# Source code for pyqtgraph.graphicsItems.InfiniteLine

    from math import atan2, degrees

    import numpy as np

    from .. import functions as fn
    from ..Point import Point
    from ..Qt import QtCore, QtGui
    from .GraphicsItem import GraphicsItem
    from .GraphicsObject import GraphicsObject
    from .TextItem import TextItem
    from .ViewBox import ViewBox

    __all__ = ['InfiniteLine', 'InfLineLabel']

    class InfiniteLine(GraphicsObject):
        """
        **Bases:** :class:`GraphicsObject <pyqtgraph.GraphicsObject>`

        Displays a line of infinite length.
        This line may be dragged to indicate a position in data coordinates.

        =============================== ===================================================
        **Signals:**
        sigDragged(self)
        sigPositionChangeFinished(self)
        sigPositionChanged(self)
        sigClicked(self, ev)
        =============================== ===================================================
        """

        sigDragged = QtCore.Signal(object)
        sigPositionChangeFinished = QtCore.Signal(object)
        sigPositionChanged = QtCore.Signal(object)
        sigClicked = QtCore.Signal(object, object)

        def __init__(self, pos=None, angle=90, pen=None, movable=False, bounds=None,
                     hoverPen=None, label=None, labelOpts=None, span=(0, 1), markers=None,
                     name=None):
            """
            =============== ==================================================================
            **Arguments:**
            pos             Position of the line. This can be a QPointF or a single value for
                            vertical/horizontal lines.
            angle           Angle of line in degrees. 0 is horizontal, 90 is vertical.
            pen             Pen to use when drawing line. Can be any arguments that are valid
                            for :func:`mkPen <pyqtgraph.mkPen>`. Default pen is transparent
                            yellow.
            hoverPen        Pen to use when the mouse cursor hovers over the line.
                            Only used when movable=True.
            movable         If True, the line can be dragged to a new position by the user.
            bounds          Optional [min, max] bounding values. Bounds are only valid if the
                            line is vertical or horizontal.
            hoverPen        Pen to use when drawing line when hovering over it. Can be any
                            arguments that are valid for :func:`mkPen <pyqtgraph.mkPen>`.
                            Default pen is red.
            label           Text to be displayed in a label attached to the line, or
                            None to show no label (default is None). May optionally
                            include formatting strings to display the line value.
            labelOpts       A dict of keyword arguments to use when constructing the
                            text label. See :class:`InfLineLabel <pyqtgraph.graphicsItems.InfiniteLine.InfLineLabel>`.
            span            Optional tuple (min, max) giving the range over the view to draw
                            the line. For example, with a vertical line, use span=(0.5, 1)
                            to draw only on the top half of the view.
            markers         List of (marker, position, size) tuples, one per marker to display
                            on the line. See the addMarker method.
            name            Name of the item
            =============== ==================================================================
            """
            self._boundingRect = None

            self._name = name

            GraphicsObject.__init__(self)

            if bounds is None:              ## allowed value boundaries for orthogonal lines
                self.maxRange = [None, None]
            else:
                self.maxRange = bounds
            self.moving = False
            self.setMovable(movable)
            self.mouseHovering = False
            self.p = [0, 0]
            self.setAngle(angle)

            if pos is None:
                pos = Point(0,0)
            self.setPos(pos)

            if pen is None:
                pen = (200, 200, 100)
            self.setPen(pen)

            if hoverPen is None:
                self.setHoverPen(color=(255,0,0), width=self.pen.width())
            else:
                self.setHoverPen(hoverPen)

            self.span = span
            self.currentPen = self.pen

            self.markers = []
            self._maxMarkerSize = 0
            if markers is not None:
                for m in markers:
                    self.addMarker(*m)

