bec_widgets.utils.crosshair#

Classes#

Crosshair

Crosshair for 1D and 2D plots.

CrosshairScatterItem

Displays a set of x/y points. Instances of this class are created

Module Contents#

class Crosshair(plot_item: pyqtgraph.PlotItem, precision: int | None = None, *, min_precision: int = 2, parent=None)#

Bases: qtpy.QtCore.QObject

Crosshair for 1D and 2D plots.

Parameters:

  • plot_item (pyqtgraph.PlotItem) – The plot item to which the crosshair will be attached.

  • precision (int | None, optional) – Fixed number of decimal places to display. If None, precision is chosen dynamically from the current view range.

  • min_precision (int, optional) – The lower bound (in decimal places) used when dynamic precision is enabled. Defaults to 2.

  • parent (QObject, optional) – Parent object for the QObject. Defaults to None.

_connect_to_theme_change()#

Connect to the theme change signal.

_current_precision() → int#

Get the current precision based on the view range or fixed precision.

_get_transformed_position(x: float, y: float, transform: qtpy.QtGui.QTransform) → tuple[qtpy.QtCore.QPointF, qtpy.QtCore.QPointF]#

Maps the given x and y coordinates to the transformed position using the provided transform. :param x: The x-coordinate to transform. :type x: float :param y: The y-coordinate to transform. :type y: float :param transform: The transformation to apply. :type transform: QTransform

_update_theme(theme: str | None = None)#

Update the theme.

apply_theme(theme: str)#

Apply the theme to the plot.

check_derivatives()#

Checks if the derivatives are enabled and updates the internal state accordingly.

check_log()#

Checks if the x or y axis is in log scale and updates the internal state accordingly.

cleanup()#
clear_markers()#

Clears the markers from the plot.

closest_x_y_value(input_x: float, list_x: list, list_y: list) → tuple#

Find the closest x and y value to the input value.

Parameters:

  • input_x (float) – Input value

  • list_x (list) – List of x values

  • list_y (list) – List of y values

Returns:

Closest x and y value

Return type:

tuple

mouse_clicked(event)#

Handles the mouse clicked event, updating the crosshair position and emitting signals.

Parameters:

event – The mouse clicked event

mouse_moved(event=None, manual_pos=None)#

Handles the mouse moved event, updating the crosshair position and emitting signals.

Parameters:

  • event (object) – The mouse moved event, which contains the scene position.

  • manual_pos (tuple, optional) – A tuple containing the (x, y) coordinates to manually set the crosshair position.

reset()#

Resets the crosshair to its initial state.

scale_emitted_coordinates(x, y)#

Scales the emitted coordinates if the axes are in log scale.

Parameters:

  • x (float) – The x-coordinate

  • y (float) – The y-coordinate

Returns:

The scaled x and y coordinates

Return type:

tuple

snap_to_data(x: float, y: float) → tuple[None, None] | tuple[collections.defaultdict[Any, list], collections.defaultdict[Any, list]]#

Finds the nearest data points to the given x and y coordinates.

Parameters:

  • x (float) – The x-coordinate of the mouse cursor

  • y (float) – The y-coordinate of the mouse cursor

Returns:

x and y values snapped to the nearest data

Return type:

tuple

update_coord_label(pos: tuple)#

Updates the coordinate label based on the crosshair position and axis scales.

Parameters:

pos (tuple) – The (x, y) position of the crosshair.

update_highlighted_curve(curve_index: int)#

Update the highlighted curve in the case of multiple curves in a plot item.

Parameters:

curve_index (int) – The index of curve to highlight

update_markers()#

Update the markers for the crosshair, creating new ones if necessary.

update_markers_on_image_change()#

Update markers when the image changes, e.g. when the image shape or transformation changes.

coord_label#
coordinatesChanged1D#
coordinatesChanged2D#
coordinatesClicked1D#
coordinatesClicked2D#
crosshairChanged#
crosshairClicked#
h_line#
highlighted_curve_index = None#
is_derivative = None#
is_log_x = None#
is_log_y = None#
items = []#
marker_2d_col = None#
marker_2d_row = None#
marker_clicked_1d#
marker_moved_1d#
property min_precision: int#

Lower bound on decimals when dynamic precision is used.

plot_item#
positionChanged#
positionClicked#
property precision: int | None#

Fixed number of decimals; None enables dynamic mode.

proxy#
v_line#
class CrosshairScatterItem(*args, **kargs)#

Bases: pyqtgraph.ScatterPlotItem

Displays a set of x/y points. Instances of this class are created automatically as part of PlotDataItem; these rarely need to be instantiated directly.

The size, shape, pen, and fill brush may be set for each point individually or for all points.

Signals:

sigPlotChanged(self)

Emitted when the data being plotted has changed

sigClicked(self, points, ev)

Emitted when points are clicked. Sends a list of all the points under the mouse pointer.

sigHovered(self, points, ev)

Emitted when the item is hovered. Sends a list of all the points under the mouse pointer.

Accepts the same arguments as setData()

setAlpha(*args, **kwargs)#
setClipToView(state)#
setDownsampling(ds=None, auto=None, method=None)#