Make it easier to improve UI event metadata. · matplotlib/matplotlib@44b6055 · GitHub
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anntzeranntzer
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Make it easier to improve UI event metadata.
Currently, UI events (MouseEvent, KeyEvent, etc.) are generated by letting the GUI-specific backends massage the native event objects into a list of args/kwargs and then call `FigureCanvasBase.motion_notify_event`/`.key_press_event`/etc. This makes it a bit tricky to improve the metadata on the events, because one needs to change the signature on both the `FigureCanvasBase` method and the event class. Moreover, the `motion_notify_event`/etc. methods are directly bound as event handlers in the gtk3 and tk backends, and thus have incompatible signatures there. Instead, the native GUI handlers can directly construct the relevant event objects and trigger the events themselves; a new `Event.process` helper method makes this even shorter (and allows to keep factoring some common functionality e.g. for tracking the last pressed button or key). As an example, this PR also updates figure_leave_event to always correctly set the event location based on the *current* cursor position, instead of the last triggered location event (which may be outdated); this can now easily be done on a backend-by-backend basis, instead of coordinating the change with FigureCanvasBase.figure_leave_event. This also exposed another (minor) issue, in that resize events often trigger *two* calls to draw_idle -- one in the GUI-specific handler, and one in FigureCanvasBase.draw_idle (now moved to ResizeEvent.process, but should perhaps instead be a callback autoconnected to "resize_event") -- could probably be fixed later.
1 parent e050f6e commit 44b6055

11 files changed

Lines changed: 243 additions & 252 deletions

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‎doc/api/next_api_changes/deprecations.rst‎

Lines changed: 13 additions & 0 deletions

‎lib/matplotlib/artist.py‎

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -488,6 +488,7 @@ def pick(self, mouseevent):
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--------
489489
set_picker, get_picker, pickable
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"""
491+
from .backend_bases import PickEvent # Circular import.
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# Pick self
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if self.pickable():
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picker = self.get_picker()
@@ -496,7 +497,8 @@ def pick(self, mouseevent):
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else:
497498
inside, prop = self.contains(mouseevent)
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if inside:
499-
self.figure.canvas.pick_event(mouseevent, self, **prop)
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PickEvent("pick_event", self.figure.canvas,
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mouseevent, self, **prop).process()
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501503
# Pick children
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for a in self.get_children():

‎lib/matplotlib/backend_bases.py‎

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Original file line numberDiff line numberDiff line change
@@ -1191,11 +1191,16 @@ class Event:
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guiEvent
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The GUI event that triggered the Matplotlib event.
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"""
1194+
11941195
def __init__(self, name, canvas, guiEvent=None):
11951196
self.name = name
11961197
self.canvas = canvas
11971198
self.guiEvent = guiEvent
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1200+
def process(self):
1201+
"""Generate an event with name ``self.name`` on ``self.canvas``."""
1202+
self.canvas.callbacks.process(self.name, self)
1203+
11991204

12001205
class DrawEvent(Event):
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"""
@@ -1238,14 +1243,28 @@ class ResizeEvent(Event):
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height : int
12391244
Height of the canvas in pixels.
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"""
1246+
12411247
def __init__(self, name, canvas):
12421248
Event.__init__(self, name, canvas)
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self.width, self.height = canvas.get_width_height()
12441250

1251+
def process(self):
1252+
super().process()
1253+
self.canvas.draw_idle()
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12451255

12461256
class CloseEvent(Event):
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"""An event triggered by a figure being closed."""
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1259+
def process(self):
1260+
try:
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super().process()
1262+
except (AttributeError, TypeError):
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pass
1264+
# Suppress AttributeError/TypeError that occur when the python
1265+
# session is being killed. It may be that a better solution would
1266+
# be a mechanism to disconnect all callbacks upon shutdown.
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12491268

