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""" Defines the PlotAxis class, and associated validator and UI.
"""
from __future__ import with_statement
# Major library import
from numpy import array, around, absolute, cos, dot, float64, inf, pi, \
sqrt, sin, transpose
# Enthought Library imports
from enable.api import ColorTrait, LineStyle
from kiva.trait_defs.kiva_font_trait import KivaFont
from traits.api import Any, Float, Int, Str, Trait, Unicode, \
Bool, Event, List, Array, Instance, Enum, Callable
# Local relative imports
from ticks import AbstractTickGenerator, DefaultTickGenerator
from abstract_mapper import AbstractMapper
from abstract_overlay import AbstractOverlay
from label import Label
from log_mapper import LogMapper
def DEFAULT_TICK_FORMATTER(val):
return ("%f"%val).rstrip("0").rstrip(".")
class PlotAxis(AbstractOverlay):
"""
The PlotAxis is a visual component that can be rendered on its own as
a standalone component or attached as an overlay to another component.
(To attach it as an overlay, set its **component** attribute.)
When it is attached as an overlay, it draws into the padding around
the component.
"""
# The mapper that drives this axis.
mapper = Instance(AbstractMapper)
# The text of the axis title.
title = Trait('', Str, Unicode) #May want to add PlotLabel option
# The font of the title.
title_font = KivaFont('modern 12')
# The spacing between the axis line and the title
title_spacing = Trait('auto', 'auto', Float)
# The color of the title.
title_color = ColorTrait("black")
# The thickness (in pixels) of each tick.
tick_weight = Float(1.0)
# The color of the ticks.
tick_color = ColorTrait("black")
# The font of the tick labels.
tick_label_font = KivaFont('modern 10')
# The color of the tick labels.
tick_label_color = ColorTrait("black")
# The rotation of the tick labels.
tick_label_rotate_angle = Float(0)
# Whether to align to corners or edges (corner is better for 45 degree rotation)
tick_label_alignment = Enum('edge', 'corner')
# The margin around the tick labels.
tick_label_margin = Int(2)
# The distance of the tick label from the axis.
tick_label_offset = Float(8.)
# Whether the tick labels appear to the inside or the outside of the plot area
tick_label_position = Enum("outside", "inside")
# A callable that is passed the numerical value of each tick label and
# that returns a string.
tick_label_formatter = Callable(DEFAULT_TICK_FORMATTER)
# The number of pixels by which the ticks extend into the plot area.
tick_in = Int(5)
# The number of pixels by which the ticks extend into the label area.
tick_out = Int(5)
# Are ticks visible at all?
tick_visible = Bool(True)
# The dataspace interval between ticks.
tick_interval = Trait('auto', 'auto', Float)
# A callable that implements the AbstractTickGenerator interface.
tick_generator = Instance(AbstractTickGenerator)
# The location of the axis relative to the plot. This determines where
# the axis title is located relative to the axis line.
orientation = Enum("top", "bottom", "left", "right")
# Is the axis line visible?
axis_line_visible = Bool(True)
# The color of the axis line.
axis_line_color = ColorTrait("black")
# The line thickness (in pixels) of the axis line.
axis_line_weight = Float(1.0)
# The dash style of the axis line.
axis_line_style = LineStyle('solid')
# A special version of the axis line that is more useful for geophysical
# plots.
small_haxis_style = Bool(False)
# Does the axis ensure that its end labels fall within its bounding area?
ensure_labels_bounded = Bool(False)
# Does the axis prevent the ticks from being rendered outside its bounds?
# This flag is off by default because the standard axis *does* render ticks
# that encroach on the plot area.
ensure_ticks_bounded = Bool(False)
# Fired when the axis's range bounds change.
updated = Event
#------------------------------------------------------------------------
# Override default values of inherited traits
#------------------------------------------------------------------------
# Background color (overrides AbstractOverlay). Axes usually let the color of
# the container show through.
bgcolor = ColorTrait("transparent")
