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""" Defines the PlotLabel class.
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from enthought.kiva import font_metrics_provider
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from enthought.traits.api import Delegate, Enum, Instance
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from abstract_overlay import AbstractOverlay
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from label import Label
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class PlotLabel(AbstractOverlay):
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""" A label used by plots.
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This class wraps a simple Label instance, and delegates some traits to it.
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# The text of the label.
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text = Delegate("_label")
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# The color of the label text.
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color = Delegate("_label", modify=True)
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# The font for the label text.
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font = Delegate("_label")
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# The angle of rotation of the label.
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angle = Delegate("_label", "rotate_angle")
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#------------------------------------------------------------------------
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# Layout-related traits
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#------------------------------------------------------------------------
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# Horizontal justification used if the label has more horizontal space
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hjustify = Enum("center", "left", "right")
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# Vertical justification used if the label has more vertical space than it
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vjustify = Enum("center", "bottom", "top")
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# The position of this label relative to the object it is overlaying.
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overlay_position = Enum("top", "bottom", "left", "right", None)
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# Should this PlotLabel modify the padding on its underlying component
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# if there is not enough room to lay out the text?
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# FIXME: This could cause cycles in layout, so not implemented for now
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#modify_component = Bool(True)
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# By default, this acts like a component and will render on the main
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# "plot" layer unless its **component** attribute gets set.
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#------------------------------------------------------------------------
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#------------------------------------------------------------------------
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# The label has a fixed height and can be resized horizontally. (Overrides
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# The Label instance this plot label is wrapping.
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_label = Instance(Label, args=())
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def __init__(self, text="", *args, **kw):
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super(PlotLabel, self).__init__(*args, **kw)
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def overlay(self, component, gc, view_bounds=None, mode="normal"):
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""" Draws this label overlaid on another component.
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Overrides AbstractOverlay.
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self._draw_overlay(gc, view_bounds, mode)
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def get_preferred_size(self):
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""" Returns the label's preferred size.
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Overrides PlotComponent.
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dummy_gc = font_metrics_provider()
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size = self._label.get_bounding_box(dummy_gc)
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""" Tells this component to do layout.
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Overrides PlotComponent.
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if self.component is not None:
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self._layout_as_overlay()
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self._layout_as_component()
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def _draw_overlay(self, gc, view_bounds=None, mode="normal"):
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""" Draws the overlay layer of a component.
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Overrides PlotComponent.
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# Perform justification and compute the correct offsets for
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width, height = self._label.get_bounding_box(gc)
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if self.hjustify == "left":
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elif self.hjustify == "right":
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x_offset = self.width - width
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elif self.hjustify == "center":
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x_offset = int((self.width - width) / 2)
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if self.vjustify == "bottom":
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elif self.vjustify == "top":
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y_offset = self.height - height
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elif self.vjustify == "center":
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y_offset = int((self.height - height) / 2)
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# XXX: Uncomment this after we fix kiva GL backend's clip stack
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#gc.clip_to_rect(self.x, self.y, self.width, self.height)
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# We have to translate to our position because the label
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# tries to draw at (0,0)
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gc.translate_ctm(self.x + x_offset, self.y + y_offset)
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def _draw_plot(self, gc, view_bounds=None, mode="normal"):
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if self.component is None:
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# We are not overlaying anything else, so we should render
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self._draw_overlay(gc, view_bounds, mode)
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def _layout_as_component(self, size=None, force=False):
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def _layout_as_overlay(self, size=None, force=False):
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""" Lays out the label as an overlay on another component.
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if self.component is not None:
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orientation = self.overlay_position
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if orientation in ("left", "right"):
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self.y = self.component.y
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self.height = self.component.height
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if orientation == "left":
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self.width = self.component.padding_left
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self.x = self.component.outer_x
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elif orientation == "right":
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self.width = self.component.padding_right
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self.x = self.component.x2 + 1
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elif orientation in ("bottom", "top"):
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self.x = self.component.x
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self.width = self.component.width
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if orientation == "bottom":
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self.height = self.component.padding_bottom
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self.y = self.component.outer_y
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elif orientation == "top":
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self.height = self.component.padding_top
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self.y = self.component.y2 + 1
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# Leave the position alone
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def _text_changed(self, old, new):
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self._label.text = new
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def _font_changed(self, old, new):
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self._label.font = new
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def _angle_changed(self, old, new):
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self._label.rotate_angle = new
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def _component_changed(self, old, new):
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self.draw_layer = "overlay"
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self.draw_layer = "plot"
added
removed
enthought/chaco/plot_label.py
