Drawing With Cairo
#!/usr/bin/env python # # [SNIPPET_NAME: Drawing With Cairo] # [SNIPPET_CATEGORIES: PyGTK, Cairo] # [SNIPPET_DESCRIPTION: Create a drawing with cairo] # [SNIPPET_AUTHOR: Jurjen Stellingwerff <[email protected]>] # [SNIPPET_LICENSE: GPL] # example cairo_demo.py import pygtk pygtk.require('2.0') import gtk import math import cairo class DrawingAreaExample: def __init__(self): window = gtk.Window(gtk.WINDOW_TOPLEVEL) window.set_title("Drawing With Cairo") window.connect("destroy", lambda w: gtk.main_quit()) self.area = gtk.DrawingArea() self.area.set_size_request(380, 300) window.add(self.area) self.area.connect("expose-event", self.expose) self.area.show() window.show() def expose(self, area, event): self.context = area.window.cairo_create() self.context.rectangle(event.area.x, event.area.y, event.area.width, event.area.height) self.context.clip() self.context.scale(event.area.width/380.0, event.area.height/300.0) self.draw_point(10,10) self.draw_points(110, 10) self.draw_line(210, 10) self.draw_lines(310, 10) self.draw_segments(10, 100) self.draw_rectangles(110, 100) self.draw_arcs(210, 100) self.draw_pixmap(310, 100) self.draw_polygon(10, 200) self.draw_rgb_image(110, 200) self.context.move_to(210, 290) self.context.show_text("Try to resize the window") return False def point(self, x, y): self.context.arc(x, y, 1, 0.0, 2.0 * math.pi) self.context.fill() def draw_point(self, x, y): self.point(x+30, y+30) self.context.move_to(x+5, y+50) self.context.show_text("Point") return def draw_points(self, x, y): points = [(x+10,y+10), (x+10,y), (x+40,y+30), (x+30,y+10), (x+50,y+10)] for px,py in points: self.point(px,py) self.context.move_to(x+5, y+50) self.context.show_text("Points") return def draw_line(self, x, y): self.context.move_to(x+10, y+10) self.context.line_to(x+20, y+30) self.context.stroke() self.context.move_to(x+5, y+50) self.context.show_text("Line") return def draw_lines(self, x, y): points = [(x+10,y), (x+40,y+30), (x+30,y+10), (x+50,y+10)] self.context.move_to(x+10, y+10) for px,py in points: self.context.line_to(px, py) self.context.set_line_width(4.5) self.context.stroke() self.context.save() self.context.set_source_rgb(1, 1, 0.7) self.context.translate(1.5, 1) self.context.move_to(x+10, y+10) for px,py in points: self.context.line_to(px, py) self.context.set_line_width(1.5) self.context.stroke() self.context.restore() self.context.set_line_width(2) self.context.move_to(x+5, y+50) self.context.show_text("Lines") return def draw_segments(self, x, y): segments = ((x+20,y+10, x+20,y+70), (x+60,y+10, x+60,y+70), (x+10,y+30 , x+70,y+30), (x+10, y+50 , x+70, y+50)) for fx, fy, tx, ty in segments: self.context.move_to(fx, fy) self.context.line_to(tx, ty) self.context.stroke() self.context.move_to(x+5, y+90) self.context.show_text("Segments") return def draw_rectangles(self, x, y): self.context.save() self.context.set_source_rgb(.6, 0, 0) self.context.rectangle(x, y, 80, 70) self.context.stroke() self.context.restore() rectangles = ((x+10, y+10, 20, 20), (x+50, y+10, 20, 20), (x+20, y+50, 40, 10)) for px, py, h, w in rectangles: self.context.rectangle(px, py, h, w) self.context.fill() self.context.move_to(x+5, y+90) self.context.show_text("Rectangles") return def draw_arcs(self, x, y): self.context.set_line_width(1) arcs = [(False, x+45, y+35, 35), (True, x+35, y+25, 5), (True, x+55, y+25, 5)] for fill, px, py, r in arcs: self.context.move_to(px+r, py) self.context.arc(px, py, r, 0, 2*math.pi) if fill: self.context.fill() else: self.context.set_source_rgb(1, 1, 0.5) self.context.fill_preserve() self.context.set_source_rgb(0, 0, 0) self.context.stroke() self.context.move_to(x+45, y+35) s = 1.66 self.context.save() self.context.scale(1, s) self.context.arc(x+45, (y+35)/s, 15, 30*math.pi/180, 150*math.pi/180) self.context.restore() self.context.save() self.context.move_to(x+5, y+90) self.context.select_font_face("serif", cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD) self.context.show_text("Arcs") self.context.restore() return def draw_pixmap(self, x, y): try: img = cairo.ImageSurface.create_from_png("gtk.png") except Exception, e: print e exit(1) self.context.save() self.context.set_source_surface(img, x+5, y+15) self.context.paint() self.context.restore() self.context.move_to(x+5, y+90) self.context.show_text("Pixmap") return def draw_polygon(self, x, y): points = [(x+10,y+20), (x+40,y+70), (x+30,y+30), (x+50,y+40)] self.context.move_to(x+10, y+60) for px,py in points: self.context.line_to(px, py) self.context.fill() self.context.move_to(x+5, y+90) self.context.show_text("Polygon") return def draw_rgb_image(self, x, y): s = 80 h = 40 self.context.save() linpat = cairo.LinearGradient(x, y, x+s, y+s) linpat.add_color_stop_rgb(0.0, 1, 1, 1) linpat.add_color_stop_rgb(1.0, 0, 1, 0) self.context.set_source(linpat) self.context.move_to(x,y) self.context.line_to(x,y+s) self.context.line_to(x+s,y+s) self.context.line_to(x+s,y) self.context.fill() linpat = cairo.LinearGradient(x, y+s, x+s, y) linpat.add_color_stop_rgba(0.0, 0, 0, 1, 1) linpat.add_color_stop_rgba(0.5, 1, 0, 1, 0) linpat.add_color_stop_rgba(1.0, 1, 0, 0, 1) self.context.set_source(linpat) self.context.move_to(x,y) self.context.line_to(x,y+s) self.context.line_to(x+s,y+s) self.context.line_to(x+s,y) self.context.fill() self.context.restore() self.context.save() self.context.move_to(x+5, y+92) self.context.set_font_size(11.5) self.context.show_text("RGB Image") self.context.restore() return def main(): gtk.main() return 0 if __name__ == "__main__": DrawingAreaExample() main()