views: Factor out SingleSplitView Observer into SingleSplitViewListener.

views/controls/single_split_view.cc

 // Copyright (c) 2011 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 "views/controls/single_split_view.h"
 
 #if defined(TOOLKIT_USES_GTK)
 #include <gdk/gdk.h>
 #endif
 
 #include "skia/ext/skia_utils_win.h"
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/gfx/canvas.h"
 #include "views/background.h"
+#include "views/controls/single_split_view_listener.h"
 
 #if defined(TOOLKIT_USES_GTK)
 #include "ui/gfx/gtk_util.h"
 #endif
 
 #if defined(USE_AURA)
 #include "ui/aura/cursor.h"
 #endif
 
 namespace views {
 
 // static
 const char SingleSplitView::kViewClassName[] =
     "views/controls/SingleSplitView";
 
 // Size of the divider in pixels.
 static const int kDividerSize = 4;
 
 SingleSplitView::SingleSplitView(View* leading,
                                  View* trailing,
                                  Orientation orientation,
-                                 Observer* observer)
+                                 SingleSplitViewListener* listener)
     : is_horizontal_(orientation == HORIZONTAL_SPLIT),
       divider_offset_(-1),
       resize_leading_on_bounds_change_(true),
-      observer_(observer) {
+      listener_(listener) {
   AddChildView(leading);
   AddChildView(trailing);
 #if defined(OS_WIN)
   set_background(
       views::Background::CreateSolidBackground(
           skia::COLORREFToSkColor(GetSysColor(COLOR_3DFACE))));
 #endif
 }
 
 void SingleSplitView::Layout() {
@@ skipping 128 matching lines @@
   // Honor the minimum size when resizing.
   gfx::Size min = child_at(0)->GetMinimumSize();
   int new_size = std::max(GetPrimaryAxisSize(min.width(), min.height()),
                           drag_info_.initial_divider_offset + delta_offset);
 
   // And don't let the view get bigger than our width.
   new_size = std::min(GetPrimaryAxisSize() - kDividerSize, new_size);
 
   if (new_size != divider_offset_) {
     set_divider_offset(new_size);
-    if (!observer_ || observer_->SplitHandleMoved(this))
+    if (!listener_ || listener_->SplitHandleMoved(this))
       Layout();
   }
   return true;
 }
 
 void SingleSplitView::OnMouseCaptureLost() {
   if (child_count() < 2)
     return;
 
   if (drag_info_.initial_divider_offset != divider_offset_) {
     set_divider_offset(drag_info_.initial_divider_offset);
-    if (!observer_ || observer_->SplitHandleMoved(this))
+    if (!listener_ || listener_->SplitHandleMoved(this))
       Layout();
   }
 }
 
 void SingleSplitView::OnBoundsChanged(const gfx::Rect& previous_bounds) {
   divider_offset_ = CalculateDividerOffset(divider_offset_, previous_bounds,
                                            bounds());
 }
 
 bool SingleSplitView::IsPointInDivider(const gfx::Point& p) {
@@ skipping 41 matching lines @@
                                             const gfx::Rect& bounds) const {
   int primary_axis_size = GetPrimaryAxisSize(bounds.width(), bounds.height());
   if (divider_offset < 0)
     // primary_axis_size may < kDividerSize during initial layout.
     return std::max(0, (primary_axis_size - kDividerSize) / 2);
   return std::min(divider_offset,
                   std::max(primary_axis_size - kDividerSize, 0));
 }
 
 }  // namespace views