// 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 CHROME_BROWSER_TAB_WINDOW_CONTROLLER_H_
#define CHROME_BROWSER_TAB_WINDOW_CONTROLLER_H_

// A class acting as the Objective-C window controller for a window that has
// tabs which can be dragged around. Tabs can be re-arranged within the same
// window or dragged into other TabWindowController windows. This class doesn't
// know anything about the actual tab implementation or model, as that is fairly
// application-specific. It only provides an API to be overridden by subclasses
// to fill in the details.
//
// This assumes that there will be a view in the nib, connected to
// |tabContentArea_|, that indicates the content that it switched when switching
// between tabs. It needs to be a regular NSView, not something like an NSBox
// because the TabStripController makes certain assumptions about how it can
// swap out subviews.

#import <Cocoa/Cocoa.h>

#import "base/cocoa_protocols_mac.h"
#include "base/scoped_nsobject.h"

@class FastResizeView;
@class TabStripView;
@class TabView;

@interface TabWindowController : NSWindowController<NSWindowDelegate> {
 @private
  IBOutlet FastResizeView* tabContentArea_;
  IBOutlet TabStripView* tabStripView_;
  NSWindow* overlayWindow_;  // Used during dragging for window opacity tricks
  NSView* cachedContentView_;  // Used during dragging for identifying which
                               // view is the proper content area in the overlay
                               // (weak)
  scoped_nsobject<NSMutableSet> lockedTabs_;
  BOOL closeDeferred_;  // If YES, call performClose: in removeOverlay:.
}
@property(readonly, nonatomic) TabStripView* tabStripView;
@property(readonly, nonatomic) FastResizeView* tabContentArea;

// Used during tab dragging to turn on/off the overlay window when a tab
// is torn off. If -deferPerformClose (below) is used, -removeOverlay will
// cause the controller to be autoreleased before returning.
- (void)showOverlay;
- (void)removeOverlay;
- (void)removeOverlayAfterDelay:(NSTimeInterval)delay;
- (NSWindow*)overlayWindow;

// Returns YES if it is ok to constrain the window's frame to fit the screen.
- (BOOL)shouldConstrainFrameRect;

// A collection of methods, stubbed out in this base class, that provide
// the implementation of tab dragging based on whatever model is most
// appropriate.

// Layout the tabs based on the current ordering of the model.
- (void)layoutTabs;

// Creates a new window by pulling the given tab out and placing it in
// the new window. Returns the controller for the new window. The size of the
// new window will be the same size as this window.
- (TabWindowController*)detachTabToNewWindow:(TabView*)tabView;

// Make room in the tab strip for |tab| at the given x coordinate. Will hide the
// new tab button while there's a placeholder. Subclasses need to call the
// superclass implementation.
- (void)insertPlaceholderForTab:(TabView*)tab
                          frame:(NSRect)frame
                  yStretchiness:(CGFloat)yStretchiness;

// Removes the placeholder installed by |-insertPlaceholderForTab:atLocation:|
// and restores the new tab button. Subclasses need to call the superclass
// implementation.
- (void)removePlaceholder;

// Returns YES if tab dragging is currently allowed. Any number of things
// can choose to disable it, such as pending animations. The default is to
// always return YES. Subclasses should override as appropriate.
- (BOOL)tabDraggingAllowed;

// Show or hide the new tab button. The button is hidden immediately, but
// waits until the next call to |-layoutTabs| to show it again.
- (void)showNewTabButton:(BOOL)show;

// Returns whether or not |tab| can still be fully seen in the tab strip or if
// its current position would cause it be obscured by things such as the edge
// of the window or the window decorations. Returns YES only if the entire tab
// is visible. The default implementation always returns YES.
- (BOOL)isTabFullyVisible:(TabView*)tab;

// Called to check if the receiver can receive dragged tabs from
// source.  Return YES if so.  The default implementation returns NO.
- (BOOL)canReceiveFrom:(TabWindowController*)source;

// Move a given tab view to the location of the current placeholder. If there is
// no placeholder, it will go at the end. |controller| is the window controller
// of a tab being dropped from a different window. It will be nil if the drag is
// within the window, otherwise the tab is removed from that window before being
// placed into this one. The implementation will call |-removePlaceholder| since
// the drag is now complete.  This also calls |-layoutTabs| internally so
// clients do not need to call it again.
- (void)moveTabView:(NSView*)view
     fromController:(TabWindowController*)controller;

// Number of tabs in the tab strip. Useful, for example, to know if we're
// dragging the only tab in the window.
- (NSInteger)numberOfTabs;

// Return the view of the selected tab.
- (NSView *)selectedTabView;

// The title of the selected tab.
- (NSString*)selectedTabTitle;

// Called to check if we are a normal window (e.g. not a pop-up) and
// want normal behavior (e.g. a tab strip).  Return YES if so.  The
// default implementation returns YES.
- (BOOL)isNormalWindow;

// Get/set whether a particular tab is draggable between windows.
- (BOOL)isTabDraggable:(NSView*)tabView;
- (void)setTab:(NSView*)tabView isDraggable:(BOOL)draggable;

// Tell the window that it needs to call performClose: as soon as the current
// drag is complete. This prevents a window (and its overlay) from going away
// during a drag.
- (void)deferPerformClose;

@end

@interface TabWindowController(ProtectedMethods)
// Tells the tab strip to forget about this tab in preparation for it being
// put into a different tab strip, such as during a drop on another window.
- (void)detachTabView:(NSView*)view;
@end

#endif  // CHROME_BROWSER_TAB_WINDOW_CONTROLLER_H_