# Dimensions that the axis is resizable in (overrides PlotComponent).
# Typically, axes are resizable in both dimensions.
resizable = "hv"
#------------------------------------------------------------------------
# Private Traits
#------------------------------------------------------------------------
# Cached position calculations
_tick_list = List # These are caches of their respective positions
_tick_positions = Any #List
_tick_label_list = Any
_tick_label_positions = Any
_tick_label_bounding_boxes = List
_major_axis_size = Float
_minor_axis_size = Float
_major_axis = Array
_title_orientation = Array
_title_angle = Float
_origin_point = Array
_inside_vector = Array
_axis_vector = Array
_axis_pixel_vector = Array
_end_axis_point = Array
ticklabel_cache = List
_cache_valid = Bool(False)
#------------------------------------------------------------------------
# Public methods
#------------------------------------------------------------------------
def __init__(self, component=None, **kwargs):
# TODO: change this back to a factory in the instance trait some day
self.tick_generator = DefaultTickGenerator()
# Override init so that our component gets set last. We want the
# _component_changed() event handler to get run last.
super(PlotAxis, self).__init__(**kwargs)
if component is not None:
self.component = component
def invalidate(self):
""" Invalidates the pre-computed layout and scaling data.
"""
self._reset_cache()
self.invalidate_draw()
return
def traits_view(self):
""" Returns a View instance for use with Traits UI. This method is
called automatically be the Traits framework when .edit_traits() is
invoked.
"""
from axis_view import AxisView
return AxisView
#------------------------------------------------------------------------
# PlotComponent and AbstractOverlay interface
#------------------------------------------------------------------------
def _do_layout(self, *args, **kw):
""" Tells this component to do layout at a given size.
Overrides Component.
"""
if self.use_draw_order and self.component is not None:
self._layout_as_overlay(*args, **kw)
else:
super(PlotAxis, self)._do_layout(*args, **kw)
return
def overlay(self, component, gc, view_bounds=None, mode='normal'):
""" Draws this component overlaid on another component.
Overrides AbstractOverlay.
"""
if not self.visible:
return
self._draw_component(gc, view_bounds, mode, component)
return
def _draw_overlay(self, gc, view_bounds=None, mode='normal'):
""" Draws the overlay layer of a component.
Overrides PlotComponent.
"""
self._draw_component(gc, view_bounds, mode)
return
def _draw_component(self, gc, view_bounds=None, mode='normal', component=None):
""" Draws the component.
This method is preserved for backwards compatibility. Overrides
PlotComponent.
"""
if not self.visible:
return
if not self._cache_valid:
if component is not None:
self._calculate_geometry_overlay(component)
else:
self._calculate_geometry()
self._compute_tick_positions(gc, component)
self._compute_labels(gc)
with gc:
# slight optimization: if we set the font correctly on the
# base gc before handing it in to our title and tick labels,
# their set_font() won't have to do any work.
gc.set_font(self.tick_label_font)
if self.axis_line_visible:
self._draw_axis_line(gc, self._origin_point, self._end_axis_point)
if self.title:
self._draw_title(gc)
self._draw_ticks(gc)
self._draw_labels(gc)
self._cache_valid = True
return
#------------------------------------------------------------------------
# Private draw routines
#------------------------------------------------------------------------
def _layout_as_overlay(self, size=None, force=False):
""" Lays out the axis as an overlay on another component.
"""
if self.component is not None:
if self.orientation in ("left", "right"):
self.y = self.component.y
self.height = self.component.height
if self.orientation == "left":
self.width = self.component.padding_left
self.x = self.component.outer_x
elif self.orientation == "right":
self.width = self.component.padding_right
self.x = self.component.x2 + 1
else:
self.x = self.component.x
self.width = self.component.width
if self.orientation == "bottom":
self.height = self.component.padding_bottom
self.y = self.component.outer_y
elif self.orientation == "top":
self.height = self.component.padding_top
self.y = self.component.y2 + 1
return
def _draw_axis_line(self, gc, startpoint, endpoint):
""" Draws the line for the axis.
