viewer

def block_all(function):
    """Block all events on canvas and view while changes are being made."""
    @wraps(function)
    def wrapper(*args, **kwargs):
        viewer = args[0]
        viewer.canvas.events.block_all()
        viewer.view3d.events.block_all()
        try:
            # Execute function
            res = function(*args, **kwargs)
        except BaseException:
            raise
        finally:
            viewer.canvas.events.unblock_all()
            viewer.view3d.events.unblock_all()
        # Return result
        return res
    return wrapper

def block_canvas(function):
    """ Decorator to block all events on canvas while changes are being made.
    """
    @wraps(function)
    def wrapper(*args, **kwargs):
        viewer = args[0]
        viewer.canvas.events.block_all()
        try:
            # Execute function
            res = function(*args, **kwargs)
        except BaseException:
            raise
        finally:
            viewer.canvas.events.unblock_all()
        # Return result
        return res
    return wrapper

def on_key_press(event):
    """Manage keyboard shortcuts for canvas."""
    canvas = event.source
    viewer = canvas._wrapper

    if event.text.lower() == 'o':
        viewer.toggle_overlay()
    elif event.text.lower() == 'l':
        viewer.show_legend = viewer.show_legend is False
    elif event.text.lower() == 'd':
        viewer.selected = []
    elif event.text.lower() == 'q':
        viewer._cycle_neurons(-1)
    elif event.text.lower() == 'w':
        viewer._cycle_neurons(1)
    elif event.text.lower() == 'h':
        viewer.hide_selected()
    elif event.text.lower() == 'u':
        viewer.unhide_neurons(check_alpha=True)
    elif event.text.lower() == 'f':
        viewer._toggle_fps()
    elif event.text.lower() == 'p':
        viewer.toggle_picking()
    elif event.text.lower() == 'b':
        viewer.toggle_bounds()
    elif event.text.lower() == '1':
        viewer.set_view('XY')
    elif event.text.lower() == '2':
        viewer.set_view('XZ')
    elif event.text.lower() == '3':
        viewer.set_view('YZ')

def on_mouse_press(event):
    """Manage picking on canvas."""
    canvas = event.source
    viewer = canvas._wrapper

    try:
        viewer.interactive = False
        canvas._overlay.interactive = False
        vis_at = viewer.visuals_at([event.pos[0] + 15,
                                    event.pos[1] + 15])
    finally:
        viewer.interactive = True
        canvas._overlay.interactive = True

    logger.debug(f'Mouse press at {event.pos}: {vis_at}')

    modifiers = [key.name for key in event.modifiers]
    if event.modifiers:
        logger.debug(f'Modifiers found: {modifiers}')

    # Iterate over visuals in this canvas at cursor position
    for v in vis_at:
        # Skip views
        if isinstance(v, scene.widgets.ViewBox):
            continue
        # If legend entry, toggle visibility
        elif isinstance(v, scene.visuals.Text):
            viewer.toggle_neurons(v._object_id)
            break
        # If control modifier, try snapping cursor
        if 'Control' in modifiers:
            viewer._snap_cursor(event.pos, v,
                                open_browser='Shift' in modifiers)
            break
        # If shift modifier, add to/remove from current selection
        elif (isinstance(v, scene.visuals.VisualNode)
              and getattr(v, '_id', None)
              and 'Shift' in modifiers):
            if v._id not in set(viewer.selected):
                viewer.selected = np.append(viewer.selected, v._id).astype('object')
            else:
                viewer.selected = viewer.selected[viewer.selected != v._id]
            break

def on_resize(event):
    """Keep overlay in place upon resize."""
    viewer = event.source._wrapper
    viewer._shortcuts.pos = (10, event.size[1])
    viewer._picking_text.pos = (10, event.size[1] - 10)
    viewer._fps_text.pos = (event.size[0] - 10, 10)

def to_rgba(c, alpha=None):
    """Convert color or array of colors to RGBA.

    matplotlib.colors.to_rgba can't deal with vispy color arrays.
    """
    # Vispy color arrays (used on meshes) have an _rgba property
    if hasattr(c, '_rgba'):
        c = c._rgba

    # Make sure we deal with an array
    c = np.asarray(c)

    if c.ndim == 2:
        if c.shape[1] == 3:
            c = np.insert(c,
                          3,
                          np.ones(c.shape[0]),
                          axis=1)

        if not isinstance(alpha, type(None)):
            c[:, 3] = alpha
    elif c.ndim == 1:
        if c.shape[0] == 3:
            c = np.insert(c, 3, 1)

        if not isinstance(alpha, type(None)):
            c[3] = alpha
    else:
        raise ValueError(f'Got {c.ndim} dimensional array of colors.')

    return c