[gnome-builder/wip/chergert/headerbar: 25/34] egg: add EggEntryBox

[Christian Hergert <chergert src gnome org>]

commit edbe22f3a33e30fa7a433a3a3f93f4ca9d709032
Author: Christian Hergert <chergert redhat com>
Date:   Tue Jun 21 00:02:41 2016 -0700

    egg: add EggEntryBox
    
    EggEntryBox looks like an entry but allows packing children like a box.
    You can set max-width-chars property to set the natural size of the box.

 contrib/egg/Makefile.am     |    2 +
 contrib/egg/egg-entry-box.c |  143 +++++++++++++++++++++++++++++++++++++++++++
 contrib/egg/egg-entry-box.h |   34 ++++++++++
 3 files changed, 179 insertions(+), 0 deletions(-)
---
diff --git a/contrib/egg/Makefile.am b/contrib/egg/Makefile.am
index 42b02ca..624736b 100644
--- a/contrib/egg/Makefile.am
+++ b/contrib/egg/Makefile.am
@@ -16,6 +16,7 @@ headers_DATA = \
        egg-counter.h \
        egg-date-time.h \
        egg-empty-state.h \
+       egg-entry-box.h \
        egg-frame-source.h \
        egg-heap.h \
        egg-menu-manager.h \
@@ -46,6 +47,7 @@ libegg_private_la_SOURCES = \
        egg-counter.c \
        egg-date-time.c \
        egg-empty-state.c \
+       egg-entry-box.c \
        egg-frame-source.c \
        egg-heap.c \
        egg-menu-manager.c \
diff --git a/contrib/egg/egg-entry-box.c b/contrib/egg/egg-entry-box.c
new file mode 100644
index 0000000..5625b1e
--- /dev/null
+++ b/contrib/egg/egg-entry-box.c
@@ -0,0 +1,143 @@
+/* egg-entry-box.c
+ *
+ * Copyright (C) 2016 Christian Hergert <chergert redhat com>
+ *
+ * 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/>.
+ */
+
+#include "egg-entry-box.h"
+
+struct _EggEntryBox
+{
+  GtkBox parent_instance;
+
+  gint max_width_chars;
+};
+
+G_DEFINE_TYPE (EggEntryBox, egg_entry_box, GTK_TYPE_BOX)
+
+enum {
+  PROP_0,
+  PROP_MAX_WIDTH_CHARS,
+  N_PROPS
+};
+
+static GParamSpec *properties [N_PROPS];
+
+static void
+egg_entry_box_get_preferred_width (GtkWidget *widget,
+                                   gint      *min_width,
+                                   gint      *nat_width)
+{
+  EggEntryBox *self = (EggEntryBox *)widget;
+
+  g_assert (EGG_IS_ENTRY_BOX (self));
+  g_assert (min_width != NULL);
+  g_assert (nat_width != NULL);
+
+  GTK_WIDGET_CLASS (egg_entry_box_parent_class)->get_preferred_width (widget, min_width, nat_width);
+
+  if (self->max_width_chars > 0)
+    {
+      PangoContext *context;
+      PangoFontMetrics *metrics;
+      gint char_width;
+      gint digit_width;
+      gint width;
+
+      context = gtk_widget_get_pango_context (widget);
+      metrics = pango_context_get_metrics (context,
+                                           pango_context_get_font_description (context),
+                                           pango_context_get_language (context));
+
+      char_width = pango_font_metrics_get_approximate_char_width (metrics);
+      digit_width = pango_font_metrics_get_approximate_digit_width (metrics);
+      width = MAX (char_width, digit_width) * self->max_width_chars / PANGO_SCALE;
+
+      if (width > *nat_width)
+        *nat_width = width;
+
+      pango_font_metrics_unref (metrics);
+    }
+}
+
+static void
+egg_entry_box_get_property (GObject    *object,
+                            guint       prop_id,
+                            GValue     *value,
+                            GParamSpec *pspec)
+{
+  EggEntryBox *self = EGG_ENTRY_BOX (object);
+
+  switch (prop_id)
+    {
+    case PROP_MAX_WIDTH_CHARS:
+      g_value_set_int (value, self->max_width_chars);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
+
+static void
+egg_entry_box_set_property (GObject      *object,
+                            guint         prop_id,
+                            const GValue *value,
+                            GParamSpec   *pspec)
+{
+  EggEntryBox *self = EGG_ENTRY_BOX (object);
+
+  switch (prop_id)
+    {
+    case PROP_MAX_WIDTH_CHARS:
+      self->max_width_chars = g_value_get_int (value);
+      gtk_widget_queue_resize (GTK_WIDGET (self));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
+
+static void
+egg_entry_box_class_init (EggEntryBoxClass *klass)
+{
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->get_property = egg_entry_box_get_property;
+  object_class->set_property = egg_entry_box_set_property;
+
+  widget_class->get_preferred_width = egg_entry_box_get_preferred_width;
+
+  properties [PROP_MAX_WIDTH_CHARS] =
+    g_param_spec_int ("max-width-chars",
+                      "Max Width Chars",
+                      "Max Width Chars",
+                      -1,
+                      G_MAXINT,
+                      -1,
+                      (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_properties (object_class, N_PROPS, properties);
+
+  gtk_widget_class_set_css_name (widget_class, "entry");
+}
+
+static void
+egg_entry_box_init (EggEntryBox *self)
+{
+  self->max_width_chars = -1;
+}
diff --git a/contrib/egg/egg-entry-box.h b/contrib/egg/egg-entry-box.h
new file mode 100644
index 0000000..0a64192
--- /dev/null
+++ b/contrib/egg/egg-entry-box.h
@@ -0,0 +1,34 @@
+/* egg-entry-box.h
+ *
+ * Copyright (C) 2016 Christian Hergert <chergert redhat com>
+ *
+ * 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/>.
+ */
+
+#ifndef EGG_ENTRY_BOX_H
+#define EGG_ENTRY_BOX_H
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define EGG_TYPE_ENTRY_BOX (egg_entry_box_get_type())
+
+G_DECLARE_FINAL_TYPE (EggEntryBox, egg_entry_box, EGG, ENTRY_BOX, GtkBox)
+
+GtkWidget *egg_entry_box_new (void);
+
+G_END_DECLS
+
+#endif /* EGG_ENTRY_BOX_H */