fsleyes.editor.editor

This module provides the Editor class, which provides functionality to edit the data in an Image overlay.

class fsleyes.editor.editor.Editor(image, overlayList, displayCtx, recordSelection=False)

Bases: fsleyes.actions.ActionProvider

The Editor class provides functionality to edit the data of an Image overlay. An Editor instance is associated with a specific Image overlay, passed to __init__().

An Editor instance uses a selection.Selection object which allows voxel selections to be made, and keeps track of all changes to both the selection and image data.

The editing process

Making changes to the data in an Image involves two steps:

1. Create a selection

2. Change the value of voxels in that selection

The first step can be peformed by working directly with the Selection object - this is accessible via the getSelection() method. The fillSelection() method can be used to perform the second step.

Some convenience methods are also provided for working with selections:

getSelection	Returns the selection.Selection instance currently in use.
fillSelection	Fills the current selection with the specified value or values.
copySelection	Copies the Image data in the current selection.
pasteSelection	Pastes the data in the given clipboard into the Image that is managed by this Editor.

Change tracking

An Editor instance keeps track of all changes made to the Image data and to the Selection Every selection/data change made is recorded using SelectionChange and ValueChange instances, which are stored in a list. These changes can be undone (and redone), through the undo() and redo() “action” methods (see the actions module). Changes to the Selection object are, by default, only recorded when the selection is cleared. However, you can track all selection changes by initialising an Editor instance with recordSelection=True.

Sometimes it is useful to treat many small changes as a single large change. For example, if a selection is being updated by dragging the mouse across a canvas, storing a separate change for every change in mouse position would result in many small changes which, if the user then wishes to undo, would have to be undone one by one. This problem can be overcome by the use of change groups. Whenever an operation similar to the above begins, you can call the startChangeGroup() method - from now on, all changes will be aggregated into one group. When the operation completes, call the endChangeGroup() to stop group changes. When undoing/redoing changes, all of the changes in a change group will be undone/redone together.

__init__(image, overlayList, displayCtx, recordSelection=False)

Create an Editor.

Parameters

• image – The Image instance being edited.

• overlayList – The OverlayList instance.

• displayCtx – The DisplayContext instance.

• recordSelection – Defaults to False. If True, changes to the selection.Selection are recorded in the change history.

__del__()

Prints a log message.

destroy()

Removes some property listeners, and clears references to objects to prevent memory leaks.

getImage()

Returns the Image associated with this Editor.

getSelection()

Returns the selection.Selection instance currently in use.

clearSelection()

Clears the selection.Selection (see selection.Selection.clearSelection()). If this Editor is not recording all selection changes (recordSelection=False in __init__()), the selection state before being cleared is saved in the change history.

invertSelection()

Inverts the current selection.

fillSelection(newVals)

Fills the current selection with the specified value or values.

Parameters

newVals – A scalar value, or a sequence containing the same number of values as the current selection size.

startChangeGroup()

Starts a change group. All subsequent changes will be grouped together, for undo()/redo() purposes, until a call to endChangeGroup().

endChangeGroup()

Ends a change group previously started by a call to startChangeGroup().

recordChanges(record=True)

Cause this Editor to either record or ignore any changes that are made to the selection or the image data until further notice.

Parameters

record – If True, changes are recorded. Otherwise they are ignored.

ignoreChanges()

Cause this Editor to ignore any changes that are made to the selection or the image data until further notice. Call the recordChanges() method to resume recording changes.

undo()

Un-does the most recent change. Returns a list containing all change objects that were undone - either ValueChange or SelectionChange objects.

redo()

Re-does the most recent undone change. Returns a list containing all change objects that were undone - either ValueChange or SelectionChange objects.

copySelection()

Copies the Image data in the current selection. Returns the data in a format that can be passed directly to the pasteSelection() method of this, or another, Editor instance.

Note

The format of the returned data might change, so I haven’t specified it.

pasteSelection(clipboard)

Pastes the data in the given clipboard into the Image that is managed by this Editor.

The clipboard is assumed to have been created by the copySelection() method of another Editor instance which is managing an Image that has the same resolution and dimensions as the Image managed by this instance.

_Editor__applyChange(change)

Called by the fillSelection() and redo() methods.

Applies the given change (either a ValueChange or a SelectionChange).

_Editor__changeMade(change)

Called by the fillSelection() and __selectionChanged() methods, whenever a data/selection change is made.

Saves the change, and updates the state of the undo()/ redo() methods.

_Editor__makeSlice(offset, shape, volume=None)

Generate a tuple of slice objects and/or integers, suitable for indexing a region of an image at the given offset, with the given shape. If the image has more than three dimensions, the generated slice will index the specified volume (assumed to be a sequence of indices).

_Editor__revertChange(change)

Called by the undo() method. Reverses the change made by the given change object, (either a ValueChange or a SelectionChange)

_Editor__selectionChanged(*a)

Called when the current Selection.selection changes.

Saves a record of the change with a SelectionChange object.

__module__ = 'fsleyes.editor.editor'

class fsleyes.editor.editor.ValueChange(overlay, volume, offset, oldVals, newVals)

Bases: object

Represents a change which has been made to the data for an Image instance. Stores the location, the old values, and the new values.

__init__(overlay, volume, offset, oldVals, newVals)

Create a ValueChange.

Parameters

• overlay – The Image instance.

• volume – Sequence of volume indices, if overlay has more than 3 dimensions.

• offset – Location (voxel coordinates) of the change.

• oldVals – A numpy array containing the old image values.

• newVals – A numpy array containing the new image values.

__dict__ = mappingproxy({'__module__': 'fsleyes.editor.editor', '__doc__': 'Represents a change which has been made to the data for an\n :class:`.Image` instance. Stores the location, the old values,\n and the new values.\n ', '__init__': <function ValueChange.__init__>, '__dict__': <attribute '__dict__' of 'ValueChange' objects>, '__weakref__': <attribute '__weakref__' of 'ValueChange' objects>})

__module__ = 'fsleyes.editor.editor'

__weakref__

list of weak references to the object (if defined)

class fsleyes.editor.editor.SelectionChange(overlay, offset, oldSelection, newSelection)

Bases: object

Represents a change which has been made to a selection.Selection instance. Stores the location, the old selection, and the new selection.

__init__(overlay, offset, oldSelection, newSelection)

Create a SelectionChange.

Parameters

• overlay – The Image instance.

• offset – Location (voxel coordinates) of the change.

• oldSelection – A numpy array containing the old selection.

• newSelection – A numpy array containing the new selection.

__dict__ = mappingproxy({'__module__': 'fsleyes.editor.editor', '__doc__': 'Represents a change which has been made to a\n :class:`.selection.Selection` instance. Stores the location, the old\n selection, and the new selection.\n ', '__init__': <function SelectionChange.__init__>, '__dict__': <attribute '__dict__' of 'SelectionChange' objects>, '__weakref__': <attribute '__weakref__' of 'SelectionChange' objects>})

__module__ = 'fsleyes.editor.editor'

__weakref__

list of weak references to the object (if defined)