From cc67cb1c1ed2f97b349d0ca5a7639caf0ef6c841 Mon Sep 17 00:00:00 2001 From: Maximilian Wagenbach Date: Wed, 11 Mar 2020 15:51:16 +0100 Subject: [PATCH] Added some documentation and error handling to the image center flag. --- src/escpos/escpos.py | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/src/escpos/escpos.py b/src/escpos/escpos.py index bfab265..3fa7eee 100644 --- a/src/escpos/escpos.py +++ b/src/escpos/escpos.py @@ -106,6 +106,9 @@ class Escpos(object): * `graphics`: prints with the `GS ( L`-command * `bitImageColumn`: prints with the `ESC *`-command + When trying to center an image make sure you have initialized the printer with a valid profile, that + contains a media width pixel field. Otherwise the centering will have no effect. + :param img_source: PIL image or filename to load: `jpg`, `gif`, `png` or `bmp` :param high_density_vertical: print in high density in vertical direction *default:* True :param high_density_horizontal: print in high density in horizontal direction *default:* True @@ -117,6 +120,10 @@ class Escpos(object): im = EscposImage(img_source) try: + if self.profile.profile_data['media']['width']['pixels'] == "Unknown": + print("The media.width.pixel field of the printer profile is not set. " + + "The center flag will have no effect.") + max_width = int(self.profile.profile_data['media']['width']['pixels']) if im.width > max_width: