Is there a cross-implementation (at minimum SBCL, CCL, Lispworks and CLISP), cross-platform (Linux/Windows/OS X) way of capturing keyboard interrupts in Common Lisp? Or more specifically, to let a keyboard interrupt through?
I've got this code snippet in a file
...
(handler-case
...
((not simple-error) () (error! +400+ ready)))
...
whose purpose is to handle errors, but let the user interrupt the program with a keyboard interrupt (which in SBCL on Linux manifests as a simple-error). However, this doesn't seem to work in CCL (where that error clause seems to trigger even when the main code doesn't throw an error).
What's the right approach in this situation?
Related
I am currently learning CMSIS-RTOS v2 and I have an issue that is bugging me and I can't find the answer I need.
I am using the STM32L476-Disco board and the joystick center button as an interrupt. I have a very simple Interrupt callback for my center joystick interrupt :
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin){
//osEventFlagsSet(evt_id,0x0001);
HAL_GPIO_TogglePin(LD5_GPIO_Port,LD5_Pin);
osThreadFlagsSet(ThId_Led_Blink,0x0001);
}
When I call osThreadFlagsSet, the microcontroller freezes and nothing else happen. This is why I've put the HAL_GPIO_TogglePin : to see if the mcu was still responding or not.
I know that my interrupt resets correctly because when I only put my pin toggle, I can toggle the Led correctly.
ThId_Led_Blink is a ThreadId
osThreadId ThId_Led_Blink;
I've checked that the ID is set correctly in my debugger and it is (it's not null).
As you can see, I've tried with osEvenFlagsSet and I have the same result.
When I check the CMSIS_RTOS v2 documentation, it does specify that osThreadFlagsSet can be called from an ISR, but I am not sure if I need to do something else in that case for the Flags to be set correctly and resolve the issue when the ISR is hanging.
Thanks for your help
So after frustrating hours of searching, I finally fixed my issue.
As described in this website : https://www.freertos.org/RTOS-Cortex-M3-M4.html, for STM32 microprocessor, you need to set the NVIC Group Priority to 4. If you look on freeRTOS, they are talking about putting this line in your code :
NVIC_PriorityGroupConfig( NVIC_PriorityGroup_4 );
However, the STM32 has it's own library for the NVIC and the correct function to set the priority group is :
HAL_NVIC_SetPriorityGrouping(4);
Why go with the same name when you can change everything?
So make sure to call this function before your kernel initialization if you are using nested interrupts with FreeRTOS/CMSIS RTOS.
Also, make sure that your nested interrupt priority is in the range of configured interrupt priority for your FreeRTOS, otherwise, the osThreadFlagsSet function will fail automatically.
When responding to an event in a textbox using C++/winrt I need to use ScrollViewer.ChangeView(). Trouble is, nothing happens when the call executes and I expect that is because at that moment the code is in the wrong thread; I have read this is the cause for lack of visible results from ChangeView(). It appears that the proper course is to use CoreDispatcher.RunAsync to update the scroller on the UI thread. The example code for this is provided only in C# and managed C++, however, and it is a tricky matter to figure out how this would look in normal C++. At any rate, I am not getting it. Does anyone have an example of the proper way to call a method on the UI thread in C++/winrt? Thanks.
[UPDATE:] I have found another method that seems to work, which I will show here, though I am still interested in an answer to the above. The other method is to create an IAsyncOperation that boils down to this:
IAsyncOperation<bool> ScrollIt(h,v, zoom){
co_await m_scroll_viewer.ChangeView(h,v,zoom);
}
The documentation entry Concurrency and asynchronous operations with C++/WinRT: Programming with thread affinity in mind explains, how to control, which thread runs certain code. This is particularly helpful in context of asynchronous functions.
C++/WinRT provides helpers winrt::resume_background() and winrt::resume_foreground(). co_await-ing either one switches to the respective thread (either a background thread, or the thread associated with the dispatcher of a control).
The following code illustrates the usage:
IAsyncOperation<bool> ScrollIt(h, v, zoom){
co_await winrt::resume_background();
// Do compute-bound work here.
// Switch to the foreground thread associated with m_scroll_viewer.
co_await winrt::resume_foreground(m_scroll_viewer.Dispatcher());
// Execute GUI-related code
m_scroll_viewer.ChangeView(h, v, zoom);
// Optionally switch back to a background thread.
