The event handling part of the test web cam function does not work. I guess I must have misunderstood something, or miss something important. So I must read the manual again.
pygame.event - Pygame v1.9.2 documentation
http://www.pygame.org/docs/ref/event.html
pygame module for interacting with events and queues
pygame.event.pump — internally process pygame event handlers
pygame.event.get — get events from the queue
pygame.event.poll — get a single event from the queue
pygame.event.wait — wait for a single event from the queue
pygame.event.peek — test if event types are waiting on the queue
pygame.event.clear — remove all events from the queue
pygame.event.event_name — get the string name from and event id
pygame.event.set_blocked — control which events are allowed on the queue
pygame.event.set_allowed — control which events are allowed on the queue
pygame.event.get_blocked — test if a type of event is blocked from the queue
pygame.event.set_grab — control the sharing of input devices with other applications
pygame.event.get_grab — test if the program is sharing input devices
pygame.event.post — place a new event on the queue
pygame.event.Event — create a new event object
Pygame handles all its event messaging through an event queue. The routines in this module help you manage that event queue. The input queue is heavily dependent on the pygame display module. If the display has not been initialized and a video mode not set, the event queue will not really work.
The queue is a regular queue of Event objects, there are a variety of ways to access the events it contains. From simply checking for the existance of events, to grabbing them directly off the stack.
All events have a type identifier. This event type is in between the values of NOEVENT and NUMEVENTS. All user defined events can have the value of USEREVENT or higher. It is recommended make sure your event id’s follow this system.
To get the state of various input devices, you can forego the event queue and access the input devices directly with their appropriate modules; mouse, key, and joystick. If you use this method, remember that pygame requires some form of communication with the system window manager and other parts of the platform. To keep pygame in synch with the system, you will need to call pygame.event.pump() to keep everything current. You’ll want to call this function usually once per game loop.
The event queue offers some simple filtering. This can help performance slightly by blocking certain event types from the queue, use the pygame.event.set_allowed() and pygame.event.set_blocked() to work with this filtering. All events default to allowed.
The event subsystem should be called from the main thread. If you want to post events into the queue from other threads, please use the fastevent package.
Joysticks will not send any events until the device has been initialized.
An Event object contains an event type and a readonly set of member data. The Event object contains no method functions, just member data. Event objects are retrieved from the pygame event queue. You can create your own new events with the pygame.event.Event() function.
Your program must take steps to keep the event queue from overflowing. If the program is not clearing or getting all events off the queue at regular intervals, it can overflow. When the queue overflows an exception is thrown.
All Event objects contain an event type identifier in the Event.type member. You may also get full access to the Event’s member data through the Event.dict method. All other member lookups will be passed through to the Event’s dictionary values.
While debugging and experimenting, you can print the Event objects for a quick display of its type and members. Events that come from the system will have a guaranteed set of member items based on the type. Here is a list of the Event members that are defined with each type.
QUIT none
ACTIVEEVENT gain, state
KEYDOWN unicode, key, mod
KEYUP key, mod
MOUSEMOTION pos, rel, buttons
MOUSEBUTTONUP pos, button
MOUSEBUTTONDOWN pos, button
JOYAXISMOTION joy, axis, value
JOYBALLMOTION joy, ball, rel
JOYHATMOTION joy, hat, value
JOYBUTTONUP joy, button
JOYBUTTONDOWN joy, button
VIDEORESIZE size, w, h
VIDEOEXPOSE none
USEREVENT code
Events support equality comparison. Two events are equal if they are the same type and have identical attribute values. Inequality checks also work.
New in version 1.9.2.
pygame.event.pump()
internally process pygame event handlers
pump() -> None
For each frame of your game, you will need to make some sort of call to the event queue. This ensures your program can internally interact with the rest of the operating system. If you are not using other event functions in your game, you should call pygame.event.pump() to allow pygame to handle internal actions.
This function is not necessary if your program is consistently processing events on the queue through the other pygame.event functions.
