# Source code for pyqtgraph.graphicsItems.ImageItem

    from __future__ import division

    from ..Qt import QtGui, QtCore
    import numpy as np
    import collections
    from .. import functions as fn
    from .. import debug as debug
    from .GraphicsObject import GraphicsObject
    from ..Point import Point

    __all__ = ['ImageItem']

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

        GraphicsObject displaying an image. Optimized for rapid update (ie video display).
        This item displays either a 2D numpy array (height, width) or
        a 3D array (height, width, RGBa). This array is optionally scaled (see
        :func:`setLevels <pyqtgraph.ImageItem.setLevels>`) and/or colored
        with a lookup table (see :func:`setLookupTable <pyqtgraph.ImageItem.setLookupTable>`)
        before being displayed.

        ImageItem is frequently used in conjunction with
        :class:`HistogramLUTItem <pyqtgraph.HistogramLUTItem>` or
        :class:`HistogramLUTWidget <pyqtgraph.HistogramLUTWidget>` to provide a GUI
        for controlling the levels and lookup table used to display the image.
        """

        sigImageChanged = QtCore.Signal()
        sigRemoveRequested = QtCore.Signal(object)  # self; emitted when 'remove' is selected from context menu

        def __init__(self, image=None, **kargs):
            """
            See :func:`setImage <pyqtgraph.ImageItem.setImage>` for all allowed initialization arguments.
            """
            GraphicsObject.__init__(self)
            self.menu = None
            self.image = None   ## original image data
            self.qimage = None  ## rendered image for display

            self.paintMode = None

            self.levels = None  ## [min, max] or [[redMin, redMax], ...]
            self.lut = None
            self.autoDownsample = False

            self.drawKernel = None
            self.border = None
            self.removable = False

            if image is not None:
                self.setImage(image, **kargs)
            else:
                self.setOpts(**kargs)

        def setCompositionMode(self, mode):
            """Change the composition mode of the item (see QPainter::CompositionMode
            in the Qt documentation). This is useful when overlaying multiple ImageItems.

            ============================================  ============================================================
            **Most common arguments:**
            QtGui.QPainter.CompositionMode_SourceOver     Default; image replaces the background if it
                                                          is opaque. Otherwise, it uses the alpha channel to blend
                                                          the image with the background.
            QtGui.QPainter.CompositionMode_Overlay        The image color is mixed with the background color to
                                                          reflect the lightness or darkness of the background.
            QtGui.QPainter.CompositionMode_Plus           Both the alpha and color of the image and background pixels
                                                          are added together.
            QtGui.QPainter.CompositionMode_Multiply       The output is the image color multiplied by the background.
            ============================================  ============================================================
            """
            self.paintMode = mode
            self.update()

        ## use setOpacity instead.
        #def setAlpha(self, alpha):
            #self.setOpacity(alpha)
            #self.updateImage()

        def setBorder(self, b):
            self.border = fn.mkPen(b)
            self.update()

        def width(self):
            if self.image is None:
                return None
            return self.image.shape[0]

        def height(self):
            if self.image is None:
                return None
            return self.image.shape[1]

        def boundingRect(self):
            if self.image is None:
                return QtCore.QRectF(0., 0., 0., 0.)
            return QtCore.QRectF(0., 0., float(self.width()), float(self.height()))

        #def setClipLevel(self, level=None):
            #self.clipLevel = level
            #self.updateImage()

        #def paint(self, p, opt, widget):
            #pass
            #if self.pixmap is not None:
                #p.drawPixmap(0, 0, self.pixmap)
                #print "paint"

        def setLevels(self, levels, update=True):
            """
            Set image scaling levels. Can be one of:

            * [blackLevel, whiteLevel]
            * [[minRed, maxRed], [minGreen, maxGreen], [minBlue, maxBlue]]

            Only the first format is compatible with lookup tables. See :func:`makeARGB <pyqtgraph.makeARGB>`
            for more details on how levels are applied.
            """
            self.levels = levels
            if update:
                self.updateImage()

        def getLevels(self):
            return self.levels
            #return self.whiteLevel, self.blackLevel

        def setLookupTable(self, lut, update=True):
            """
            Set the lookup table (numpy array) to use for this image. (see
            :func:`makeARGB <pyqtgraph.makeARGB>` for more information on how this is used).
            Optionally, lut can be a callable that accepts the current image as an
            argument and returns the lookup table to use.

