Custom extension of BoxZoomTool

Following the discussion here, I decided to attempt creating a custom extension for the BoxZoomTool, adding a property that would change when the zoom completed, to be able to call a Python callback for on_change events (x_range and y_range on_change fired too many events, and caused strange image updating for my app). I followed the User Guide to create a custom.ts and then created an instance and passed it to the Figure. The Bokeh app itself is working, but I don’t get any difference (i.e. my custom _pan_end event doesn’t seem to fire, no console log output). I’m sure I’m doing something wrong with calling _pan_end, but I’m not sure which other BoxZoomTool method to override.

custom.ts:

import * as p from “core/properties”

import {BoxZoomTool, BoxZoomToolView} from “models/tools/gestures/box_zoom_tool”

import {GestureTool, GestureToolView} from “./gesture_tool”

export class CustomView extends BoxZoomToolView{

_pan_end(e){

	super._pan_end(e)

	console.log("Made it to _pan_end")

	console.log($(this.mode.zoom_end))

	this.model.zoom_end = !this.model.zoom_end

	console.log($(this.mode.zoom_end))

}

}

export class Custom extends BoxZoomTool{

default_view: BoxZoomToolView

type: "Custom"

tool_name: "Custom Box Zoom"

}

Custom.define({

zoom_end: [p.Bool, false ]

})

``

run_custom.py

#!/usr/bin python

import numpy as np

from bokeh.io import curdoc

from bokeh.layouts import layout

from bokeh.models import Slider, Button, BoxZoomTool

from bokeh.plotting import figure, ColumnDataSource

from bokeh.core.properties import Bool

from bokeh.util.compiler import TypeScript

class Custom(BoxZoomTool):

__implementation__ = "custom.ts" #TypeScript(JS_CODE)

zoom_end = Bool(default=False)

custom = Custom(zoom_end=False)

p =figure(tools = [custom])

p.line([1,2,3],[1,2,3])

i = 0

def zoom_end_update(attr,old,new):

i += 1

print str(i) + ' Zoom ended!!!!'

custom.on_change(‘zoom_end’,zoom_end_update)

#slider = Slider(start=0, end=10, value=1, step=.1, title=“Stuff”)

curdoc().add_root§

``

OK, it was a stupid mistake, in the coffee script my default_view was still pointing at BoxZoomToolView instead of CustomView. Works great now.

···

On Wednesday, August 30, 2017 at 5:28:40 PM UTC-4, MichaelC wrote:

Following the discussion here, I decided to attempt creating a custom extension for the BoxZoomTool, adding a property that would change when the zoom completed, to be able to call a Python callback for on_change events (x_range and y_range on_change fired too many events, and caused strange image updating for my app). I followed the User Guide to create a custom.ts and then created an instance and passed it to the Figure. The Bokeh app itself is working, but I don’t get any difference (i.e. my custom _pan_end event doesn’t seem to fire, no console log output). I’m sure I’m doing something wrong with calling _pan_end, but I’m not sure which other BoxZoomTool method to override.

custom.ts:

import * as p from “core/properties”

import {BoxZoomTool, BoxZoomToolView} from “models/tools/gestures/box_zoom_tool”

import {GestureTool, GestureToolView} from “./gesture_tool”

export class CustomView extends BoxZoomToolView{

_pan_end(e){

  super._pan_end(e)
  console.log("Made it to _pan_end")
  console.log($(this.mode.zoom_end))
  this.model.zoom_end = !this.model.zoom_end
  console.log($(this.mode.zoom_end))

}

}

export class Custom extends BoxZoomTool{

default_view: BoxZoomToolView

type: “Custom”

tool_name: “Custom Box Zoom”

}

Custom.define({

zoom_end: [p.Bool, false ]

})

``

run_custom.py

#!/usr/bin python

import numpy as np

from bokeh.io import curdoc

from bokeh.layouts import layout

from bokeh.models import Slider, Button, BoxZoomTool

from bokeh.plotting import figure, ColumnDataSource

from bokeh.core.properties import Bool

from bokeh.util.compiler import TypeScript

class Custom(BoxZoomTool):

implementation = “custom.ts” #TypeScript(JS_CODE)

zoom_end = Bool(default=False)

custom = Custom(zoom_end=False)

p =figure(tools = [custom])

p.line([1,2,3],[1,2,3])

i = 0

def zoom_end_update(attr,old,new):

i += 1

print str(i) + ’ Zoom ended!!!’

custom.on_change(‘zoom_end’,zoom_end_update)

#slider = Slider(start=0, end=10, value=1, step=.1, title=“Stuff”)

curdoc().add_root§

``