// Return an appropriate value.
co_return {};
}
In our Qt5-based application, many messages like this are displayed in the console:
0x1beccb0 void QWindowPrivate::setTopLevelScreen(QScreen*, bool) ( QScreen(0xd25b80) ): Attempt to set a screen on a child window.
It does not prevent the application from running, but I would like to fix them, since it tends to indicate that there is probably something wrong that we are doing. The code is quite large (cannot be included in the post, it is there: http://gforge.inria.fr/frs/?group_id=1465). I cannot ask you to take a look at it (too big), but maybe you will have an idea with the following additional information:
The messages appear only under Linux, and not under Windows
Our application is a 3D modeler, that has several QGLWidgets for
displaying 3D content. If I remove the QGLWidgets, then the messages
disappear.
In the debugger, if I put a breakpoint on
QWindowPrivate::setTopLevelScreen(), it is called by:
kernel/qwindow.cpp:368
368 q->connect(screen, SIGNAL(destroyed(QObject*)), q, SLOT(screenDestroyed(QObject*)));
Update1:
I put a breakpoint on QMessageLogger::warning (qDebug() is a macro that uses this function), now I can better see the stack that looks like:
#0 0x00007fffefa50600 in QMessageLogger::warning() const#plt () from /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#1 0x00007fffefa851cb in QWindowPrivate::setTopLevelScreen (this=0xd330e0, newScreen=0x7201a0, recreate=<optimized out>)
at kernel/qwindow.cpp:371
#2 0x00007fffefa7f2f5 in QGuiApplicationPrivate::processWindowSystemEvent (e=e#entry=0x760600)
at kernel/qguiapplication.cpp:1608
#3 0x00007fffefa631f8 in QWindowSystemInterface::sendWindowSystemEvents (flags=...)
at kernel/qwindowsysteminterface.cpp:625
#4 0x00007fffeb7d4100 in userEventSourceDispatch (source=<optimized out>)
at eventdispatchers/qeventdispatcher_glib.cpp:70
(More stack frames follow...)
In QGuiApplicationPrivate::processWindowSystemEvent, it is handling a QWindowSystemInterfacePrivate::ThemeChange event:
1608 case QWindowSystemInterfacePrivate::ThemeChange:
1609 QGuiApplicationPrivate::processThemeChanged(
1610 static_cast<QWindowSystemInterfacePrivate::ThemeChangeEvent *>(e));
1611 break;
Update2:
Nearly there !! It is when I call setMinimumWidth() / setMinimumHeight() on a QGLWidget. Now I'd like to know why...
Update3:
More information: the messages are only displayed when I have two screens connected to my computer.
Finally, I understood what happens:
The warning messages occur whenever setMinimumWidth() / setMinimumHeight() are called on a QGLWidget under Linux with a dual screen display.
This is probably a bug in Qt. It will probably be not fixed, since it is recommended in the documentation to use the new QOpenGLWidget instead, that appeared in Qt 5.4 (note: "OpenGL" instead of "GL"), which I did and the warning messages disappeared.
Edit: I saw a message from someone that had problems with text not rendering properly with the new QOpenGLWidget which I answer here: When using the new QOpenGLWidget, one needs to take care that it no longer has an independent OpenGL context, it shares the OpenGL context with Qt (therefore, OpenGL states modified in the rendering function needs to be restored after exiting the rendering function, for instance blending mode).
I have made a custom virtual keyboard widget for my kiosk application, and now comes the time when I want it to produce fake keyboard events and feed them to an QLineEdit of choice.
I do the following:
// target is the QWidget to receive the events
// k is the Qt::Key (keycode) I want to send (Testing with an 'A')
Qt::Key k=Qt::Key_A;
if(0!=target){
//According to docs this will be freed once posted
QKeyEvent * press=new QKeyEvent(QKeyEvent::KeyPress, (int )k,0);
QKeyEvent * release=new QKeyEvent(QKeyEvent::KeyRelease, (int )k,0);
//Give the target focus just to be sure it is available for input
target->setFocus();
//Post the events (queue up and let the target consume them when the eventloop gets around to the target)
QCoreApplication::postEvent ( target, press) ;
QCoreApplication::postEvent ( target, release) ;
}
I see the target widget receive focus, but there are no letters typed into the input field like I would expect. What am I doing wrong? Which assumptions are wrong?
