1wxIdleEvent(3) Erlang Module Definition wxIdleEvent(3)
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6 wxIdleEvent - Functions for wxIdleEvent class
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9 This class is used for idle events, which are generated when the system
10 becomes idle. Note that, unless you do something specifically, the idle
11 events are not sent if the system remains idle once it has become it,
12 e.g. only a single idle event will be generated until something else
13 resulting in more normal events happens and only then is the next idle
14 event sent again.
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16 If you need to ensure a continuous stream of idle events, you can ei‐
17 ther use requestMore/2 method in your handler or call ?wxWakeUpIdle()
18 periodically (for example from a timer event handler), but note that
19 both of these approaches (and especially the first one) increase the
20 system load and so should be avoided if possible.
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22 By default, idle events are sent to all windows, including even the
23 hidden ones because they may be shown if some condition is met from
24 their wxEVT_IDLE (or related wxEVT_UPDATE_UI) handler. The children of
25 hidden windows do not receive idle events however as they can't change
26 their state in any way noticeable by the user. Finally, the global
27 wxApp (not implemented in wx) object also receives these events, as
28 usual, so it can be used for any global idle time processing.
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30 If sending idle events to all windows is causing a significant overhead
31 in your application, you can call setMode/1 with the value wxI‐
32 DLE_PROCESS_SPECIFIED, and set the wxWS_EX_PROCESS_IDLE extra window
33 style for every window which should receive idle events, all the other
34 ones will not receive them in this case.
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36 Delayed Action Mechanism
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38 wxIdleEvent can be used to perform some action "at slightly later
39 time". This can be necessary in several circumstances when, for what‐
40 ever reason, something can't be done in the current event handler. For
41 example, if a mouse event handler is called with the mouse button
42 pressed, the mouse can be currently captured and some operations with
43 it - notably capturing it again - might be impossible or lead to unde‐
44 sirable results. If you still want to capture it, you can do it from
45 wxEVT_IDLE handler when it is called the next time instead of doing it
46 immediately.
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48 This can be achieved in two different ways: when using static event ta‐
49 bles, you will need a flag indicating to the (always connected) idle
50 event handler whether the desired action should be performed. The orig‐
51 inally called handler would then set it to indicate that it should in‐
52 deed be done and the idle handler itself would reset it to prevent it
53 from doing the same action again.
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55 Using dynamically connected event handlers things are even simpler as
56 the original event handler can simply wxEvtHandler::Connect() (not im‐
57 plemented in wx) or wxEvtHandler::Bind() (not implemented in wx) the
58 idle event handler which would only be executed then and could wx‐
59 EvtHandler::Disconnect() (not implemented in wx) or wxEvtHandler::Un‐
60 bind() (not implemented in wx) itself.
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62 See: Overview events, wxUpdateUIEvent, wxWindow::OnInternalIdle (not
63 implemented in wx)
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65 This class is derived (and can use functions) from: wxEvent
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67 wxWidgets docs: wxIdleEvent
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70 Use wxEvtHandler:connect/3 with wxIdleEventType to subscribe to events
71 of this type.
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74 wxIdleEvent() = wx:wx_object()
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76 wxIdle() = #wxIdle{type = wxIdleEvent:wxIdleEventType()}
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78 wxIdleEventType() = idle
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81 getMode() -> wx:wx_enum()
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83 Static function returning a value specifying how wxWidgets will
84 send idle events: to all windows, or only to those which specify
85 that they will process the events.
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87 See: setMode/1
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89 requestMore(This) -> ok
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91 Types:
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93 This = wxIdleEvent()
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95 requestMore(This, Options :: [Option]) -> ok
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97 Types:
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99 This = wxIdleEvent()
100 Option = {needMore, boolean()}
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102 Tells wxWidgets that more processing is required.
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104 This function can be called by an OnIdle handler for a window or
105 window event handler to indicate that wxApp::OnIdle should for‐
106 ward the OnIdle event once more to the application windows.
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108 If no window calls this function during OnIdle, then the appli‐
109 cation will remain in a passive event loop (not calling OnIdle)
110 until a new event is posted to the application by the windowing
111 system.
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113 See: moreRequested/1
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115 moreRequested(This) -> boolean()
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117 Types:
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119 This = wxIdleEvent()
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121 Returns true if the OnIdle function processing this event re‐
122 quested more processing time.
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124 See: requestMore/2
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126 setMode(Mode) -> ok
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128 Types:
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130 Mode = wx:wx_enum()
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132 Static function for specifying how wxWidgets will send idle
133 events: to all windows, or only to those which specify that they
134 will process the events.
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138wxWidgets team. wx 2.2.1 wxIdleEvent(3)