Experiments with a new tabstrip + animator

views/animator.h

+// Copyright (c) 2009 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_ANIMATOR_H_
+#define VIEWS_ANIMATOR_H_
+
+#include <xutility>
+
+#include "app/animation.h"
+#include "base/gfx/rect.h"
+#include "base/ref_counted.h"
+#include "base/scoped_ptr.h"
+
+class SlideAnimation;
+
+////////////////////////////////////////////////////////////////////////////////
+// ALERT!
+//
+// This API is preliminary and subject to change. Talk to beng before using it!
+//
+
+namespace views {
+
+class View;
+
+class AnimatorDelegate {
+ public:
+  // Returns the view in the visual layout whose trailing edge the view that
+  // hosts an animator should be clamped to during animations, when
+  // ANIMATE_CLAMP is specified in combination with ANIMATE_X or ANIMATE_Y.
+  virtual View* GetClampedView(View* host) = 0;
+
+  // Notifies the delegate that the active animation running for |host| has
+  // completed.
+  virtual void AnimationCompletedForHost(View* host) = 0;
+};
+
+// An animator is an object that can animate actions on a host view. Once
+// created, an Animator is typically owned by its host view.
+class Animator : public AnimationDelegate {
+ public:
+  enum BoundsChangeFlags {
+    ANIMATE_NONE = 0x0,     // Don't animate anything... o_O
+    ANIMATE_X = 0x1,        // Animate the host view's x position
+    ANIMATE_Y = 0x2,        // Animate the host view's y position
+    ANIMATE_WIDTH = 0x4,    // Animate the host view's width
+    ANIMATE_HEIGHT = 0x8,   // Animate the host view's height
+    ANIMATE_CLAMP = 0x10    // Clamp the host view's x or y position to the
+                            // trailing edge of the view returned by
+                            // AnimatorDelegate::GetClampedView.
+  };
+
+  // Creates the animator for the specified host view. Optionally an
+  // AnimationContext can be provided to animate multiple views from a single
+  // animation.
+  explicit Animator(View* host);
+  Animator(View* host, AnimatorDelegate* delegate);
+  virtual ~Animator();
+
+  // Returns true if the animator is currently animating.
+  bool IsAnimating() const;
+
+  // Moves/sizes the host view to the specified bounds. |direction| is a
+  // combination of the above flags indicating what aspects of the bounds should
+  // be animated.
+  void AnimateToBounds(const gfx::Rect& bounds, int direction);
+  void AnimateToBounds(int x, int y, int width, int height, int direction) {
+    AnimateToBounds(gfx::Rect(x, y, std::max(0, width), std::max(0, height)),
+                    direction);
+  }
+
+  // Overridden from AnimationDelegate:
+  virtual void AnimationEnded(const Animation* animation);
+  virtual void AnimationProgressed(const Animation* animation);
+  virtual void AnimationCanceled(const Animation* animation);
+
+ private:
+  void InitAnimation();
+
+  // Get the current X/Y position of the host view, clamped to the right edge of
+  // the previous view in the visual layout, if applicable (See
+  // AnimatorDelegate for more info).
+  int GetClampedX() const;
+  int GetClampedY() const;
+
+  // The view that this animator is attached to.
+  View* host_;
+
+  // Start and end bounds for the animation.
+  gfx::Rect start_bounds_;
+  gfx::Rect target_bounds_;
+
+  // The animation used by this animator.
+  scoped_ptr<SlideAnimation> animation_;
+
+  // A delegate object that provides information about surrounding views.
+  // Will be NULL during this class' destructor.
+  AnimatorDelegate* delegate_;
+
+  // Some combination of BoundsChangeFlags indicating the type of bounds change
+  // the host view is subject to.
+  int direction_;
+
+  DISALLOW_COPY_AND_ASSIGN(Animator);
+};
+
+}  // namespace views
+
+#endif  // #ifndef VIEWS_ANIMATOR_H_