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Diffstat (limited to 'src/gs-css.c')
| -rw-r--r-- | src/gs-css.c | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/src/gs-css.c b/src/gs-css.c new file mode 100644 index 0000000..ff81855 --- /dev/null +++ b/src/gs-css.c @@ -0,0 +1,308 @@ +/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- + * vi:set noexpandtab tabstop=8 shiftwidth=8: + * + * Copyright (C) 2017 Richard Hughes <richard@hughsie.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +/** + * SECTION:gs-css + * @title: GsCss + * @stability: Unstable + * @short_description: Parse, validate and rewrite CSS resources + */ + +#include "config.h" + +#include <gtk/gtk.h> +#include <appstream.h> + +#include "gs-css.h" + +struct _GsCss +{ + GObject parent_instance; + GHashTable *ids; + GsCssRewriteFunc rewrite_func; + gpointer rewrite_func_data; +}; + +G_DEFINE_TYPE (GsCss, gs_css, G_TYPE_OBJECT) + +static void +_cleanup_string (GString *str) +{ + /* remove leading newlines */ + while (g_str_has_prefix (str->str, "\n") || g_str_has_prefix (str->str, " ")) + g_string_erase (str, 0, 1); + + /* remove trailing newlines */ + while (g_str_has_suffix (str->str, "\n") || g_str_has_suffix (str->str, " ")) + g_string_truncate (str, str->len - 1); +} + +/** + * gs_css_parse: + * @self: a #GsCss + * @markup: come CSS, or %NULL + * @error: a #GError or %NULL + * + * Parses the CSS markup and does some basic validation checks on the input. + * + * Returns: %TRUE for success + */ +gboolean +gs_css_parse (GsCss *self, const gchar *markup, GError **error) +{ + g_auto(GStrv) parts = NULL; + g_autoptr(GString) markup_str = NULL; + + /* no data */ + if (markup == NULL || markup[0] == '\0') + return TRUE; + + /* old style, no IDs */ + markup_str = g_string_new (markup); + as_gstring_replace (markup_str, "@datadir@", DATADIR); + if (!g_str_has_prefix (markup_str->str, "#")) { + g_hash_table_insert (self->ids, + g_strdup ("tile"), + g_string_free (g_steal_pointer (&markup_str), FALSE)); + return TRUE; + } + + /* split up CSS into ID chunks, e.g. + * + * #tile {border-radius: 0;} + * #name {color: white;} + */ + parts = g_strsplit (markup_str->str + 1, "\n#", -1); + for (guint i = 0; parts[i] != NULL; i++) { + g_autoptr(GString) current_css = NULL; + g_autoptr(GString) current_key = NULL; + for (guint j = 1; parts[i][j] != '\0'; j++) { + const gchar ch = parts[i][j]; + if (ch == '{') { + if (current_key != NULL || current_css != NULL) { + g_set_error_literal (error, + G_IO_ERROR, + G_IO_ERROR_INVALID_DATA, + "invalid '{'"); + return FALSE; + } + current_key = g_string_new_len (parts[i], j); + current_css = g_string_new (NULL); + _cleanup_string (current_key); + + /* already added */ + if (g_hash_table_lookup (self->ids, current_key->str) != NULL) { + g_set_error (error, + G_IO_ERROR, + G_IO_ERROR_INVALID_DATA, + "duplicate ID '%s'", + current_key->str); + return FALSE; + } + continue; + } + if (ch == '}') { + if (current_key == NULL || current_css == NULL) { + g_set_error_literal (error, + G_IO_ERROR, + G_IO_ERROR_INVALID_DATA, + "invalid '}'"); + return FALSE; + } + _cleanup_string (current_css); + g_hash_table_insert (self->ids, + g_string_free (current_key, FALSE), + g_string_free (current_css, FALSE)); + current_key = NULL; + current_css = NULL; + continue; + } + if (current_css != NULL) + g_string_append_c (current_css, ch); + } + if (current_key != NULL || current_css != NULL) { + g_set_error_literal (error, + G_IO_ERROR, + G_IO_ERROR_INVALID_DATA, + "missing '}'"); + return FALSE; + } + } + + /* success */ + return TRUE; +} + +/** + * gs_css_get_markup_for_id: + * @self: a #GsCss + * @id: an ID, or %NULL for the default + * + * Gets the CSS markup for a specific ID. + * + * Returns: %TRUE for success + */ +const gchar * +gs_css_get_markup_for_id (GsCss *self, const gchar *id) +{ + if (id == NULL) + id = "tile"; + return g_hash_table_lookup (self->ids, id); +} + +static void +_css_parsing_error_cb (GtkCssProvider *provider, + GtkCssSection *section, + GError *error, + gpointer user_data) +{ + GError **error_parse = (GError **) user_data; + if (*error_parse != NULL) { + const GtkCssLocation *start_location; + + start_location = gtk_css_section_get_start_location (section); + g_warning ("ignoring parse error %" G_GSIZE_FORMAT ":%" G_GSIZE_FORMAT ": %s", + start_location->lines + 1, + start_location->line_chars, + error->message); + return; + } + *error_parse = g_error_copy (error); +} + +static gboolean +gs_css_validate_part (GsCss *self, const gchar *markup, GError **error) +{ + g_autofree gchar *markup_new = NULL; + g_autoptr(GError) error_parse = NULL; + g_autoptr(GString) str = NULL; + g_autoptr(GtkCssProvider) provider = NULL; + + /* nothing set */ + if (markup == NULL) + return TRUE; + + /* remove custom class if NULL */ + str = g_string_new (NULL); + g_string_append (str, ".themed-widget {"); + if (self->rewrite_func != NULL) { + markup_new = self->rewrite_func (self->rewrite_func_data, + markup, + error); + if (markup_new == NULL) + return FALSE; + } else { + markup_new = g_strdup (markup); + } + g_string_append (str, markup_new); + g_string_append (str, "}"); + + /* set up custom provider */ + provider = gtk_css_provider_new (); + g_signal_connect (provider, "parsing-error", + G_CALLBACK (_css_parsing_error_cb), &error_parse); + gtk_style_context_add_provider_for_display (gdk_display_get_default (), + GTK_STYLE_PROVIDER (provider), + GTK_STYLE_PROVIDER_PRIORITY_APPLICATION); + gtk_css_provider_load_from_data (provider, str->str, -1); + if (error_parse != NULL) { + if (error != NULL) + *error = g_error_copy (error_parse); + return FALSE; + } + return TRUE; +} + +/** + * gs_css_validate: + * @self: a #GsCss + * @error: a #GError or %NULL + * + * Validates each part of the CSS markup. + * + * Returns: %TRUE for success + */ +gboolean +gs_css_validate (GsCss *self, GError **error) +{ + g_autoptr(GList) keys = NULL; + + /* check each CSS ID */ + keys = g_hash_table_get_keys (self->ids); + for (GList *l = keys; l != NULL; l = l->next) { + const gchar *tmp; + const gchar *id = l->data; + if (g_strcmp0 (id, "tile") != 0 && + g_strcmp0 (id, "name") != 0 && + g_strcmp0 (id, "summary") != 0) { + g_set_error (error, + G_IO_ERROR, + G_IO_ERROR_INVALID_DATA, + "Invalid CSS ID '%s'", + id); + return FALSE; + } + tmp = g_hash_table_lookup (self->ids, id); + if (!gs_css_validate_part (self, tmp, error)) + return FALSE; + } + + /* success */ + return TRUE; +} + +/** + * gs_css_set_rewrite_func: + * @self: a #GsCss + * @func: a #GsCssRewriteFunc or %NULL + * @user_data: user data to pass to @func + * + * Sets a function to be used when rewriting CSS before it is parsed. + * + * Returns: %TRUE for success + */ +void +gs_css_set_rewrite_func (GsCss *self, GsCssRewriteFunc func, gpointer user_data) +{ + self->rewrite_func = func; + self->rewrite_func_data = user_data; +} + +static void +gs_css_finalize (GObject *object) +{ + GsCss *self = GS_CSS (object); + g_hash_table_unref (self->ids); + G_OBJECT_CLASS (gs_css_parent_class)->finalize (object); +} + +static void +gs_css_class_init (GsCssClass *klass) +{ + GObjectClass *object_class = G_OBJECT_CLASS (klass); + object_class->finalize = gs_css_finalize; +} + +static void +gs_css_init (GsCss *self) +{ + self->ids = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free); +} + +/** + * gs_css_new: + * + * Return value: a new #GsCss object. + **/ +GsCss * +gs_css_new (void) +{ + GsCss *self; + self = g_object_new (GS_TYPE_CSS, NULL); + return GS_CSS (self); +} |