views: Factor out SingleSplitView Observer into SingleSplitViewListener.

R=sky@chromium.org

Review URL: http://codereview.chromium.org/8351007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@107168 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 47 insertions, 26 deletions

diff --git a/views/controls/single_split_view.cc b/views/controls/single_split_view.cc
index d67e113..79df3fd 100644
--- a/views/controls/single_split_view.cc
+++ b/views/controls/single_split_view.cc
@@ -12,6 +12,7 @@
 #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"
@@ -33,11 +34,11 @@ 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)
@@ -186,7 +187,7 @@ bool SingleSplitView::OnMouseDragged(const MouseEvent& event) {
 
   if (new_size != divider_offset_) {
     set_divider_offset(new_size);
-    if (!observer_ || observer_->SplitHandleMoved(this))
+    if (!listener_ || listener_->SplitHandleMoved(this))
       Layout();
   }
   return true;
@@ -198,7 +199,7 @@ void SingleSplitView::OnMouseCaptureLost() {
 
   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();
   }
 }
diff --git a/views/controls/single_split_view.h b/views/controls/single_split_view.h
index 6d4fc6b..7cb8540 100644
--- a/views/controls/single_split_view.h
+++ b/views/controls/single_split_view.h
@@ -11,11 +11,13 @@
 
 namespace views {
 
+class SingleSplitViewListener;
+
 // SingleSplitView lays out two views next to each other, either horizontally
 // or vertically. A splitter exists between the two views that the user can
 // drag around to resize the views.
-// Observer's SplitHandleMoved notification helps to monitor user initiated
-// layout changes.
+// SingleSplitViewListener's SplitHandleMoved notification helps to monitor user
+// initiated layout changes.
 class VIEWS_EXPORT SingleSplitView : public View {
  public:
   enum Orientation {
@@ -23,24 +25,12 @@ class VIEWS_EXPORT SingleSplitView : public View {
     VERTICAL_SPLIT
   };
 
-  // Internal class name
   static const char kViewClassName[];
 
-  class Observer {
-   public:
-    // Invoked when split handle is moved by the user. |source|'s divider_offset
-    // is already set to the new value, but Layout has not happened yet.
-    // Returns false if the layout has been handled by the observer, returns
-    // true if |source| should do it by itself.
-    virtual bool SplitHandleMoved(SingleSplitView* source) = 0;
-   protected:
-    virtual ~Observer() {}
-  };
-
   SingleSplitView(View* leading,
                   View* trailing,
                   Orientation orientation,
-                  Observer* observer);
+                  SingleSplitViewListener* listener);
 
   virtual void Layout() OVERRIDE;
   virtual std::string GetClassName() const OVERRIDE;
@@ -95,10 +85,9 @@ class VIEWS_EXPORT SingleSplitView : public View {
 
   // Calculates the new |divider_offset| based on the changes of split view
   // bounds.
-  int CalculateDividerOffset(
-      int divider_offset,
-      const gfx::Rect& previous_bounds,
-      const gfx::Rect& new_bounds) const;
+  int CalculateDividerOffset(int divider_offset,
+                             const gfx::Rect& previous_bounds,
+                             const gfx::Rect& new_bounds) const;
 
   // Returns divider offset within primary axis size range for given split
   // view |bounds|.
@@ -131,8 +120,8 @@ class VIEWS_EXPORT SingleSplitView : public View {
 
   bool resize_leading_on_bounds_change_;
 
-  // Observer to notify about user initiated handle movements. Not own by us.
-  Observer* observer_;
+  // Listener to notify about user initiated handle movements. Not owned.
+  SingleSplitViewListener* listener_;
 
   // The accessible name of this view.
   string16 accessible_name_;
diff --git a/views/controls/single_split_view_listener.h b/views/controls/single_split_view_listener.h
new file mode 100644
index 0000000..6d38aad
--- /dev/null
+++ b/views/controls/single_split_view_listener.h
@@ -0,0 +1,29 @@
+// 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.
+
+#ifndef VIEWS_CONTROLS_SINGLE_SPLIT_VIEW_LISTENER_H_
+#define VIEWS_CONTROLS_SINGLE_SPLIT_VIEW_LISTENER_H_
+#pragma once
+
+namespace views {
+
+class SingleSplitView;
+
+// An interface implemented by objects that want to be notified when the
+// splitter moves.
+class SingleSplitViewListener {
+ public:
+  // Invoked when split handle is moved by the user. |sender|'s divider_offset
+  // is already set to the new value, but Layout has not happened yet.
+  // Returns false if the layout has been handled by the listener, returns
+  // true if |sender| should do it by itself.
+  virtual bool SplitHandleMoved(SingleSplitView* sender) = 0;
+
+ protected:
+  virtual ~SingleSplitViewListener() {}
+};
+
+}  // namespace views
+
+#endif  // VIEWS_CONTROLS_SINGLE_SPLIT_VIEW_LISTENER_H_
diff --git a/views/controls/single_split_view_unittest.cc b/views/controls/single_split_view_unittest.cc
index c3375d8..28a9aa0 100644
--- a/views/controls/single_split_view_unittest.cc
+++ b/views/controls/single_split_view_unittest.cc
@@ -6,6 +6,7 @@
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "views/controls/single_split_view.h"
+#include "views/controls/single_split_view_listener.h"
 
 using ::testing::_;
 using ::testing::Return;
@@ -43,7 +44,7 @@ static void VerifySplitViewLayout(const views::SingleSplitView& split) {
   }
 }
 
-class MockObserver : public views::SingleSplitView::Observer {
+class MockObserver : public views::SingleSplitViewListener {
  public:
   MOCK_METHOD1(SplitHandleMoved, bool(views::SingleSplitView*));
 };
diff --git a/views/views.gyp b/views/views.gyp
index 98f3d64..467d196 100644
--- a/views/views.gyp
+++ b/views/views.gyp
@@ -207,6 +207,7 @@
         'controls/separator.h',
         'controls/single_split_view.cc',
         'controls/single_split_view.h',
+        'controls/single_split_view_listener.h',
         'controls/tabbed_pane/native_tabbed_pane_gtk.cc',
         'controls/tabbed_pane/native_tabbed_pane_gtk.h',
         'controls/tabbed_pane/native_tabbed_pane_win.cc',