diff options
Diffstat (limited to '')
| -rw-r--r-- | src/gs-description-box.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/src/gs-description-box.c b/src/gs-description-box.c new file mode 100644 index 0000000..72acd06 --- /dev/null +++ b/src/gs-description-box.c @@ -0,0 +1,358 @@ +/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- + * vi:set noexpandtab tabstop=8 shiftwidth=8: + * + * Copyright (C) 2020 Red Hat <www.redhat.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +/** + * SECTION:gs-desription-box + * @title: GsDescriptionBox + * @stability: Stable + * @short_description: Show description text in a way that can show more/less lines + * + * Show a description in an expandable form with "Show More" button when + * there are too many lines to be shown. The button is hidden when + * the description is short enough. The button changes to "Show Less" + * to be able to collapse it. + */ + +#include "config.h" + +#include <glib/gi18n.h> + +#include "gs-description-box.h" + +#define MAX_COLLAPSED_LINES 4 + +struct _GsDescriptionBox { + GtkWidget parent; + GtkWidget *box; + GtkLabel *label; + GtkButton *button; + gchar *text; + gboolean is_collapsed; + gboolean needs_recalc; + gint last_width; + gint last_height; + guint idle_update_id; +}; + +G_DEFINE_TYPE (GsDescriptionBox, gs_description_box, GTK_TYPE_WIDGET) + +static void +gs_description_box_update_content (GsDescriptionBox *box) +{ + GtkAllocation allocation; + PangoLayout *layout; + gint n_lines; + const gchar *text; + + if (!box->text || !*(box->text)) { + gtk_widget_hide (GTK_WIDGET (box)); + box->needs_recalc = TRUE; + return; + } + + gtk_widget_get_allocation (GTK_WIDGET (box), &allocation); + + if (!box->needs_recalc && box->last_width == allocation.width && box->last_height == allocation.height) + return; + + box->needs_recalc = allocation.width <= 1 || allocation.height <= 1; + box->last_width = allocation.width; + box->last_height = allocation.height; + + text = box->is_collapsed ? _("_Show More") : _("_Show Less"); + /* FIXME: Work around a flickering issue in GTK: + * https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/3949 */ + if (g_strcmp0 (text, gtk_button_get_label (box->button)) != 0) + gtk_button_set_label (box->button, text); + + gtk_label_set_markup (box->label, box->text); + gtk_label_set_lines (box->label, -1); + gtk_label_set_ellipsize (box->label, PANGO_ELLIPSIZE_NONE); + + layout = gtk_label_get_layout (box->label); + n_lines = pango_layout_get_line_count (layout); + + gtk_widget_set_visible (GTK_WIDGET (box->button), n_lines > MAX_COLLAPSED_LINES); + + if (box->is_collapsed && n_lines > MAX_COLLAPSED_LINES) { + PangoLayoutLine *line; + GString *str; + GSList *opened_markup = NULL; + gint start_index, line_index, in_markup = 0; + + line = pango_layout_get_line_readonly (layout, MAX_COLLAPSED_LINES); + + line_index = line->start_index; + + /* Pango does not count markup in the text, thus calculate the position manually */ + for (start_index = 0; box->text[start_index] && line_index > 0; start_index++) { + if (box->text[start_index] == '<') { + if (box->text[start_index + 1] == '/') { + g_autofree gchar *value = opened_markup->data; + opened_markup = g_slist_remove (opened_markup, value); + } else { + const gchar *end = strchr (box->text + start_index, '>'); + opened_markup = g_slist_prepend (opened_markup, g_strndup (box->text + start_index + 1, end - (box->text + start_index) - 1)); + } + in_markup++; + } else if (box->text[start_index] == '>') { + g_warn_if_fail (in_markup > 0); + in_markup--; + } else if (!in_markup) { + /* Encoded characters count as one */ + if (box->text[start_index] == '&') { + const gchar *end = strchr (box->text + start_index, ';'); + if (end) + start_index += end - box->text - start_index; + } + + line_index--; + } + } + str = g_string_sized_new (start_index); + g_string_append_len (str, box->text, start_index); + + /* Cut white spaces from the end of the string, thus it doesn't look bad when it's ellipsized. */ + while (str->len > 0 && strchr ("\r\n\t ", str->str[str->len - 1])) { + str->len--; + } + + str->str[str->len] = '\0'; + + /* Close any opened tags after cutting the text */ + for (GSList *link = opened_markup; link; link = g_slist_next (link)) { + const gchar *tag = link->data; + g_string_append_printf (str, "</%s>", tag); + } + + gtk_label_set_lines (box->label, MAX_COLLAPSED_LINES); + gtk_label_set_ellipsize (box->label, PANGO_ELLIPSIZE_END); + gtk_label_set_markup (box->label, str->str); + + g_slist_free_full (opened_markup, g_free); + g_string_free (str, TRUE); + } +} + +static void +gs_description_box_read_button_clicked_cb (GtkButton *button, + gpointer user_data) +{ + GsDescriptionBox *box = user_data; + + g_return_if_fail (GS_IS_DESCRIPTION_BOX (box)); + + box->is_collapsed = !box->is_collapsed; + box->needs_recalc = TRUE; + + gs_description_box_update_content (box); +} + +static gboolean +update_description_in_idle_cb (gpointer data) +{ + GsDescriptionBox *box = GS_DESCRIPTION_BOX (data); + + gs_description_box_update_content (box); + box->idle_update_id = 0; + + return G_SOURCE_REMOVE; +} + +static void +gs_description_box_measure (GtkWidget *widget, + GtkOrientation orientation, + gint for_size, + gint *minimum, + gint *natural, + gint *minimum_baseline, + gint *natural_baseline) +{ + GsDescriptionBox *box = GS_DESCRIPTION_BOX (widget); + + gtk_widget_measure (box->box, orientation, + for_size, + minimum, natural, + minimum_baseline, + natural_baseline); + + if (!box->idle_update_id) + box->idle_update_id = g_idle_add (update_description_in_idle_cb, box); +} + +static void +gs_description_box_size_allocate (GtkWidget *widget, + int width, + int height, + int baseline) +{ + GsDescriptionBox *box = GS_DESCRIPTION_BOX (widget); + GtkAllocation allocation; + + allocation.x = 0; + allocation.y = 0; + allocation.width = width; + allocation.height = height; + + gtk_widget_size_allocate (box->box, &allocation, baseline); + + if (!box->idle_update_id) + box->idle_update_id = g_idle_add (update_description_in_idle_cb, box); +} + +static GtkSizeRequestMode +gs_description_box_get_request_mode (GtkWidget *widget) +{ + return gtk_widget_get_request_mode (GS_DESCRIPTION_BOX (widget)->box); +} + +static void +gs_description_box_dispose (GObject *object) +{ + GsDescriptionBox *box = GS_DESCRIPTION_BOX (object); + + g_clear_handle_id (&box->idle_update_id, g_source_remove); + g_clear_pointer (&box->box, gtk_widget_unparent); + + G_OBJECT_CLASS (gs_description_box_parent_class)->dispose (object); +} + +static void +gs_description_box_finalize (GObject *object) +{ + GsDescriptionBox *box = GS_DESCRIPTION_BOX (object); + + g_clear_pointer (&box->text, g_free); + + G_OBJECT_CLASS (gs_description_box_parent_class)->finalize (object); +} + +static void +gs_description_box_init (GsDescriptionBox *box) +{ + GtkStyleContext *style_context; + GtkWidget *widget; + + box->is_collapsed = TRUE; + + box->box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 24); + gtk_widget_set_parent (GTK_WIDGET (box->box), GTK_WIDGET (box)); + + style_context = gtk_widget_get_style_context (GTK_WIDGET (box)); + gtk_style_context_add_class (style_context, "application-details-description"); + + widget = gtk_label_new (""); + g_object_set (G_OBJECT (widget), + "hexpand", TRUE, + "halign", GTK_ALIGN_FILL, + "vexpand", FALSE, + "valign", GTK_ALIGN_START, + "visible", TRUE, + "max-width-chars", 40, + "selectable", TRUE, + "wrap", TRUE, + "xalign", 0.0, + NULL); + + gtk_box_append (GTK_BOX (box->box), widget); + + style_context = gtk_widget_get_style_context (widget); + gtk_style_context_add_class (style_context, "label"); + + box->label = GTK_LABEL (widget); + + widget = gtk_button_new_with_mnemonic (_("_Show More")); + + g_object_set (G_OBJECT (widget), + "hexpand", FALSE, + "halign", GTK_ALIGN_CENTER, + "vexpand", FALSE, + "valign", GTK_ALIGN_CENTER, + "visible", TRUE, + NULL); + + gtk_box_append (GTK_BOX (box->box), widget); + + style_context = gtk_widget_get_style_context (widget); + gtk_style_context_add_class (style_context, "button"); + gtk_style_context_add_class (style_context, "circular"); + + box->button = GTK_BUTTON (widget); + + g_signal_connect (box->button, "clicked", + G_CALLBACK (gs_description_box_read_button_clicked_cb), box); +} + +static void +gs_description_box_class_init (GsDescriptionBoxClass *klass) +{ + GObjectClass *object_class; + GtkWidgetClass *widget_class; + + object_class = G_OBJECT_CLASS (klass); + object_class->dispose = gs_description_box_dispose; + object_class->finalize = gs_description_box_finalize; + + widget_class = GTK_WIDGET_CLASS (klass); + widget_class->get_request_mode = gs_description_box_get_request_mode; + widget_class->measure = gs_description_box_measure; + widget_class->size_allocate = gs_description_box_size_allocate; +} + +GtkWidget * +gs_description_box_new (void) +{ + return g_object_new (GS_TYPE_DESCRIPTION_BOX, NULL); +} + +const gchar * +gs_description_box_get_text (GsDescriptionBox *box) +{ + g_return_val_if_fail (GS_IS_DESCRIPTION_BOX (box), NULL); + + return box->text; +} + +void +gs_description_box_set_text (GsDescriptionBox *box, + const gchar *text) +{ + g_return_if_fail (GS_IS_DESCRIPTION_BOX (box)); + + if (g_strcmp0 (text, box->text) != 0) { + g_free (box->text); + box->text = g_strdup (text); + box->needs_recalc = TRUE; + + gtk_widget_set_visible (GTK_WIDGET (box), text && *text); + + gtk_widget_queue_resize (GTK_WIDGET (box)); + } +} + +gboolean +gs_description_box_get_collapsed (GsDescriptionBox *box) +{ + g_return_val_if_fail (GS_IS_DESCRIPTION_BOX (box), FALSE); + + return box->is_collapsed; +} + +void +gs_description_box_set_collapsed (GsDescriptionBox *box, + gboolean collapsed) +{ + g_return_if_fail (GS_IS_DESCRIPTION_BOX (box)); + + if ((collapsed ? 1 : 0) != (box->is_collapsed ? 1 : 0)) { + box->is_collapsed = collapsed; + box->needs_recalc = TRUE; + + gtk_widget_queue_resize (GTK_WIDGET (box)); + } +} |