Make tooltips toplevel windows on Linux

chrome/browser/ui/libgtk2ui/native_theme_gtk2.cc

 // Copyright (c) 2013 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 "chrome/browser/ui/libgtk2ui/native_theme_gtk2.h"
 
 #include <gtk/gtk.h>
 
 #include "chrome/browser/ui/libgtk2ui/chrome_gtk_menu_subclasses.h"
 #include "chrome/browser/ui/libgtk2ui/skia_utils_gtk2.h"
@@ skipping 86 matching lines @@
 namespace libgtk2ui {
 
 // static
 NativeThemeGtk2* NativeThemeGtk2::instance() {
   CR_DEFINE_STATIC_LOCAL(NativeThemeGtk2, s_native_theme, ());
   return &s_native_theme;
 }
 
 NativeThemeGtk2::NativeThemeGtk2()
     : fake_window_(NULL),
+      fake_tooltip_(NULL),
       fake_menu_item_(NULL) {
 }
 
 NativeThemeGtk2::~NativeThemeGtk2() {
   if (fake_window_)
     gtk_widget_destroy(fake_window_);
+  if (fake_tooltip_)
+    gtk_widget_destroy(fake_tooltip_);
+
   fake_entry_.Destroy();
   fake_label_.Destroy();
   fake_button_.Destroy();
   fake_tree_.Destroy();
   fake_menu_.Destroy();
 }
 
 SkColor NativeThemeGtk2::GetSystemColor(ColorId color_id) const {
   return GdkColorToSkColor(GetSystemGdkColor(color_id));
 }
@@ skipping 119 matching lines @@
       return GetEntryStyle()->text[GTK_STATE_INSENSITIVE];
     case kColorId_TextfieldReadOnlyBackground:
       return GetEntryStyle()->base[GTK_STATE_INSENSITIVE];
     case kColorId_TextfieldSelectionColor:
       return GetEntryStyle()->text[GTK_STATE_SELECTED];
     case kColorId_TextfieldSelectionBackgroundFocused:
       return GetEntryStyle()->base[GTK_STATE_SELECTED];
 
     // Tooltips
     case kColorId_TooltipBackground:
-      return GetWindowStyle()->bg[GTK_STATE_NORMAL];
+      return GetTooltipStyle()->bg[GTK_STATE_NORMAL];
+    case kColorId_TooltipText:
+      return GetTooltipStyle()->fg[GTK_STATE_NORMAL];
 
     // Trees and Tables (implemented on GTK using the same class)
     case kColorId_TableBackground:
     case kColorId_TreeBackground:
       return GetTreeStyle()->bg[GTK_STATE_NORMAL];
     case kColorId_TableText:
     case kColorId_TreeText:
       return GetTreeStyle()->text[GTK_STATE_NORMAL];
     case kColorId_TableSelectedText:
     case kColorId_TableSelectedTextUnfocused:
@@ skipping 107 matching lines @@
   return gtk_rc_get_style(fake_button_.get());
 }
 
 GtkStyle* NativeThemeGtk2::GetTreeStyle() const {
   if (!fake_tree_.get())
     fake_tree_.Own(gtk_tree_view_new());
 
   return gtk_rc_get_style(fake_tree_.get());
 }
 
+GtkStyle* NativeThemeGtk2::GetTooltipStyle() const {
+  if (!fake_tooltip_) {
+    fake_tooltip_ = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+    gtk_widget_set_name(fake_tooltip_, "gtk-tooltip");

[pkotwicz, 2014/05/16 02:22:53]

I found this by luck. I have not found any official documentation which suggests
doing this.

"gtk-tooltip" is mentioned in _gtk_rc_init()
gtk_tooltip_init() does call gtk_widget_set_name() with "gtk-tooltip"

This returns the correct colors when the tooltip colors are changed via
gnome-color-chooser

[Elliot Glaysher, 2014/05/16 19:39:42]

A lot of this stuff isn't documented and has to be inferred from the  gtk source
code, sadly.

+    gtk_widget_realize(fake_tooltip_);
+  }
+  return gtk_rc_get_style(fake_tooltip_);
+}
+
 GtkStyle* NativeThemeGtk2::GetMenuStyle() const {
   if (!fake_menu_.get())
     fake_menu_.Own(gtk_menu_new());
   return gtk_rc_get_style(fake_menu_.get());
 }
 
 GtkStyle* NativeThemeGtk2::GetMenuItemStyle() const {
   if (!fake_menu_item_) {
     if (!fake_menu_.get())
       fake_menu_.Own(gtk_custom_menu_new());
 
     fake_menu_item_ = gtk_custom_menu_item_new();
     gtk_menu_shell_append(GTK_MENU_SHELL(fake_menu_.get()), fake_menu_item_);
   }
 
   return gtk_rc_get_style(fake_menu_item_);
 }
 
 }  // namespace libgtk2ui