            # Cache variables for managing bounds
            self._endPoints = [0, 1] #
            self._bounds = None
            self._lastViewSize = None

            if label is not None:
                labelOpts = {} if labelOpts is None else labelOpts
                self.label = InfLineLabel(self, text=label, **labelOpts)

        def setMovable(self, m):
            """Set whether the line is movable by the user."""
            self.movable = m
            self.setAcceptHoverEvents(m)

        def setBounds(self, bounds):
            """Set the (minimum, maximum) allowable values when dragging."""
            self.maxRange = bounds
            self.setValue(self.value())

        def bounds(self):
            """Return the (minimum, maximum) values allowed when dragging.
            """
            return self.maxRange[:]

        def setPen(self, *args, **kwargs):
            """Set the pen for drawing the line. Allowable arguments are any that are valid
            for :func:`mkPen <pyqtgraph.mkPen>`."""
            self.pen = fn.mkPen(*args, **kwargs)
            if not self.mouseHovering:
                self.currentPen = self.pen
                self.update()

        def setHoverPen(self, *args, **kwargs):
            """Set the pen for drawing the line while the mouse hovers over it.
            Allowable arguments are any that are valid
            for :func:`mkPen <pyqtgraph.mkPen>`.

            If the line is not movable, then hovering is also disabled.

            Added in version 0.9.9."""
            # If user did not supply a width, then copy it from pen
            widthSpecified = ((len(args) == 1 and
                               (isinstance(args[0], QtGui.QPen) or
                               (isinstance(args[0], dict) and 'width' in args[0]))
                              ) or 'width' in kwargs)
            self.hoverPen = fn.mkPen(*args, **kwargs)
            if not widthSpecified:
                self.hoverPen.setWidth(self.pen.width())

            if self.mouseHovering:
                self.currentPen = self.hoverPen
                self.update()

        def addMarker(self, marker, position=0.5, size=10.0):
            """Add a marker to be displayed on the line.

            ============= =========================================================
            **Arguments**
            marker        String indicating the style of marker to add:
                          ``'<|'``, ``'|>'``, ``'>|'``, ``'|<'``, ``'<|>'``,
                          ``'>|<'``, ``'^'``, ``'v'``, ``'o'``
            position      Position (0.0-1.0) along the visible extent of the line
                          to place the marker. Default is 0.5.
            size          Size of the marker in pixels. Default is 10.0.
            ============= =========================================================
            """
            path = QtGui.QPainterPath()
            if marker == 'o':
                path.addEllipse(QtCore.QRectF(-0.5, -0.5, 1, 1))
            if '<|' in marker:
                p = QtGui.QPolygonF([Point(0.5, 0), Point(0, -0.5), Point(-0.5, 0)])
                path.addPolygon(p)
                path.closeSubpath()
            if '|>' in marker:
                p = QtGui.QPolygonF([Point(0.5, 0), Point(0, 0.5), Point(-0.5, 0)])
                path.addPolygon(p)
                path.closeSubpath()
            if '>|' in marker:
                p = QtGui.QPolygonF([Point(0.5, -0.5), Point(0, 0), Point(-0.5, -0.5)])
                path.addPolygon(p)
                path.closeSubpath()
            if '|<' in marker:
                p = QtGui.QPolygonF([Point(0.5, 0.5), Point(0, 0), Point(-0.5, 0.5)])
                path.addPolygon(p)
                path.closeSubpath()
            if '^' in marker:
                p = QtGui.QPolygonF([Point(0, -0.5), Point(0.5, 0), Point(0, 0.5)])
                path.addPolygon(p)
                path.closeSubpath()
            if 'v' in marker:
                p = QtGui.QPolygonF([Point(0, -0.5), Point(-0.5, 0), Point(0, 0.5)])
                path.addPolygon(p)
                path.closeSubpath()

            self.markers.append((path, position, size))
            self._maxMarkerSize = max([m[2] / 2. for m in self.markers])
            self.update()

        def clearMarkers(self):
            """ Remove all markers from this line.
            """
            self.markers = []
            self._maxMarkerSize = 0
            self.update()

        def setAngle(self, angle):
            """
            Takes angle argument in degrees.
            0 is horizontal; 90 is vertical.

            Note that the use of value() and setValue() changes if the line is
            not vertical or horizontal.
            """
            self.angle = angle #((angle+45) % 180) - 45   ##  -45 <= angle < 135
            self.resetTransform()
            self.setRotation(self.angle)
            self.update()

        def setPos(self, pos):

            if isinstance(pos, (list, tuple, np.ndarray)) and not np.ndim(pos) == 0:
                newPos = list(pos)
            elif isinstance(pos, QtCore.QPointF):
                newPos = [pos.x(), pos.y()]
            else:
                if self.angle == 90:
                    newPos = [pos, 0]
                elif self.angle == 0:
                    newPos = [0, pos]
                else:
                    raise Exception("Must specify 2D coordinate for non-orthogonal lines.")

