PagerTabStripView/Sources/Modifiers/NavBarModifier.swift

56 lines
1.9 KiB
Swift

//
// NavBarModifier.swift
// PagerTabStrip
//
// Created by Cecilia Pirotto on 26/7/21.
//
import SwiftUI
internal struct NavBarModifier: ViewModifier {
@EnvironmentObject var pagerSettings: PagerSettings
@Binding private var indexSelected: Int
@Binding private var itemCount: Int
private var navBarItemWidth: CGFloat {
let totalItemWidth = (pagerSettings.width - (pagerSettings.tabItemSpacing * CGFloat(itemCount - 1)))
return totalItemWidth / CGFloat(itemCount)
}
public init(itemCount: Binding<Int>, selection: Binding<Int>) {
self._indexSelected = selection
self._itemCount = itemCount
}
func body(content: Content) -> some View {
VStack(alignment: .leading, spacing: 0) {
HStack(spacing: pagerSettings.tabItemSpacing) {
if itemCount > 0 && pagerSettings.width > 0 {
ForEach(0...itemCount-1, id: \.self) { idx in
NavBarItem(id: idx, selection: $indexSelected)
.frame(height: pagerSettings.tabItemHeight)
}
}
}
.frame(height: pagerSettings.tabItemHeight)
HStack {
if let width = navBarItemWidth, width > 0, width <= pagerSettings.width {
let x = -self.pagerSettings.contentOffset / CGFloat(itemCount) + width / 2
Rectangle()
.fill(pagerSettings.indicatorBarColor)
.animation(.default)
.frame(width: width)
.position(x: x, y: 0)
}
}
.frame(height: pagerSettings.indicatorBarHeight)
content
}
}
}
internal extension GeometryReader {
func navBar(itemCount: Binding<Int>, selection: Binding<Int>) -> some View {
return self.modifier(NavBarModifier(itemCount: itemCount, selection: selection))
}
}