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Merged
merged 2 commits into from
Aug 27, 2015
Merged

ENH: Add API to manage view state in custom Axes. #4795

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eb80fe5
ENH: Add API to manage view state in custom Axes.
QuLogic Jul 26, 2015
7e582b1
ENH: Allow custom Axes to implement zoom-to-rect.
QuLogic Jul 28, 2015
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161 changes: 161 additions & 0 deletions lib/matplotlib/axes/_base.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3132,6 +3132,167 @@ def set_navigate_mode(self, b):
"""
self._navigate_mode = b

def _get_view(self):
"""
Save information required to reproduce the current view.

Called before a view is changed, such as during a pan or zoom
initiated by the user. You may return any information you deem
necessary to describe the view.

.. note::

Intended to be overridden by new projection types, but if not, the
default implementation saves the view limits. You *must* implement
:meth:`_set_view` if you implement this method.
"""
xmin, xmax = self.get_xlim()
ymin, ymax = self.get_ylim()
return (xmin, xmax, ymin, ymax)

def _set_view(self, view):
"""
Apply a previously saved view.

Called when restoring a view, such as with the navigation buttons.

.. note::

Intended to be overridden by new projection types, but if not, the
default implementation restores the view limits. You *must*
implement :meth:`_get_view` if you implement this method.
"""
xmin, xmax, ymin, ymax = view
self.set_xlim((xmin, xmax))
self.set_ylim((ymin, ymax))

def _set_view_from_bbox(self, bbox, original_view, direction='in',
mode=None, twinx=False, twiny=False):
"""
Update view from a selection bbox.

.. note::

Intended to be overridden by new projection types, but if not, the
default implementation sets the view limits to the bbox directly.

Parameters
----------

bbox : tuple
The selected bounding box limits, in *display* coordinates.

original_view : any
A view saved from before initiating the selection, the result of
calling :meth:`_get_view`.

direction : str
The direction to apply the bounding box.
* `'in'` - The bounding box describes the view directly, i.e.,
it zooms in.
* `'out'` - The bounding box describes the size to make the
existing view, i.e., it zooms out.

mode : str or None
The selection mode, whether to apply the bounding box in only the
`'x'` direction, `'y'` direction or both (`None`).

twinx : bool
Whether this axis is twinned in the *x*-direction.

twiny : bool
Whether this axis is twinned in the *y*-direction.
"""

lastx, lasty, x, y = bbox

x0, y0, x1, y1 = original_view
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I'm not really sure why it's necessary to use the frozen view here. Unlike pan/zoom mode, with zoom-to-rect, there's only one time that the view can change (when the button's released), so I wonder if I can just use the existing view limits here?

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@tacaswell before merging this, can you confirm that this doesn't have any bad side effects?
I have tested it, and it works fine, but I'm not sure that frozen isn't necessary.


# zoom to rect
inverse = self.transData.inverted()
lastx, lasty = inverse.transform_point((lastx, lasty))
x, y = inverse.transform_point((x, y))
Xmin, Xmax = self.get_xlim()
Ymin, Ymax = self.get_ylim()

if twinx:
x0, x1 = Xmin, Xmax
else:
if Xmin < Xmax:
if x < lastx:
x0, x1 = x, lastx
else:
x0, x1 = lastx, x
if x0 < Xmin:
x0 = Xmin
if x1 > Xmax:
x1 = Xmax
else:
if x > lastx:
x0, x1 = x, lastx
else:
x0, x1 = lastx, x
if x0 > Xmin:
x0 = Xmin
if x1 < Xmax:
x1 = Xmax

if twiny:
y0, y1 = Ymin, Ymax
else:
if Ymin < Ymax:
if y < lasty:
y0, y1 = y, lasty
else:
y0, y1 = lasty, y
if y0 < Ymin:
y0 = Ymin
if y1 > Ymax:
y1 = Ymax
else:
if y > lasty:
y0, y1 = y, lasty
else:
y0, y1 = lasty, y
if y0 > Ymin:
y0 = Ymin
if y1 < Ymax:
y1 = Ymax

if direction == 'in':
if mode == 'x':
self.set_xlim((x0, x1))
elif mode == 'y':
self.set_ylim((y0, y1))
else:
self.set_xlim((x0, x1))
self.set_ylim((y0, y1))
elif direction == 'out':
if self.get_xscale() == 'log':
alpha = np.log(Xmax / Xmin) / np.log(x1 / x0)
rx1 = pow(Xmin / x0, alpha) * Xmin
rx2 = pow(Xmax / x0, alpha) * Xmin
else:
alpha = (Xmax - Xmin) / (x1 - x0)
rx1 = alpha * (Xmin - x0) + Xmin
rx2 = alpha * (Xmax - x0) + Xmin
if self.get_yscale() == 'log':
alpha = np.log(Ymax / Ymin) / np.log(y1 / y0)
ry1 = pow(Ymin / y0, alpha) * Ymin
ry2 = pow(Ymax / y0, alpha) * Ymin
else:
alpha = (Ymax - Ymin) / (y1 - y0)
ry1 = alpha * (Ymin - y0) + Ymin
ry2 = alpha * (Ymax - y0) + Ymin

if mode == 'x':
self.set_xlim((rx1, rx2))
elif mode == 'y':
self.set_ylim((ry1, ry2))
else:
self.set_xlim((rx1, rx2))
self.set_ylim((ry1, ry2))

