from PyQt4.QtCore import pyqtSignal
from PyQt4.QtGui import QAction, QIcon, QPixmap
from matplotlib.backends.backend_qt4agg import NavigationToolbar2QTAgg as NavigationToolbar, NavigationToolbar2QTAgg

__author__ = 'markusro'


class CustomToolbar(NavigationToolbar):
    # our spanChanged signal
    spanSelectedTrigger = pyqtSignal(float, float, name='spanChanged')

    def __init__(self, plotCanvas, plotWidget, parent=None):
        NavigationToolbar.__init__(self, plotCanvas, plotWidget, coordinates=True)
        self.canvas = plotCanvas
        # Span select Button
        #self.span_button = QAction(QIcon("border-1d-right-icon.png" ), "Span", self)
        self.span_button = QAction(QIcon(QPixmap(":/icons/fit_limits.png")), "Fit Limits", self)
        self.span_button.setCheckable(True)

        self.cids = []
        self.cids.append(self.canvas.mpl_connect('button_press_event', self.press))
        self.cids.append(self.canvas.mpl_connect('motion_notify_event', self.onmove))
        self.cids.append(self.canvas.mpl_connect('button_release_event', self.release))
        self.cids.append(self.canvas.mpl_connect('draw_event', self.update_background))


        #    act.setCheckable(True)
        # add actions before the coordinates widget
        self.insertAction(self.actions()[-1], self.span_button)

        self.buttons = {}
        self._pressed = False
        self.background = None
        self.span = None
        self.istart = 0
        self.iend = 0
        self.xstart = 0
        self.xend = 0

    def set_span(self, x1, x2):
        #trans = blended_transform_factory(self.axes.transData, self.axes.transAxes)
        cur = self.span.get_xy()
        cur[0, 0] = x1
        cur[1, 0] = x1
        cur[2, 0] = x2
        cur[3, 0] = x2
        self.span.set_xy(cur)

    def ignore(self, event):
        # 'return ``True`` if *event* should be ignored'
        return event.inaxes != self.canvas.axes or event.button != 1

    def update_background(self, event):
        #if self.canvas.axes is None:
        #    raise SyntaxError,"Need an axes reference!"
        self.background = self.canvas.copy_from_bbox(self.canvas.axes.bbox)

    def press(self, event):
        if self.span_button.isChecked():
            if self.background is None:
                self.update_background()
            else:
                self.canvas.restore_region(self.background)
            self.xstart = event.xdata
            self.istart = event.x
            if self.span is None:
                self.span = self.canvas.axes.axvspan(event.xdata, event.xdata, alpha=0.10, color="k", animated=False)
            else:
                self.set_span(event.xdata, event.xdata)
            self._pressed = True

    def onmove(self, event):
        if self.span_button.isChecked() and self._pressed and not self.ignore(event):
            self.set_span(self.xstart, event.xdata)
            self.update()

    def update(self):
        """Overrides method of NavigationToolbar.
        Allows fast drawing of the span selector with blitting
        """
        self.canvas.restore_region(self.background)
        self.canvas.axes.draw_artist(self.span)
        for line in self.canvas.axes.get_lines():
            self.canvas.axes.draw_artist(line)
        self.canvas.blit(self.canvas.axes.bbox)

    def release(self, event):
        self.span_button.setChecked(False)
        self.xend = event.xdata
        self.iend = event.x
        if self.iend < self.istart:
            self.iend, self.istart = self.istart, self.iend
        #print "released", self.xstart, self.xend
        if self._pressed:
            if self.ignore(event):
                self.istart = 0
            self.spanSelectedTrigger.emit(self.xstart, self.xend)
            self._pressed = False