'''
.. _motionevent:
Motion Event
============
The :class:`MotionEvent` is the base class used for events provided by
pointing devices (touch and non-touch). This class defines all the properties
and methods needed to handle 2D and 3D movements but has many more
capabilities.
Usually you would never need to create the :class:`MotionEvent` yourself as
this is the role of the :mod:`~kivy.input.providers`.
Flow of the motion events
-------------------------
1. The :class:`MotionEvent` 's are gathered from input providers by
:class:`~kivy.base.EventLoopBase`.
2. Post processing is performed by registered processors
:mod:`~kivy.input.postproc`.
3. :class:`~kivy.base.EventLoopBase` dispatches all motion events using
`on_motion` event to all registered listeners including the
:class:`~kivy.core.window.WindowBase`.
4. Once received in :meth:`~kivy.core.window.WindowBase.on_motion` events
(touch or non-touch) are all registered managers. If a touch event is not
handled by at least one manager, then it is dispatched through
:meth:`~kivy.core.window.WindowBase.on_touch_down`,
:meth:`~kivy.core.window.WindowBase.on_touch_move` and
:meth:`~kivy.core.window.WindowBase.on_touch_up`.
5. Widgets receive events in :meth:`~kivy.uix.widget.Widget.on_motion` method
(if passed by a manager) or on `on_touch_xxx` methods.
Motion events and event managers
--------------------------------
A motion event is a touch event if its :attr:`MotionEvent.is_touch` is set to
`True`. Beside `is_touch` attribute, :attr:`MotionEvent.type_id` can be used to
check for event's general type. Currently two types are dispatched by
input providers: "touch" and "hover".
Event managers can be used to dispatch any motion event throughout the widget
tree and a manager uses `type_id` to specify which event types it want to
receive. See :mod:`~kivy.eventmanager` to learn how to define and register
an event manager.
A manager can also assign a new `type_id` to
:attr:`MotionEvent.type_id` before dispatching it to the widgets. This useful
when dispatching a specific event::
class MouseTouchManager(EventManagerBase):
type_ids = ('touch',)
def dispatch(self, etype, me):
accepted = False
if me.device == 'mouse':
me.push() # Save current type_id and other values
me.type_id = 'mouse_touch'
self.window.transform_motion_event_2d(me)
# Dispatch mouse touch event to widgets which registered
# to receive 'mouse_touch'
for widget in self.window.children[:]:
if widget.dispatch('on_motion', etype, me):
accepted = True
break
me.pop() # Restore
return accepted
Listening to a motion event
---------------------------
If you want to receive all motion events, touch or not, you can bind the
MotionEvent from the :class:`~kivy.core.window.Window` to your own callback::
def on_motion(self, etype, me):
# will receive all motion events.
pass
Window.bind(on_motion=on_motion)
You can also listen to changes of the mouse position by watching
:attr:`~kivy.core.window.WindowBase.mouse_pos`.
Profiles
--------
The :class:`MotionEvent` stores device specific information in various
properties listed in the :attr:`~MotionEvent.profile`.
For example, you can receive a MotionEvent that has an angle, a fiducial
ID, or even a shape. You can check the :attr:`~MotionEvent.profile`
attribute to see what is currently supported by the MotionEvent provider.
This is a short list of the profile values supported by default. Please check
the :attr:`MotionEvent.profile` property to see what profile values are
available.
============== ================================================================
Profile value Description
-------------- ----------------------------------------------------------------
angle 2D angle. Accessed via the `a` property.
button Mouse button ('left', 'right', 'middle', 'scrollup' or
'scrolldown'). Accessed via the `button` property.
markerid Marker or Fiducial ID. Accessed via the `fid` property.
pos 2D position. Accessed via the `x`, `y` or `pos` properties.
pos3d 3D position. Accessed via the `x`, `y` or `z` properties.
pressure Pressure of the contact. Accessed via the `pressure` property.
shape Contact shape. Accessed via the `shape` property .
