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Diffstat (limited to '')
| -rw-r--r-- | panels/network/cc-qr-code.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/panels/network/cc-qr-code.c b/panels/network/cc-qr-code.c new file mode 100644 index 0000000..b803011 --- /dev/null +++ b/panels/network/cc-qr-code.c @@ -0,0 +1,197 @@ +/* -*- mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*- */ +/* cc-qr-code.c + * + * Copyright 2019 Purism SPC + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * Author(s): + * Mohammed Sadiq <sadiq@sadiqpk.org> + * + * SPDX-License-Identifier: GPL-3.0-or-later + */ + +#undef G_LOG_DOMAIN +#define G_LOG_DOMAIN "cc-qr-code" + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include "cc-qr-code.h" +#include "qrcodegen.c" + +/** + * SECTION: cc-qr_code + * @title: CcQrCode + * @short_description: A Simple QR Code wrapper around libqrencode + * @include: "cc-qr-code.h" + * + * Generate a QR image from a given text. + */ + +struct _CcQrCode +{ + GObject parent_instance; + + gchar *text; + cairo_surface_t *surface; + gint size; + gint scale; +}; + +G_DEFINE_TYPE (CcQrCode, cc_qr_code, G_TYPE_OBJECT) + + +static void +cc_qr_code_finalize (GObject *object) +{ + CcQrCode *self = (CcQrCode *)object; + + g_clear_pointer (&self->surface, cairo_surface_destroy); + g_clear_pointer (&self->text, g_free); + + G_OBJECT_CLASS (cc_qr_code_parent_class)->finalize (object); +} + +static void +cc_qr_code_class_init (CcQrCodeClass *klass) +{ + GObjectClass *object_class = G_OBJECT_CLASS (klass); + + object_class->finalize = cc_qr_code_finalize; +} + +static void +cc_qr_code_init (CcQrCode *self) +{ +} + +CcQrCode * +cc_qr_code_new (void) +{ + return g_object_new (CC_TYPE_QR_CODE, NULL); +} + +gboolean +cc_qr_code_set_text (CcQrCode *self, + const gchar *text) +{ + g_return_val_if_fail (CC_IS_QR_CODE (self), FALSE); + g_return_val_if_fail (!text || *text, FALSE); + + if (g_strcmp0 (text, self->text) == 0) + return FALSE; + + /* Clear cairo surface that is cached */ + g_clear_pointer (&self->surface, cairo_surface_destroy); + g_free (self->text); + self->text = g_strdup (text); + + return TRUE; +} + +static void +cc_cairo_fill_pixel (cairo_t *cr, + int x, + int y, + int padding, + int scale) +{ + cairo_rectangle (cr, + x * scale + padding, + y * scale + padding, + scale, scale); + cairo_fill (cr); +} + +cairo_surface_t * +cc_qr_code_get_surface (CcQrCode *self, + gint size, + gint scale) +{ + uint8_t qr_code[qrcodegen_BUFFER_LEN_FOR_VERSION (qrcodegen_VERSION_MAX)]; + uint8_t temp_buf[qrcodegen_BUFFER_LEN_FOR_VERSION (qrcodegen_VERSION_MAX)]; + cairo_t *cr; + gint pixel_size, padding, qr_size; + gboolean success = FALSE; + + g_return_val_if_fail (CC_IS_QR_CODE (self), NULL); + g_return_val_if_fail (size > 0, NULL); + g_return_val_if_fail (scale > 0, NULL); + + if (!self->text || !*self->text) + { + g_warn_if_reached (); + cc_qr_code_set_text (self, "invalid text"); + } + + if (self->surface && + self->size == size && + self->scale == scale) + return self->surface; + + self->size = size; + self->scale = scale; + g_clear_pointer (&self->surface, cairo_surface_destroy); + + success = qrcodegen_encodeText (self->text, + temp_buf, + qr_code, + qrcodegen_Ecc_LOW, + qrcodegen_VERSION_MIN, + qrcodegen_VERSION_MAX, + qrcodegen_Mask_AUTO, + FALSE); + + if (!success) + return NULL; + + self->surface = cairo_image_surface_create (CAIRO_FORMAT_RGB24, size * scale, size * scale); + cairo_surface_set_device_scale (self->surface, scale, scale); + cr = cairo_create (self->surface); + cairo_set_antialias (cr, CAIRO_ANTIALIAS_NONE); + + /* Draw white background */ + cairo_set_source_rgba (cr, 1, 1, 1, 1); + cairo_rectangle (cr, 0, 0, size * scale, size * scale); + cairo_fill (cr); + + qr_size = qrcodegen_getSize(qr_code); + pixel_size = MAX (1, size / (qr_size)); + padding = (size - qr_size * pixel_size) / 2; + + /* If subpixel size is big and margin is pretty small, + * increase the margin */ + if (pixel_size > 4 && padding < 12) + { + pixel_size--; + padding = (size - qr_size * pixel_size) / 2; + } + + /* Now draw the black QR code pixels */ + cairo_set_source_rgba (cr, 0, 0, 0, 1); + for (int row = 0; row < qr_size; row++) + { + for (int column = 0; column < qr_size; column++) + { + if (qrcodegen_getModule (qr_code, row, column)) + cc_cairo_fill_pixel (cr, column, row, padding, pixel_size); + } + } + + cairo_destroy (cr); + + return self->surface; +} |