PS: I know that this could be solved by using existing virtual keyboards or at least using the platform interface as is done in this post. In our approach we have decided to build the kayboard into the application to obtain full control over the UX and keyboard design.
Thanks!
Since no-one stepped up, I will try to provide some closure.
It turns out that Qt5 comes with a library of testing facilities called testlib. It has all sorts of goodies to facilitate easy creation, management and running of unit tests for Qt application. Among these facilities there is a set of functions for sending fake events such as fake typing of text, mouse clicks etc. It is quite comprehensive and covers many use-cases. Since this is used internally by Qt developers to test Qt itself it is also production proven code.
I simply copied what I needed from there.
I'm porting an archaic C++/Carbon program to Obj-C and Cocoa. The current version uses asynchronous usb reads and GetNextEvent to read the data.
When I try to compile this in Objective C, GetNextEvent isn't found because it's in the Carbon framework.
Searching Apple support yields nothing of use.
EDIT TO ADD:
Ok, so what I'm trying to do is run a document scanner through USB. I have set up the USBDeviceInterface and the USBInterfaceInterface (who came up with THAT name???) and I call (*usbInterfaceInterface)->WritePipeTO() to ask the scanner to scan. I believe this works. AT least the flatbed light moves across the page...
Then I try to use *(usbInterfaceInterface))->ReadPipeAsyncTO() to read data. I give this function a callback function, USBDoneProc().
The general structure is:
StartScan()
WaitForScan()
StartScan() calls the WritePipeTO and the ReadPipeAsyncTO
WaitForScan() has this:
while (deviceActive) {
EventRecord event;
GetNextEvent(0,&event);
if (gDataPtr != saveDataPtr) { // more data up the timeout
timeoutTicks = TickCount() + 60 * 60;
saveDataPtr = gDataPtr;
}
if (TickCount() > timeoutTicks) {
deviceActive = false;
}
}
Meanwhile, USBDoneProc incrementing gDataPtr to be the end of the data that we've read so far. It gets called several times during the asynchronous read, called automatically by the callback, as far as I can tell.
If I cake out the GetNextEvent() call in the WORKING code the USBDoneProc doesn't get called until the asynchronous readpipe timesout.
So it looks to me that I need something to give control back to the event handler so that the USBRead interrupts can actually interrupt and make the USBDoneProcget called...
Does that make any sense?
thanks.
I suppose the nearest thing to a Cocoa equivalent would be -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:]. But bear in mind that GetNextEvent is archaic even for Carbon. The preferred way of handing events is the "don't call us, we'll call you" scheme, where the app calls NSApplicationMain or RunApplicationEventLoop and events are dispatched to you.
EDIT to add: Does you app have a normal event loop? If so, maybe WaitForScan could start a Carbon timer and return to the event loop. Each time the timer fires, do what you did in the WaitForScan loop.
there is a USB hidapi that works for mac on windows.
http://www.signal11.us/oss/hidapi/
may this could be of help to you?
It works fine (I can list the connected USB devices and connect/write/read to a device);
however, if i USB device is connected/disconnected during the runtime of the application, I don't see the new connected/disconnected devices.
See: https://github.com/signal11/hidapi/issues/14
If I add the following code to hidapi, then hidapi detects the new USB devices.
#include <Carbon/Carbon.h>
void check_apple_events() {
printf("check_apple_events\n");
RgnHandle cursorRgn = NULL;
Boolean gotEvent=TRUE;
EventRecord event;
while (gotEvent) {
gotEvent = WaitNextEvent(everyEvent, &event, 0L, cursorRgn);
}
}
I need to compile this on OSX10.5 because it uses Carbon instead of Cocoa.
I am currently looking how to transform this to Cocoa.
you are also trying to move your code to cocoa, right?
let me know if you find out; I'll post it here if I get it.
regards,
David
Have you considered throwing the whole thing out and using Image Kit's new-in-10.6 scanner support instead? Even if it's custom, writing a TWAIN driver for it might be easier (and is certainly better) than trying to twist Cocoa into a GetNextEvent shape.