            ## check bounds (only works for orthogonal lines)
            if self.angle == 90:
                if self.maxRange[0] is not None:
                    newPos[0] = max(newPos[0], self.maxRange[0])
                if self.maxRange[1] is not None:
                    newPos[0] = min(newPos[0], self.maxRange[1])
            elif self.angle == 0:
                if self.maxRange[0] is not None:
                    newPos[1] = max(newPos[1], self.maxRange[0])
                if self.maxRange[1] is not None:
                    newPos[1] = min(newPos[1], self.maxRange[1])

            if self.p != newPos:
                self.p = newPos
                self.viewTransformChanged()
                GraphicsObject.setPos(self, Point(self.p))
                self.sigPositionChanged.emit(self)

        def getXPos(self):
            return self.p[0]

        def getYPos(self):
            return self.p[1]

        def getPos(self):
            return self.p

        def value(self):
            """Return the value of the line. Will be a single number for horizontal and
            vertical lines, and a list of [x,y] values for diagonal lines."""
            if self.angle%180 == 0:
                return self.getYPos()
            elif self.angle%180 == 90:
                return self.getXPos()
            else:
                return self.getPos()

        def setValue(self, v):
            """Set the position of the line. If line is horizontal or vertical, v can be
            a single value. Otherwise, a 2D coordinate must be specified (list, tuple and
            QPointF are all acceptable)."""
            self.setPos(v)

        ## broken in 4.7
        #def itemChange(self, change, val):
            #if change in [self.GraphicsItemChange.ItemScenePositionHasChanged, self.GraphicsItemChange.ItemSceneHasChanged]:
                #self.updateLine()
                #print "update", change
                #print self.getBoundingParents()
            #else:
                #print "ignore", change
            #return GraphicsObject.itemChange(self, change, val)

        def setSpan(self, mn, mx):
            if self.span != (mn, mx):
                self.span = (mn, mx)
                self.update()

        def _computeBoundingRect(self):
            #br = UIGraphicsItem.boundingRect(self)
            vr = self.viewRect()  # bounds of containing ViewBox mapped to local coords.
            if vr is None:
                return QtCore.QRectF()

            # compute the pixel size orthogonal to the line
            # this is more complicated than it seems, maybe it can be simplified
            _, ortho = self.pixelVectors(direction=Point(1, 0))
            px = 0 if ortho is None else ortho.y()

            pw = max(self.pen.width() / 2, self.hoverPen.width() / 2)
            w = (self._maxMarkerSize + pw + 1) * px
            br = QtCore.QRectF(vr)
            br.setBottom(-w)
            br.setTop(w)

            length = br.width()
            left = br.left() + length * self.span[0]
            right = br.left() + length * self.span[1]
            br.setLeft(left)
            br.setRight(right)
            br = br.normalized()

            vs = self.getViewBox().size()

            if self._bounds != br or self._lastViewSize != vs:
                self._bounds = br
                self._lastViewSize = vs
                self.prepareGeometryChange()

            self._endPoints = (left, right)
            self._lastViewRect = vr

            return self._bounds

        def boundingRect(self):
            if self._boundingRect is None:
                self._boundingRect = self._computeBoundingRect()
            return self._boundingRect

        def paint(self, p, *args):
            if self.angle % 180 not in (0, 90):
                p.setRenderHint(p.RenderHint.Antialiasing)

            left, right = self._endPoints
            pen = self.currentPen
            pen.setJoinStyle(QtCore.Qt.PenJoinStyle.MiterJoin)
            p.setPen(pen)
            p.drawLine(Point(left, 0), Point(right, 0))

            if len(self.markers) == 0:
                return

            # paint markers in native coordinate system
            tr = p.transform()
            p.resetTransform()

            start = tr.map(Point(left, 0))
            end = tr.map(Point(right, 0))
            up = tr.map(Point(left, 1))
            dif = end - start
            length = Point(dif).length()
            angle = degrees(atan2(dif.y(), dif.x()))

            p.translate(start)
            p.rotate(angle)

