EligibilityStatusViewController.swift

//
//  EligibilityStatusViewController.swift
//  C3PRO
//
//  Created by Pascal Pfiffner on 22/10/15.
//  Copyright © 2015 Boston Children's Hospital. All rights reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
//

import UIKit
import ResearchKit


/**
View controller to inform about eligible or ineligible status.

Simple implementation, you must assign all properties before the view is loaded, dynamic changes are not currently supported!
*/
open class EligibilityStatusViewController: UIViewController {
	
	/// The image to show at the top, defaults to "logo_disease".
	open var imageName = "logo_disease"
	
	/// Text to show at the top, bold.
	open var titleText: String?
	
	/// Text to show below the title, in normal body font but dark grey.
	open var subText: String?
	
	var actionButton: UIButton?
	
	/// To inform the receiver that the action button cannot yet be enabled.
	open var waitingForAction = false {
		didSet {
			actionButton?.isEnabled = !waitingForAction
		}
	}
	
	/// The title of the one and only action button, which appears at the bottom **if** `onActionButtonTap` is defined.
	open var actionButtonTitle = "Start Consent".c3_localized("Start Consent button title")
	
	/// Action to perform when the one and only action button is tapped.
	open var onActionButtonTap: ((_ controller: UIViewController) -> Void)? {
		didSet {
			actionButton?.isHidden = nil == onActionButtonTap
		}
	}
	
	
	// MARK: - Actions
	
	func didTapActionButton(_ button: UIButton) {
		if let exec = onActionButtonTap {
			exec(self)
		}
	}
	
	
	// MARK: - View Tasks
	
	override open func loadView() {
		super.loadView()
		view.backgroundColor = UIColor.white
		
		let desc = UIFontDescriptor.preferredFontDescriptor(withTextStyle: UIFontTextStyle.body)
		
		let content = UIView()
		content.translatesAutoresizingMaskIntoConstraints = false
		
		// logo image
		let img = UIImageView(image: UIImage(named: imageName))
		img.translatesAutoresizingMaskIntoConstraints = false
		content.addSubview(img)
		content.addConstraint(NSLayoutConstraint(item: img, attribute: .top, relatedBy: .equal, toItem: content, attribute: .top, multiplier: 1.0, constant: 0.0))
		content.addConstraint(NSLayoutConstraint(item: img, attribute: .centerX, relatedBy: .equal, toItem: content, attribute: .centerX, multiplier: 1.0, constant: 0.0))
		
		// text labels
		var lastView: UIView = img
		if let text = titleText {
			let label = UILabel()
			label.translatesAutoresizingMaskIntoConstraints = false
			label.numberOfLines = 0
			label.textAlignment = .center
			label.font = UIFont(descriptor: desc.withSymbolicTraits([.traitBold])!, size: desc.pointSize)
			label.text = text
			
			content.addSubview(label)
			content.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "|-[label]-|", options: [], metrics: nil, views: ["label": label]))
			content.addConstraint(NSLayoutConstraint(item: label, attribute: .top, relatedBy: .equal, toItem: lastView, attribute: .bottom, multiplier: 1.0, constant: 20.0))
			lastView = label
		}
		
		if let text = subText {
			let label = UILabel()
			label.translatesAutoresizingMaskIntoConstraints = false
			label.numberOfLines = 0
			label.textAlignment = .center
			label.textColor = UIColor.darkGray
			label.font = UIFont(descriptor: desc, size: desc.pointSize)
			label.text = text
			
			content.addSubview(label)
			content.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "|-[label]-|", options: [], metrics: nil, views: ["label": label]))
			content.addConstraint(NSLayoutConstraint(item: label, attribute: .top, relatedBy: .equal, toItem: lastView, attribute: .bottom, multiplier: 1.0, constant: 20.0))
			lastView = label
		}
		content.addConstraint(NSLayoutConstraint(item: lastView, attribute: .bottom, relatedBy: .equal, toItem: content, attribute: .bottom, multiplier: 1.0, constant: 0.0))
		
		// button
		let button = BorderedButton()
		button.translatesAutoresizingMaskIntoConstraints = false
		button.setTitle(actionButtonTitle, for: UIControlState())
		button.isHidden = nil == onActionButtonTap
		button.isEnabled = !waitingForAction
		button.addTarget(self, action: #selector(EligibilityStatusViewController.didTapActionButton(_:)), for: .touchUpInside)
		actionButton = button
		
		// main layout
		view.addSubview(content)
		view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "|-[content]-|", options: [], metrics: nil, views: ["content": content]))
		view.addConstraint(NSLayoutConstraint(item: content, attribute: .centerY, relatedBy: .equal, toItem: view, attribute: .centerY, multiplier: 1.0, constant: 0.0))
		view.addSubview(button)
		view.addConstraint(NSLayoutConstraint(item: button, attribute: .centerX, relatedBy: .equal, toItem: view, attribute: .centerX, multiplier: 1.0, constant: 0.0))
		view.addConstraint(NSLayoutConstraint(item: button, attribute: .width, relatedBy: .greaterThanOrEqual, toItem: nil, attribute: .notAnAttribute, multiplier: 0.0, constant: 180.0))
		view.addConstraint(NSLayoutConstraint(item: button, attribute: .bottom, relatedBy: .equal, toItem: bottomLayoutGuide, attribute: .top, multiplier: 1.0, constant: -20.0))
	}
}