Infobar system refactor.

chrome/browser/infobars/infobar.h

 // 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.
 
 #ifndef CHROME_BROWSER_INFOBARS_INFOBAR_H_
 #define CHROME_BROWSER_INFOBARS_INFOBAR_H_
 
 #include <utility>
 
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "build/build_config.h"
+#include "base/memory/scoped_ptr.h"
 #include "chrome/browser/infobars/infobar_delegate.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/animation/animation_delegate.h"
 #include "ui/gfx/animation/slide_animation.h"
 #include "ui/gfx/size.h"
 
 class InfoBarContainer;
 class InfoBarService;
 
+// InfoBar is a cross-platform base class for an infobar "view" (in the MVC
+// sense), which owns a corresponding InfoBarDelegate "model".  Typically,
+// a caller will call XYZInfoBarDelegate::Create() and pass in the
+// InfoBarService for the relevant tab.  This will create an XYZInfoBarDelegate,
+// create a platform-specific subclass of InfoBar to own it, and then call
+// InfoBarService::AddInfoBar() to give it ownership of the infobar.
+// During its life, the InfoBar may be shown and hidden as the owning tab is
+// switched between the foreground and background.  Eventually, InfoBarService
+// will instruct the InfoBar to close itself.  At this point, the InfoBar will
+// optionally animate closed; once it's no longer visible, it deletes itself,
+// destroying the InfoBarDelegate in the process.
+//
+// Thus, InfoBarDelegate and InfoBar implementations can assume they share
+// lifetimes, and not NULL-check each other; but if one needs to reach back into
+// the owning InfoBarService, it must check whether that's still possible.
 class InfoBar : public gfx::AnimationDelegate {
  public:
   // These are the types passed as Details for infobar-related notifications.
-  typedef InfoBarDelegate AddedDetails;
-  typedef std::pair<InfoBarDelegate*, bool> RemovedDetails;
-  typedef std::pair<InfoBarDelegate*, InfoBarDelegate*> ReplacedDetails;
+  typedef InfoBar AddedDetails;
+  typedef std::pair<InfoBar*, bool> RemovedDetails;
+  typedef std::pair<InfoBar*, InfoBar*> ReplacedDetails;
 
   // Platforms must define these.
   static const int kDefaultBarTargetHeight;
   static const int kSeparatorLineHeight;
   static const int kDefaultArrowTargetHeight;
   static const int kMaximumArrowTargetHeight;
   // The half-width (see comments on |arrow_half_width_| below) scales to its
   // default and maximum values proportionally to how the height scales to its.
   static const int kDefaultArrowTargetHalfWidth;
   static const int kMaximumArrowTargetHalfWidth;
 
-  InfoBar(InfoBarService* owner, InfoBarDelegate* delegate);
+  explicit InfoBar(scoped_ptr<InfoBarDelegate> delegate);
   virtual ~InfoBar();
 
   static SkColor GetTopColor(InfoBarDelegate::Type infobar_type);
   static SkColor GetBottomColor(InfoBarDelegate::Type infobar_type);
 
-  InfoBarDelegate* delegate() { return delegate_; }
+  InfoBarService* owner() { return owner_; }
+  InfoBarDelegate* delegate() { return delegate_.get(); }
+  const InfoBarDelegate* delegate() const { return delegate_.get(); }
   void set_container(InfoBarContainer* container) { container_ = container; }
 
+  // Sets |owner_|.  This also calls StoreActiveEntryUniqueID() on |delegate_|.
+  // This must only be called once as there's no way to extract an infobar from
+  // its owner without deleting it, for reparenting in another tab.
+  void SetOwner(InfoBarService* owner);
+
   // Makes the infobar visible.  If |animate| is true, the infobar is then
   // animated to full size.
   void Show(bool animate);
 
