Abstract base classes define the primitives that renderers and graphics contexts must implement to serve as a matplotlib backend
Bases: matplotlib.backend_bases.Event
An event triggered by a figure being closed
In addition to the Event attributes, the following event attributes are defined:
Bases: object
Bases: matplotlib.backend_bases.Event
An event triggered by a draw operation on the canvas
In addition to the Event attributes, the following event attributes are defined:
Bases: object
A matplotlib event. Attach additional attributes as defined in FigureCanvasBase.mpl_connect(). The following attributes are defined and shown with their default values
Bases: object
The canvas the figure renders into.
Public attributes
- figure
- A matplotlib.figure.Figure instance
blit the canvas in bbox (default entire canvas)
Backend derived classes should call this function on any mouse button press. x,y are the canvas coords: 0,0 is lower, left. button and key are as defined in MouseEvent.
This method will be call all functions connected to the ‘button_press_event’ with a MouseEvent instance.
Backend derived classes should call this function on any mouse button release.
This method will be call all functions connected to the ‘button_release_event’ with a MouseEvent instance.
This method will be called by all functions connected to the ‘close_event’ with a CloseEvent
Draw a cursor in the event.axes if inaxes is not None. Use native GUI drawing for efficiency if possible
This method will be call all functions connected to the ‘draw_event’ with a DrawEvent
Backend derived classes should call this function when entering canvas
Flush the GUI events for the figure. Implemented only for backends with GUIs.
Return a string, which includes extension, suitable for use as a default filename.
Get the default savefig file format as specified in rcParam savefig.format. Returned string excludes period. Overridden in backends that only support a single file type.
Return dict of savefig file formats supported by this backend
Return a dict of savefig file formats supported by this backend, where the keys are a file type name, such as ‘Joint Photographic Experts Group’, and the values are a list of filename extensions used for that filetype, such as [‘jpg’, ‘jpeg’].
Return the figure width and height in points or pixels (depending on the backend), truncated to integers
Get the title text of the window containing the figure. Return None if there is no window (e.g., a PS backend).
Set the child axes which are currently grabbing the mouse events. Usually called by the widgets themselves. It is an error to call this if the mouse is already grabbed by another axes.
Called when GUI is idle.
Returns True when the renderer is in the process of saving to a file, rather than rendering for an on-screen buffer.
This method will be call all functions connected to the ‘key_press_event’ with a KeyEvent
This method will be call all functions connected to the ‘key_release_event’ with a KeyEvent
Backend derived classes should call this function when leaving canvas
Backend derived classes should call this function on any motion-notify-event.
This method will be call all functions connected to the ‘motion_notify_event’ with a MouseEvent instance.
Connect event with string s to func. The signature of func is:
def func(event)
where event is a matplotlib.backend_bases.Event. The following events are recognized
For the location events (button and key press/release), if the mouse is over the axes, the variable event.inaxes will be set to the Axes the event occurs is over, and additionally, the variables event.xdata and event.ydata will be defined. This is the mouse location in data coords. See KeyEvent and MouseEvent for more info.
Return value is a connection id that can be used with mpl_disconnect().
Example usage:
def on_press(event):
print('you pressed', event.button, event.xdata, event.ydata)
cid = canvas.mpl_connect('button_press_event', on_press)
Disconnect callback id cid
Example usage:
cid = canvas.mpl_connect('button_press_event', on_press)
#...later
canvas.mpl_disconnect(cid)
Creates a new backend-specific subclass of backend_bases.Timer. This is useful for getting periodic events through the backend’s native event loop. Implemented only for backends with GUIs.
optional arguments:
Mouse event processor which highlights the artists under the cursor. Connect this to the ‘motion_notify_event’ using:
canvas.mpl_connect('motion_notify_event',canvas.onHilite)
Mouse event processor which removes the top artist under the cursor. Connect this to the ‘mouse_press_event’ using:
canvas.mpl_connect('mouse_press_event',canvas.onRemove)
This method will be called by artists who are picked and will fire off PickEvent callbacks registered listeners
Render the figure to hardcopy. Set the figure patch face and edge colors. This is useful because some of the GUIs have a gray figure face color background and you’ll probably want to override this on hardcopy.
Arguments are:
Release the mouse grab held by the axes, ax. Usually called by the widgets. It is ok to call this even if you ax doesn’t have the mouse grab currently.
set the canvas size in pixels
This method will be call all functions connected to the ‘resize_event’ with a ResizeEvent
Backend derived classes should call this function on any scroll wheel event. x,y are the canvas coords: 0,0 is lower, left. button and key are as defined in MouseEvent.
This method will be call all functions connected to the ‘scroll_event’ with a MouseEvent instance.
Set the title text of the window containing the figure. Note that this has no effect if there is no window (e.g., a PS backend).
