linux: Use gtk-cursor-blink from GtkSettings to set the caret blink interval

BUG=20772
TEST=Open gnome-keyboard-properties. Un-set the "Cursor Blinking" checkbox. Open a new tab in chromium and the cursor should not blink.  Do the same with the slider, and the rate of blinking should vary.

Review URL: http://codereview.chromium.org/398003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@38168 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 28 insertions, 1 deletions

diff --git a/chrome/common/gtk_util.cc b/chrome/common/gtk_util.cc
index d989750..907f9b9 100644
--- a/chrome/common/gtk_util.cc
+++ b/chrome/common/gtk_util.cc
@@ -467,11 +467,19 @@ GtkWidget* IndentWidget(GtkWidget* content) {
 void UpdateGtkFontSettings(RendererPreferences* prefs) {
   DCHECK(prefs);
 
+  // From http://library.gnome.org/devel/gtk/unstable/GtkSettings.html, this is
+  // the default value for gtk-cursor-blink-time.
+  static const gint kGtkDefaultCursorBlinkTime = 1200;
+
+  gint cursor_blink_time = kGtkDefaultCursorBlinkTime;
+  gboolean cursor_blink = TRUE;
   gint antialias = 0;
   gint hinting = 0;
   gchar* hint_style = NULL;
   gchar* rgba_style = NULL;
   g_object_get(gtk_settings_get_default(),
+               "gtk-cursor-blink-time", &cursor_blink_time,
+               "gtk-cursor-blink", &cursor_blink,
                "gtk-xft-antialias", &antialias,
                "gtk-xft-hinting", &hinting,
                "gtk-xft-hintstyle", &hint_style,
@@ -484,6 +492,15 @@ void UpdateGtkFontSettings(RendererPreferences* prefs) {
   prefs->subpixel_rendering =
       RENDERER_PREFERENCES_SUBPIXEL_RENDERING_SYSTEM_DEFAULT;
 
+  if (cursor_blink) {
+    // Dividing by 2*1000ms follows the WebKit GTK port and makes the blink
+    // frequency appear similar to the omnibox.  Without this the blink is too
+    // slow.
+    prefs->caret_blink_interval = cursor_blink_time / 2000.;
+  } else {
+    prefs->caret_blink_interval = 0;
+  }
+
   // g_object_get() doesn't tell us whether the properties were present or not,
   // but if they aren't (because gnome-settings-daemon isn't running), we'll get
   // NULL values for the strings.
diff --git a/chrome/common/render_messages.h b/chrome/common/render_messages.h
index b50b0d1..ed99e66 100644
--- a/chrome/common/render_messages.h
+++ b/chrome/common/render_messages.h
@@ -1627,6 +1627,7 @@ struct ParamTraits<RendererPreferences> {
     WriteParam(m, p.inactive_selection_bg_color);
     WriteParam(m, p.inactive_selection_fg_color);
     WriteParam(m, p.browser_handles_top_level_requests);
+    WriteParam(m, p.caret_blink_interval);
   }
   static bool Read(const Message* m, void** iter, param_type* p) {
     if (!ReadParam(m, iter, &p->can_accept_load_drops))
@@ -1673,6 +1674,9 @@ struct ParamTraits<RendererPreferences> {
     if (!ReadParam(m, iter, &p->browser_handles_top_level_requests))
       return false;
 
+    if (!ReadParam(m, iter, &p->caret_blink_interval))
+      return false;
+
     return true;
   }
   static void Log(const param_type& p, std::wstring* l) {
diff --git a/chrome/common/renderer_preferences.h b/chrome/common/renderer_preferences.h
index 30b267f..7a55b17 100644
--- a/chrome/common/renderer_preferences.h
+++ b/chrome/common/renderer_preferences.h
@@ -66,6 +66,11 @@ struct RendererPreferences {
   // Browser wants a look at all top level requests
   bool browser_handles_top_level_requests;
 
+  // Cursor blink rate in seconds.
+  // Currently only changed from default on Linux.  Uses |gtk-cursor-blink|
+  // from GtkSettings.
+  double caret_blink_interval;
+
   RendererPreferences()
       : can_accept_load_drops(true),
         should_antialias_text(true),
@@ -80,7 +85,8 @@ struct RendererPreferences {
         active_selection_fg_color(0),
         inactive_selection_bg_color(0),
         inactive_selection_fg_color(0),
-        browser_handles_top_level_requests(false) {
+        browser_handles_top_level_requests(false),
+        caret_blink_interval(0) {
   }
 };