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Source code for kivy.input.motionevent

'''
.. _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.

.. note::

    You never create the :class:`MotionEvent` yourself: this is the role of the
    :mod:`~kivy.input.providers`.

Motion Event and Touch
----------------------

We differentiate between a Motion Event and Touch event. A Touch event is a
:class:`MotionEvent` with the `pos` profile. Only these events are dispatched
throughout the widget tree.

1. The :class:`MotionEvent` 's are gathered from input providers.
2. All the :class:`MotionEvent` 's are dispatched from
    :meth:`~kivy.core.window.WindowBase.on_motion`.
3. If a :class:`MotionEvent` has a `pos` profile, we dispatch it 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`.

Listening to a Motion Event
---------------------------

If you want to receive all MotionEvents, Touch or not, you can bind the
MotionEvent from the :class:`~kivy.core.window.Window` to your own callback::

    def on_motion(self, etype, motionevent):
        # 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.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 (touch or non-touch). :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', 'id', '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): if self.__class__ == MotionEvent: raise NotImplementedError('class MotionEvent is abstract') MotionEvent.__uniq_id += 1 #: True if the Motion Event is a Touch. Can be also verified is #: `pos` is :attr:`profile`. self.is_touch = False #: 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') #: Uniq ID of the touch. You can safely use this property, it will be #: never the same accross all existing touches. self.uid = MotionEvent.__uniq_id #: Device used for creating this touch self.device = device # For grab self.grab_list = [] self.grab_exclusive_class = None self.grab_state = False #: Used to determine which widget the touch is being dispatched to. #: Check the :meth:`grab` function for more information. self.grab_current = None #: Profiles currently used in the touch self.profile = [] #: Id of the touch, not uniq. This is generally the Id set by the input #: provider, like ID in TUIO. If you have multiple TUIO source, #: the same id can be used. Prefer to use :attr:`uid` attribute #: instead. self.id = id #: Shape of the touch, 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 touch creation self.time_start = time() #: Time of the last update self.time_update = self.time_start #: Time of the end event (last touch usage) self.time_end = -1 #: Indicate if the touch is a double tap or not self.is_double_tap = False #: Indicate if the touch 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 touch. self.ud = EnhancedDictionary() self.depack(args)
[docs] def depack(self, args): '''Depack `args` into attributes of the class''' # set initial position and last position if self.osx is None: self.psx = self.osx = self.sx self.psy = self.osy = self.sy self.psz = self.osz = 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. You can grab a touch 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 ''' if not self.is_touch: raise Exception('Grab works only for Touch MotionEvents.') if self.grab_exclusive_class is not None: raise Exception('Cannot grab the touch, touch is exclusive') 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 touch ''' 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 move(self, args): '''Move the touch to another position ''' self.px = self.x self.py = self.y self.pz = self.z self.psx = self.sx self.psy = self.sy self.psz = 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 ''' sx, sy = self.sx, self.sy if rotation == 0: self.x = sx * float(w) self.y = sy * float(h) elif rotation == 90: sx, sy = sy, 1 - sx self.x = sx * float(h) self.y = sy * float(w) elif rotation == 180: sx, sy = 1 - sx, 1 - sy self.x = sx * float(w) self.y = sy * float(h) elif rotation == 270: sx, sy = 1 - sy, sx self.x = sx * float(h) self.y = sy * float(w) if p: self.z = self.sz * float(p) if smode: if smode == 'pan': self.y -= kheight elif smode == 'scale': self.y += (kheight * ( (self.y - kheight) / (h - kheight))) - kheight if self.ox is None: self.px = self.ox = self.x self.py = self.oy = self.y self.pz = self.oz = self.z 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 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 apply_transform_2d(self, transform): '''Apply a transformation on x, y, z, px, py, pz, ox, oy, oz, dx, dy, dz ''' self.x, self.y = self.pos = transform(self.x, self.y) self.px, self.py = transform(self.px, self.py) self.ox, self.oy = transform(self.ox, self.oy) self.dx = self.x - self.px self.dy = self.y - self.py
[docs] def copy_to(self, to): '''Copy some attribute to another touch object.''' for attr in self.__attrs__: to.__setattr__(attr, copy(self.__getattribute__(attr)))
[docs] def distance(self, other_touch): '''Return the distance between the current touch and another touch. ''' 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 touch in the screen coordinate system (self.ox, self.oy)''' return self.ox, self.oy @property def ppos(self): '''Return the previous position of the touch 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 is a mousewheel scrolling .. versionadded:: 1.6.0 ''' return 'button' in self.profile and 'scroll' in self.button