Improved formatting of image values under cursor when a colorbar is present

When a colorbar is present, its formatter is now used to format the image

values under the mouse cursor in the status bar. For example, for an image

displaying the values 10,000 and 10,001, the statusbar will now (using default

settings) display the values as ``0.0+1e4`` and ``1.0+1e4`` (or ``10000.0``

and ``10001.0`` if the offset-text is disabled on the colorbar), whereas both

values were previously displayed as ``1e+04``.

To format image values under the mouse cursor into the status bar, we now

use the image's colorbar formatter (creating a hidden one on-the-fly if

necessary). For example, for an image displaying the values 10,000 and

10,001, the statusbar will now (using default settings) display the values as

``0.0+1e4`` and ``1.0+1e4`` (or ``10000.0`` and ``10001.0`` if the offset-text

is disabled on colorbars), whereas both values were previously displayed as

``1e+04``.

returnarr[i,j]

defformat_cursor_data(self,data):

ifself.colorbar:

return ("["

+cbook.strip_math(self.colorbar.formatter(data))

+cbook.strip_math(self.colorbar.formatter.get_offset())

+"]")

else:

returnsuper().format_cursor_data(data)

ifnotself.colorbar:

frommatplotlib.figureimportFigure

fig=Figure()

ax=fig.subplots()

self.colorbar=fig.colorbar(self,cax=ax)

list(ax.yaxis.iter_ticks())

return ("["

+cbook.strip_math(self.colorbar.formatter(data))

+cbook.strip_math(self.colorbar.formatter.get_offset())

+"]")

classNonUniformImage(AxesImage):

xdisp,ydisp=ax.transData.transform_point([0,0])

event=MouseEvent('motion_notify_event',fig.canvas,xdisp,ydisp)

assertim.get_cursor_data(event)==10000

assertim.format_cursor_data(im.get_cursor_data(event))=="[1e+04]"

fig.colorbar(im)

fig.canvas.draw()# This is necessary to set up the colorbar formatter.

assertim.get_cursor_data(event)==10000

assertim.format_cursor_data(im.get_cursor_data(event))=="[0.0+1e4]"