============== ================================================================
If you want to know whether the current :class:`MotionEvent` has an angle::
def on_touch_move(self, touch):
if 'angle' in touch.profile:
print('The touch angle is', touch.a)
If you want to select only the fiducials::
def on_touch_move(self, touch):
if 'markerid' not in touch.profile:
return
'''
__all__ = ('MotionEvent', )
import weakref
from inspect import isroutine
from copy import copy
from time import time
from kivy.eventmanager import MODE_DEFAULT_DISPATCH
from kivy.vector import Vector
class EnhancedDictionary(dict):
def __getattr__(self, attr):
try:
return self.__getitem__(attr)
except KeyError:
return super(EnhancedDictionary, self).__getattr__(attr)
def __setattr__(self, attr, value):
self.__setitem__(attr, value)
class MotionEventMetaclass(type):
def __new__(mcs, name, bases, attrs):
__attrs__ = []
for base in bases:
if hasattr(base, '__attrs__'):
__attrs__.extend(base.__attrs__)
if '__attrs__' in attrs:
__attrs__.extend(attrs['__attrs__'])
attrs['__attrs__'] = tuple(__attrs__)
return super(MotionEventMetaclass, mcs).__new__(mcs, name,
bases, attrs)
MotionEventBase = MotionEventMetaclass('MotionEvent', (object, ), {})
[docs]class MotionEvent(MotionEventBase):
'''Abstract class that represents an input event.
:Parameters:
`id`: str
unique ID of the MotionEvent
`args`: list
list of parameters, passed to the depack() function
'''
__uniq_id = 0
__attrs__ = \
('device', 'push_attrs', 'push_attrs_stack',
'is_touch', 'type_id', 'id', 'dispatch_mode', 'shape', 'profile',
# current position, in 0-1 range
'sx', 'sy', 'sz',
# first position set, in 0-1 range
'osx', 'osy', 'osz',
# last position set, in 0-1 range
'psx', 'psy', 'psz',
# delta from the last position and current one, in 0-1 range
'dsx', 'dsy', 'dsz',
# current position, in screen range
'x', 'y', 'z',
# first position set, in screen range
'ox', 'oy', 'oz',
# last position set, in 0-1 range
'px', 'py', 'pz',
# delta from the last position and current one, in screen range
'dx', 'dy', 'dz',
'time_start',
'is_double_tap', 'double_tap_time',
'is_triple_tap', 'triple_tap_time',
'ud')
def __init__(self, device, id, args, is_touch=False, type_id=None):
if self.__class__ == MotionEvent:
raise NotImplementedError('class MotionEvent is abstract')
MotionEvent.__uniq_id += 1
#: True if the MotionEvent is a touch.
self.is_touch = is_touch
#: (Experimental) String to identify event type.
#:
#: .. versionadded:: 2.1.0
self.type_id = type_id
#: (Experimental) Used by a event manager or a widget to assign
#: the dispatching mode. Defaults to
#: :const:`~kivy.eventmanager.MODE_DEFAULT_DISPATCH`. See
#: :mod:`~kivy.eventmanager` for available modes.
#:
#: .. versionadded:: 2.1.0
self.dispatch_mode = MODE_DEFAULT_DISPATCH
#: Attributes to push by default, when we use :meth:`push` : x, y, z,
#: dx, dy, dz, ox, oy, oz, px, py, pz.
self.push_attrs_stack = []
self.push_attrs = ('x', 'y', 'z', 'dx', 'dy', 'dz', 'ox', 'oy', 'oz',
'px', 'py', 'pz', 'pos', 'type_id', 'dispatch_mode')
#: Uniq ID of the event. You can safely use this property, it will be
#: never the same across all existing events.
self.uid = MotionEvent.__uniq_id
#: Device used for creating this event.
self.device = device
# For grab
self.grab_list = []
self.grab_exclusive_class = None
self.grab_state = False
#: Used to determine which widget the event is being dispatched to.
#: Check the :meth:`grab` function for more information.
self.grab_current = None
#: Currently pressed button.
self.button = None
#: Profiles currently used in the event.
self.profile = []
#: Id of the event, not unique. This is generally the Id set by the
#: input provider, like ID in TUIO. If you have multiple TUIO sources,
#: then same id can be used. Prefer to use :attr:`uid` attribute
#: instead.
self.id = id
#: Shape of the touch event, subclass of
#: :class:`~kivy.input.shape.Shape`.
#: By default, the property is set to None.
self.shape = None
#: X position, in 0-1 range.
self.sx = 0.0
#: Y position, in 0-1 range.
self.sy = 0.0
#: Z position, in 0-1 range.
self.sz = 0.0
#: Origin X position, in 0-1 range.
self.osx = None
#: Origin Y position, in 0-1 range.
self.osy = None
#: Origin Z position, in 0-1 range.
self.osz = None
#: Previous X position, in 0-1 range.
self.psx = None
#: Previous Y position, in 0-1 range.
self.psy = None
#: Previous Z position, in 0-1 range.
self.psz = None
#: Delta between self.sx and self.psx, in 0-1 range.
self.dsx = None
#: Delta between self.sy and self.psy, in 0-1 range.
