# Source code for pyqtgraph.graphicsItems.LinearRegionItem

    from ..Qt import QtGui, QtCore
    from .UIGraphicsItem import UIGraphicsItem
    from .InfiniteLine import InfiniteLine
    from .. import functions as fn
    from .. import debug as debug

    __all__ = ['LinearRegionItem']

    class LinearRegionItem(UIGraphicsItem):
        """
        **Bases:** :class:`UIGraphicsItem <pyqtgraph.UIGraphicsItem>`

        Used for marking a horizontal or vertical region in plots.
        The region can be dragged and is bounded by lines which can be dragged individually.

        ===============================  =============================================================================
        **Signals:**
        sigRegionChangeFinished(self)    Emitted when the user has finished dragging the region (or one of its lines)
                                         and when the region is changed programatically.
        sigRegionChanged(self)           Emitted while the user is dragging the region (or one of its lines)
                                         and when the region is changed programatically.
        ===============================  =============================================================================
        """

        sigRegionChangeFinished = QtCore.Signal(object)
        sigRegionChanged = QtCore.Signal(object)
        Vertical = 0
        Horizontal = 1

        def __init__(self, values=[0,1], orientation=None, brush=None, movable=True, bounds=None):
            """Create a new LinearRegionItem.

            ==============  =====================================================================
            **Arguments:**
            values          A list of the positions of the lines in the region. These are not
                            limits; limits can be set by specifying bounds.
            orientation     Options are LinearRegionItem.Vertical or LinearRegionItem.Horizontal.
                            If not specified it will be vertical.
            brush           Defines the brush that fills the region. Can be any arguments that
                            are valid for :func:`mkBrush <pyqtgraph.mkBrush>`. Default is
                            transparent blue.
            movable         If True, the region and individual lines are movable by the user; if
                            False, they are static.
            bounds          Optional [min, max] bounding values for the region
            ==============  =====================================================================
            """

            UIGraphicsItem.__init__(self)
            if orientation is None:
                orientation = LinearRegionItem.Vertical
            self.orientation = orientation
            self.bounds = QtCore.QRectF()
            self.blockLineSignal = False
            self.moving = False
            self.mouseHovering = False

            if orientation == LinearRegionItem.Horizontal:
                self.lines = [
                    InfiniteLine(QtCore.QPointF(0, values[0]), 0, movable=movable, bounds=bounds),
                    InfiniteLine(QtCore.QPointF(0, values[1]), 0, movable=movable, bounds=bounds)]
            elif orientation == LinearRegionItem.Vertical:
                self.lines = [
                    InfiniteLine(QtCore.QPointF(values[1], 0), 90, movable=movable, bounds=bounds),
                    InfiniteLine(QtCore.QPointF(values[0], 0), 90, movable=movable, bounds=bounds)]
            else:
                raise Exception('Orientation must be one of LinearRegionItem.Vertical or LinearRegionItem.Horizontal')

            for l in self.lines:
                l.setParentItem(self)
                l.sigPositionChangeFinished.connect(self.lineMoveFinished)
                l.sigPositionChanged.connect(self.lineMoved)

            if brush is None:
                brush = QtGui.QBrush(QtGui.QColor(0, 0, 255, 50))
            self.setBrush(brush)

            self.setMovable(movable)

        def getRegion(self):
            """Return the values at the edges of the region."""
            #if self.orientation[0] == 'h':
                #r = (self.bounds.top(), self.bounds.bottom())
            #else:
                #r = (self.bounds.left(), self.bounds.right())
            r = [self.lines[0].value(), self.lines[1].value()]
            return (min(r), max(r))

        def setRegion(self, rgn):
            """Set the values for the edges of the region.

            ==============   ==============================================
            **Arguments:**
            rgn              A list or tuple of the lower and upper values.
            ==============   ==============================================
            """
            if self.lines[0].value() == rgn[0] and self.lines[1].value() == rgn[1]:
                return
            self.blockLineSignal = True
            self.lines[0].setValue(rgn[0])
            self.blockLineSignal = False
            self.lines[1].setValue(rgn[1])
            #self.blockLineSignal = False
            self.lineMoved()
            self.lineMoveFinished()

        def setBrush(self, *br, **kargs):
            """Set the brush that fills the region. Can have any arguments that are valid
            for :func:`mkBrush <pyqtgraph.mkBrush>`.
            """
            self.brush = fn.mkBrush(*br, **kargs)
            self.currentBrush = self.brush

        def setBounds(self, bounds):
            """Optional [min, max] bounding values for the region. To have no bounds on the
            region use [None, None].
            Does not affect the current position of the region unless it is outside the new bounds.
            See :func:`setRegion <pyqtgraph.LinearRegionItem.setRegion>` to set the position
            of the region."""
            for l in self.lines:
                l.setBounds(bounds)

        def setMovable(self, m):
            """Set lines to be movable by the user, or not. If lines are movable, they will
            also accept HoverEvents."""
            for l in self.lines:
                l.setMovable(m)
            self.movable = m
            self.setAcceptHoverEvents(m)