Start an event loop. This is used to start a blocking event loop so that interactive functions, such as ginput and waitforbuttonpress, can wait for events. This should not be confused with the main GUI event loop, which is always running and has nothing to do with this.
This is implemented only for backends with GUIs.
Start an event loop. This is used to start a blocking event loop so that interactive functions, such as ginput and waitforbuttonpress, can wait for events. This should not be confused with the main GUI event loop, which is always running and has nothing to do with this.
This function provides default event loop functionality based on time.sleep that is meant to be used until event loop functions for each of the GUI backends can be written. As such, it throws a deprecated warning.
Call signature:
start_event_loop_default(self,timeout=0)
This call blocks until a callback function triggers stop_event_loop() or timeout is reached. If timeout is <=0, never timeout.
Stop an event loop. This is used to stop a blocking event loop so that interactive functions, such as ginput and waitforbuttonpress, can wait for events.
This is implemented only for backends with GUIs.
Stop an event loop. This is used to stop a blocking event loop so that interactive functions, such as ginput and waitforbuttonpress, can wait for events.
Call signature:
stop_event_loop_default(self)
Instantiate an instance of FigureCanvasClass
This is used for backend switching, e.g., to instantiate a FigureCanvasPS from a FigureCanvasGTK. Note, deep copying is not done, so any changes to one of the instances (e.g., setting figure size or line props), will be reflected in the other
Bases: object
Helper class for pyplot mode, wraps everything up into a neat bundle
Public attibutes:
Get the title text of the window containing the figure. Return None for non-GUI backends (e.g., a PS backend).
Implement the default mpl key bindings defined at Navigation Keyboard Shortcuts
The returned id from connecting the default key handler via FigureCanvasBase.mpl_connnect().
To disable default key press handling:
manager, canvas = figure.canvas.manager, figure.canvas
canvas.mpl_disconnect(manager.key_press_handler_id)
“For gui backends, resize the window (in pixels).
Set the title text of the window containing the figure. Note that this has no effect for non-GUI backends (e.g., a PS backend).
For GUI backends, show the figure window and redraw. For non-GUI backends, raise an exception to be caught by show(), for an optional warning.
Display message in a popup – GUI only
Bases: object
An abstract base class that provides color, line styles, etc...
Copy properties from gc to self
Return the alpha value used for blending - not supported on all backends
Return true if the object should try to do antialiased rendering
Return the capstyle as a string in (‘butt’, ‘round’, ‘projecting’)
Return the clip path in the form (path, transform), where path is a Path instance, and transform is an affine transform to apply to the path before clipping.
Return the dash information as an offset dashlist tuple.
The dash list is a even size list that gives the ink on, ink off in pixels.
See p107 of to PostScript BLUEBOOK for more info.
Default value is None
Return whether the value given by get_alpha() should be used to override any other alpha-channel values.
Return the object identifier if one is set, None otherwise.
Gets the current hatch style
Returns a Path for the current hatch.
Return the line join style as one of (‘miter’, ‘round’, ‘bevel’)
Return the linestyle: one of (‘solid’, ‘dashed’, ‘dashdot’, ‘dotted’).
Return the line width in points as a scalar
returns a tuple of three or four floats from 0-1.
Returns the sketch parameters for the artist.
| Returns: | sketch_params : tuple or None A 3-tuple with the following elements:
May return None if no sketch parameters were set. |
|---|
returns the snap setting which may be:
- True: snap vertices to the nearest pixel center
- False: leave vertices as-is
- None: (auto) If the path contains only rectilinear line segments, round to the nearest pixel center
returns a url if one is set, None otherwise
Restore the graphics context from the stack - needed only for backends that save graphics contexts on a stack
Set the alpha value used for blending - not supported on all backends. If alpha=None (the default), the alpha components of the foreground and fill colors will be used to set their respective transparencies (where applicable); otherwise, alpha will override them.
True if object should be drawn with antialiased rendering
Set the capstyle as a string in (‘butt’, ‘round’, ‘projecting’)
Set the clip path and transformation. Path should be a TransformedPath instance.
Set the clip rectangle with sequence (left, bottom, width, height)
Set the dash style for the gc.
Set the foreground color. fg can be a MATLAB format string, a html hex color string, an rgb or rgba unit tuple, or a float between 0 and 1. In the latter case, grayscale is used.
If you know fg is rgba, set isRGBA=True for efficiency.
Sets the id.
