I'm using some Carbon code in my Cocoa project for handling global key events (shortcuts) from other applications. Currently I have setup a kEventHotKeyReleased event handler and I can successfully obtain hot keys when my application is not active. That triggers some operation in my application.
The problem I have with the behavior of kEventHotKeyReleased is:
Say for example I press the Cmd-Shift-P key combination. As soon as I release the "P" key the hot key event is triggered. I need to be able to trigger the event (or manually trigger it) when all of the keys are unpressed (i.e: the Cmd and Shift keys are released too).
It is easy to monitor for hot keys but I have seen nothing for monitoring individual keystrokes. If I could monitor the modifier key states I would be in business.
Any hints on how to do this?
Thanks in advance!
UPDATE:
I've tried using kEventRawKeyUp and kEventRawKeyModifiersChanged but while kEventHotKeyReleased works those two don't even though I set them up in the exact same way as kEventHotKeyReleased.
EventTypeSpec eventTypes[] = {{kEventClassKeyboard, kEventHotKeyReleased}, {kEventClassKeyboard, kEventRawKeyUp}};
// Changing the order in the list does not help, nor does removing kEventHotKeyReleased
OSStatus err = InstallApplicationEventHandler(&globalHotkeyHandler, GetEventTypeCount(eventTypes), eventTypes, NULL, NULL);
// err == noErr after this line
The globalHotKeyHandler method is called for kEventHotKeyReleased, but not for kEventRawKeyUp for some reason I can't seem to grasp. Here's what my globalHotKeyHandler method looks like:
OSStatus globalHotkeyHandler(EventHandlerCallRef nextHandler, EventRef anEvent, void *userData) {
NSLog(#"Something happened!");
}
Is there an additional call that needs to be made or something else I forgot?
N.B: At first glance, it seems like it could be that Access for Assistive Devices is disabled but it is not. So I'm pretty clueless.
UPDATE 2:
I investigated a bit on the CGEventTap Leibowitzn suggested and I came up with this setup:
CFMachPortRef keyUpEventTap = CGEventTapCreate(kCGHIDEventTap,kCGHeadInsertEventTap,kCGEventTapOptionListenOnly,kCGEventKeyUp,&keyUpCallback,NULL);
CFRunLoopSourceRef keyUpRunLoopSourceRef = CFMachPortCreateRunLoopSource(NULL, keyUpEventTap, 0);
CFRelease(keyUpEventTap);
CFRunLoopAddSource(CFRunLoopGetCurrent(), keyUpRunLoopSourceRef, kCFRunLoopDefaultMode);
CFRelease(keyUpRunLoopSourceRef);
... and the callback:
CGEventRef keyUpCallback (CGEventTapProxy proxy, CGEventType type, CGEventRef event, void *refcon) {
NSLog(#"KeyUp event tapped!");
return event;
}
As you can see I'm using kCGEventKeyUp as the mask for the event tap but somehow I'm receiving mouse down events ??!??
UPDATE 3:
Ok forget that, I overlooked the line in the doc that said to use CGEventMaskBit(kCGEventKeyUp) for this parameter, so the correct call is:
CGEventTapCreate(kCGHIDEventTap,kCGHeadInsertEventTap,kCGEventTapOptionListenOnly,CGEventMaskBit(kCGEventKeyUp),&keyUpCallback,NULL);
I'm still having a problem though: modifier keys do not trigger the kCGEventKeyUp...
UPDATE 4:
Ok forget that again... I'm bound to answer to my own questions 5 minutes after asking them today huh!
To intercept modifier keys, use kCGEventFlagsChanged:
CGEventTapCreate(kCGHIDEventTap,kCGHeadInsertEventTap,kCGEventTapOptionListenOnly,CGEventMaskBit(kCGEventFlagsChanged),&callbackFunction,NULL);
So in essence I got the key and modifier key state detection working, but I'm still interested in knowing why kEventRawKeyUp doesn't work...
N.B: Also note that I'm developing on Tiger with the goal of having support for new and older versions of the OS as much as possible. CGEventTap is 10.4+ only so I'll be using this for now but a backwards-compatible solution would be welcome.
One option is to use EventTaps. This lets you monitor all keyboard events. See:
http://developer.apple.com/mac/library/documentation/Carbon/Reference/QuartzEventServicesRef/Reference/reference.html#//apple_ref/c/func/CGEventTapCreate
Unfortunately event taps will stop working if an application is requesting secure input. For example Quicken.
