second option seems better to me. The workflow is as follows:
Attach a slot to the QWebFrame::javascriptWindowObjectCleared() signal. At this point, call QWebFrame::evaluateJavascript() to add code similar to the following:
window.onload = function() { // page has fully loaded }
Put whatever code you need in that function. You might want to add a QObject to the page via QWebFrame::addToJavaScriptWindowObject() and then call a function on that object. This code will only execute when the page is fully loaded.
Hopefully this answers the question!
To check the load of specific element you can use a QTimer. Something like this in python:
#pyqtSlot()
def on_webView_loadFinished(self):
self.tObject = QTimer()
self.tObject.setInterval(1000)
self.tObject.setSingleShot(True)
self.tObject.timeout.connect(self.on_tObject_timeout)
self.tObject.start()
#pyqtSlot()
def on_tObject_timeout(self):
dElement = self.webView.page().currentFrame().documentElement()
element = dElement.findFirst("css selector")
if element.isNull():
self.tObject.start()
else:
print "Page loaded"
When your initial html/images/etc finishes loading, that's it. It is completely loaded. This fact doesn't change if you then decide to use some javascript to get some extra data, page views or whatever after the fact.
That said, what I suspect you want to do here is expose a QtScript object/interface to your view that you can invoke from your page's script, effectively providing a "callback" into your C++ once you've decided (from the page script) that you've have "completely loaded".
Hope this helps give you a direction to try...
The OP thought it was due to delayed AJAX requests but there also could be another reason that also explains why a very short time delay fixes the problem. There is a bug that causes the described behaviour:
https://bugreports.qt-project.org/browse/QTBUG-37377
To work around this problem the loadingFinished() signal must be connected using queued connection.
This is a Windows Forms application. I have a function which captures some mouse events modally till a condition is met. For example, I would like to wait for the user to select a point in the window's client area (or optionally cancel the operation using the Escape key) before the function returns. I am using the following structure:
Application::AddMessageFilter(someFilter);
while(someFilter->HasUserSelectedAPoint_Or_HitEscapeKey()){
Application::DoEvents();
}
Application::RemoveMessageFilter(someFilter);
This works quite nicely except for taking up nearly 100% CPU usage when control enters the while loop. I am looking for an alternative similar to what is shown below:
Application::AddMessageFilter(someFilter);
while(someFilter->HasUserSelectedAPoint_Or_HitEscapeKey()){
// Assuming that ManagedGetMessage() below is a blocking
// call which yields control to the OS
if(ManagedGetMessage())
Application::DoEvents();
}
Application::RemoveMessageFilter(someFilter);
What is the right way to use IMessageFilter and DoEvents? How do I surrender control to the OS till a message is received? Any GetMessage equivalent in the managed world?
You could sleep the thread for 500ms or so between DoEvents() calls. Experiment with different values to see what feels right.