按钮事件：on_press 或 on_release
on_press 和 on_release 事件可绑定到 Button 小部件。我们可以使用on_touch_down来模拟on_press事件，使用on_touch_up来模拟on_release事件。
事件：on_touch_down
使用 on_touch_down 事件，检查 touch 与我们的小部件的 碰撞，并检查 按钮配置文件 .如果按钮配置文件，检查鼠标按钮点击，或鼠标滚轮滚动（scrollup或scrolldown)。如果单击按钮，则抓取触摸事件，增加触摸事件计数器，然后开始重复缩放。
事件：on_touch_up
使用on_touch_up事件，检查触摸事件是否被抓取，如果被抓取则取消抓取触摸事件，减少触摸事件计数器，如果触摸事件计数器为零，则停止重复缩放。
片段
def on_touch_down(self, touch):
if self.collide_point(*touch.pos):
if 'button' in touch.profile:
if touch.button in ("right", "left"):
...
dist = 1 if touch.button == 'left' else -1
touch.grab(self)
self._touch_count += 1
...
return True
elif touch.is_mouse_scrolling:
dist = 1 if touch.button == 'scrollup' else -1
...
return True
return super(..., self).on_touch_down(touch)
def on_touch_up(self, touch):
if touch.grab_current == self:
touch.ungrab(self)
self._touch_count -= 1
if self._touch_count == 0:
print("\tanimate to the closest zoom")
return True
return super(RootWidget, self).on_touch_up(touch)
Programming Guide » Input management » Touch event basics
默认情况下，触摸事件被调度到所有当前显示的
小部件。这意味着无论是否发生，小部件都会接收到触摸事件
是否在他们的物理区域内。
为了提供最大的灵活性，Kivy 调度
所有小部件的事件，并让它们决定如何对它们做出反应。
如果您只想响应小部件内的触摸事件，您
只需检查碰撞。
Motion Event » Profiles
配置文件值：按钮
描述：鼠标按钮（‘左’，
'right'、'middle'、'scrollup' 或 'scrolldown'）。通过访问
按钮属性。
is_mouse_scrolling
如果触摸是鼠标滚轮滚动，则返回 True
示例
main.py
>
from math import sin
from kivy.garden.graph import Graph, MeshLinePlot
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import NumericProperty
class RootWidget(BoxLayout):
_touch_count = NumericProperty(0)
def __init__(self, **kwargs):
super(RootWidget, self).__init__(**kwargs)
self.graph = Graph(xlabel='X', ylabel='Y', x_ticks_minor=5,
x_ticks_major=25, y_ticks_major=1,
y_grid_label=True, x_grid_label=True, padding=5,
x_grid=True, y_grid=True, xmin=-0, xmax=100, ymin=-1, ymax=1)
plot = MeshLinePlot(color=[1, 0, 0, 1])
plot.points = [(x, sin(x / 10.)) for x in range(0, 101)]
self.graph.add_plot(plot)
self.add_widget(self.graph)
def on_touch_down(self, touch):
"""
If the touch falls inside of our widget, we check button profile. If mouse button click, we set dist to 1 for
left mouse button clicked else -1 for right mouse button clicked. If not mouse button click, we check for mouse
wheel scrolling. If mouse is scrolling, we set dist to 1 if scrollup else -1 for scrolldown. If mouse button
clicked or mouse wheel scrolling, we return True, indicating that we have consumed the touch and don’t want it
to propagate any further.
Finally, if the touch falls outside our widget, not mouse button clicked (left / right button clicked), or not
mouse wheel scrolling, we call the original event using super(…) and return the result. This allows the touch
event propagation to continue as it would normally have occurred.
:param touch:
:return:
"""
print("\non_touch_down:")
if self.collide_point(*touch.pos):
if 'button' in touch.profile:
if touch.button in ("right", "left"):
print("\t", touch.button, "mouse clicked")
print("\ttouch.pos =", touch.pos)
dist = 1 if touch.button == 'left' else -1
self.zoom(dist)
return True
elif touch.is_mouse_scrolling:
print("\tmouse wheel", touch.button)
print("\ttouch.pos =", touch.pos)
dist = 1 if touch.button == 'scrollup' else -1
self.zoom(dist)
return True
return super(RootWidget, self).on_touch_down(touch)
def on_touch_up(self, touch):
print("\non_touch_up:")
if touch.grab_current == self:
print("\ttouch.button is", touch.button)
print("\ttouch.pos is", touch.pos)
touch.ungrab(self)
self._touch_count -= 1
if self._touch_count == 0:
# TODO
print("\tanimate to the closest zoom")
return True
return super(RootWidget, self).on_touch_up(touch)
def zoom(self, dist):
self.graph.xmax += dist * 10
self.graph.xmin += dist
class GraphDemo(App):
def build(self):
return RootWidget()
if __name__ == "__main__":
GraphDemo().run()
输出