Gtk3: Refactor GtkButtonImageSource::GetImageForScale

chrome/browser/ui/libgtkui/gtk_ui.cc

 // 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 "chrome/browser/ui/libgtkui/gtk_ui.h"
 
 #include <math.h>
 #include <pango/pango.h>
 #include <X11/Xcursor/Xcursor.h>
 
@@ skipping 98 matching lines @@
   ~GtkButtonImageSource() override {}
 
   gfx::ImageSkiaRep GetImageForScale(float scale) override {
     int width = width_ * scale;
     int height = height_ * scale;
 
     SkBitmap border;
     border.allocN32Pixels(width, height);
     border.eraseColor(0);
 
+    cairo_surface_t* surface = cairo_image_surface_create_for_data(
+        static_cast<unsigned char*>(border.getAddr(0, 0)), CAIRO_FORMAT_ARGB32,
+        width, height, width * 4);
+    cairo_t* cr = cairo_create(surface);
+
+#if GTK_MAJOR_VERSION == 2
     // Create a temporary GTK button to snapshot
     GtkWidget* window = gtk_offscreen_window_new();
     GtkWidget* button = gtk_toggle_button_new();
 
     if (state_ == ui::NativeTheme::kPressed)
       gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(button), true);
     else if (state_ == ui::NativeTheme::kDisabled)
       gtk_widget_set_sensitive(button, false);
 
     gtk_widget_set_size_request(button, width, height);
     gtk_container_add(GTK_CONTAINER(window), button);
 
     if (is_blue_)
       TurnButtonBlue(button);
 
     gtk_widget_show_all(window);
 
-    cairo_surface_t* surface = cairo_image_surface_create_for_data(
-        static_cast<unsigned char*>(border.getAddr(0, 0)), CAIRO_FORMAT_ARGB32,
-        width, height, width * 4);
-    cairo_t* cr = cairo_create(surface);
-
-#if GTK_MAJOR_VERSION == 2
     if (focus_)
       GTK_WIDGET_SET_FLAGS(button, GTK_HAS_FOCUS);
 
     int w, h;
     GdkPixmap* pixmap;
 
     {
       // http://crbug.com/346740
       ANNOTATE_SCOPED_MEMORY_LEAK;
       pixmap = gtk_widget_get_snapshot(button, nullptr);
     }
 
     gdk_drawable_get_size(GDK_DRAWABLE(pixmap), &w, &h);
     GdkColormap* colormap = gdk_drawable_get_colormap(pixmap);
     GdkPixbuf* pixbuf = gdk_pixbuf_get_from_drawable(
         nullptr, GDK_DRAWABLE(pixmap), colormap, 0, 0, 0, 0, w, h);
 
     gdk_cairo_set_source_pixbuf(cr, pixbuf, 0, 0);
     cairo_paint(cr);
 
     g_object_unref(pixbuf);
     g_object_unref(pixmap);
+
+    gtk_widget_destroy(window);
 #else
-    GtkStyleContext* context = gtk_widget_get_style_context(button);
+    ScopedStyleContext context = GetStyleContextFromCss(
+        is_blue_ ? "GtkButton#button.default.suggested-action"
+                 : "GtkButton#button");
+    GtkStateFlags state_flags = StateToStateFlags(state_);
+    if (focus_) {
+      state_flags =
+          static_cast<GtkStateFlags>(state_flags | GTK_STATE_FLAG_FOCUSED);
+    }
+    gtk_style_context_set_state(context, state_flags);
     gtk_render_background(context, cr, 0, 0, width, height);
     gtk_render_frame(context, cr, 0, 0, width, height);
     if (focus_)
       gtk_render_focus(context, cr, 0, 0, width, height);
 #endif
 
     cairo_destroy(cr);
     cairo_surface_destroy(surface);
 
-    gtk_widget_destroy(window);
-
     return gfx::ImageSkiaRep(border, scale);
   }
 
  private:
   bool is_blue_;
   bool focus_;
   ui::NativeTheme::State state_;
   int width_;
   int height_;
 
@@ skipping 890 matching lines @@
 
 float GtkUi::GetDeviceScaleFactor() const {
   return device_scale_factor_;
 }
 
 }  // namespace libgtkui
 
 views::LinuxUI* BuildGtkUi() {
   return new libgtkui::GtkUi;
 }