            up = up - start
            det = up.x() * dif.y() - dif.x() * up.y()
            p.scale(1, 1 if det > 0 else -1)

            p.setBrush(fn.mkBrush(self.currentPen.color()))
            #p.setPen(fn.mkPen(None))
            tr = p.transform()
            for path, pos, size in self.markers:
                p.setTransform(tr)
                x = length * pos
                p.translate(x, 0)
                p.scale(size, size)
                p.drawPath(path)

        def dataBounds(self, axis, frac=1.0, orthoRange=None):
            if axis == 0:
                return None   ## x axis should never be auto-scaled
            else:
                return (0,0)

        def mouseDragEvent(self, ev):
            if self.movable and ev.button() == QtCore.Qt.MouseButton.LeftButton:
                if ev.isStart():
                    self.moving = True
                    self.cursorOffset = self.pos() - self.mapToParent(ev.buttonDownPos())
                    self.startPosition = self.pos()
                ev.accept()

                if not self.moving:
                    return

                self.setPos(self.cursorOffset + self.mapToParent(ev.pos()))
                self.sigDragged.emit(self)
                if ev.isFinish():
                    self.moving = False
                    self.sigPositionChangeFinished.emit(self)

        def mouseClickEvent(self, ev):
            self.sigClicked.emit(self, ev)
            if self.moving and ev.button() == QtCore.Qt.MouseButton.RightButton:
                ev.accept()
                self.setPos(self.startPosition)
                self.moving = False
                self.sigDragged.emit(self)
                self.sigPositionChangeFinished.emit(self)

        def hoverEvent(self, ev):
            if (not ev.isExit()) and self.movable and ev.acceptDrags(QtCore.Qt.MouseButton.LeftButton):
                self.setMouseHover(True)
            else:
                self.setMouseHover(False)

        def setMouseHover(self, hover):
            ## Inform the item that the mouse is (not) hovering over it
            if self.mouseHovering == hover:
                return
            self.mouseHovering = hover
            if hover:
                self.currentPen = self.hoverPen
            else:
                self.currentPen = self.pen
            self.update()

        def viewTransformChanged(self):
            """
            Called whenever the transformation matrix of the view has changed.
            (eg, the view range has changed or the view was resized)
            """
            self._boundingRect = None
            GraphicsItem.viewTransformChanged(self)

        def setName(self, name):
            self._name = name

        def name(self):
            return self._name

    class InfLineLabel(TextItem):
        """
        A TextItem that attaches itself to an InfiniteLine.

        This class extends TextItem with the following features:

          * Automatically positions adjacent to the line at a fixed position along
            the line and within the view box.
          * Automatically reformats text when the line value has changed.
          * Can optionally be dragged to change its location along the line.
          * Optionally aligns to its parent line.

        =============== ==================================================================
        **Arguments:**
        line            The InfiniteLine to which this label will be attached.
        text            String to display in the label. May contain a {value} formatting
                        string to display the current value of the line.
        movable         Bool; if True, then the label can be dragged along the line.
        position        Relative position (0.0-1.0) within the view to position the label
                        along the line.
        anchors         List of (x,y) pairs giving the text anchor positions that should
                        be used when the line is moved to one side of the view or the
                        other. This allows text to switch to the opposite side of the line
                        as it approaches the edge of the view. These are automatically
                        selected for some common cases, but may be specified if the
                        default values give unexpected results.
        =============== ==================================================================

        All extra keyword arguments are passed to TextItem. A particularly useful
        option here is to use `rotateAxis=(1, 0)`, which will cause the text to
        be automatically rotated parallel to the line.
        """

        def __init__(self, line, text="", movable=False, position=0.5, anchors=None, **kwds):
            self.line = line
            self.movable = movable
            self.moving = False
            self.orthoPos = position  # text will always be placed on the line at a position relative to view bounds
            self.format = text
            self.line.sigPositionChanged.connect(self.valueChanged)
            self._endpoints = (None, None)
            if anchors is None:
                # automatically pick sensible anchors
                rax = kwds.get('rotateAxis', None)
                if rax is not None:
                    if tuple(rax) == (1,0):
                        anchors = [(0.5, 0), (0.5, 1)]
                    else:
                        anchors = [(0, 0.5), (1, 0.5)]
                else:
                    if line.angle % 180 == 0:
                        anchors = [(0.5, 0), (0.5, 1)]
                    else:
                        anchors = [(0, 0.5), (1, 0.5)]