"""
with gc:
gc.set_antialias(0)
gc.set_line_width(self.axis_line_weight)
gc.set_stroke_color(self.axis_line_color_)
gc.set_line_dash(self.axis_line_style_)
gc.move_to(*around(startpoint))
gc.line_to(*around(endpoint))
gc.stroke_path()
return
def _draw_title(self, gc, label=None, axis_offset=None):
""" Draws the title for the axis.
"""
if label is None:
title_label = Label(text=self.title,
font=self.title_font,
color=self.title_color,
rotate_angle=self.title_angle)
else:
title_label = label
# get the _rotated_ bounding box of the label
tl_bounds = array(title_label.get_bounding_box(gc), float64)
text_center_to_corner = -tl_bounds/2.0
# which axis are we moving away from the axis line along?
axis_index = self._major_axis.argmin()
if self.title_spacing != 'auto':
axis_offset = self.title_spacing
if (self.title_spacing) and (axis_offset is None ):
if not self.ticklabel_cache:
axis_offset = 25
else:
axis_offset = max([l._bounding_box[axis_index] for l in self.ticklabel_cache]) * 1.3
offset = (self._origin_point+self._end_axis_point)/2
axis_dist = self.tick_out + tl_bounds[axis_index]/2.0 + axis_offset
offset -= self._inside_vector * axis_dist
offset += text_center_to_corner
gc.translate_ctm(*offset)
title_label.draw(gc)
gc.translate_ctm(*(-offset))
return
def _draw_ticks(self, gc):
""" Draws the tick marks for the axis.
"""
if not self.tick_visible:
return
gc.set_stroke_color(self.tick_color_)
gc.set_line_width(self.tick_weight)
gc.set_antialias(False)
gc.begin_path()
tick_in_vector = self._inside_vector*self.tick_in
tick_out_vector = self._inside_vector*self.tick_out
for tick_pos in self._tick_positions:
gc.move_to(*(tick_pos + tick_in_vector))
gc.line_to(*(tick_pos - tick_out_vector))
gc.stroke_path()
return
def _draw_labels(self, gc):
""" Draws the tick labels for the axis.
"""
# which axis are we moving away from the axis line along?
axis_index = self._major_axis.argmin()
inside_vector = self._inside_vector
if self.tick_label_position == "inside":
inside_vector = -inside_vector
for i in range(len(self._tick_label_positions)):
#We want a more sophisticated scheme than just 2 decimals all the time
ticklabel = self.ticklabel_cache[i]
tl_bounds = self._tick_label_bounding_boxes[i]
#base_position puts the tick label at a point where the vector
#extending from the tick mark inside 8 units
#just touches the rectangular bounding box of the tick label.
#Note: This is not necessarily optimal for non
#horizontal/vertical axes. More work could be done on this.
base_position = self._tick_label_positions[i].copy()
axis_dist = self.tick_label_offset + tl_bounds[axis_index]/2.0
base_position -= inside_vector * axis_dist
base_position -= tl_bounds/2.0
if self.tick_label_alignment == 'corner':
if self.orientation in ("top", "bottom"):
base_position[0] += tl_bounds[0]/2.0
elif self.orientation == "left":
base_position[1] -= tl_bounds[1]/2.0
elif self.orientation == "right":
base_position[1] += tl_bounds[1]/2.0
if self.ensure_labels_bounded:
bound_idx = self._major_axis.argmax()
if i == 0:
base_position[bound_idx] = max(base_position[bound_idx],
self._origin_point[bound_idx])
elif i == len(self._tick_label_positions)-1:
base_position[bound_idx] = min(base_position[bound_idx],
self._end_axis_point[bound_idx] - \
tl_bounds[bound_idx])
tlpos = around(base_position)
gc.translate_ctm(*tlpos)
ticklabel.draw(gc)
gc.translate_ctm(*(-tlpos))
return
#------------------------------------------------------------------------
# Private methods for computing positions and layout
#------------------------------------------------------------------------
def _reset_cache(self):
""" Clears the cached tick positions, labels, and label positions.