OSStatus err = InstallApplicationEventHandler(&globalHotkeyHandler, GetEventTypeCount(eventTypes), eventTypes, NULL, NULL);
This is not global. This installs the handler only when your own application is active, and (I believe) after the Carbon Event Manager's own event filters.
You need to use InstallEventHandler, which takes an event target as its first parameter (InstallApplicationEventHandler is a macro that passes the application event target).
For events that occur while your application is not active, the target you want is GetEventMonitorTarget(). For events that occur while your application is active, the target you want is GetEventDispatcherTarget(). To catch events no matter what application is active, install your handler on both targets.
Nowadays, though, I'd just use CGEventTaps, as Leibowitzn suggested.
Related
I've noticed that when a control such as an AutoSuggestBox has a callback, the callback is executed both when a user interacts with the control and when my code changes the associated value.
For example, if I set the TextChanged property on an AutoSuggestBox, the function is called even when my code sets the Text property to an initial value.
This is causing problems in my application in the form of both bugs and unnecessary function calls. You may be wondering how the code came to be in this state -- the answer is, I don't know. The project was handed off to me from another developer and I've been tasked to fix a number of bugs.
Although I can individually hunt down all the places in the code where this happens and temporarily remove the callback, I'm wondering if there is an easier way, for example a property I can set on the control that says, "don't call the callbacks when it is the code making a change rather than the UI".
For the AutoSuggestBox.TextChanged event, the attribute of the trigger reason is provided in AutoSuggestBoxTextChangedEventArgs, and you can judge based on this
private void AutoSuggestBox_TextChanged(AutoSuggestBox sender, AutoSuggestBoxTextChangedEventArgs args)
{
if (args.Reason == AutoSuggestionBoxTextChangeReason.ProgrammaticChange)
{
return;
}
//other code
}
For other controls, you need to deal with them according to your situation.
Best regards.
I'm working on a Windows Form Application in which I have embedded a Windows Media Player that lets you play video files. The unique thing is that I have changed the extension of the media files (for reasons which I can't get into here). For instance, "xyz.wmv" might be called "xyz.ext". They play just fine, but before they play, I get the message:
"The file you are attempting to play has an extension that does not match the file format. Playing the file may result in unexpected behaviour. Do you want the Player to try to play the file?"
You can click yes and you can even check the box to not show that message again, but I don't want that for all the obvious reasons including the fact that it confuses users. I have looked into the .settings properties but I cannot find a way to suppress this message and more importantly other messages that might come up.
The .ext (for example) extension is not known to media player, hence the warning.
What you can do to change this is modify the registry and register this extension. This is described officially here: File Name Extension Registry Settings
The most simple way to do it is to create a registry key like this:
HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Player\Extensions\.ext
And add two key values:
Runtime (DWORD): 6
Permissions (DWORD): 15 (or 0xF in hexa)
This is shown here:
NOTE: this answer was originally in response to a bounty question and edit which was removed on how to do this via code. Parts of this are still relevant to the original question.
You can do this pretty straight forward IF you have admin rights as you need to edit the registry. Not sure how far you will get without admin rights and can test later, but here is how to do this via code (in a real implementation I would do this as part of a setup - or check if the keys exist each time which seems wasteful):
You need to add one key (showing two here for registering the extensions, you may need additional keys for auto-play or a setting on the player):
private void Form1_Load(object sender, EventArgs e) {
/*This first key is not necessary - and if you will be using common
* extensions like mp4, skip this step altogether!!
*/
RegistryKey key = Registry.CurrentUser.OpenSubKey("Software", true)
.OpenSubKey("Classes", true);
key.CreateSubKey(".myExt");
key = key.OpenSubKey(".myExt", true);
key.SetValue("", "WMP11.AssocFile.myExt");
key.SetValue("Content Type", "video/x-ms-wmv");
key.SetValue("PerceivedType", "video");
/*Here is the magic key which will make the dialog go away*/
key = Registry.CurrentUser.OpenSubKey("Software", true)
.OpenSubKey("Microsoft", true)
.OpenSubKey("MediaPlayer", true)
.OpenSubKey("Player", true)
.OpenSubKey("Extensions", true);
key.CreateSubKey(".myExt");
key = key.OpenSubKey(".myExt", true);
key.SetValue("", "");
key.SetValue("Permissions", 0x20);
axWindowsMediaPlayer1.URL = #"C:\Users\Public\Documents\Wildlife.myExt";
}
Media Player creates other keys when you add through its dialog, but the only one definitely needed is: HKEY_Current_User.Software.Microsoft.MediaPlayer.Player.Extensions
If you want to see all the keys Media Player adds,
choose a crazy extension,
click always allow when prompted and then
search the registry for all the keys that get created.