            Ordinarily, this table is supplied by a :class:`HistogramLUTItem <pyqtgraph.HistogramLUTItem>`
            or :class:`GradientEditorItem <pyqtgraph.GradientEditorItem>`.
            """
            self.lut = lut
            if update:
                self.updateImage()

        def setAutoDownsample(self, ads):
            """
            Set the automatic downsampling mode for this ImageItem.

            Added in version 0.9.9
            """
            self.autoDownsample = ads
            self.qimage = None
            self.update()

        def setOpts(self, update=True, **kargs):

            if 'lut' in kargs:
                self.setLookupTable(kargs['lut'], update=update)
            if 'levels' in kargs:
                self.setLevels(kargs['levels'], update=update)
            #if 'clipLevel' in kargs:
                #self.setClipLevel(kargs['clipLevel'])
            if 'opacity' in kargs:
                self.setOpacity(kargs['opacity'])
            if 'compositionMode' in kargs:
                self.setCompositionMode(kargs['compositionMode'])
            if 'border' in kargs:
                self.setBorder(kargs['border'])
            if 'removable' in kargs:
                self.removable = kargs['removable']
                self.menu = None
            if 'autoDownsample' in kargs:
                self.setAutoDownsample(kargs['autoDownsample'])
            if update:
                self.update()

        def setRect(self, rect):
            """Scale and translate the image to fit within rect (must be a QRect or QRectF)."""
            self.resetTransform()
            self.translate(rect.left(), rect.top())
            self.scale(rect.width() / self.width(), rect.height() / self.height())

        def clear(self):
            self.image = None
            self.prepareGeometryChange()
            self.informViewBoundsChanged()
            self.update()

        def setImage(self, image=None, autoLevels=None, **kargs):
            """
            Update the image displayed by this item. For more information on how the image
            is processed before displaying, see :func:`makeARGB <pyqtgraph.makeARGB>`

            =================  =========================================================================
            **Arguments:**
            image              (numpy array) Specifies the image data. May be 2D (width, height) or
                               3D (width, height, RGBa). The array dtype must be integer or floating
                               point of any bit depth. For 3D arrays, the third dimension must
                               be of length 3 (RGB) or 4 (RGBA).
            autoLevels         (bool) If True, this forces the image to automatically select
                               levels based on the maximum and minimum values in the data.
                               By default, this argument is true unless the levels argument is
                               given.
            lut                (numpy array) The color lookup table to use when displaying the image.
                               See :func:`setLookupTable <pyqtgraph.ImageItem.setLookupTable>`.
            levels             (min, max) The minimum and maximum values to use when rescaling the image
                               data. By default, this will be set to the minimum and maximum values
                               in the image. If the image array has dtype uint8, no rescaling is necessary.
            opacity            (float 0.0-1.0)
            compositionMode    see :func:`setCompositionMode <pyqtgraph.ImageItem.setCompositionMode>`
            border             Sets the pen used when drawing the image border. Default is None.
            autoDownsample     (bool) If True, the image is automatically downsampled to match the
                               screen resolution. This improves performance for large images and
                               reduces aliasing.
            =================  =========================================================================
            """
            profile = debug.Profiler()

            gotNewData = False
            if image is None:
                if self.image is None:
                    return
            else:
                gotNewData = True
                shapeChanged = (self.image is None or image.shape != self.image.shape)
                self.image = image.view(np.ndarray)
                if self.image.shape[0] > 2**15-1 or self.image.shape[1] > 2**15-1:
                    if 'autoDownsample' not in kargs:
                        kargs['autoDownsample'] = True
                if shapeChanged:
                    self.prepareGeometryChange()
                    self.informViewBoundsChanged()

            profile()

            if autoLevels is None:
                if 'levels' in kargs:
                    autoLevels = False
                else:
                    autoLevels = True
            if autoLevels:
                img = self.image
                while img.size > 2**16:
                    img = img[::2, ::2]
                mn, mx = img.min(), img.max()
                if mn == mx:
                    mn = 0
                    mx = 255
                kargs['levels'] = [mn,mx]

            profile()

            self.setOpts(update=False, **kargs)

            profile()

            self.qimage = None
            self.update()

            profile()

            if gotNewData:
                self.sigImageChanged.emit()

        def updateImage(self, *args, **kargs):
            ## used for re-rendering qimage from self.image.

