On Sat, May 13, 2017 at 05:00:43PM -0700, Dan Hitt wrote: > So it appears that when you draw in a drawing area, using commands > like (cairo_)move_to and (cairo_)line_to, the path is rendered > relative to the top left of the area. > > More explicitly, if you try to figure out how far you can draw, the x > and y values from get_allocation(...) are not relevant, only the width > and height. > > Or in other words, the location at the top left of the drawing area > has coordinates (0, 0) and at the bottom right has coordinates (width, > height), rather than (x, y) and (x+width, y+height), at least as far > as primitives like move_to and line_to are concerned. > > This sure seems to be true on my system (debian stretch) using gtk3, > but if i'm wrong, please correct me.
Yes, you are correct, things do work this way. > Also, is this documented anywhere, or am i the only person clueless > enough to try to get to the top left by going to the x,y returned by > get_allocation, instead of to (0,0)? This is documented in the draw signal docs [1]. Cheers, Tadej [1] https://developer.gnome.org/gtk3/stable/GtkWidget.html#GtkWidget-draw -- Tadej Borovšak tadeb...@gmail.com tadej.borov...@gmail.com _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
