mac: Makeshift UI for scroll feedback.

chrome/browser/ui/cocoa/history_overlay_controller.h

+// 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 CHROME_BROWSER_UI_COCOA_OVERLAY_PANEL_CONTROLLER_H_
+#define CHROME_BROWSER_UI_COCOA_OVERLAY_PANEL_CONTROLLER_H_
+#pragma once
+
+#import <Cocoa/Cocoa.h>
+
+#import "base/mac/cocoa_protocols.h"
+#include "base/memory/scoped_nsobject.h"
+
+@class OverlayFrameView;
+
+enum HistoryOverlayMode {
+  kHistoryOverlayModeBack,
+  kHistoryOverlayModeForward
+};
+
+// The HistoryOverlayController manages the overlay HUD panel which displays
+// navigation gesture icons within a browser window.
+@interface HistoryOverlayController : NSWindowController<NSWindowDelegate> {
+ @private
+  HistoryOverlayMode mode_;
+
+  // The content view of the window that this controller manages.
+  OverlayFrameView* contentView_;  // Weak, owned by the window.
+
+  scoped_nsobject<NSWindow> parent_;
+}
+
+// Designated initializer.
+- (id)initForMode:(HistoryOverlayMode)mode;
+
+// Shows the panel.
+- (void)showPanelForWindow:(NSWindow*)window;
+
+// Updates the appearance of the overlay based on track gesture progress.
+- (void)setProgress:(CGFloat)gestureAmount;
+
+// Schedules a fade-out animation and then closes the window,
+// which will release the controller.
+- (void)dismiss;
+@end
+
+#endif  // CHROME_BROWSER_UI_COCOA_OVERLAY_PANEL_CONTROLLER_H_