"""
self._tick_positions = []
self._tick_label_list = []
self._tick_label_positions = []
return
def _compute_tick_positions(self, gc, overlay_component=None):
""" Calculates the positions for the tick marks.
"""
if (self.mapper is None):
self._reset_cache()
self._cache_valid = True
return
datalow = self.mapper.range.low
datahigh = self.mapper.range.high
screenhigh = self.mapper.high_pos
screenlow = self.mapper.low_pos
if overlay_component is not None:
origin = getattr(overlay_component, 'origin', 'bottom left')
if self.orientation in ("top", "bottom"):
if "right" in origin:
flip_from_gc = True
else:
flip_from_gc = False
elif self.orientation in ("left", "right"):
if "top" in origin:
flip_from_gc = True
else:
flip_from_gc = False
if flip_from_gc:
screenlow, screenhigh = screenhigh, screenlow
if (datalow == datahigh) or (screenlow == screenhigh) or \
(datalow in [inf, -inf]) or (datahigh in [inf, -inf]):
self._reset_cache()
self._cache_valid = True
return
if datalow > datahigh:
raise RuntimeError, "DataRange low is greater than high; unable to compute axis ticks."
if not self.tick_generator:
return
if hasattr(self.tick_generator, "get_ticks_and_labels"):
# generate ticks and labels simultaneously
tmp = self.tick_generator.get_ticks_and_labels(datalow, datahigh,
screenlow, screenhigh)
if len(tmp) == 0:
tick_list = []
labels = []
else:
tick_list, labels = tmp
# compute the labels here
self.ticklabel_cache = [Label(text=lab,
font=self.tick_label_font,
color=self.tick_label_color) \
for lab in labels]
self._tick_label_bounding_boxes = [array(ticklabel.get_bounding_box(gc), float64) \
for ticklabel in self.ticklabel_cache]
else:
scale = 'log' if isinstance(self.mapper, LogMapper) else 'linear'
if self.small_haxis_style:
tick_list = array([datalow, datahigh])
else:
tick_list = array(self.tick_generator.get_ticks(datalow, datahigh,
datalow, datahigh,
self.tick_interval,
use_endpoints=False,
scale=scale), float64)
mapped_tick_positions = (array(self.mapper.map_screen(tick_list))-screenlow) / \
(screenhigh-screenlow)
self._tick_positions = around(array([self._axis_vector*tickpos + self._origin_point \
for tickpos in mapped_tick_positions]))
self._tick_label_list = tick_list
self._tick_label_positions = self._tick_positions
return
def _compute_labels(self, gc):
"""Generates the labels for tick marks.
Waits for the cache to become invalid.
"""
# tick labels are already computed
if hasattr(self.tick_generator, "get_ticks_and_labels"):
return
formatter = self.tick_label_formatter
def build_label(val):
tickstring = formatter(val) if formatter is not None else str(val)
return Label(text=tickstring,
font=self.tick_label_font,
color=self.tick_label_color,
rotate_angle=self.tick_label_rotate_angle,
margin=self.tick_label_margin)
self.ticklabel_cache = [build_label(val) for val in self._tick_label_list]
self._tick_label_bounding_boxes = [array(ticklabel.get_bounding_box(gc), float)
for ticklabel in self.ticklabel_cache]
return
def _calculate_geometry(self):
screenhigh = self.mapper.high_pos
screenlow = self.mapper.low_pos
if self.orientation in ('top', 'bottom'):
self._major_axis_size = self.bounds[0]
self._minor_axis_size = self.bounds[1]
self._major_axis = array([1., 0.])
