[ios] BubbleViewController and BubbleView stubs.

ios/chrome/browser/ui/bubble_promo/bubble_view_controller.h

+// Copyright 2017 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 IOS_CHROME_BROWSER_UI_BUBBLE_PROMO_BUBBLE_VIEW_CONTROLLER_H_
+#define IOS_CHROME_BROWSER_UI_BUBBLE_PROMO_BUBBLE_VIEW_CONTROLLER_H_
+
+#import <UIKit/UIKit.h>
+
+@class BubbleConfiguration;
+
+enum class BubbleArrowDirection;

[edchin, 2017/07/01 15:29:28]

Both of these should be defined in this header file.

[helenlyang, 2017/07/05 20:35:37]

Done.

+enum class BubbleAlignment;
+
+// View controller that manages a speech bubble-shaped view, which displays a
+// message in white text and points to the UI element of interest.

[edchin, 2017/07/01 15:29:28]

White text is irrelevant.

[helenlyang, 2017/07/05 20:35:37]

Removed.

+@interface BubbleViewController : UIViewController
+
+// The preferred origin of |self.view|. Note that this does not set

[edchin, 2017/07/01 15:29:28]

"Preferred origin" assumes that the BubbleVC knows about the coordinate system
of the parent. 
It does not. We can instead implement -sizeThatFits:(CGSize)size. Please remove
this property.

https://developer.apple.com/documentation/uikit/uiview/1622625-sizethatfits?l...

[helenlyang, 2017/07/05 20:35:37]

Removed for now, but may change based on our discussion with
Mark.

The issue here is that BVC needs to know where the arrow is
positioned in the bubble in order to properly attach to the target
element. This would require some calculation that accounts for
intrinsic content size, alignment, and arrow direction, which may be
best to keep in BubbleVC.

+// |self.view.frame.origin|; it is the responsibility of BubbleVC's containing
+// view controller to properly set the frame of |self.view|.
+@property(nonatomic, readonly) CGPoint bubbleOrigin;
+
+// Initializes the bubble with the configuration object, which gives information
+// such as text, arrow direction, alignment, and the UI element it points to.
+- (instancetype)initWithConfiguration:(BubbleConfiguration*)configuration

[edchin, 2017/07/01 15:29:28]

I suggest that we initialize with the necessary information directly. 
Please initWith text, pointingDirection, and alignment. 
Please do not include the UI element in this initializer.

[helenlyang, 2017/07/05 20:35:37]

Done. I stuck with the "arrowDirection" parameter name for this reason:
(https://codereview.chromium.org/2964233002/diff/40001/ios/chrome/browser/ui/b...)
but will change it to pointingDirection if we change the enum name.

[edchin, 2017/07/06 04:56:19]

Acknowledged.

+    NS_DESIGNATED_INITIALIZER;
+
+- (instancetype)initWithNibName:(NSString*)nibNameOrNil
+                         bundle:(NSBundle*)nibBundleOrNil NS_UNAVAILABLE;
+
+- (instancetype)initWithCoder:(NSCoder*)aDecoder NS_UNAVAILABLE;

[edchin, 2017/07/01 15:29:27]

The important one to set as unavailable is -init; The initWithNib and
initWithCoder are only used with storyboard or Nibs/Xibs. 
We don't use that in chromium. Feel free to leave them for completeness. Just
add -init;

[helenlyang, 2017/07/05 20:35:37]

Done.

[edchin, 2017/07/06 04:56:19]

As I was doing some other work, I discovered that initWithNib actually is the
designated initializer for UIViewController. 
My comment still applies, but just wanted to note this discovery.

+
+// Animates the bubble in with a fade-in.
+- (void)animateContentIn;
+
+// Dismisses the bubble. If |animated| is true, the bubble fades out.
+- (void)dismissAnimated:(BOOL)animated;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_BUBBLE_PROMO_BUBBLE_VIEW_CONTROLLER_H_