From 8ab609e4e7824e8150f4620c41f1d62c092ebb05 Mon Sep 17 00:00:00 2001 From: Emmanuele Bassi Date: Mon, 1 Jul 2019 19:22:48 +0100 Subject: [PATCH] Add custom parser for guides defined in GtkBuilder UI files Like we describe constraints, we can also define guides. --- gtk/gtkconstraintlayout.c | 160 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) diff --git a/gtk/gtkconstraintlayout.c b/gtk/gtkconstraintlayout.c index ccca990f93..4623798b5e 100644 --- a/gtk/gtkconstraintlayout.c +++ b/gtk/gtkconstraintlayout.c @@ -103,6 +103,27 @@ * The "source" and "target" attributes can be set to "super" to indicate * that the constraint target is the widget using the GtkConstraintLayout. * + * Additionally, the "constraints" element can also contain a description + * of the #GtkConstraintGuides used by the layout: + * + * |[ + * + * + * + * + * ]| + * + * The "guide" element has the following optional attributes: + * + * - "min-width", "nat-width", and "max-width", describe the minimum, + * natural, and maximum width of the guide, respectively + * - "min-height", "nat-height", and "max-height", describe the minimum, + * natural, and maximum height of the guide, respectively + * - "strength" describes the strength of the constraint on the natural + * size of the guide; if not specified, the constraint is assumed to + * have a medium strength + * - "name" describes a name for the guide, useful when debugging + * * # Using the Visual Format Language * * Complex constraints can be described using a compact syntax called VFL, @@ -1187,6 +1208,7 @@ typedef struct { GtkConstraintLayout *layout; GtkBuilder *builder; GList *constraints; + GList *guides; } ConstraintsParserData; typedef struct { @@ -1200,6 +1222,14 @@ typedef struct { double multiplier; } ConstraintData; +typedef struct { + char *name; + char *strength; + struct { + int min, nat, max; + } sizes[2]; +} GuideData; + static void constraint_data_free (gpointer _data) { @@ -1215,6 +1245,17 @@ constraint_data_free (gpointer _data) g_free (data); } +static void +guide_data_free (gpointer _data) +{ + GuideData *data = _data; + + g_free (data->name); + g_free (data->strength); + + g_free (data); +} + static void parse_double (const char *string, double *value_p, @@ -1241,6 +1282,32 @@ parse_double (const char *string, errno = saved_errno; } +static void +parse_int (const char *string, + int *value_p, + int default_value) +{ + gint64 value; + char *endptr; + int saved_errno; + + if (string == NULL || string[0] == '\0') + { + *value_p = default_value; + return; + } + + saved_errno = errno; + errno = 0; + value = g_ascii_strtoll (string, &endptr, 10); + if (errno == 0 && endptr != string) + *value_p = (int) value; + else + *value_p = default_value; + + errno = saved_errno; +} + static GtkConstraint * constraint_data_to_constraint (const ConstraintData *data, GtkBuilder *builder, @@ -1322,6 +1389,8 @@ constraint_data_to_constraint (const ConstraintData *data, data->strength, &strength, error); + if (!res) + return NULL; } else strength = GTK_CONSTRAINT_STRENGTH_REQUIRED; @@ -1340,6 +1409,38 @@ constraint_data_to_constraint (const ConstraintData *data, strength); } +static GtkConstraintGuide * +guide_data_to_guide (const GuideData *data, + GtkBuilder *builder, + GError **error) +{ + int strength; + gboolean res; + + if (data->strength != NULL) + { + res = _gtk_builder_enum_from_string (GTK_TYPE_CONSTRAINT_STRENGTH, + data->strength, + &strength, + error); + if (!res) + return NULL; + } + else + strength = GTK_CONSTRAINT_STRENGTH_MEDIUM; + + return g_object_new (GTK_TYPE_CONSTRAINT_GUIDE, + "min-width", data->sizes[GTK_ORIENTATION_HORIZONTAL].min, + "nat-width", data->sizes[GTK_ORIENTATION_HORIZONTAL].nat, + "max-width", data->sizes[GTK_ORIENTATION_HORIZONTAL].max, + "min-height", data->sizes[GTK_ORIENTATION_VERTICAL].min, + "nat-height", data->sizes[GTK_ORIENTATION_VERTICAL].nat, + "max-height", data->sizes[GTK_ORIENTATION_VERTICAL].max, + "strength", strength, + "name", data->name, + NULL); +} + static void constraints_start_element (GMarkupParseContext *context, const char *element_name, @@ -1399,6 +1500,44 @@ constraints_start_element (GMarkupParseContext *context, data->constraints = g_list_prepend (data->constraints, cdata); } + else if (strcmp (element_name, "guide") == 0) + { + const char *min_width, *nat_width, *max_width; + const char *min_height, *nat_height, *max_height; + const char *strength_str; + const char *name; + GuideData *gdata; + + if (!_gtk_builder_check_parent (data->builder, context, "constraints", error)) + return; + + if (!g_markup_collect_attributes (element_name, attr_names, attr_values, error, + G_MARKUP_COLLECT_STRING | G_MARKUP_COLLECT_OPTIONAL, "min-width", &min_width, + G_MARKUP_COLLECT_STRING | G_MARKUP_COLLECT_OPTIONAL, "nat-width", &nat_width, + G_MARKUP_COLLECT_STRING | G_MARKUP_COLLECT_OPTIONAL, "max-width", &max_width, + G_MARKUP_COLLECT_STRING | G_MARKUP_COLLECT_OPTIONAL, "min-height", &min_height, + G_MARKUP_COLLECT_STRING | G_MARKUP_COLLECT_OPTIONAL, "nat-height", &nat_height, + G_MARKUP_COLLECT_STRING | G_MARKUP_COLLECT_OPTIONAL, "max-height", &max_height, + G_MARKUP_COLLECT_STRING | G_MARKUP_COLLECT_OPTIONAL, "strength", &strength_str, + G_MARKUP_COLLECT_STRING | G_MARKUP_COLLECT_OPTIONAL, "name", &name, + G_MARKUP_COLLECT_INVALID)) + { + _gtk_builder_prefix_error (data->builder, context, error); + return; + } + + gdata = g_new0 (GuideData, 1); + parse_int (min_width, &(gdata->sizes[GTK_ORIENTATION_HORIZONTAL].min), 0); + parse_int (nat_width, &(gdata->sizes[GTK_ORIENTATION_HORIZONTAL].nat), 0); + parse_int (max_width, &(gdata->sizes[GTK_ORIENTATION_HORIZONTAL].max), G_MAXINT); + parse_int (min_height, &(gdata->sizes[GTK_ORIENTATION_VERTICAL].min), 0); + parse_int (nat_height, &(gdata->sizes[GTK_ORIENTATION_VERTICAL].nat), 0); + parse_int (max_height, &(gdata->sizes[GTK_ORIENTATION_VERTICAL].max), G_MAXINT); + gdata->name = g_strdup (name); + gdata->strength = g_strdup (strength_str); + + data->guides = g_list_prepend (data->guides, gdata); + } else { _gtk_builder_error_unhandled_tag (data->builder, context, @@ -1436,6 +1575,7 @@ gtk_constraint_layout_custom_tag_start (GtkBuildable *buildable, data->layout = g_object_ref (GTK_CONSTRAINT_LAYOUT (buildable)); data->builder = builder; data->constraints = NULL; + data->guides = NULL; *parser = constraints_parser; *parser_data = data; @@ -1468,6 +1608,25 @@ gtk_constraint_layout_custom_finished (GtkBuildable *buildable, { GList *l; + data->guides = g_list_reverse (data->guides); + for (l = data->guides; l != NULL; l = l->next) + { + const GuideData *gdata = l->data; + GtkConstraintGuide *g; + GError *error = NULL; + + g = guide_data_to_guide (gdata, builder, &error); + if (error != NULL) + { + g_critical ("Unable to parse guide definition: %s", + error->message); + g_error_free (error); + continue; + } + + gtk_constraint_layout_add_guide (data->layout, g); + } + data->constraints = g_list_reverse (data->constraints); for (l = data->constraints; l != NULL; l = l->next) { @@ -1493,6 +1652,7 @@ gtk_constraint_layout_custom_finished (GtkBuildable *buildable, } g_list_free_full (data->constraints, constraint_data_free); + g_list_free_full (data->guides, guide_data_free); g_object_unref (data->layout); g_free (data); }