12501269
class LocationEvent(Event):
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"""
@@ -1360,11 +1379,16 @@ class MouseEvent(LocationEvent):
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Note that in the nbagg backend, both the middle and right clicks
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return RIGHT since right clicking will bring up the context menu in
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some browsers.
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Note that LEFT and RIGHT actually refer to the "primary" and
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"secondary" buttons, i.e. if the user inverts their left and right
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buttons ("left-handed setting") then the LEFT button will be the one
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physically on the right.
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1388+
If this is unset, *name* is "scroll_event", and and *step* is nonzero,
1389+
then this will be set to "up" or "down" depending on the sign of
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*step*.
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key : None or str
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The key pressed when the mouse event triggered, e.g. 'shift'.
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See `KeyEvent`.
@@ -1403,11 +1427,27 @@ def __init__(self, name, canvas, x, y, button=None, key=None,
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LocationEvent.__init__(self, name, canvas, x, y, guiEvent=guiEvent)
14041428
if button in MouseButton.__members__.values():
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button = MouseButton(button)
1430+
if name == "scroll_event" and button is None:
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if step > 0:
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button = "up"
1433+
elif step < 0:
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button = "down"
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self.button = button
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self.key = key
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self.step = step
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self.dblclick = dblclick
14101439

1440+
def process(self):
1441+
if self.name == "button_press_event":
1442+
self.canvas._button = self.button
1443+
elif self.name == "button_release_event":
1444+
self.canvas._button = None
1445+
if self.button is None and self.name != "scroll_event":
1446+
self.button = self.canvas._button
1447+
if self.key is None:
1448+
self.key = self.canvas._key
1449+
super().process()
1450+
14111451
def __str__(self):
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return (f"{self.name}: "
14131453
f"xy=({self.x}, {self.y}) xydata=({self.xdata}, {self.ydata}) "
@@ -1448,8 +1488,11 @@ def on_pick(event):
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14491489
cid = fig.canvas.mpl_connect('pick_event', on_pick)
14501490
"""
1491+
14511492
def __init__(self, name, canvas, mouseevent, artist,
14521493
guiEvent=None, **kwargs):
1494+
if guiEvent is None:
1495+
guiEvent = mouseevent.guiEvent
14531496
Event.__init__(self, name, canvas, guiEvent)
14541497
self.mouseevent = mouseevent
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self.artist = artist
@@ -1490,10 +1533,18 @@ def on_key(event):
14901533
14911534
cid = fig.canvas.mpl_connect('key_press_event', on_key)
14921535
"""
1536+
14931537
def __init__(self, name, canvas, key, x=0, y=0, guiEvent=None):
14941538
LocationEvent.__init__(self, name, canvas, x, y, guiEvent=guiEvent)
14951539
self.key = key
14961540

1541+
def process(self):
1542+
if self.name == "key_press_event":
1543+
self.canvas._key = self.key
1544+
elif self.name == "key_release_event":
1545+
self.canvas._key = None
1546+
super().process()
1547+
14971548

14981549
def _get_renderer(figure, print_method, *, draw_disabled=False):
14991550
"""
@@ -1651,12 +1702,14 @@ def blit(self, bbox=None):
16511702
def resize(self, w, h):
16521703
"""Set the canvas size in pixels."""
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1705+
@cbook.deprecated("3.3", alternative="DrawEvent(...).process()")
16541706
def draw_event(self, renderer):
16551707
"""Pass a `DrawEvent` to all functions connected to ``draw_event``."""
16561708
s = 'draw_event'
16571709
event = DrawEvent(s, self, renderer)
16581710
self.callbacks.process(s, event)
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1712+
@cbook.deprecated("3.3", alternative="ResizeEvent(...).process()")
16601713
def resize_event(self):
16611714
"""
16621715
Pass a `ResizeEvent` to all functions connected to ``resize_event``.
@@ -1666,6 +1719,7 @@ def resize_event(self):
16661719
self.callbacks.process(s, event)
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self.draw_idle()
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1722+
@cbook.deprecated("3.3", alternative="CloseEvent(...).process()")
16691723
def close_event(self, guiEvent=None):
16701724
"""
16711725
Pass a `CloseEvent` to all functions connected to ``close_event``.
@@ -1682,6 +1736,7 @@ def close_event(self, guiEvent=None):
16821736
# AttributeError occurs on OSX with qt4agg upon exiting
16831737
# with an open window; 'callbacks' attribute no longer exists.
16841738

