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-rw-r--r--src/interface-gtk/gtk-label.c271
1 files changed, 271 insertions, 0 deletions
diff --git a/src/interface-gtk/gtk-label.c b/src/interface-gtk/gtk-label.c
new file mode 100644
index 0000000..537269d
--- /dev/null
+++ b/src/interface-gtk/gtk-label.c
@@ -0,0 +1,271 @@
+/*
+ * Copyright (C) 2012-2021 Robin Haberkorn
+ *
+ * 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/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <string.h>
+
+#include <glib.h>
+#include <glib/gprintf.h>
+
+#include <gdk/gdk.h>
+#include <gtk/gtk.h>
+
+#include "sciteco.h"
+#include "string-utils.h"
+
+#include "gtk-label.h"
+
+#define GDK_TO_PANGO_COLOR(X) ((guint16)((X) * G_MAXUINT16))
+
+struct _TecoGtkLabel {
+ GtkLabel parent_instance;
+
+ PangoColor fg, bg;
+ guint16 fg_alpha, bg_alpha;
+
+ teco_string_t string;
+};
+
+G_DEFINE_TYPE(TecoGtkLabel, teco_gtk_label, GTK_TYPE_LABEL)
+
+/** Overrides GObject::finalize() (object destructor) */
+static void
+teco_gtk_label_finalize(GObject *obj_self)
+{
+ TecoGtkLabel *self = TECO_GTK_LABEL(obj_self);
+
+ teco_string_clear(&self->string);
+
+ /* chain up to parent class */
+ G_OBJECT_CLASS(teco_gtk_label_parent_class)->finalize(obj_self);
+}
+
+/** Overrides GtkWidget::style_updated() */
+static void
+teco_gtk_label_style_updated(GtkWidget *widget)
+{
+ TecoGtkLabel *self = TECO_GTK_LABEL(widget);
+
+ /* chain to parent class */
+ GTK_WIDGET_CLASS(teco_gtk_label_parent_class)->style_updated(widget);
+
+ GtkStyleContext *style = gtk_widget_get_style_context(widget);
+
+ GdkRGBA normal_color;
+ gtk_style_context_get_color(style, GTK_STATE_NORMAL, &normal_color);
+ self->bg.red = GDK_TO_PANGO_COLOR(normal_color.red);
+ self->bg.green = GDK_TO_PANGO_COLOR(normal_color.green);
+ self->bg.blue = GDK_TO_PANGO_COLOR(normal_color.blue);
+ self->bg_alpha = GDK_TO_PANGO_COLOR(normal_color.alpha);
+
+ /*
+ * If Pango does not support transparent foregrounds,
+ * it will at least use a high-contrast foreground.
+ *
+ * NOTE: It would be very hard to get an appropriate background
+ * color even if Gtk supports it since the label itself may
+ * not have one but one of its parents.
+ *
+ * FIXME: We may want to honour the background color,
+ * so we can at least get decent reverse text when setting
+ * the background color in the CSS.
+ */
+ self->fg.red = normal_color.red > 0.5 ? 0 : G_MAXUINT16;
+ self->fg.green = normal_color.green > 0.5 ? 0 : G_MAXUINT16;
+ self->fg.blue = normal_color.blue > 0.5 ? 0 : G_MAXUINT16;
+ /* try hard to get a transparent foreground anyway */
+ self->fg_alpha = 0;
+
+ /*
+ * The widget might be styled after the text has been set on it,
+ * we must recreate the Pango attributes.
+ */
+ if (self->string.len > 0) {
+ PangoAttrList *attribs = NULL;
+ g_autofree gchar *plaintext = NULL;
+
+ teco_gtk_label_parse_string(self->string.data, self->string.len,
+ &self->fg, self->fg_alpha,
+ &self->bg, self->bg_alpha,
+ &attribs, &plaintext);
+
+ gtk_label_set_attributes(GTK_LABEL(self), attribs);
+ pango_attr_list_unref(attribs);
+
+ g_assert(!g_strcmp0(plaintext, gtk_label_get_text(GTK_LABEL(self))));
+ }
+}
+
+static void
+teco_gtk_label_class_init(TecoGtkLabelClass *klass)
+{
+ GTK_WIDGET_CLASS(klass)->style_updated = teco_gtk_label_style_updated;
+ G_OBJECT_CLASS(klass)->finalize = teco_gtk_label_finalize;
+}
+
+static void teco_gtk_label_init(TecoGtkLabel *self) {}
+
+GtkWidget *
+teco_gtk_label_new(const gchar *str, gssize len)
+{
+ TecoGtkLabel *widget = TECO_GTK_LABEL(g_object_new(TECO_TYPE_GTK_LABEL, NULL));
+
+ teco_gtk_label_set_text(widget, str, len);
+
+ return GTK_WIDGET(widget);
+}
+
+static void
+teco_gtk_label_add_highlight_attribs(PangoAttrList *attribs, PangoColor *fg, guint16 fg_alpha,
+ PangoColor *bg, guint16 bg_alpha, guint index, gsize len)
+{
+ PangoAttribute *attr;
+
+ /*
+ * NOTE: Transparent foreground do not seem to work,
+ * even in Pango v1.38.
