1XGETDEVICEMOTIONEVEN(3) XGETDEVICEMOTIONEVEN(3)
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6 XGetDeviceMotionEvents, XDeviceTimeCoord - get device motion history
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9 #include <X11/extensions/XInput.h>
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11 XDeviceTimeCoord *XGetDeviceMotionEvents( Display *display,
12 XDevice *device,
13 Time start,
14 Time stop,
15 int *nevents_return,
16 int *mode_return,
17 int *axis_count_return);
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19 display
20 Specifies the connection to the X server.
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22 device
23 Specifies the device whose motion history is to be
24 queried.
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26 start, stop
27 Specify the time interval in which the events are
28 returned from the motion history buffer. You can pass a
29 timestamp or CurrentTime.
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31 nevents_return
32 Returns the number of events from the motion history
33 buffer.
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35 mode_return
36 Returns the mode of the device (Absolute or Relative).
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38 axis_count_return
39 Returns the count of axes being reported.
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42 The server may retain the recent history of the device motion
43 and do so to a finer granularity than is reported by
44 DeviceMotionNotify events. The XGetDeviceMotionEvents request
45 makes this history available.
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47 The XGetDeviceMotionEvents request returns all events in the
48 motion history buffer that fall between the specified start and
49 stop times, inclusive. If the start time is later than the stop
50 time or if the start time is in the future, no events are
51 returned. If the stop time is in the future, it is equivalent
52 to specifying CurrentTime.
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54 The mode indicates whether the device is reporting absolute
55 positional data (mode = Absolute ) or relative motion data
56 (mode = Relative ). Some devices allow their mode to be changed
57 via the XSetDeviceMode request. These constants are defined in
58 the file XI.h. The axis_count returns the number of axes or
59 valuators being reported by the device.
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61 XGetDeviceMotionEvents can generate a BadDevice, or BadMatch
62 error.
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64 Structures
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66 The XDeviceTimeCoord structure contains:
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68 typedef struct {
69 Time time;
70 int *data;
71 } XDeviceTimeCoord;
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73 The time member is set to the time, in milliseconds. The data
74 member is a pointer to an array of integers. These integers are
75 set to the values of each valuator or axis reported by the
76 device. There is one element in the array per axis of motion
77 reported by the device. The value of the array elements depends
78 on the mode of the device. If the mode is Absolute, the values
79 are the raw values generated by the device. These may be scaled
80 by client programs using the maximum values that the device can
81 generate. The maximum value for each axis of the device is
82 reported in the max_val field of the XAxisInfo returned by the
83 XListInputDevices request. If the mode is Relative, the data
84 values are the relative values generated by the device.
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86 You should use XFreeDeviceMotionEvents to free the data
87 returned by this request.
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89 Errors returned by this request: BadDevice, BadMatch.
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92 BadDevice
93 An invalid device was specified. The specified device
94 does not exist or has not been opened by this client via
95 XOpenInputDevice. This error may also occur if the
96 specified device is the X keyboard or X pointer device.
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98 BadMatch
99 This error may occur if an XGetDeviceMotionEvents
100 request is made specifying a device that has no
101 valuators and reports no axes of motion.
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105 06/19/2019 XGETDEVICEMOTIONEVEN(3)