The above code is tested and working for me - confirming the dialog before adding the keys and the lack of any dialog after.
This is a good generic process for programmatically adding file associations and default programs to the Windows Registry from .NET. You have to be careful about registering the extension (the first key I set above) IF the extension already exists (TEST FOR THIS). Otherwise the above code will happily overwrite your current values. All you really should need is the one added to: HKEY_Current_User.Software.Microsoft.MediaPlayer.Player.Extensions anyway. Think it through, check in advance, and test before you go crazy in the registry!!
It is also always a great idea to backup your registry before playing with it.
Final note: missed your question on how to reproduce once you have clicked always allow: just remove the entry in HKEY_Current_User.Software.Microsoft.MediaPlayer.Player.Extensions and voila!
This answer assumes you have a working knowledge of regedit.
Final note #2: Response geared to the questions in the Bounty. Other errors can be suppressed by setting telling Media Player to allow you to handle error events and then writing your custom handler. I have not done this before so cannot comment on the ease and what can/cannot be controlled through this method.
The Windows Media Player control does not raise an exception when it encounters an error such as an invalid URL. Instead, it signals an event. Your application should handle error events sent by the Player.
These can then be handled by creating / registering a MediaError event:
private void axWindowsMediaPlayer1_MediaError(object sender, AxWMPLib._WMPOCXEvents_MediaErrorEvent e) {
// Handle errors and profit!
}
Then set this as the handler in the Events property window for your control - same for other events such as ErrorEvent.
When Mission Control runs, it prevents applications from receiving keyboard and mouse events. It also leaves the last application running thinking that it still has focus. This is a problem for me because I don't receive keyUp or mouseUp events if I start Mission Control with a mouse button or a key held down and my application will behave as if that mouse button or key is held down.
I would like a way to either read both keyboard and mouse events even when Mission Control is active, or a way of detecting that Mission Control is active. Ideally, I would like to be able to do the latter since I effectively can't use my application when Mission Control is running.
I've tried a couple of things with no luck:
Use addGlobalMonitorForEventsMatchingMask to register a global monitor for keyboard and mouse events. This captures mouse events (but not keyboard events, although the documentation says keyDown events should be sent to the global monitor) when I switch to another application, but Mission Control doesn't seem to let events propagate to global monitors.
Check [[NSRunningApplication currentApplication] {isActive, ownsMenuBar}].
Apparently, my application is active even though it's not receiving events!
Check [NSApp keyWindow] != nil.
Apparently, one of my windows should be receiving key events. None of them are.
Check if Mission Control is one of the running applications returned by [NSWorkspace runningApplications]. Mission Control does not show up in this list when it's running.
Edit:
I've finally worked around this problem (albeit not in a very satisfactory way). For the mouse, it turns out that you can query the state of the pressed buttons with [NSEvent pressedMouseButtons]. I simply keep track of what I think the mouse state should be from NSLeftMouseDown and NSLeftMouseUp events and compare that to [NSEvent pressedMouseButtons] every so often to make sure that they're consistent. If they're not, then I know that something has hijacked my NSLeftMouseUp event and act accordingly.
For the keyboard, I could not find a way to query the keyboard state, so I couldn't do a similar workaround. I ended up disabling application switching using presentation options when keys are pressed.
At least in OS X 10.10, you can use this code to check if Mission Control is active or not:
func missionControlIsActive() -> Bool
{
var result: Bool = false
let windowInfosRef = CGWindowListCopyWindowInfo(CGWindowListOption(kCGWindowListOptionOnScreenOnly), CGWindowID(0)) // CGWindowID(0) is equal to kCGNullWindowID
let windowList: NSArray = windowInfosRef.takeRetainedValue() // We own the returned CFArrayRef
for entry in windowList
{
if (entry.objectForKey("kCGWindowOwnerName") as! String) == "Dock"
{
var bounds: NSDictionary = entry.objectForKey("kCGWindowBounds") as! NSDictionary
if (bounds.objectForKey("Y") as! NSNumber) == -1
{
result = true
}
}
}
return result
}
In a nutshell, the code checks if a specific window owned by the OS X Dock process is visible on the screen and if it is in a specific position. If both conditions are met, Mission Control will be active right now. Code will work in a sandboxed app and no privileges for assistive devices are required.
Did you try on bash level using NSTask? Something like ps -faxU <username> should list all running processes and then you could parse the output, or indeed you could use ps -faxU <username> | grep -i "mission control" (At the top of my head I am not sure how the process may be called, but sth like "mission control" seems legit). Not the most elegant solution maybe, but if nothing else works it may be worth it.