self._title_orientation = array([0.,1.])
self.title_angle = 0.0
if self.orientation == 'top':
self._origin_point = array(self.position) + self._major_axis * screenlow
self._inside_vector = array([0.,-1.])
else: #self.oriention == 'bottom'
self._origin_point = array(self.position) + array([0., self.bounds[1]]) + self._major_axis*screenlow
self._inside_vector = array([0., 1.])
elif self.orientation in ('left', 'right'):
self._major_axis_size = self.bounds[1]
self._minor_axis_size = self.bounds[0]
self._major_axis = array([0., 1.])
self._title_orientation = array([-1., 0])
if self.orientation == 'left':
self._origin_point = array(self.position) + array([self.bounds[0], 0.]) + self._major_axis*screenlow
self._inside_vector = array([1., 0.])
self.title_angle = 90.0
else: #self.orientation == 'right'
self._origin_point = array(self.position) + self._major_axis * screenlow
self._inside_vector = array([-1., 0.])
self.title_angle = 270.0
if self.ensure_ticks_bounded:
self._origin_point -= self._inside_vector*self.tick_in
self._end_axis_point = (screenhigh-screenlow)*self._major_axis + self._origin_point
self._axis_vector = self._end_axis_point - self._origin_point
# This is the vector that represents one unit of data space in terms of screen space.
self._axis_pixel_vector = self._axis_vector/sqrt(dot(self._axis_vector,self._axis_vector))
return
def _calculate_geometry_overlay(self, overlay_component=None):
if overlay_component is None:
overlay_component = self
component_origin = getattr(overlay_component, "origin", 'bottom left')
screenhigh = self.mapper.high_pos
screenlow = self.mapper.low_pos
if self.orientation in ('top', 'bottom'):
self._major_axis_size = overlay_component.bounds[0]
self._minor_axis_size = overlay_component.bounds[1]
self._major_axis = array([1., 0.])
self._title_orientation = array([0.,1.])
self.title_angle = 0.0
if self.orientation == 'top':
self._origin_point = array([overlay_component.x, overlay_component.y2])
self._inside_vector = array([0.0, -1.0])
else:
self._origin_point = array([overlay_component.x, overlay_component.y])
self._inside_vector = array([0.0, 1.0])
if "right" in component_origin:
screenlow, screenhigh = screenhigh, screenlow
elif self.orientation in ('left', 'right'):
self._major_axis_size = overlay_component.bounds[1]
self._minor_axis_size = overlay_component.bounds[0]
self._major_axis = array([0., 1.])
self._title_orientation = array([-1., 0])
if self.orientation == 'left':
self._origin_point = array([overlay_component.x, overlay_component.y])
self._inside_vector = array([1.0, 0.0])
self.title_angle = 90.0
else:
self._origin_point = array([overlay_component.x2, overlay_component.y])
self._inside_vector = array([-1.0, 0.0])
self.title_angle = 270.0
if "top" in component_origin:
screenlow, screenhigh = screenhigh, screenlow
if self.ensure_ticks_bounded:
self._origin_point -= self._inside_vector*self.tick_in
self._end_axis_point = (screenhigh-screenlow)*self._major_axis + self._origin_point