Set the foreground color to be a gray level with frac
Sets the hatch style for filling
Set the join style to be one of (‘miter’, ‘round’, ‘bevel’)
Set the linestyle to be one of (‘solid’, ‘dashed’, ‘dashdot’, ‘dotted’). One may specify customized dash styles by providing a tuple of (offset, dash pairs). For example, the predefiend linestyles have following values.:
‘dashed’ : (0, (6.0, 6.0)), ‘dashdot’ : (0, (3.0, 5.0, 1.0, 5.0)), ‘dotted’ : (0, (1.0, 3.0)),
Set the linewidth in points
Sets the the sketch parameters.
| Parameters: | scale : float, optional
length : float, optional
randomness : float, optional
|
|---|
Sets the snap setting which may be:
- True: snap vertices to the nearest pixel center
- False: leave vertices as-is
- None: (auto) If the path contains only rectilinear line segments, round to the nearest pixel center
Sets the url for links in compatible backends
Bases: matplotlib.backend_bases.Event
An event triggered by the GUI backend when it is idle – useful for passive animation
Bases: matplotlib.backend_bases.LocationEvent
A key event (key press, key release).
Attach additional attributes as defined in FigureCanvasBase.mpl_connect().
In addition to the Event and LocationEvent attributes, the following attributes are defined:
Note
Modifier keys will be prefixed to the pressed key and will be in the order “ctrl”, “alt”, “super”. The exception to this rule is when the pressed key is itself a modifier key, therefore “ctrl+alt” and “alt+control” can both be valid key values.
Example usage:
def on_key(event):
print('you pressed', event.key, event.xdata, event.ydata)
cid = fig.canvas.mpl_connect('key_press_event', on_key)
Bases: matplotlib.backend_bases.Event
An event that has a screen location
The following additional attributes are defined and shown with their default values.
In addition to the Event attributes, the following event attributes are defined:
x, y in figure coords, 0,0 = bottom, left
Bases: matplotlib.backend_bases.LocationEvent
In addition to the Event and LocationEvent attributes, the following attributes are defined:
Example usage:
def on_press(event):
print('you pressed', event.button, event.xdata, event.ydata)
cid = fig.canvas.mpl_connect('button_press_event', on_press)
x, y in figure coords, 0,0 = bottom, left button pressed None, 1, 2, 3, ‘up’, ‘down’
Bases: object
Base class for the navigation cursor, version 2
backends must implement a canvas that handles connections for ‘button_press_event’ and ‘button_release_event’. See FigureCanvasBase.mpl_connect() for more information
They must also define
- save_figure()
- save the current figure
- set_cursor()
- if you want the pointer icon to change
- _init_toolbar()
- create your toolbar widget
- draw_rubberband() (optional)
- draw the zoom to rect “rubberband” rectangle
- press() (optional)
- whenever a mouse button is pressed, you’ll be notified with the event
- release() (optional)
- whenever a mouse button is released, you’ll be notified with the event
- dynamic_update() (optional)
- dynamically update the window while navigating
- set_message() (optional)
- display message
- set_history_buttons() (optional)
- you can change the history back / forward buttons to indicate disabled / enabled state.
That’s it, we’ll do the rest!
move back up the view lim stack
the drag callback in pan/zoom mode
the drag callback in zoom mode
Redraw the canvases, update the locators
Draw a rectangle rubberband to indicate zoom limits
Move forward in the view lim stack
Restore the original view
Activate the pan/zoom tool. pan with left button, zoom with right
Called whenver a mouse button is pressed.
the press mouse button in pan/zoom mode callback
the press mouse button in zoom to rect mode callback
push the current view limits and position onto the stack
this will be called whenever mouse button is released
the release mouse button callback in pan/zoom mode
the release mouse button callback in zoom to rect mode
Save the current figure
Set the current cursor to one of the Cursors enums values
Enable or disable back/forward button
Display a message on toolbar or in status bar
Reset the axes stack
Activate zoom to rect mode
Bases: exceptions.Exception
Bases: matplotlib.backend_bases.Event
a pick event, fired when the user picks a location on the canvas sufficiently close to an artist.
Attrs: all the Event attributes plus
Example usage:
line, = ax.plot(rand(100), 'o', picker=5) # 5 points tolerance
def on_pick(event):
thisline = event.artist
xdata, ydata = thisline.get_data()
ind = event.ind
print('on pick line:', zip(xdata[ind], ydata[ind]))
cid = fig.canvas.mpl_connect('pick_event', on_pick)
Bases: object
An abstract base class to handle drawing/rendering operations.
The following methods must be implemented in the backend for full functionality (though just implementing draw_path() alone would give a highly capable backend):
The following methods should be implemented in the backend for optimization reasons:
Close a grouping element with label s Is only currently used by backend_svg
Draw a Gouraud-shaded triangle.
points is a 3x2 array of (x, y) points for the triangle.
colors is a 3x4 array of RGBA colors for each point of the triangle.
transform is an affine transform to apply to the points.
