Kivy hover

This example show how to used a kivy hover. This kind of widget can easily be customize for your purpose. See hover widgets in the library and the examples to customize your widgets (link) Because it use kivy to render the cursor, it will not interfer with matplotlib draw or blit method. Nearest and compare hover can be also used in your matplotlib figure just like ploty library.

kivy_hover example

add_hover function

To activate the hover feature, you need to use the add_hover function. This can be import as follow:

from kivy_matplotlib_widget.uix.hover_widget import add_hover

This function require 1 input, the figure instance

add_hover(fig)

other options are also available with this function

mode (str) : mode behavior (option: 'touch', 'desktop'. Default 'touch')
hover_type : type of hover (option: 'nearest', 'compare'. Default 'nearest')
hover_widget : hover widget used (Default nearest: GeneralHover. Default compare: GeneralCompareHover)

kivy_matplotib_widget have several hover include

from kivy_matplotlib_widget.uix.hover_widget import (GeneralHover,
                                                    HoverVerticalText,
                                                    InfoHover,
                                                    GeneralCompareHover,
                                                    TagCompareHover,
                                                    MatplotlibStyleHover
                                                    )

Hover widget	Description
`GeneralHover`	General hover with vertical line (text is horizontal)
`HoverVerticalText`	hover with vertical text (x and y use 2 rows)
`InfoHover`	hover with extra information
`GeneralCompareHover`	General compare hover (all the values are inside a box)
`TagCompareHover`	Plotly look-a-like compar hover
`MatplotlibStyleHover`	hover like matplotlib cursor (horizontal and vertica line + text outside axis)

Note

If you want to customized a hover for your purpose, you can create a new hover widget base on the source code and use it into the add_hover function.

Example with nearest and compare hover

based on 'example_compare_hover' example

from kivy.utils import platform
from kivy.config import Config

#avoid conflict between mouse provider and touch (very important with touch device)
#no need for android platform
if platform != 'android':
    Config.set('input', 'mouse', 'mouse,disable_on_activity')
else:
    #for android, we remove mouse input to not get extra touch 
    Config.remove_option('input', 'mouse')

from kivy.lang import Builder
from kivy.app import App
from kivy_matplotlib_widget.uix.hover_widget import add_hover,HoverVerticalText,InfoHover,TagCompareHover
from matplotlib.ticker import FormatStrFormatter

#generate 2 figures
import matplotlib.pyplot as plt
fig, ax1 = plt.subplots(1, 1)
ax1.plot([0,1,2,3], [1,2,8,9],label='line1')
ax1.plot([0,1,2,3,4], [10,11,8.1,20,21],label='line2')
ax1.plot([0,1,2,3,4], [10,10.5,8.2,25,15],label='line3')
fig.subplots_adjust(left=0.13,top=0.9,right=0.93,bottom=0.2)

fig2, ax2 = plt.subplots(1, 1)
ax2.plot([0,1,2,3], [1,2,8,9],label='line1')
ax2.plot([0,1,2,3,4], [10,11,8.1,20,21],label='line2')
ax2.plot([0,1,2,3,4], [10,10.5,8.2,25,15],label='line3')
fig2.subplots_adjust(left=0.13,top=0.9,right=0.93,bottom=0.2)

KV = '''
Screen
    figure_wgt:figure_wgt
    figure_wgt2:figure_wgt2
    BoxLayout:
        orientation:'vertical'
        BoxLayout:
            size_hint_y:0.15
            Button:
                text:"home"
                on_release:app.home()
            ToggleButton:
                group:'touch_mode'
                state:'down'
                text:"pan" 
                on_release:
                    app.set_touch_mode('pan')
                    self.state='down'
            ToggleButton:
                group:'touch_mode'
                text:"zoom box"  
                on_release:
                    app.set_touch_mode('zoombox')
                    self.state='down'  

        BoxLayout:
            size_hint_y:0.15
            ToggleButton:
                group:'hover_mode'
                text:"nearest hover"  
                on_release:
                    app.change_hover_type('nearest')
                    self.state='down' 
            ToggleButton:
                group:'hover_mode'
                text:"compare hover"  
                state:'down'
                on_release:
                    app.change_hover_type('compare')
                    self.state='down'                    

        MatplotFigure:
            id:figure_wgt 

        MatplotFigure:
            id:figure_wgt2                   
'''

class Test(App):

    def build(self):  
        self.screen=Builder.load_string(KV)
        return self.screen

    def on_start(self, *args):
        self.screen.figure_wgt.figure = fig

        ax=self.screen.figure_wgt.figure.axes[0]
        self.screen.figure_wgt.register_lines(list(ax.get_lines()))
        ax.set_title('General compare hover')

        #set x/y formatter for hover data
        self.screen.figure_wgt.cursor_xaxis_formatter = FormatStrFormatter('%.2f')
        self.screen.figure_wgt.cursor_yaxis_formatter = FormatStrFormatter('%.1f')  

        #add compare hover
        add_hover(self.screen.figure_wgt,mode='desktop',hover_type='compare')        

        ##figure2
        self.screen.figure_wgt2.figure = fig2

        ax=self.screen.figure_wgt2.figure.axes[0]
        self.screen.figure_wgt2.register_lines(list(ax.get_lines()))
        ax.set_title('Tag compare hover')

        #set x/y formatter for hover data
        self.screen.figure_wgt2.cursor_xaxis_formatter = FormatStrFormatter('%.2f')
        self.screen.figure_wgt2.cursor_yaxis_formatter = FormatStrFormatter('%.1f')  

        #add compare hover
        add_hover(self.screen.figure_wgt2,mode='desktop',hover_type='compare',hover_widget=TagCompareHover()) 

    def set_touch_mode(self,mode):
        self.screen.figure_wgt.touch_mode=mode
        self.screen.figure_wgt2.touch_mode=mode

    def home(self):
        self.screen.figure_wgt.home()
        self.screen.figure_wgt2.home()

    def change_hover_type(self,hover_type):
        add_hover(self.screen.figure_wgt,mode='desktop',hover_type=hover_type)
        add_hover(self.screen.figure_wgt2,mode='desktop',hover_type=hover_type)

Test().run()

Kivy hover

add_hover function

available hover widget

Example with nearest and compare hover