Raspberry 上的 Kivy：光标在 window 之外

Question

我正在使用 Python3 和 Kivy 1.11.0dev 在我的 RaspberryPi 3 上开发一个 GUI。 GUI 正在运行，它在启动后运行全屏显示（据我所知，自 Kivy 1.9.x 不可能运行 Kivy 应用程序作为 window) 并且鼠标光标可见。现在唯一的问题是，如果用户向左、向右、向上或向下移动太远，则可能会将鼠标移出可见区域。如果出现这种情况，就很难让光标回到可见区域。

我尝试了很多方法来防止这种情况发生或自动将光标移回 window 但没有成功。在类似的帖子中，我尝试了这样的事情：

Window.bind(on_cursor_leave=self.on_leave)

def on_leave(self, *args):
    if self.hold:
    print('Cursor leaved Window')
    # call api calls here

我也试过抢鼠标

Window.bind(grab_mouse=self.on_leave)

有没有人有办法在离开后将光标放回可见区域，或者在光标不能离开的地方设置边框？

编辑：也许这个输出有帮助：

[INFO   ] [Logger      ] Record log in /home/pi/.kivy/logs/kivy_18-07-30_8.txt
[INFO   ] [Image       ] Providers: img_tex, img_dds, img_sdl2, img_pil, img_gif (img_ffpyplayer ignored)
[INFO   ] [Kivy        ] v1.11.0.dev0, git-0471549, 20180720
[INFO   ] [Python      ] v3.4.2 (default, Oct 19 2014, 13:31:11) 
[GCC 4.9.1]
[INFO   ] [KivyMD      ] KivyMD version: 0.1.2
[INFO   ] [Factory     ] 194 symbols loaded
[INFO   ] [Text        ] Provider: sdl2
[INFO   ] [Window      ] Provider: egl_rpi
[INFO   ] [GL          ] Using the "OpenGL ES 2" graphics system
[INFO   ] [GL          ] Backend used <gl>
[INFO   ] [GL          ] OpenGL version <b'OpenGL ES 2.0'>
[INFO   ] [GL          ] OpenGL vendor <b'Broadcom'>
[INFO   ] [GL          ] OpenGL renderer <b'VideoCore IV HW'>
[INFO   ] [GL          ] OpenGL parsed version: 2, 0
[INFO   ] [GL          ] Shading version <b'OpenGL ES GLSL ES 1.00'>
[INFO   ] [GL          ] Texture max size <2048>
[INFO   ] [GL          ] Texture max units <8>
[INFO   ] [Window      ] virtual keyboard not allowed, single mode, not docked
[INFO   ] [GL          ] NPOT texture support is available
xclip version 0.12
Copyright (C) 2001-2008 Kim Saunders et al.
Distributed under the terms of the GNU GPL
[INFO   ] [Clipboard   ] Provider: xclip
[INFO   ] [CutBuffer   ] cut buffer support enabled
[INFO   ] [ProbeSysfs  ] device match: /dev/input/event0
[INFO   ] [HIDInput    ] Read event from </dev/input/event0>
[INFO   ] [ProbeSysfs  ] device match: /dev/input/event1
[INFO   ] [HIDInput    ] Read event from </dev/input/event1>
[INFO   ] [Base        ] Start application main loop
[INFO   ] [HIDMotionEvent] using <b'MLK USB Composite Device\x00                                                                                                                                                                                                                                       '>
[INFO   ] [HIDMotionEvent] using <b'MLK USB Composite Device\x00

Answer 1

解决方案

在构造函数 __init__() 中，将 on_cursor_leave 事件绑定到回调方法，例如cursor_leave().
在 cursor_leave() 方法中使用 Window.grab_mouse()。详情请参考示例

片段

class GrabMouseDemo(Label):

    def __init__(self, **kwargs):
        super(GrabMouseDemo, self).__init__(**kwargs)
        Window.bind(mouse_pos=self.mouse_pos)
        Window.bind(on_cursor_leave=self.cursor_leave)

Window » grab_mouse()

grab_mouse()
Grab mouse - so won’t leave window

Note

This feature requires the SDL2 window provider.

例子

from kivy.app import App
from kivy.uix.label import Label
from kivy.core.window import Window


class GrabMouseDemo(Label):

    def __init__(self, **kwargs):
        super(GrabMouseDemo, self).__init__(**kwargs)
        Window.bind(mouse_pos=self.mouse_pos)
        Window.bind(on_cursor_leave=self.cursor_leave)

    def mouse_pos(self, window, pos):
        self.text = str(pos)

    def cursor_leave(self, window):
        print("cursor_leave:")
        Window.grab_mouse()


class TestApp(App):
    title = "Kivy Grab Mouse Demo"

    def build(self):
        return GrabMouseDemo()


if __name__ == "__main__":
    TestApp().run()

输出

Answer 2

此时我的做法是：

class WSRMEGUI(BoxLayout):
    ...

    def __init__(self, **kwargs):
        super(WSRMEGUI, self).__init__(**kwargs)
        Window.bind(mouse_pos=self.mouse_pos)

    def mouse_pos(self, window, pos):
        poswidth = int(pos[0])
        posheight = int(pos[1])
        winwidth = int(window.width)
        winheight = int(window.height)


        if poswidth <= 0:
            Window.grab_mouse()
        if poswidth > winwidth:
            Window.grab_mouse()
        if posheight < 0:
            Window.grab_mouse()
        if posheight > winheight:
            Window.grab_mouse()

所以如果光标离开 window

Window.grab_mouse()

每次都调用但没有任何效果...有没有办法在他离开允许区域时将光标设置回window？

Answer 3

好的，我解决了问题。这不是我最喜欢的解决方案，但它有效：

# Set mouse back to visible window when leaving 1920x1080
def mouse_pos(self, window, pos):
    try:
        #pos_width = int(pos[0])
        #pos_height = int(pos[1])

        if int(pos[0]) <= 0:                # Mouse outside, LEFT
            window.mouse_pos = (5, int(pos[1]))
        if int(pos[0]) > self.win_width:    # Mouse outside, RIGHT
            window.mouse_pos = (1900, int(pos[1]))
        if int(pos[1]) < 0:                 # Mouse outside, BOTTOM
            window.mouse_pos = (int(pos[0]), 20)
        if int(pos[1]) > self.win_height:   # Mouse outside, TOP
            window.mouse_pos = (int(pos[0]), 1060)

他离开window时光标向后移动。

Raspberry 上的 Kivy：光标在 window 之外

Kivy on Raspberry: Cursor is outside of window

python

kivy

raspberry-pi3

解决方案

片段

例子

输出