[Mac] First part of Omnibox decoration refactor. Enable ev bubble.

chrome/browser/cocoa/location_bar/location_bar_decoration.h

+// Copyright (c) 2010 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 CHROME_BROWSER_COCOA_LOCATION_BAR_LOCATION_BAR_DECORATION_H_
+#define CHROME_BROWSER_COCOA_LOCATION_BAR_LOCATION_BAR_DECORATION_H_
+
+#import <Cocoa/Cocoa.h>
+
+#import "base/basictypes.h"
+
+// Base class for decorations at the left and right of the location
+// bar.  For instance, the location icon.
+
+// |LocationBarDecoration| and subclasses should approximately
+// parallel the classes provided under views/location_bar/.  The term
+// "decoration" is used because "view" has strong connotations in
+// Cocoa, and while these are view-like, they aren't views at all.
+// Decorations are more like Cocoa cells, except implemented in C++ to
+// allow more similarity to the other platform implementations.
+
+class LocationBarDecoration {
+ public:
+  LocationBarDecoration()
+      : visible_(false) {
+  }
+  virtual ~LocationBarDecoration() {}
+
+  // Determines whether the decoration is visible.
+  virtual bool IsVisible() const {
+    return visible_;
+  }
+  virtual void SetVisible(bool visible) {
+    visible_ = visible;
+  }
+
+  // Decorations can change their size to fit the available space.
+  // Returns the width the decoration will use in the space allotted,
+  // or |kOmittedWidth| if it should be omitted.
+  virtual CGFloat GetWidthForSpace(CGFloat width);
+
+  // Draw the decoration in the frame provided.  The frame will be
+  // generated from an earlier call to |GetWidthForSpace()|.
+  virtual void DrawInFrame(NSRect frame, NSView* control_view);
+
+  // Returns the tooltip for this decoration, return |nil| for no tooltip.
+  virtual NSString* GetToolTip() { return nil; }
+
+  // Determine if the item can act as a drag source.
+  virtual bool IsDraggable() { return false; }
+
+  // The image to drag.
+  virtual NSImage* GetDragImage() { return nil; }
+
+  // The pasteboard to drag.
+  virtual NSPasteboard* GetDragPasteboard() { return nil; }
+
+  // Called on mouse down.  Return |false| to indicate that the press
+  // was not processed and should be handled by the cell.
+  virtual bool OnMousePressed(NSRect frame) { return false; }
+
+  // Called to get the right-click menu, return |nil| for no menu.
+  virtual NSMenu* GetMenu() { return nil; }
+
+  // Width returned by |GetWidthForSpace()| when the item should be
+  // omitted for this width;
+  static const CGFloat kOmittedWidth;
+
+ private:
+  bool visible_;
+
+  DISALLOW_COPY_AND_ASSIGN(LocationBarDecoration);
+};
+
+#endif  // CHROME_BROWSER_COCOA_LOCATION_BAR_LOCATION_BAR_DECORATION_H_