            ## can we make any assumptions here that speed things up?
            ## dtype, range, size are all the same?
            defaults = {
                'autoLevels': False,
            }
            defaults.update(kargs)
            return self.setImage(*args, **defaults)

        def render(self):
            # Convert data to QImage for display.

            profile = debug.Profiler()
            if self.image is None or self.image.size == 0:
                return
            if isinstance(self.lut, collections.Callable):
                lut = self.lut(self.image)
            else:
                lut = self.lut

            if self.autoDownsample:
                # reduce dimensions of image based on screen resolution
                o = self.mapToDevice(QtCore.QPointF(0,0))
                x = self.mapToDevice(QtCore.QPointF(1,0))
                y = self.mapToDevice(QtCore.QPointF(0,1))
                w = Point(x-o).length()
                h = Point(y-o).length()
                xds = max(1, int(1/w))
                yds = max(1, int(1/h))
                image = fn.downsample(self.image, xds, axis=0)
                image = fn.downsample(image, yds, axis=1)
            else:
                image = self.image

            argb, alpha = fn.makeARGB(image.transpose((1, 0, 2)[:image.ndim]), lut=lut, levels=self.levels)
            self.qimage = fn.makeQImage(argb, alpha, transpose=False)

        def paint(self, p, *args):
            profile = debug.Profiler()
            if self.image is None:
                return
            if self.qimage is None:
                self.render()
                if self.qimage is None:
                    return
                profile('render QImage')
            if self.paintMode is not None:
                p.setCompositionMode(self.paintMode)
                profile('set comp mode')

            p.drawImage(QtCore.QRectF(0,0,self.image.shape[0],self.image.shape[1]), self.qimage)
            profile('p.drawImage')
            if self.border is not None:
                p.setPen(self.border)
                p.drawRect(self.boundingRect())

        def save(self, fileName, *args):
            """Save this image to file. Note that this saves the visible image (after scale/color changes), not the original data."""
            if self.qimage is None:
                self.render()
            self.qimage.save(fileName, *args)

        def getHistogram(self, bins='auto', step='auto', targetImageSize=200, targetHistogramSize=500, **kwds):
            """Returns x and y arrays containing the histogram values for the current image.
            For an explanation of the return format, see numpy.histogram().

            The *step* argument causes pixels to be skipped when computing the histogram to save time.
            If *step* is 'auto', then a step is chosen such that the analyzed data has
            dimensions roughly *targetImageSize* for each axis.

            The *bins* argument and any extra keyword arguments are passed to
            np.histogram(). If *bins* is 'auto', then a bin number is automatically
            chosen based on the image characteristics:

            * Integer images will have approximately *targetHistogramSize* bins,
              with each bin having an integer width.
            * All other types will have *targetHistogramSize* bins.

            This method is also used when automatically computing levels.
            """
            if self.image is None:
                return None,None
            if step == 'auto':
                step = (np.ceil(self.image.shape[0] / targetImageSize),
                        np.ceil(self.image.shape[1] / targetImageSize))
            if np.isscalar(step):
                step = (step, step)
            stepData = self.image[::step[0], ::step[1]]

            if bins == 'auto':
                if stepData.dtype.kind in "ui":
                    mn = stepData.min()
                    mx = stepData.max()
                    step = np.ceil((mx-mn) / 500.)
                    bins = np.arange(mn, mx+1.01*step, step, dtype=np.int)
                    if len(bins) == 0:
                        bins = [mn, mx]
                else:
                    bins = 500

            kwds['bins'] = bins
            hist = np.histogram(stepData, **kwds)

            return hist[1][:-1], hist[0]

        def setPxMode(self, b):
            """
            Set whether the item ignores transformations and draws directly to screen pixels.
            If True, the item will not inherit any scale or rotation transformations from its
            parent items, but its position will be transformed as usual.
            (see GraphicsItem::ItemIgnoresTransformations in the Qt documentation)
            """
            self.setFlag(self.ItemIgnoresTransformations, b)

        def setScaledMode(self):
            self.setPxMode(False)

        def getPixmap(self):
            if self.qimage is None:
                self.render()
                if self.qimage is None:
                    return None
            return QtGui.QPixmap.fromImage(self.qimage)

        def pixelSize(self):
            """return scene-size of a single pixel in the image"""
            br = self.sceneBoundingRect()
            if self.image is None:
                return 1,1
            return br.width()/self.width(), br.height()/self.height()

        def viewTransformChanged(self):
            if self.autoDownsample:
                self.qimage = None
                self.update()

        #def mousePressEvent(self, ev):
            #if self.drawKernel is not None and ev.button() == QtCore.Qt.LeftButton:
                #self.drawAt(ev.pos(), ev)
                #ev.accept()
            #else:
                #ev.ignore()

