[ios] BubbleViewController and BubbleView stubs.

ios/chrome/browser/ui/bubble_promo/bubble_configuration.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_CONFIGURATION_H_
+#define IOS_CHROME_BROWSER_UI_BUBBLE_PROMO_BUBBLE_CONFIGURATION_H_
+
+#import <UIKit/UIKit.h>
+
+// Defines the direction for the bubble to point.
+enum class BubbleArrowDirection {

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

How about calling it "PointingDirection"? This should be in the BubbleVC header.

[helenlyang, 2017/07/05 20:35:36]

I felt that "BubbleArrowDirection" was more consistent with the
UIPopoverArrowDirection enum used by UIPopoverPresentationController (see
https://developer.apple.com/documentation/uikit/uipopoverpresentationcontroll...).

However, happy to change to "PointingDirection" if you think it would be
more clear.

[edchin, 2017/07/06 04:56:18]

Good point. And good application of consistency with existing code. You've
changed my mind!

+  // Bubble is below the target UI element and the arrow is pointing up.
+  UP,
+  // Bubble is above the target UI element and the arrow is pointing down.
+  DOWN
+};
+
+// Alignment of the bubble relative to the arrow.
+enum class BubbleAlignment { LEADING, CENTER, TRAILING };

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

This should be in the BubbleVC header.

[helenlyang, 2017/07/05 20:35:36]

Done.

+
+// Configuration object for BubbleViewController that provides information
+// needed to set the position and text of the bubble.
+@interface BubbleConfiguration : NSObject

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

The original purpose of this class was to extract the target element
from a branch of the parent view hierarchy. I think most of the properties
here really belong in the bubbleVC itself.

[helenlyang, 2017/07/05 20:35:36]

Agreed; removed this class as you suggested. 

+
+@property(nonatomic) NSString* displayText;

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

Drawing inspiration from UILabel and UIButton, the property "text" should be
descriptive enough.
There should be a memory management attribute for this property. 

[helenlyang, 2017/07/05 20:35:36]

I've added a label property to BubbleView. Since its text can be set
during initialization, I don't think we need a text property.

[edchin, 2017/07/06 04:56:18]

Acknowledged.

+@property(nonatomic) BubbleAlignment* alignment;

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

Enums should not be pointers. Pointers are only used for objects.
You can think of an enum like a primitive type (such as a number).

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

Done.

+@property(nonatomic) BubbleArrowDirection* arrowDirection;
+// View of the targeted UI element.
+@property(nonatomic, weak) UIView* elementView;
+// View that the bubble will be displayed in.
+@property(nonatomic, readonly, weak) UIView* bubbleSuperview;
+// Frame of |elementView| relative to |bubbleSuperview|'s coordinate system.
+// This is the rectangle in which the bubble will be anchored.
+@property(nonatomic, readonly) CGRect sourceRect;
+
+// Initializes the BubbleConfiguration object with default values.
+- (instancetype)initWithBubbleSuperview:(UIView*)bubbleSuperview
+    NS_DESIGNATED_INITIALIZER;
+- (instancetype)init NS_UNAVAILABLE;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_BUBBLE_PROMO_BUBBLE_CONFIGURATION_H_