Draws a series of Gouraud triangles.
points is a Nx3x2 array of (x, y) points for the trianglex.
colors is a Nx3x4 array of RGBA colors for each point of the triangles.
transform is an affine transform to apply to the points.
Draw the image instance into the current axes;
Draws a marker at each of the vertices in path. This includes all vertices, including control points on curves. To avoid that behavior, those vertices should be removed before calling this function.
This provides a fallback implementation of draw_markers that makes multiple calls to draw_path(). Some backends may want to override this method in order to draw the marker only once and reuse it multiple times.
Draws a Path instance using the given affine transform.
Draws a collection of paths selecting drawing properties from the lists facecolors, edgecolors, linewidths, linestyles and antialiaseds. offsets is a list of offsets to apply to each of the paths. The offsets in offsets are first transformed by offsetTrans before being applied. offset_position may be either “screen” or “data” depending on the space that the offsets are in.
This provides a fallback implementation of draw_path_collection() that makes multiple calls to draw_path(). Some backends may want to override this in order to render each set of path data only once, and then reference that path multiple times with the different offsets, colors, styles etc. The generator methods _iter_collection_raw_paths() and _iter_collection() are provided to help with (and standardize) the implementation across backends. It is highly recommended to use those generators, so that changes to the behavior of draw_path_collection() can be made globally.
This provides a fallback implementation of draw_quad_mesh() that generates paths and then calls draw_path_collection().
Draw the text instance
backend implementers note
When you are trying to determine if you have gotten your bounding box right (which is what enables the text layout/alignment to work properly), it helps to change the line in text.py:
if 0: bbox_artist(self, renderer)
to if 1, and then the actual bounding box will be plotted along with your text.
Return true if y small numbers are top for renderer Is used for drawing text (matplotlib.text) and images (matplotlib.image) only
return the canvas width and height in display coords
Get the factor by which to magnify images passed to draw_image(). Allows a backend to have images at a different resolution to other artists.
return the matplotlib.texmanager.TexManager instance
get the width and height, and the offset from the bottom to the baseline (descent), in display coords of the string s with FontProperties prop
Return an instance of a GraphicsContextBase
Open a grouping element with label s. If gid is given, use gid as the id of the group. Is only currently used by backend_svg.
override this method for renderers that do not necessarily want to rescale and composite raster images. (like SVG)
override this method for renderers that support arbitrary scaling of image (most of the vector backend).
Convert points to display units
return points converted to pixels
You need to override this function (unless your backend doesn’t have a dpi, e.g., postscript or svg). Some imaging systems assume some value for pixels per inch:
points to pixels = points * pixels_per_inch/72.0 * dpi/72.0
Used in AggRenderer. Switch to a temporary renderer for image filtering effects.
Used in MixedModeRenderer. Switch to the raster renderer.
Used in AggRenderer. Switch back to the original renderer. The contents of the temporary renderer is processed with the filter_func and is drawn on the original renderer as an image.
Used in MixedModeRenderer. Switch back to the vector renderer and draw the contents of the raster renderer as an image on the vector renderer.
Bases: matplotlib.backend_bases.Event
An event triggered by a canvas resize
In addition to the Event attributes, the following event attributes are defined:
Bases: object
Simple base class to generate a show() callable in backends.
Subclass must override mainloop() method.
Bases: object
A base class for providing timer events, useful for things animations. Backends need to implement a few specific methods in order to use their own timing mechanisms so that the timer events are integrated into their event loops.
Mandatory functions that must be implemented:
- _timer_start: Contains backend-specific code for starting the timer
- _timer_stop: Contains backend-specific code for stopping the timer
Optional overrides:
- _timer_set_single_shot: Code for setting the timer to single shot operating mode, if supported by the timer object. If not, the Timer class itself will store the flag and the _on_timer method should be overridden to support such behavior.
- _timer_set_interval: Code for setting the interval on the timer, if there is a method for doing so on the timer object.
- _on_timer: This is the internal function that any timer object should call, which will handle the task of running all callbacks that have been set.
Attributes:
- interval: The time between timer events in milliseconds. Default is 1000 ms.
- single_shot: Boolean flag indicating whether this timer should operate as single shot (run once and then stop). Defaults to False.
- callbacks: Stores list of (func, args) tuples that will be called upon timer events. This list can be manipulated directly, or the functions add_callback and remove_callback can be used.
Register func to be called by timer when the event fires. Any additional arguments provided will be passed to func.
Remove func from list of callbacks. args and kwargs are optional and used to distinguish between copies of the same function registered to be called with different arguments.
Start the timer object. interval is optional and will be used to reset the timer interval first if provided.
Stop the timer.
Return the registered default canvas for given file format. Handles deferred import of required backend.
Implement the default mpl key bindings for the canvas and toolbar described at Navigation Keyboard Shortcuts
Register a backend for saving to a given file format.