        #def mouseMoveEvent(self, ev):
            ##print "mouse move", ev.pos()
            #if self.drawKernel is not None:
                #self.drawAt(ev.pos(), ev)

        #def mouseReleaseEvent(self, ev):
            #pass

        def mouseDragEvent(self, ev):
            if ev.button() != QtCore.Qt.LeftButton:
                ev.ignore()
                return
            elif self.drawKernel is not None:
                ev.accept()
                self.drawAt(ev.pos(), ev)

        def mouseClickEvent(self, ev):
            if ev.button() == QtCore.Qt.RightButton:
                if self.raiseContextMenu(ev):
                    ev.accept()
            if self.drawKernel is not None and ev.button() == QtCore.Qt.LeftButton:
                self.drawAt(ev.pos(), ev)

        def raiseContextMenu(self, ev):
            menu = self.getMenu()
            if menu is None:
                return False
            menu = self.scene().addParentContextMenus(self, menu, ev)
            pos = ev.screenPos()
            menu.popup(QtCore.QPoint(pos.x(), pos.y()))
            return True

        def getMenu(self):
            if self.menu is None:
                if not self.removable:
                    return None
                self.menu = QtGui.QMenu()
                self.menu.setTitle("Image")
                remAct = QtGui.QAction("Remove image", self.menu)
                remAct.triggered.connect(self.removeClicked)
                self.menu.addAction(remAct)
                self.menu.remAct = remAct
            return self.menu

        def hoverEvent(self, ev):
            if not ev.isExit() and self.drawKernel is not None and ev.acceptDrags(QtCore.Qt.LeftButton):
                ev.acceptClicks(QtCore.Qt.LeftButton) ## we don't use the click, but we also don't want anyone else to use it.
                ev.acceptClicks(QtCore.Qt.RightButton)
                #self.box.setBrush(fn.mkBrush('w'))
            elif not ev.isExit() and self.removable:
                ev.acceptClicks(QtCore.Qt.RightButton)  ## accept context menu clicks
            #else:
                #self.box.setBrush(self.brush)
            #self.update()

        def tabletEvent(self, ev):
            print(ev.device())
            print(ev.pointerType())
            print(ev.pressure())

        def drawAt(self, pos, ev=None):
            pos = [int(pos.x()), int(pos.y())]
            dk = self.drawKernel
            kc = self.drawKernelCenter
            sx = [0,dk.shape[0]]
            sy = [0,dk.shape[1]]
            tx = [pos[0] - kc[0], pos[0] - kc[0]+ dk.shape[0]]
            ty = [pos[1] - kc[1], pos[1] - kc[1]+ dk.shape[1]]

            for i in [0,1]:
                dx1 = -min(0, tx[i])
                dx2 = min(0, self.image.shape[0]-tx[i])
                tx[i] += dx1+dx2
                sx[i] += dx1+dx2

                dy1 = -min(0, ty[i])
                dy2 = min(0, self.image.shape[1]-ty[i])
                ty[i] += dy1+dy2
                sy[i] += dy1+dy2

            ts = (slice(tx[0],tx[1]), slice(ty[0],ty[1]))
            ss = (slice(sx[0],sx[1]), slice(sy[0],sy[1]))
            mask = self.drawMask
            src = dk

            if isinstance(self.drawMode, collections.Callable):
                self.drawMode(dk, self.image, mask, ss, ts, ev)
            else:
                src = src[ss]
                if self.drawMode == 'set':
                    if mask is not None:
                        mask = mask[ss]
                        self.image[ts] = self.image[ts] * (1-mask) + src * mask
                    else:
                        self.image[ts] = src
                elif self.drawMode == 'add':
                    self.image[ts] += src
                else:
                    raise Exception("Unknown draw mode '%s'" % self.drawMode)
                self.updateImage()

        def setDrawKernel(self, kernel=None, mask=None, center=(0,0), mode='set'):
            self.drawKernel = kernel
            self.drawKernelCenter = center
            self.drawMode = mode
            self.drawMask = mask

        def removeClicked(self):
            ## Send remove event only after we have exited the menu event handler
            self.removeTimer = QtCore.QTimer()
            self.removeTimer.timeout.connect(self.emitRemoveRequested)
            self.removeTimer.start(0)

        def emitRemoveRequested(self):
            self.removeTimer.timeout.disconnect(self.emitRemoveRequested)
            self.sigRemoveRequested.emit(self)