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-rw-r--r--src/gs-description-box.c358
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diff --git a/src/gs-description-box.c b/src/gs-description-box.c
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+/* -*- 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));
+ }
+}