+ * Perhaps, this has been fixed in later versions.
+ */
+#if PANGO_VERSION_CHECK(1,38,0)
+ attr = pango_attr_foreground_alpha_new(fg_alpha);
+ attr->start_index = index;
+ attr->end_index = index + len;
+ pango_attr_list_insert(attribs, attr);
+
+ attr = pango_attr_background_alpha_new(bg_alpha);
+ attr->start_index = index;
+ attr->end_index = index + len;
+ pango_attr_list_insert(attribs, attr);
+#endif
+
+ attr = pango_attr_foreground_new(fg->red, fg->green, fg->blue);
+ attr->start_index = index;
+ attr->end_index = index + len;
+ pango_attr_list_insert(attribs, attr);
+
+ attr = pango_attr_background_new(bg->red, bg->green, bg->blue);
+ attr->start_index = index;
+ attr->end_index = index + len;
+ pango_attr_list_insert(attribs, attr);
+}
+
+void
+teco_gtk_label_parse_string(const gchar *str, gssize len, PangoColor *fg, guint16 fg_alpha,
+ PangoColor *bg, guint16 bg_alpha, PangoAttrList **attribs, gchar **text)
+{
+ if (len < 0)
+ len = strlen(str);
+
+ /*
+ * Approximate size of unformatted text.
+ */
+ gsize text_len = 1; /* for trailing 0 */
+ for (gint i = 0; i < len; i++)
+ text_len += TECO_IS_CTL(str[i]) ? 3 : 1;
+
+ *attribs = pango_attr_list_new();
+ *text = g_malloc(text_len);
+
+ gint index = 0;
+ while (len > 0) {
+ /*
+ * NOTE: This mapping is similar to
+ * teco_view_set_presentations()
+ */
+ switch (*str) {
+ case '\e':
+ teco_gtk_label_add_highlight_attribs(*attribs,
+ fg, fg_alpha,
+ bg, bg_alpha,
+ index, 1);
+ (*text)[index++] = '$';
+ break;
+ case '\r':
+ teco_gtk_label_add_highlight_attribs(*attribs,
+ fg, fg_alpha,
+ bg, bg_alpha,
+ index, 2);
+ (*text)[index++] = 'C';
+ (*text)[index++] = 'R';
+ break;
+ case '\n':
+ teco_gtk_label_add_highlight_attribs(*attribs,
+ fg, fg_alpha,
+ bg, bg_alpha,
+ index, 2);
+ (*text)[index++] = 'L';
+ (*text)[index++] = 'F';
+ break;
+ case '\t':
+ teco_gtk_label_add_highlight_attribs(*attribs,
+ fg, fg_alpha,
+ bg, bg_alpha,
+ index, 3);
+ (*text)[index++] = 'T';
+ (*text)[index++] = 'A';
+ (*text)[index++] = 'B';
+ break;
+ default:
+ if (TECO_IS_CTL(*str)) {
+ teco_gtk_label_add_highlight_attribs(*attribs,
+ fg, fg_alpha,
+ bg, bg_alpha,
+ index, 2);
+ (*text)[index++] = '^';
+ (*text)[index++] = TECO_CTL_ECHO(*str);
+ } else {
+ (*text)[index++] = *str;
+ }
+ break;
+ }
+
+ str++;
+ len--;
+ }
+
+ /* null-terminate generated text */
+ (*text)[index] = '\0';
+}
+
+void
+teco_gtk_label_set_text(TecoGtkLabel *self, const gchar *str, gssize len)
+{
+ g_return_if_fail(self != NULL);
+ g_return_if_fail(TECO_IS_GTK_LABEL(self));
+
+ teco_string_clear(&self->string);
+ teco_string_init(&self->string, str, len < 0 ? strlen(str) : len);
+
+ g_autofree gchar *plaintext = NULL;
+
+ if (self->string.len > 0) {
+ PangoAttrList *attribs = NULL;
+
+ teco_gtk_label_parse_string(self->string.data, self->string.len,
+ &self->fg, self->fg_alpha,
+ &self->bg, self->bg_alpha,
+ &attribs, &plaintext);
+
+ gtk_label_set_attributes(GTK_LABEL(self), attribs);
+ pango_attr_list_unref(attribs);
+ }
+
+ gtk_label_set_text(GTK_LABEL(self), plaintext);
+}
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