self._axis_vector = self._end_axis_point - self._origin_point
# This is the vector that represents one unit of data space in terms of screen space.
self._axis_pixel_vector = self._axis_vector/sqrt(dot(self._axis_vector,self._axis_vector))
return
#------------------------------------------------------------------------
# Event handlers
#------------------------------------------------------------------------
def _bounds_changed(self, old, new):
super(PlotAxis, self)._bounds_changed(old, new)
self._layout_needed = True
self._invalidate()
def _bounds_items_changed(self, event):
super(PlotAxis, self)._bounds_items_changed(event)
self._layout_needed = True
self._invalidate()
def _mapper_changed(self, old, new):
if old is not None:
old.on_trait_change(self.mapper_updated, "updated", remove=True)
if new is not None:
new.on_trait_change(self.mapper_updated, "updated")
self._invalidate()
def mapper_updated(self):
"""
Event handler that is bound to this axis's mapper's **updated** event
"""
self._invalidate()
def _position_changed(self, old, new):
super(PlotAxis, self)._position_changed(old, new)
self._cache_valid = False
def _position_items_changed(self, event):
super(PlotAxis, self)._position_items_changed(event)
self._cache_valid = False
def _position_changed_for_component(self):
self._cache_valid = False
def _position_items_changed_for_component(self):
self._cache_valid = False
def _bounds_changed_for_component(self):
self._cache_valid = False
self._layout_needed = True
def _bounds_items_changed_for_component(self):
self._cache_valid = False
self._layout_needed = True
def _origin_changed_for_component(self):
self._invalidate()
def _updated_fired(self):
"""If the axis bounds changed, redraw."""
self._cache_valid = False
return
def _invalidate(self):
self._cache_valid = False
self.invalidate_draw()
if self.component:
self.component.invalidate_draw()
return
def _component_changed(self):
if self.mapper is not None:
# If there is a mapper set, just leave it be.
return
# Try to pick the most appropriate mapper for our orientation
# and what information we can glean from our component.
attrmap = { "left": ("ymapper", "y_mapper", "value_mapper"),
"bottom": ("xmapper", "x_mapper", "index_mapper"), }
attrmap["right"] = attrmap["left"]
attrmap["top"] = attrmap["bottom"]
component = self.component
attr1, attr2, attr3 = attrmap[self.orientation]
for attr in attrmap[self.orientation]:
if hasattr(component, attr):
self.mapper = getattr(component, attr)
break
return
#------------------------------------------------------------------------
# The following event handlers just invalidate our previously computed
# Label instances and backbuffer if any of our visual attributes change.
# TODO: refactor this stuff and the caching of contained objects (e.g. Label)
#------------------------------------------------------------------------
def _title_changed(self):
self.invalidate_draw()
if self.component:
self.component.invalidate_draw()
return
def _anytrait_changed(self, name, old, new):
""" For every trait that defines a visual attribute
we just call _invalidate() when a change is made.
"""
invalidate_traits = [
'title_font',
'title_spacing',
'title_color',
'tick_weight',
'tick_color',
'tick_label_font',
'tick_label_color',
'tick_label_rotate_angle',
'tick_label_alignment',
'tick_label_margin',
'tick_label_offset',
'tick_label_position',
'tick_label_formatter',
'tick_in',
'tick_out',
'tick_visible',
'tick_interval',
'tick_generator',
'orientation',
'axis_line_visible',
'axis_line_color',
'axis_line_weight',
'axis_line_style',
'small_haxis_style',
'ensure_labels_bounded',
'ensure_ticks_bounded',
]
if name in invalidate_traits:
self._invalidate()
#------------------------------------------------------------------------
# Persistence-related methods
#------------------------------------------------------------------------
def __getstate__(self):
dont_pickle = [
'_tick_list',
'_tick_positions',
'_tick_label_list',
'_tick_label_positions',
'_tick_label_bounding_boxes',
'_major_axis_size',
'_minor_axis_size',
'_major_axis',
'_title_orientation',
'_title_angle',
'_origin_point',
'_inside_vector',
'_axis_vector',
'_axis_pixel_vector',
'_end_axis_point',
'_ticklabel_cache',
'_cache_valid'
]
state = super(PlotAxis,self).__getstate__()
for key in dont_pickle:
if state.has_key(key):
del state[key]
return state
def __setstate__(self, state):
super(PlotAxis,self).__setstate__(state)
self._mapper_changed(None, self.mapper)
self._reset_cache()
self._cache_valid = False
return
# EOF ########################################################################
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