self.dsy = None
#: Delta between self.sz and self.psz, in 0-1 range.
self.dsz = None
#: X position, in window range.
self.x = 0.0
#: Y position, in window range.
self.y = 0.0
#: Z position, in window range.
self.z = 0.0
#: Origin X position, in window range.
self.ox = None
#: Origin Y position, in window range.
self.oy = None
#: Origin Z position, in window range.
self.oz = None
#: Previous X position, in window range.
self.px = None
#: Previous Y position, in window range.
self.py = None
#: Previous Z position, in window range.
self.pz = None
#: Delta between self.x and self.px, in window range.
self.dx = None
#: Delta between self.y and self.py, in window range.
self.dy = None
#: Delta between self.z and self.pz, in window range.
self.dz = None
#: Position (X, Y), in window range.
self.pos = (0.0, 0.0)
#: Initial time of the event creation.
self.time_start = time()
#: Time of the last update.
self.time_update = self.time_start
#: Time of the end event (last event usage).
self.time_end = -1
#: Indicate if the touch event is a double tap or not.
self.is_double_tap = False
#: Indicate if the touch event is a triple tap or not.
#:
#: .. versionadded:: 1.7.0
self.is_triple_tap = False
#: If the touch is a :attr:`is_double_tap`, this is the time
#: between the previous tap and the current touch.
self.double_tap_time = 0
#: If the touch is a :attr:`is_triple_tap`, this is the time
#: between the first tap and the current touch.
#:
#: .. versionadded:: 1.7.0
self.triple_tap_time = 0
#: User data dictionary. Use this dictionary to save your own data on
#: the event.
self.ud = EnhancedDictionary()
#: If set to `True` (default) keeps first previous position
#: (X, Y, Z in 0-1 range) and ignore all other until
#: :meth:`MotionEvent.dispatch_done` is called from the `EventLoop`.
#:
#: This attribute is needed because event provider can make many calls
#: to :meth:`MotionEvent.move`, but for all those calls event is
#: dispatched to the listeners only once. Assigning `False` will keep
#: latest previous position. See :meth:`MotionEvent.move`.
#:
#: .. versionadded:: 2.1.0
self.sync_with_dispatch = True
#: Keep first previous position if :attr:`sync_with_dispatch` is
#: `True`.
self._keep_prev_pos = True
#: Flag that first dispatch of this event is done.
self._first_dispatch_done = False
self.depack(args)
[docs] def depack(self, args):
'''Depack `args` into attributes of the class'''
if self.osx is None \
or self.sync_with_dispatch and not self._first_dispatch_done:
# Sync origin/previous/current positions until the first
# dispatch (etype == 'begin') is done.
self.osx = self.psx = self.sx
self.osy = self.psy = self.sy
self.osz = self.psz = self.sz
# update the delta
self.dsx = self.sx - self.psx
self.dsy = self.sy - self.psy
self.dsz = self.sz - self.psz
[docs] def grab(self, class_instance, exclusive=False):
'''Grab this motion event.
If this event is a touch you can grab it if you want to receive
subsequent :meth:`~kivy.uix.widget.Widget.on_touch_move` and
:meth:`~kivy.uix.widget.Widget.on_touch_up` events, even if the touch
is not dispatched by the parent:
.. code-block:: python
def on_touch_down(self, touch):
touch.grab(self)
def on_touch_move(self, touch):
if touch.grab_current is self:
# I received my grabbed touch
else:
# it's a normal touch
def on_touch_up(self, touch):
if touch.grab_current is self:
# I receive my grabbed touch, I must ungrab it!
touch.ungrab(self)
else:
# it's a normal touch
pass
.. versionchanged:: 2.1.0
Allowed grab for non-touch events.
'''
if self.grab_exclusive_class is not None:
raise Exception('Event is exclusive and cannot be grabbed')
class_instance = weakref.ref(class_instance.__self__)
if exclusive:
self.grab_exclusive_class = class_instance
self.grab_list.append(class_instance)
[docs] def ungrab(self, class_instance):
'''Ungrab a previously grabbed motion event.
'''
class_instance = weakref.ref(class_instance.__self__)
if self.grab_exclusive_class == class_instance:
self.grab_exclusive_class = None
if class_instance in self.grab_list:
self.grab_list.remove(class_instance)
[docs] def dispatch_done(self):
'''Notify that dispatch to the listeners is done.
Called by the :meth:`EventLoopBase.post_dispatch_input`.
.. versionadded:: 2.1.0
'''
self._keep_prev_pos = True
self._first_dispatch_done = True
[docs] def move(self, args):
'''Move to another position.
