Text and lines in pycairo

Question

I'm having a little bit of trouble with pycairo. I want to draw a chord chart, but for some reason I don't quite understand it only displays the text, not the lines it should be drawing.

I use pygtk (3.0) and pycairo. Here's the result of what this code draws

Here's the code:

    def gen_chart(self, wid, cr):

            x = 10
            y = 60

            cr.set_source_rgb(0, 0, 0)
            cr.set_line_width(1)
            cr.select_font_face("Open Sans", cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_NORMAL)
            cr.set_font_size(40)

            cr.move_to(x, y)
            cr.line_to(x, y)

            counter = 1
            for measure in chord_list: # The list is declared earlier in the source                    
                    x += 10
                    for chord in measure:
                            cr.move_to(x, y)
                            cr.show_text(chord)
                            x += 100
                    if counter % 4 == 0 or counter == 4:
                            x = 10
                            y += 60
                            cr.move_to(x, y)
                            cr.line_to(x, y)
                            counter += 1
                    counter += 1

            cr.move_to(x, y + 10)
            cr.move_to(x, y + 10)
            cr.stroke()

Thanks in advance to anyone who can help me.

Answer 1

The problem with the code is that it "draws" a line to the same coordinate, so it becomes a point which has no 2d properties, and that's why it doesn't draw anything. The corrected code:

def gen_chart(self, wid, cr):

    x = 10
    y = 60

    cr.set_source_rgb(0, 0, 0)
    cr.set_line_width(1)
    cr.select_font_face("Open Sans", cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_NORMAL)
    cr.set_font_size(40)

    cr.move_to(x, y)
    cr.line_to(x, y)

    counter = 1
    for measure in chord_list:                   
        x += 10
        for chord in measure:
            cr.move_to(x, y)
            cr.show_text(chord)
            x += 100
        if counter % 4 == 0 or counter == 4:
            x = 10
            y += 60
            cr.move_to(x, y)
            cr.line_to(x, y + 10)
        counter += 1
    counter += 1

cr.move_to(x, y + 80)
cr.stroke()