There are important things that must be dealt with internally in the event queue. The main window may need to be repainted or respond to the system. If you fail to make a call to the event queue for too long, the system may decide your program has locked up.
pygame.event.get()
get events from the queue
get() -> Eventlist
get(type) -> Eventlist
get(typelist) -> Eventlist
This will get all the messages and remove them from the queue. If a type or sequence of types is given only those messages will be removed from the queue.
If you are only taking specific events from the queue, be aware that the queue could eventually fill up with the events you are not interested.
pygame.event.poll()
get a single event from the queue
poll() -> Event
Returns a single event from the queue. If the event queue is empty an event of type pygame.NOEVENT will be returned immediately. The returned event is removed from the queue.
pygame.event.wait()
wait for a single event from the queue
wait() -> Event
Returns a single event from the queue. If the queue is empty this function will wait until one is created. The event is removed from the queue once it has been returned. While the program is waiting it will sleep in an idle state. This is important for programs that want to share the system with other applications.
pygame.event.peek()
test if event types are waiting on the queue
peek(type) -> bool
peek(typelist) -> bool
Returns true if there are any events of the given type waiting on the queue. If a sequence of event types is passed, this will return True if any of those events are on the queue.
pygame.event.clear()
remove all events from the queue
clear() -> None
clear(type) -> None
clear(typelist) -> None
Remove all events or events of a specific type from the queue. This has the same effect as pygame.event.get() except nothing is returned. This can be slightly more effecient when clearing a full event queue.
pygame.event.event_name()
get the string name from and event id
event_name(type) -> string
Pygame uses integer ids to represent the event types. If you want to report these types to the user they should be converted to strings. This will return a the simple name for an event type. The string is in the WordCap style.
pygame.event.set_blocked()
control which events are allowed on the queue
set_blocked(type) -> None
set_blocked(typelist) -> None
set_blocked(None) -> None
The given event types are not allowed to appear on the event queue. By default all events can be placed on the queue. It is safe to disable an event type multiple times.
If None is passed as the argument, this has the opposite effect and ALL of the event types are allowed to be placed on the queue.
pygame.event.set_allowed()
control which events are allowed on the queue
set_allowed(type) -> None
set_allowed(typelist) -> None
set_allowed(None) -> None
The given event types are allowed to appear on the event queue. By default all events can be placed on the queue. It is safe to enable an event type multiple times.
If None is passed as the argument, NONE of the event types are allowed to be placed on the queue.
pygame.event.get_blocked()
test if a type of event is blocked from the queue
get_blocked(type) -> bool
Returns true if the given event type is blocked from the queue.
pygame.event.set_grab()
control the sharing of input devices with other applications
set_grab(bool) -> None
When your program runs in a windowed environment, it will share the mouse and keyboard devices with other applications that have focus. If your program sets the event grab to True, it will lock all input into your program.
It is best to not always grab the input, since it prevents the user from doing other things on their system.
pygame.event.get_grab()
test if the program is sharing input devices
get_grab() -> bool
Returns true when the input events are grabbed for this application. Use pygame.event.set_grab() to control this state.
pygame.event.post()
place a new event on the queue
post(Event) -> None
This places a new event at the end of the event queue. These Events will later be retrieved from the other queue functions.
This is usually used for placing pygame.USEREVENT events on the queue. Although any type of event can be placed, if using the sytem event types your program should be sure to create the standard attributes with appropriate values.
pygame.event.Event()
create a new event object
Event(type, dict) -> Event
Event(type, **attributes) -> Event
Creates a new event with the given type. The event is created with the given attributes and values. The attributes can come from a dictionary argument with string keys, or from keyword arguments. The event object exposes its dictionary as attribute __dict__, and also as dict for backward compatibility.
Attributes type, __dict__, and dict are readonly. Other attributes are mutable. There are no methods attached to an Event object.
Mutable attributes are new to Pygame 1.9.2.
.END
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