'''
if self.sync_with_dispatch:
if self._keep_prev_pos:
self.psx, self.psy, self.psz = self.sx, self.sy, self.sz
self._keep_prev_pos = False
else:
self.psx, self.psy, self.psz = self.sx, self.sy, self.sz
self.time_update = time()
self.depack(args)
[docs] def scale_for_screen(self, w, h, p=None, rotation=0,
smode='None', kheight=0):
'''Scale position for the screen.
.. versionchanged:: 2.1.0
Max value for `x`, `y` and `z` is changed respectively to `w` - 1,
`h` - 1 and `p` - 1.
'''
x_max, y_max = max(0, w - 1), max(0, h - 1)
absolute = self.to_absolute_pos
self.x, self.y = absolute(self.sx, self.sy, x_max, y_max, rotation)
self.ox, self.oy = absolute(self.osx, self.osy, x_max, y_max, rotation)
self.px, self.py = absolute(self.psx, self.psy, x_max, y_max, rotation)
z_max = 0 if p is None else max(0, p - 1)
self.z = self.sz * z_max
self.oz = self.osz * z_max
self.pz = self.psz * z_max
if smode:
# Adjust y for keyboard height
if smode == 'pan' or smode == 'below_target':
self.y -= kheight
self.oy -= kheight
self.py -= kheight
elif smode == 'scale':
offset = kheight * (self.y - h) / (h - kheight)
self.y += offset
self.oy += offset
self.py += offset
# Update delta values
self.dx = self.x - self.px
self.dy = self.y - self.py
self.dz = self.z - self.pz
# Cache position
self.pos = self.x, self.y
[docs] def to_absolute_pos(self, nx, ny, x_max, y_max, rotation):
'''Transforms normalized (0-1) coordinates `nx` and `ny` to absolute
coordinates using `x_max`, `y_max` and `rotation`.
:raises:
`ValueError`: If `rotation` is not one of: 0, 90, 180 or 270
.. versionadded:: 2.1.0
'''
if rotation == 0:
return nx * x_max, ny * y_max
elif rotation == 90:
return ny * y_max, (1 - nx) * x_max
elif rotation == 180:
return (1 - nx) * x_max, (1 - ny) * y_max
elif rotation == 270:
return (1 - ny) * y_max, nx * x_max
raise ValueError('Invalid rotation %s, '
'valid values are 0, 90, 180 or 270' % rotation)
[docs] def push(self, attrs=None):
'''Push attribute values in `attrs` onto the stack.
'''
if attrs is None:
attrs = self.push_attrs
values = [getattr(self, x) for x in attrs]
self.push_attrs_stack.append((attrs, values))
[docs] def pop(self):
'''Pop attributes values from the stack.
'''
attrs, values = self.push_attrs_stack.pop()
for i in range(len(attrs)):
setattr(self, attrs[i], values[i])
[docs] def copy_to(self, to):
'''Copy some attribute to another motion event object.'''
for attr in self.__attrs__:
to.__setattr__(attr, copy(self.__getattribute__(attr)))
[docs] def distance(self, other_touch):
'''Return the distance between the two events.
'''
return Vector(self.pos).distance(other_touch.pos)
def update_time_end(self):
self.time_end = time()
# facilities
@property
def dpos(self):
'''Return delta between last position and current position, in the
screen coordinate system (self.dx, self.dy).'''
return self.dx, self.dy
@property
def opos(self):
'''Return the initial position of the motion event in the screen
coordinate system (self.ox, self.oy).'''
return self.ox, self.oy
@property
def ppos(self):
'''Return the previous position of the motion event in the screen
coordinate system (self.px, self.py).'''
return self.px, self.py
@property
def spos(self):
'''Return the position in the 0-1 coordinate system (self.sx, self.sy).
'''
return self.sx, self.sy
def __str__(self):
basename = str(self.__class__)
classname = basename.split('.')[-1].replace('>', '').replace('\'', '')
return '<%s spos=%s pos=%s>' % (classname, self.spos, self.pos)
def __repr__(self):
out = []
for x in dir(self):
v = getattr(self, x)
if x[0] == '_':
continue
if isroutine(v):
continue
out.append('%s="%s"' % (x, v))
return '<%s %s>' % (
self.__class__.__name__,
' '.join(out))
@property
def is_mouse_scrolling(self, *args):
'''Returns True if the touch event is a mousewheel scrolling
.. versionadded:: 1.6.0
'''
return 'button' in self.profile and 'scroll' in self.button
