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from enthought.traits.api import Bool, Enum, Float, Tuple
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from base_zoom_tool import BaseZoomTool
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class DragZoom(DragTool, BaseZoomTool):
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from better_zoom import BetterZoom
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class DragZoom(DragTool, BetterZoom):
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""" A zoom tool that zooms continuously with a mouse drag movement, instead
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of using a zoom box or range.
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# Whether to restrict zoom to the domain of the mappers
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restrict_domain = Bool(False)
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zoom_to_mouse = Bool(False)
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#------------------------------------------------------------------------------
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#------------------------------------------------------------------------------
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# Compute the zoom amount based on the pixel difference between
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# the previous mouse event and the current one.
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if self.maintain_aspect_ratio:
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zoom_x = zoom_y = self._calc_zoom(self._prev_y, event.y)
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zoom_x = self._calc_zoom(self._prev_x, event.x)
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zoom_y = self._calc_zoom(self._prev_y, event.y)
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low_pt, high_pt = self._map_coordinate_box((c.x, c.y), (c.x2, c.y2))
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# The original screen bounds are used to test if we've reached max_zoom
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orig_low, orig_high = self._orig_screen_bounds
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datarange_list = [(0, c.x_mapper, zoom_x), (1, c.y_mapper, zoom_y)]
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for ndx, mapper, zoom in datarange_list:
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datarange = mapper.range
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if self.single_axis and ndx != self._determine_axis():
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mouse_val = self._original_data[ndx]
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newlow = mouse_val - zoom * (mouse_val - low_pt[ndx])
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newhigh = mouse_val + zoom * (high_pt[ndx] - mouse_val)
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ol, oh = orig_low[ndx], orig_high[ndx]
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if self._zoom_limit_reached(ol, oh, newlow, newhigh):
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# prohibit zooming outside the domain of the axis
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if self.restrict_domain:
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# This happens when the orientation of the axis is reversed.
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newlow, newhigh = newhigh, newlow
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domain_min, domain_max = getattr(mapper, "domain_limits", (None,None))
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if domain_min is not None and newlow < domain_min:
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if domain_max is not None and newhigh > domain_max:
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datarange.set_bounds(newlow, newhigh)
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self._prev_y = event.y
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self._prev_x = event.x
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self.component.request_redraw()
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# invert the zoom so scrolling up zooms in
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self.zoom_in_x(zoom_x)
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self.zoom_in_y(zoom_y)
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def drag_start(self, event, capture_mouse=True):
added
removed
enthought/chaco/tools/drag_zoom.py
