gtk: Add gtk_util from Chromium.

atom.gyp

@@ -127,6 +127,8 @@
       'browser/ui/gtk/gtk_custom_menu.h',
       'browser/ui/gtk/gtk_custom_menu_item.cc',
       'browser/ui/gtk/gtk_custom_menu_item.h',
+      'browser/ui/gtk/gtk_util.cc',
+      'browser/ui/gtk/gtk_util.h',
       'browser/ui/gtk/gtk_window_util.cc',
       'browser/ui/gtk/gtk_window_util.h',
       'browser/ui/message_box.h',

browser/ui/gtk/gtk_util.cc

@@ -0,0 +1,89 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "browser/ui/gtk/gtk_util.h"
+
+#include <cairo/cairo.h>
+
+#include "base/logging.h"
+
+namespace gtk_util {
+
+namespace {
+
+const char kBoldLabelMarkup[] = "<span weight='bold'>%s</span>";
+
+// Returns the approximate number of characters that can horizontally fit in
+// |pixel_width| pixels.
+int GetCharacterWidthForPixels(GtkWidget* widget, int pixel_width) {
+  DCHECK(gtk_widget_get_realized(widget))
+      << " widget must be realized to compute font metrics correctly";
+
+  PangoContext* context = gtk_widget_create_pango_context(widget);
+  GtkStyle* style = gtk_widget_get_style(widget);
+  PangoFontMetrics* metrics = pango_context_get_metrics(context,
+      style->font_desc, pango_context_get_language(context));
+
+  // This technique (max of char and digit widths) matches the code in
+  // gtklabel.c.
+  int char_width = pixel_width * PANGO_SCALE /
+      std::max(pango_font_metrics_get_approximate_char_width(metrics),
+               pango_font_metrics_get_approximate_digit_width(metrics));
+
+  pango_font_metrics_unref(metrics);
+  g_object_unref(context);
+
+  return char_width;
+}
+
+void OnLabelRealize(GtkWidget* label, gpointer pixel_width) {
+  gtk_label_set_width_chars(
+      GTK_LABEL(label),
+      GetCharacterWidthForPixels(label, GPOINTER_TO_INT(pixel_width)));
+}
+
+}  // namespace
+
+GtkWidget* LeftAlignMisc(GtkWidget* misc) {
+  gtk_misc_set_alignment(GTK_MISC(misc), 0, 0.5);
+  return misc;
+}
+
+GtkWidget* CreateBoldLabel(const std::string& text) {
+  GtkWidget* label = gtk_label_new(NULL);
+  char* markup = g_markup_printf_escaped(kBoldLabelMarkup, text.c_str());
+  gtk_label_set_markup(GTK_LABEL(label), markup);
+  g_free(markup);
+
+  return LeftAlignMisc(label);
+}
+
+bool IsWidgetAncestryVisible(GtkWidget* widget) {
+  GtkWidget* parent = widget;
+  while (parent && gtk_widget_get_visible(parent))
+    parent = gtk_widget_get_parent(parent);
+  return !parent;
+}
+
+void SetLabelWidth(GtkWidget* label, int pixel_width) {
+  gtk_label_set_line_wrap(GTK_LABEL(label), TRUE);
+  gtk_misc_set_alignment(GTK_MISC(label), 0, 0.5);
+
+  // Do the simple thing in LTR because the bug only affects right-aligned
+  // text. Also, when using the workaround, the label tries to maintain
+  // uniform line-length, which we don't really want.
+  if (gtk_widget_get_direction(label) == GTK_TEXT_DIR_LTR) {
+    gtk_widget_set_size_request(label, pixel_width, -1);
+  } else {
+    // The label has to be realized before we can adjust its width.
+    if (gtk_widget_get_realized(label)) {
+      OnLabelRealize(label, GINT_TO_POINTER(pixel_width));
+    } else {
+      g_signal_connect(label, "realize", G_CALLBACK(OnLabelRealize),
+                       GINT_TO_POINTER(pixel_width));
+    }
+  }
+}
+
+}  // namespace gtk_util

browser/ui/gtk/gtk_util.h

@@ -0,0 +1,31 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_BROWSER_UI_GTK_GTK_UTIL_H_
+#define ATOM_BROWSER_UI_GTK_GTK_UTIL_H_
+
+#include <gtk/gtk.h>
+#include <string>
+
+namespace gtk_util {
+
+// Left-align the given GtkMisc and return the same pointer.
+GtkWidget* LeftAlignMisc(GtkWidget* misc);
+
+// Create a left-aligned label with the given text in bold.
+GtkWidget* CreateBoldLabel(const std::string& text);
+
+// Checks whether a widget is actually visible, i.e. whether it and all its
+// ancestors up to its toplevel are visible.
+bool IsWidgetAncestryVisible(GtkWidget* widget);
+
+// Sets the given label's size request to |pixel_width|. This will cause the
+// label to wrap if it needs to. The reason for this function is that some
+// versions of GTK mis-align labels that have a size request and line wrapping,
+// and this function hides the complexity of the workaround.
+void SetLabelWidth(GtkWidget* label, int pixel_width);
+
+}  // namespace gtk_util
+
+#endif  // ATOM_BROWSER_UI_GTK_GTK_UTIL_H_