from gi.repository import WebKit
from gi.repository import Gdk
from gi.repository import GObject


class _WebView(WebKit.WebView):

    __gsignals__ = {
        'touch-change-page': (GObject.SignalFlags.RUN_FIRST, GObject.TYPE_NONE,
                ([bool])),
    }

    def __init__(self, only_to_measure=False):
        WebKit.WebView.__init__(self)
        self._only_to_measure = only_to_measure

    def setup_touch(self):
        self.get_window().set_events(self.get_window().get_events() |
                Gdk.EventMask.TOUCH_MASK)
        self.connect('event', self.__event_cb)

    def __event_cb(self, widget, event):
        if event.type == Gdk.EventType.TOUCH_BEGIN:
            x = event.touch.x
            view_width = widget.get_allocation().width
            if x > view_width * 3 / 4:
                self.emit('touch-change-page', True)
            elif x < view_width * 1 / 4:
                self.emit('touch-change-page', False)

    def get_page_height(self):
        '''
        Gets height (in pixels) of loaded (X)HTML page.
        This is done via javascript at the moment
        '''
        hide_scrollbar_js = ''
        if self._only_to_measure:
            hide_scrollbar_js = \
                    'document.documentElement.style.overflow = "hidden";'

        js = 'document.documentElement.style.margin = "50px";' + \
        'oldtitle=document.title;' + \
        'if (document.body == null) {' + \
        'document.title = 0} else {' + \
        hide_scrollbar_js + \
        'document.title=Math.max(document.body.scrollHeight, ' + \
        'document.body.offsetHeight,document.documentElement.clientHeight,' + \
        'document.documentElement.scrollHeight, ' + \
        'document.documentElement.offsetHeight)};'
        self.execute_script(js)
        ret = self.get_main_frame().get_title()
        js = 'document.title=oldtitle;'
        self.execute_script(js)
        try:
            return int(ret)
        except ValueError:
            return 0

    def add_bottom_padding(self, incr):
        '''
        Adds incr pixels of padding to the end of the loaded (X)HTML page.
        This is done via javascript at the moment
        '''
        js = ('var newdiv = document.createElement("div");' + \
        'newdiv.style.height = "%dpx";document.body.appendChild(newdiv);' \
        % incr)
        self.execute_script(js)

    def highlight_next_word(self):
        '''
        Highlight next word (for text to speech)
        '''
        self.execute_script('highLightNextWord();')

    def go_to_link(self, id_link):
        self.execute_script('window.location.href = "%s";' % id_link)

    def get_vertical_position_element(self, id_link):
        '''
        Get the vertical position of a element, in pixels
        '''
        # remove the first '#' char
        id_link = id_link[1:]
        js = "oldtitle = document.title;" \
                "obj = document.getElementById('%s');" \
                "var top = 0;" \
                "if(obj.offsetParent) {" \
                "    while(1) {" \
                "      top += obj.offsetTop;" \
                "      if(!obj.offsetParent) {break;};" \
                "      obj = obj.offsetParent;" \
                "    };" \
                "}" \
                "else if(obj.y) { top += obj.y; };" \
                "document.title=top;" % id_link
        self.execute_script(js)
        ret = self.get_main_frame().get_title()
        js = 'document.title=oldtitle;'
        self.execute_script(js)
        try:
            return int(ret)
        except ValueError:
            return 0