散景服务器获取鼠标位置 [英] bokeh server get mouse position

问题描述

我正在开发一个具有bokeh(0.12.2)的交互式应用程序，该应用程序可根据特定的交互更新地块.

I am developing an interactive app with bokeh (0.12.2) that updates plots based on specific interactions.

目前，我使用滑块更改图形中字形的位置，但实际上我想访问特定图形中鼠标的位置.

For now I use sliders to change positions of a glyph in a plot, but I actually want to access the position of my mouse within a specific plot.

数据集是多维矩阵(张量)，密集数据，每个图在特定位置显示一个维.如果更改一个图上标记字形的位置，则需要更新其他图，这意味着我必须根据更新后的位置对数据集进行切片.

The dataset is a multidimensional matrix (tensor), dense data, and each plot displays one dimension at a specific location. If I change the position of the marker glyph on one plot, the other plots need to be updated, which means I have to slice my dataset according to the updated position.

这是一个简单的示例，我试图使用悬停工具在bokeh服务器更新功能中获取鼠标数据:

Here's a simple example I tried to get the mouse data in my bokeh server update function using the hover tool:

from bokeh.plotting import figure, ColumnDataSource
from bokeh.models import CustomJS, HoverTool
from bokeh.io import curdoc

s = ColumnDataSource(data=dict(x=[0, 1], y=[0, 1]))
callback = CustomJS(args=dict(s=s), code="""
        var geometry = cb_data['geometry'];
        var mouse_x = geometry.x;
        var mouse_y = geometry.y;
        var x = s.get('data')['x'];
        var y = s.get('data')['y'];
        x[0] = mouse_x;
        y[0] = mouse_y;
        s.trigger('change');
    """)
hover_tool = HoverTool(callback=callback)
p = figure(x_range=(0, 1), y_range=(0, 1), tools=[hover_tool])
p.circle(x='x', y='y', source=s)


def update():
    print s.data

curdoc().add_root(p)
curdoc().add_periodic_callback(update, 1000)

不幸的是，服务器仅输出:

Unfortunately, the server only outputs:

{'y':[0，1]，'x':[0，1]}

{'y': [0, 1], 'x': [0, 1]}

{'y':[0，1]，'x':[0，1]}

{'y': [0, 1], 'x': [0, 1]}

{'y':[0，1]，'x':[0，1]}

{'y': [0, 1], 'x': [0, 1]}

{'y':[0，1]，'x':[0，1]}

{'y': [0, 1], 'x': [0, 1]}

是否有一种方法可以访问鼠标位置(在python代码中)?甚至访问一个字形的位置就足够了(因为我可以使用一些javascript代码来更改该字形的位置).

Is there a way to access the mouse position (in python code)? Even accessing the position of a glyph would be sufficient (because I can change the position of the glyph with some javascript code).

编辑:所以我最近发现可以使用此 tool_events.on_change().不幸的是，它仅适用于 TapTool ， LassoSelectTool 和 BoxSelectTool ，不适用于 HoverTool :

EDIT: So I recently found out that there is this tool_events.on_change() that I could use for this purpose. Unfortunately it does only work for TapTool, LassoSelectTool and BoxSelectTool, not for HoverTool:

from bokeh.plotting import figure
from bokeh.io import curdoc
from bokeh.models.tools import BoxSelectTool, TapTool, HoverTool, LassoSelectTool
from bokeh.models.ranges import Range1d

TOOLS = [TapTool(), LassoSelectTool(), BoxSelectTool(), HoverTool()]
p = figure(tools=TOOLS,
           x_range=Range1d(start=0.0, end=10.0),
           y_range=Range1d(start=0.0, end=10.0))

def tool_events_callback(attr, old, new):
    print attr, 'callback', new

p.tool_events.on_change('geometries', tool_events_callback)
curdoc().add_root(p)

基于我在这里找到的答案:

Based on an answer I found here: How can I get data from a ColumnDataSource object which is synchronized with local variables of Bokeh's CustomJS function?. The problem with this solution is that I cannot use pan and trigger the tool_events callback. I can only click (TapTool) or pan and trigger a callback only once (Lasso/BoxSelectTool). I actually wish to trigger such a callback on every mouse move..

推荐答案

所以我最近发现您可以为此使用自定义模型.这意味着扩展现有工具，例如GestureTool，但实现/覆盖您自己的功能.您需要运行bokeh服务器(显然).

So I recently found out that you can use custom models for this purpose. This means, extending an existing tool, e.g. GestureTool but implementing / overriding your own functions. You need to run a bokeh server (obviously).

$ bokeh serve dir_with_mainfile/

我现在使用的是以下内容: 创建文件MouseMoveTool.py:

What I am using right now is the following: Create a file MouseMoveTool.py:

from bokeh.models import Tool
class MouseMoveTool(Tool):
    # assuming your models are saved in subdirectory models/
    with open('models/MouseMoveTool.coffee', 'r') as f:
        controls = f.read()
    __implementation__ = controls

然后创建MouseMoveTool.coffee:

Then create MouseMoveTool.coffee:

p = require "core/properties"
GestureTool = require "models/tools/gestures/gesture_tool"

class MouseMoveToolView extends GestureTool.View
     ### Override the _pan function ###
     _pan: (e) ->
        frame = @plot_model.frame
        canvas = @plot_view.canvas

        vx = canvas.sx_to_vx(e.bokeh.sx)
        vy = canvas.sy_to_vy(e.bokeh.sy)
        if not frame.contains(vx, vy)
            return null

        # x and y are your mouse coordinates relative to the axes values
        x = frame.x_mappers.default.map_from_target(vx)
        y = frame.y_mappers.default.map_from_target(vy)

        # update the model's geometry attribute. this will trigger
        # the tool_events.on_change('geometries', ..) callback
        # in your python code.
        @plot_model.plot.tool_events.geometries = [{x:x, y:y}]

class MouseMoveTool extends GestureTool.Model
    default_view: MouseMoveToolView
    type: "MouseMoveTool"

    tool_name: "Mouse Move Tool"
    icon: "bk-tool-icon-pan"
    event_type: "pan"
    default_order: 13

module.exports =
    Model: MouseMoveTool
    View: MouseMoveToolView

之后，您可以在main.py程序中使用您的工具:

After that you can use your tool in your main.py program:

from models.MouseMoveTool import MouseMoveTool
p = figure(plot_width=300, plot_height=300, tools=[MouseMoveTool()])
p.tool_events.on_change('geometries', on_mouse_move)

def on_mouse_move(attr, old, new):
    print new[0] # will print {x:.., y:..} coordinates

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