1739+
@cbook.deprecated("3.3", alternative="KeyEvent(...).process()")
16851740
def key_press_event(self, key, guiEvent=None):
16861741
"""
16871742
Pass a `KeyEvent` to all functions connected to ``key_press_event``.
@@ -1692,6 +1747,7 @@ def key_press_event(self, key, guiEvent=None):
16921747
s, self, key, self._lastx, self._lasty, guiEvent=guiEvent)
16931748
self.callbacks.process(s, event)
16941749

1750+
@cbook.deprecated("3.3", alternative="KeyEvent(...).process()")
16951751
def key_release_event(self, key, guiEvent=None):
16961752
"""
16971753
Pass a `KeyEvent` to all functions connected to ``key_release_event``.
@@ -1702,6 +1758,7 @@ def key_release_event(self, key, guiEvent=None):
17021758
self.callbacks.process(s, event)
17031759
self._key = None
17041760

1761+
@cbook.deprecated("3.3", alternative="PickEvent(...).process()")
17051762
def pick_event(self, mouseevent, artist, **kwargs):
17061763
"""
17071764
Callback processing for pick events.
@@ -1715,6 +1772,7 @@ def pick_event(self, mouseevent, artist, **kwargs):
17151772
**kwargs)
17161773
self.callbacks.process(s, event)
17171774

1775+
@cbook.deprecated("3.3", alternative="MouseEvent(...).process()")
17181776
def scroll_event(self, x, y, step, guiEvent=None):
17191777
"""
17201778
Callback processing for scroll events.
@@ -1735,6 +1793,7 @@ def scroll_event(self, x, y, step, guiEvent=None):
17351793
step=step, guiEvent=guiEvent)
17361794
self.callbacks.process(s, mouseevent)
17371795

1796+
@cbook.deprecated("3.3", alternative="MouseEvent(...).process()")
17381797
def button_press_event(self, x, y, button, dblclick=False, guiEvent=None):
17391798
"""
17401799
Callback processing for mouse button press events.
@@ -1752,6 +1811,7 @@ def button_press_event(self, x, y, button, dblclick=False, guiEvent=None):
17521811
dblclick=dblclick, guiEvent=guiEvent)
17531812
self.callbacks.process(s, mouseevent)
17541813

1814+
@cbook.deprecated("3.3", alternative="MouseEvent(...).process()")
17551815
def button_release_event(self, x, y, button, guiEvent=None):
17561816
"""
17571817
Callback processing for mouse button release events.
@@ -1776,6 +1836,7 @@ def button_release_event(self, x, y, button, guiEvent=None):
17761836
self.callbacks.process(s, event)
17771837
self._button = None
17781838

1839+
@cbook.deprecated("3.3", alternative="MouseEvent(...).process()")
17791840
def motion_notify_event(self, x, y, guiEvent=None):
17801841
"""
17811842
Callback processing for mouse movement events.
@@ -1801,6 +1862,7 @@ def motion_notify_event(self, x, y, guiEvent=None):
18011862
guiEvent=guiEvent)
18021863
self.callbacks.process(s, event)
18031864

1865+
@cbook.deprecated("3.3", alternative="LocationEvent(...).process()")
18041866
def leave_notify_event(self, guiEvent=None):
18051867
"""
18061868
Callback processing for the mouse cursor leaving the canvas.
@@ -1817,6 +1879,7 @@ def leave_notify_event(self, guiEvent=None):
18171879
LocationEvent.lastevent = None
18181880
self._lastx, self._lasty = None, None
18191881

1882+
@cbook.deprecated("3.3", alternative="LocationEvent(...).process()")
18201883
def enter_notify_event(self, guiEvent=None, xy=None):
18211884
"""
18221885
Callback processing for the mouse cursor entering the canvas.

‎lib/matplotlib/backends/_backend_tk.py‎

Lines changed: 30 additions & 17 deletions

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