Support dynamic font size

[tedgonzalez]

source: https://developer.apple.com/videos/play/wwdc2017/245/

system font

label.font = UIFont.preferredFont(forTextStyle: style)
label.adjustsFontForContentSizeCategory = true

where style is based on:

custom font

/// ios 11 
label.font = UIFontMetrics.default.scaledFont(for: customFont) //default means .body
label.font = UIFontMetrics(forTextStyle: style).scaledFont(for: customFont)

/// Make sure to set lines to 0

label.numberOfLines = 0

layout (Auto layout Techniques in Interface Builder WWDC 2017)

secondLabel.firstBaselineAnchor.constraintEqualToSystemSpacingBelow(firstLabel.lastBaselineAnchor, multiplier: 1.0)

/// For side to side labels

if traitCollection.preferredContentSizeCategory > .extraLarge {
    // vertical stack
} else {
    // horizontal stack
}

/// updating layout when traitCollection changes

override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
    if traitCollection.preferredContentSizeCategory.isAccessibilityCategory != previousTraitCollection?.preferredContentSizeCategory.isAccessibilityCategory {
        /// updateLayout
    }
}

/// Table Views
/// standard table views with detail text label adjust automatically

tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = <a reasonable estimate>

tableView.sectionHeaderHeight = UITableViewAutomaticDimension
tableView.estimatedSectionHeaderHeight = <a reasonable estimate>

tableView.sectionFooterHeight = UITableVIewAutomaticDimension
tableView.estimatedSectionFooterHeight = <a reasonable estimate>

/// images in UIImageView, UIButton, NSTextAttachment
Use pdf, preserve vector data checkbox in asset catalog
Interface builder

imageView.adjustsImageSizeForAccessibilityContentSizeCategory = true

/// images in tabBarItems
Use pdf, preserve vector data checkbox in asset catalog
/// images in tabBarItems that doesn't have pdf
barButtonItem.largeContentSizeImage = largerImage

[tedgonzalez]

Please start with destination address in app