May be i'm missing something, but have you tried to use event taps instead of global monitoring?
It does appear that DTrace has some ability to see Mission Control being activated. Try running:
sudo fs_usage -filesys | grep Mission
from the command line and then launching the Mission Control app from the /Application folder.
You should see a lot of output related to Mission Control starting up. Unfortunately, this same output did not appear by using the keyboard short cut or swiping. Of course, using DTrace in production code is not something I would actually recommend.
C++ and Qt implementation works in latest OS X.
bool Window::missionControlIsActive() {
bool result = false;
CFArrayRef windows = CGWindowListCopyWindowInfo(kCGWindowListOptionOnScreenOnly+kCGWindowListExcludeDesktopElements, kCGNullWindowID);
for (int i = 0; i < CFArrayGetCount(windows) ; i++) {
auto cfMutableDictionaryRef_dict = (CFMutableDictionaryRef)CFArrayGetValueAtIndex( windows, i );
auto cfStringRef_name = (CFStringRef)CFDictionaryGetValue(cfMutableDictionaryRef_dict, kCGWindowName);
if (QString::fromCFString(cfStringRef_name) != u"") continue;
auto cfStringRef_ownerName = (CFStringRef)CFDictionaryGetValue(cfMutableDictionaryRef_dict, kCGWindowOwnerName);
if (QString::fromCFString(cfStringRef_ownerName) != u"Dock") continue;
auto cfDictRef_bounds = (CFDictionaryRef)CFDictionaryGetValue(cfMutableDictionaryRef_dict, kCGWindowBounds);
auto cfNumRef_bounds_Y = (CFNumberRef)CFDictionaryGetValue(cfDictRef_bounds, QString("Y").toCFString());
double num;
CFNumberGetValue(cfNumRef_bounds_Y, kCFNumberFloat64Type, &num);
if (num > 1.0 and num < 1000000) continue;
result = true;
break;
}
CFRelease(windows);
return result;
}
Using this code, I may register a global event handler:
[NSEvent addGlobalMonitorForEventsMatchingMask: NSKeyDownMask
handler: ^(NSEvent *incomingEvent) {
NSString *chars = [[incomingEvent characters] lowercaseString];
unichar character = [chars characterAtIndex:0];
// do something useful
NSLog(#"keydown globally! Which key? This key: %c", character);
}];
Unfortunately, events get passed along to this monitor, if support for assistive devices is enabled. Without assistive devices being enabled, no events get passed along.
Form the documentation:
Key-related events may only be monitored if accessibility is enabled or if your
application is trusted for accessibility access (see AXIsProcessTrusted).
I wonder, if another method exists, which passes along events without forcing the user to enable specific features of OS X.
While I didn't find a solution in Apple's docs, a solution must exist. E.g. the MAS-downloaded version of Alfred allows to define a hotkey.
Interestingly, Alfred's preferences only shows special keys and points out, that certain special key combinations may not work.
Since I basically want to show / hide a 'global' non-activating panel, I probably should simply prepare a system service. Should I?
You could try creating a Quartz Event Tap, with kCGSessionEventTap as the location.
Quartz Event Services Reference
Sample code from Mac OS X Internals
I've successfully got a demo app intercepting keyboard events. Here's the handler for them.
CGEventRef keyUpCallback (CGEventTapProxy proxy, CGEventType type, CGEventRef event, void *refcon) {
NSLog(#"KeyUp event tapped!");
return;
}
I want to do different things depending on which application sent the event. How can I tell which application it is?
The application that is receiving keystrokes is presumably the active application, so you could handle the event differently depending on which application is active. You can use the activeapplication method from NSWorkspace to get the name of the active application.
See also this thread about getting the active application.
Here how it goes:
int64_t processIdTarget = CGEventGetIntegerValueField(event, kCGEventTargetUnixProcessID);
int64_t processIdSource = CGEventGetIntegerValueField(event, kCGEventSourceUnixProcessID);
processIdSource shows you application sender and processIdTarget stands for receiver.
For example you can open virtual keyboard and send events with it. As virtual keyboard is process in user space you will get it's pid as processIdSource. But for most of cases you will get 0 as processIdSource.
After you got application's pid you can create NSRunningApplication instance and get bunch of information from it.
This shows process ID of the application that sent the event:
NSLog(#"Target PID:%lld",CGEventGetIntegerValueField(event, kCGEventTargetUnixProcessID));