            self.anchors = anchors
            TextItem.__init__(self, **kwds)
            self.setParentItem(line)
            self.valueChanged()

        def valueChanged(self):
            if not self.isVisible():
                return
            value = self.line.value()
            self.setText(self.format.format(value=value))
            self.updatePosition()

        def getEndpoints(self):
            # calculate points where line intersects view box
            # (in line coordinates)
            if self._endpoints[0] is None:
                lr = self.line.boundingRect()
                pt1 = Point(lr.left(), 0)
                pt2 = Point(lr.right(), 0)

                if self.line.angle % 90 != 0:
                    # more expensive to find text position for oblique lines.
                    view = self.getViewBox()
                    if not self.isVisible() or not isinstance(view, ViewBox):
                        # not in a viewbox, skip update
                        return (None, None)
                    p = QtGui.QPainterPath()
                    p.moveTo(pt1)
                    p.lineTo(pt2)
                    p = self.line.itemTransform(view)[0].map(p)
                    vr = QtGui.QPainterPath()
                    vr.addRect(view.boundingRect())
                    paths = vr.intersected(p).toSubpathPolygons(QtGui.QTransform())
                    if len(paths) > 0:
                        l = list(paths[0])
                        pt1 = self.line.mapFromItem(view, l[0])
                        pt2 = self.line.mapFromItem(view, l[1])
                self._endpoints = (pt1, pt2)
            return self._endpoints

        def updatePosition(self):
            # update text position to relative view location along line
            self._endpoints = (None, None)
            pt1, pt2 = self.getEndpoints()
            if pt1 is None:
                return
            pt = pt2 * self.orthoPos + pt1 * (1-self.orthoPos)
            self.setPos(pt)

            # update anchor to keep text visible as it nears the view box edge
            vr = self.line.viewRect()
            if vr is not None:
                self.setAnchor(self.anchors[0 if vr.center().y() < 0 else 1])

        def setVisible(self, v):
            TextItem.setVisible(self, v)
            if v:
                self.valueChanged()

        def setMovable(self, m):
            """Set whether this label is movable by dragging along the line.
            """
            self.movable = m
            self.setAcceptHoverEvents(m)

        def setPosition(self, p):
            """Set the relative position (0.0-1.0) of this label within the view box
            and along the line.

            For horizontal (angle=0) and vertical (angle=90) lines, a value of 0.0
            places the text at the bottom or left of the view, respectively.
            """
            self.orthoPos = p
            self.updatePosition()

        def setFormat(self, text):
            """Set the text format string for this label.

            May optionally contain "{value}" to include the lines current value
            (the text will be reformatted whenever the line is moved).
            """
            self.format = text
            self.valueChanged()

        def mouseDragEvent(self, ev):
            if self.movable and ev.button() == QtCore.Qt.MouseButton.LeftButton:
                if ev.isStart():
                    self._moving = True
                    self._cursorOffset = self._posToRel(ev.buttonDownPos())
                    self._startPosition = self.orthoPos
                ev.accept()

                if not self._moving:
                    return

                rel = self._posToRel(ev.pos())
                self.orthoPos = fn.clip_scalar(self._startPosition + rel - self._cursorOffset, 0., 1.)
                self.updatePosition()
                if ev.isFinish():
                    self._moving = False

        def mouseClickEvent(self, ev):
            if self.moving and ev.button() == QtCore.Qt.MouseButton.RightButton:
                ev.accept()
                self.orthoPos = self._startPosition
                self.moving = False

        def hoverEvent(self, ev):
            if not ev.isExit() and self.movable:
                ev.acceptDrags(QtCore.Qt.MouseButton.LeftButton)

        def viewTransformChanged(self):
            GraphicsItem.viewTransformChanged(self)
            self.updatePosition()
            TextItem.viewTransformChanged(self)

        def _posToRel(self, pos):
            # convert local position to relative position along line between view bounds
            pt1, pt2 = self.getEndpoints()
            if pt1 is None:
                return 0
            pos = self.mapToParent(pos)
            return (pos.x() - pt1.x()) / (pt2.x()-pt1.x())