-  // Makes the infobar hidden.  If |animate| is true, the infobar is first
-  // animated to zero size.  Once the infobar is hidden, it is removed from its
-  // container (triggering its deletion), and its delegate is closed.
+  // Makes the infobar hidden.  If |animate| is false, the infobar is
+  // immediately removed from the container, and, if now unowned, deleted.  If
+  // |animate| is true, the infobar is animated to zero size, ultimately
+  // triggering a call to AnimationEnded().
   void Hide(bool animate);
 
   // Changes the target height of the arrow portion of the infobar.  This has no
   // effect once the infobar is animating closed.
   void SetArrowTargetHeight(int height);
 
-  // Notifies the infobar that it is no longer owned and should close its
-  // delegate once it is invisible.
+  // Notifies the infobar that it is no longer owned and should delete itself
+  // once it is invisible.
   void CloseSoon();
 
+  // Forwards a close request to our owner.  This is a no-op if we're already
+  // unowned.
+  void RemoveSelf();
+
   // Changes the target height of the main ("bar") portion of the infobar.
   void SetBarTargetHeight(int height);
 
   const gfx::SlideAnimation& animation() const { return animation_; }
   int arrow_height() const { return arrow_height_; }
   int arrow_target_height() const { return arrow_target_height_; }
   int arrow_half_width() const { return arrow_half_width_; }
   int total_height() const { return arrow_height_ + bar_height_; }
 
  protected:
   // gfx::AnimationDelegate:
   virtual void AnimationProgressed(const gfx::Animation* animation) OVERRIDE;
 
-  // Forwards a close request to our owner.
-  // NOTE: Subclasses should not call this if we're already unowned.
-  void RemoveSelf();
-
   // Given a control with size |prefsize|, returns the centered y position
   // within us, taking into account animation so the control "slides in" (or
   // out) as we animate open and closed.
   int OffsetY(const gfx::Size& prefsize) const;
 
-  InfoBarService* owner() const { return owner_; }
   const InfoBarContainer* container() const { return container_; }
   InfoBarContainer* container() { return container_; }
   gfx::SlideAnimation* animation() { return &animation_; }
   int bar_height() const { return bar_height_; }
   int bar_target_height() const { return bar_target_height_; }
 
   // Platforms may optionally override these if they need to do work during
   // processing of the given calls.
+  virtual void PlatformSpecificSetOwner() {}
   virtual void PlatformSpecificShow(bool animate) {}
   virtual void PlatformSpecificHide(bool animate) {}
   virtual void PlatformSpecificOnCloseSoon() {}
   virtual void PlatformSpecificOnHeightsRecalculated() {}
 
  private:
   // gfx::AnimationDelegate:
   virtual void AnimationEnded(const gfx::Animation* animation) OVERRIDE;
 
   // Finds the new desired arrow and bar heights, and if they differ from the
   // current ones, calls PlatformSpecificOnHeightRecalculated().  Informs our
   // container our state has changed if either the heights have changed or
   // |force_notify| is set.
   void RecalculateHeights(bool force_notify);
 
-  // Checks whether we're closed.  If so, notifies the container that it should
-  // remove us (which will cause the platform-specific code to asynchronously
-  // delete us) and closes the delegate.
+  // Checks whether the infobar is unowned and done with all animations.  If so,
+  // notifies the container that it should remove this infobar, and deletes
+  // itself.
   void MaybeDelete();
 
   InfoBarService* owner_;
-  InfoBarDelegate* delegate_;
+  scoped_ptr<InfoBarDelegate> delegate_;
   InfoBarContainer* container_;
   gfx::SlideAnimation animation_;
 
   // The current and target heights of the arrow and bar portions, and half the
   // current arrow width.  (It's easier to work in half-widths as we draw the
   // arrow as two halves on either side of a center point.)
   int arrow_height_;         // Includes both fill and top stroke.
   int arrow_target_height_;
   int arrow_half_width_;     // Includes only fill.
   int bar_height_;           // Includes both fill and bottom separator.
   int bar_target_height_;
 
   DISALLOW_COPY_AND_ASSIGN(InfoBar);
 };
 
 #endif  // CHROME_BROWSER_INFOBARS_INFOBAR_H_