def start_pan(self, x, y, button):
"""
Called when a pan operation has started.
Expand Down
114 changes: 16 additions & 98 deletions lib/matplotlib/backend_bases.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2925,8 +2925,7 @@ def press_zoom(self, event):
for i, a in enumerate(self.canvas.figure.get_axes()):
if (x is not None and y is not None and a.in_axes(event) and
a.get_navigate() and a.can_zoom()):
self._xypress.append((x, y, a, i, a.viewLim.frozen(),
a.transData.frozen()))
self._xypress.append((x, y, a, i, a._get_view()))

id1 = self.canvas.mpl_connect('motion_notify_event', self.drag_zoom)
id2 = self.canvas.mpl_connect('key_press_event',
Expand All @@ -2949,17 +2948,15 @@ def _switch_off_zoom_mode(self, event):

def push_current(self):
"""push the current view limits and position onto the stack"""
lims = []
views = []
pos = []
for a in self.canvas.figure.get_axes():
xmin, xmax = a.get_xlim()
ymin, ymax = a.get_ylim()
lims.append((xmin, xmax, ymin, ymax))
views.append(a._get_view())
# Store both the original and modified positions
pos.append((
a.get_position(True).frozen(),
a.get_position().frozen()))
self._views.push(lims)
self._views.push(views)
self._positions.push(pos)
self.set_history_buttons()

Expand Down Expand Up @@ -2999,7 +2996,7 @@ def drag_zoom(self, event):

if self._xypress:
x, y = event.x, event.y
lastx, lasty, a, ind, lim, trans = self._xypress[0]
lastx, lasty, a, ind, view = self._xypress[0]

# adjust x, last, y, last
x1, y1, x2, y2 = a.bbox.extents
Expand Down Expand Up @@ -3028,23 +3025,14 @@ def release_zoom(self, event):

for cur_xypress in self._xypress:
x, y = event.x, event.y
lastx, lasty, a, ind, lim, trans = cur_xypress
lastx, lasty, a, ind, view = cur_xypress
# ignore singular clicks - 5 pixels is a threshold
if abs(x - lastx) < 5 or abs(y - lasty) < 5:
self._xypress = None
self.release(event)
self.draw()
return

x0, y0, x1, y1 = lim.extents

# zoom to rect
inverse = a.transData.inverted()
lastx, lasty = inverse.transform_point((lastx, lasty))
x, y = inverse.transform_point((x, y))
Xmin, Xmax = a.get_xlim()
Ymin, Ymax = a.get_ylim()

# detect twinx,y axes and avoid double zooming
twinx, twiny = False, False
if last_a:
Expand All @@ -3055,83 +3043,15 @@ def release_zoom(self, event):
twiny = True
last_a.append(a)

if twinx:
x0, x1 = Xmin, Xmax
else:
if Xmin < Xmax:
if x < lastx:
x0, x1 = x, lastx
else:
x0, x1 = lastx, x
if x0 < Xmin:
x0 = Xmin
if x1 > Xmax:
x1 = Xmax
else:
if x > lastx:
x0, x1 = x, lastx
else:
x0, x1 = lastx, x
if x0 > Xmin:
x0 = Xmin
if x1 < Xmax:
x1 = Xmax

if twiny:
y0, y1 = Ymin, Ymax
else:
if Ymin < Ymax:
if y < lasty:
y0, y1 = y, lasty
else:
y0, y1 = lasty, y
if y0 < Ymin:
y0 = Ymin
if y1 > Ymax:
y1 = Ymax
else:
if y > lasty:
y0, y1 = y, lasty
else:
y0, y1 = lasty, y
if y0 > Ymin:
y0 = Ymin
if y1 < Ymax:
y1 = Ymax

if self._button_pressed == 1:
if self._zoom_mode == "x":
a.set_xlim((x0, x1))
elif self._zoom_mode == "y":
a.set_ylim((y0, y1))
else:
a.set_xlim((x0, x1))
a.set_ylim((y0, y1))
direction = 'in'
elif self._button_pressed == 3:
if a.get_xscale() == 'log':
alpha = np.log(Xmax / Xmin) / np.log(x1 / x0)
rx1 = pow(Xmin / x0, alpha) * Xmin
rx2 = pow(Xmax / x0, alpha) * Xmin
else:
alpha = (Xmax - Xmin) / (x1 - x0)
rx1 = alpha * (Xmin - x0) + Xmin
rx2 = alpha * (Xmax - x0) + Xmin
if a.get_yscale() == 'log':
alpha = np.log(Ymax / Ymin) / np.log(y1 / y0)
ry1 = pow(Ymin / y0, alpha) * Ymin
ry2 = pow(Ymax / y0, alpha) * Ymin
else:
alpha = (Ymax - Ymin) / (y1 - y0)
ry1 = alpha * (Ymin - y0) + Ymin
ry2 = alpha * (Ymax - y0) + Ymin

if self._zoom_mode == "x":
a.set_xlim((rx1, rx2))
elif self._zoom_mode == "y":
a.set_ylim((ry1, ry2))
else:
a.set_xlim((rx1, rx2))
a.set_ylim((ry1, ry2))
direction = 'out'
else:
continue

a._set_view_from_bbox((lastx, lasty, x, y), view, direction,
self._zoom_mode, twinx, twiny)

self.draw()
self._xypress = None
Expand Down Expand Up @@ -3164,16 +3084,14 @@ def _update_view(self):
position stack for each axes
"""

lims = self._views()
if lims is None:
views = self._views()
if views is None:
return
pos = self._positions()
if pos is None:
return
for i, a in enumerate(self.canvas.figure.get_axes()):
xmin, xmax, ymin, ymax = lims[i]
a.set_xlim((xmin, xmax))
a.set_ylim((ymin, ymax))
a._set_view(views[i])
# Restore both the original and modified positions
a.set_position(pos[i][0], 'original')
a.set_position(pos[i][1], 'active')
Expand Down
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