        def boundingRect(self):
            br = UIGraphicsItem.boundingRect(self)
            rng = self.getRegion()
            if self.orientation == LinearRegionItem.Vertical:
                br.setLeft(rng[0])
                br.setRight(rng[1])
            else:
                br.setTop(rng[0])
                br.setBottom(rng[1])
            return br.normalized()

        def paint(self, p, *args):
            profiler = debug.Profiler()
            UIGraphicsItem.paint(self, p, *args)
            p.setBrush(self.currentBrush)
            p.setPen(fn.mkPen(None))
            p.drawRect(self.boundingRect())

        def dataBounds(self, axis, frac=1.0, orthoRange=None):
            if axis == self.orientation:
                return self.getRegion()
            else:
                return None

        def lineMoved(self):
            if self.blockLineSignal:
                return
            self.prepareGeometryChange()
            #self.emit(QtCore.SIGNAL('regionChanged'), self)
            self.sigRegionChanged.emit(self)

        def lineMoveFinished(self):
            #self.emit(QtCore.SIGNAL('regionChangeFinished'), self)
            self.sigRegionChangeFinished.emit(self)

        #def updateBounds(self):
            #vb = self.view().viewRect()
            #vals = [self.lines[0].value(), self.lines[1].value()]
            #if self.orientation[0] == 'h':
                #vb.setTop(min(vals))
                #vb.setBottom(max(vals))
            #else:
                #vb.setLeft(min(vals))
                #vb.setRight(max(vals))
            #if vb != self.bounds:
                #self.bounds = vb
                #self.rect.setRect(vb)

        #def mousePressEvent(self, ev):
            #if not self.movable:
                #ev.ignore()
                #return
            #for l in self.lines:
                #l.mousePressEvent(ev)  ## pass event to both lines so they move together
            ##if self.movable and ev.button() == QtCore.Qt.LeftButton:
                ##ev.accept()
                ##self.pressDelta = self.mapToParent(ev.pos()) - QtCore.QPointF(*self.p)
            ##else:
                ##ev.ignore()

        #def mouseReleaseEvent(self, ev):
            #for l in self.lines:
                #l.mouseReleaseEvent(ev)

        #def mouseMoveEvent(self, ev):
            ##print "move", ev.pos()
            #if not self.movable:
                #return
            #self.lines[0].blockSignals(True)  # only want to update once
            #for l in self.lines:
                #l.mouseMoveEvent(ev)
            #self.lines[0].blockSignals(False)
            ##self.setPos(self.mapToParent(ev.pos()) - self.pressDelta)
            ##self.emit(QtCore.SIGNAL('dragged'), self)

        def mouseDragEvent(self, ev):
            if not self.movable or int(ev.button() & QtCore.Qt.LeftButton) == 0:
                return
            ev.accept()

            if ev.isStart():
                bdp = ev.buttonDownPos()
                self.cursorOffsets = [l.pos() - bdp for l in self.lines]
                self.startPositions = [l.pos() for l in self.lines]
                self.moving = True

            if not self.moving:
                return

            #delta = ev.pos() - ev.lastPos()
            self.lines[0].blockSignals(True)  # only want to update once
            for i, l in enumerate(self.lines):
                l.setPos(self.cursorOffsets[i] + ev.pos())
                #l.setPos(l.pos()+delta)
                #l.mouseDragEvent(ev)
            self.lines[0].blockSignals(False)
            self.prepareGeometryChange()

            if ev.isFinish():
                self.moving = False
                self.sigRegionChangeFinished.emit(self)
            else:
                self.sigRegionChanged.emit(self)

        def mouseClickEvent(self, ev):
            if self.moving and ev.button() == QtCore.Qt.RightButton:
                ev.accept()
                for i, l in enumerate(self.lines):
                    l.setPos(self.startPositions[i])
                self.moving = False
                self.sigRegionChanged.emit(self)
                self.sigRegionChangeFinished.emit(self)

        def hoverEvent(self, ev):
            if self.movable and (not ev.isExit()) and ev.acceptDrags(QtCore.Qt.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:
                c = self.brush.color()
                c.setAlpha(c.alpha() * 2)
                self.currentBrush = fn.mkBrush(c)
            else:
                self.currentBrush = self.brush
            self.update()

        #def hoverEnterEvent(self, ev):
            #print "rgn hover enter"
            #ev.ignore()
            #self.updateHoverBrush()

        #def hoverMoveEvent(self, ev):
            #print "rgn hover move"
            #ev.ignore()
            #self.updateHoverBrush()

        #def hoverLeaveEvent(self, ev):
            #print "rgn hover leave"
            #ev.ignore()
            #self.updateHoverBrush(False)

        #def updateHoverBrush(self, hover=None):
            #if hover is None:
                #scene = self.scene()
                #hover = scene.claimEvent(self, QtCore.Qt.LeftButton, scene.Drag)

            #if hover:
                #self.currentBrush = fn.mkBrush(255, 0,0,100)
            #else:
                #self.currentBrush = self.brush
            #self.update()