private void HandleTabBarHeightChanged(object sender, int height)
{
if (null == base.Container ||
!(sender is BottomNavigationView bottomNavView) ||
!(bottomNavView.Parent is ViewGroup viewGroup) ||
null == renderer)
{
return;
}
var layoutParams = renderer.LayoutParameters as Android.Widget.RelativeLayout.LayoutParams;
var tabHeight = TabEffect.GetCustomTabHeight(Element);
if (null == layoutParams || null == tabHeight || tabHeight.Mode == TabHeightMode.Absolute)
{
return;
}
var viewHeight = 0;
//double formHeight = 0;
if (tabHeight.Mode == TabHeightMode.RelativeToNativeTabBar)
{
//formHeight = Container.Context.FromPixels(height) + tabHeight.Value;
viewHeight = height + (int)Container.Context.ToPixels(tabHeight.Value);
}
else
{
//formHeight = Container.Context.FromPixels(height) * tabHeight.Value;
viewHeight = (int)((double)height * Container.Context.ToPixels(tabHeight.Value));
}
if (viewHeight != layoutParams.Height)
{
layoutParams.Height = viewHeight;
renderer.LayoutParameters = layoutParams;
}
}
public MainPage()
{
On <Xamarin.Forms.PlatformConfiguration.Android>().SetToolbarPlacement(ToolbarPlacement.Bottom);
TabEffect.SetCustomTabHeight(this, new TabHeight(TabHeightMode.RelativeToNativeTabBar, 16));
TabEffect.SetBottomContentOffset(this, 16);
InitializeComponent();
CurrentPage = Children[1];
foreach (var c in Children)
{
c.On <iOS>().SetUseSafeArea(true);
}
}
protected override void OnAttached()
{
var effect = Element.Effects.FirstOrDefault(x => x is SignKeys.Effects.CustomTabViewEffect);
if (effect == null || Container == null)
{
return;
}
var containerRef = new WeakReference <ViewGroup>(Container);
var meRef = new WeakReference <CustomTabViewEffectImpl>(this);
Device.InvokeOnMainThreadAsync(() =>
{
if (containerRef.TryGetTarget(out ViewGroup container) &&
meRef.TryGetTarget(out CustomTabViewEffectImpl me) &&
container.GetChildView <BottomNavigationView>() is BottomNavigationView bottomNavView &&
TabEffect.GetTabView(me.Element) is VisualElement xfView)
{
bottomNavView.DisableView();
var renderer = (VisualElementRenderer <Xamarin.Forms.View>)Xamarin.Forms.Platform.Android.Platform.CreateRendererWithContext(xfView, container.Context);
Xamarin.Forms.Platform.Android.Platform.SetRenderer(xfView, renderer);
renderer.Elevation = bottomNavView.Elevation + 1;
renderer.Tracker.UpdateLayout();
me.renderer = renderer;
var viewHeight = me.CaculateTabHeight(bottomNavView);
me.layoutChangeListener = new RendererLayoutChangeListener();
renderer.AddOnLayoutChangeListener(me.layoutChangeListener);
var layoutParams = new Android.Widget.RelativeLayout.LayoutParams(
Android.Widget.RelativeLayout.LayoutParams.MatchParent,
viewHeight);
//layoutParams.AddRule(Android.Widget.LayoutRules.AlignTop, bottomNavView.Id);
layoutParams.AddRule(Android.Widget.LayoutRules.AlignBottom, bottomNavView.Id);
var parentView = (Android.Widget.RelativeLayout)bottomNavView.Parent;
parentView.AddView(renderer, layoutParams);
}
});
}
int CaculateTabHeight(BottomNavigationView bottomNavView)
{
var xfView = renderer.Element;
var tabHeight = TabEffect.GetCustomTabHeight(Element);
int viewHeight = 0;
var formViewHeight = xfView.HeightRequest;
if (null == tabHeight)
{
viewHeight = (int)Container.Context.ToPixels(xfView.HeightRequest);
}
else if (tabHeight.Mode == TabHeightMode.Absolute)
{
viewHeight = (int)Container.Context.ToPixels(tabHeight.Value);
formViewHeight = tabHeight.Value;
}
else if (bottomNavView != null)
{
if (tabHeight.Mode == TabHeightMode.RelativeToNativeTabBar)
{
viewHeight = (int)Math.Round((double)bottomNavView.Height + Container.Context.ToPixels(tabHeight.Value));
formViewHeight = Container.Context.FromPixels(bottomNavView.Height) + tabHeight.Value;
}
else
{
viewHeight = (int)Math.Round((double)bottomNavView.Height * tabHeight.Value);
formViewHeight = Container.Context.FromPixels((double)bottomNavView.Height * tabHeight.Value);
}
tabBarLayoutChangeListener = new TabBarLayoutChangeListener();
tabBarLayoutChangeListener.HeightChanged += HandleTabBarHeightChanged;
bottomNavView.AddOnLayoutChangeListener(tabBarLayoutChangeListener);
}
if (bottomNavView != null)
{
renderer.Layout(0, 0, bottomNavView.Width, viewHeight);
xfView.Layout(new Rectangle(0, 0, Container.Context.FromPixels(bottomNavView.Width), formViewHeight));
}
return(viewHeight);
}
protected override void OnAttached()
{
var effect = Element.Effects.FirstOrDefault(x => x is SignKeys.Effects.CustomTabViewEffect);
if (effect == null || Container == null)
{
return;
}
var containerRef = new WeakReference <UIView>(Container);
var meRef = new WeakReference <CustomTabViewEffectImpl>(this);
Device.InvokeOnMainThreadAsync(() =>
{
if (containerRef.TryGetTarget(out UIView container) &&
meRef.TryGetTarget(out CustomTabViewEffectImpl me))
{
if (!(TabEffect.GetTabView(me.Element) is VisualElement xfView))
{
return;
}
me.rendererContainer = new RendererContainer(xfView);
container.AddSubview(me.rendererContainer);
me.rendererContainer.LeadingAnchor.ConstraintEqualTo(container.LeadingAnchor).Active = true;
me.rendererContainer.TrailingAnchor.ConstraintEqualTo(container.TrailingAnchor).Active = true;
me.rendererContainer.BottomAnchor.ConstraintEqualTo(container.BottomAnchor).Active = true;
//me.rendererContainer.HeightAnchor.ConstraintEqualTo((nfloat)xfView.HeightRequest + container.SafeAreaInsets.Bottom).Active = true;
var heightConfig = TabEffect.GetCustomTabHeight(me.Element);
var tabBar = me.Container.Subviews?.FirstOrDefault((v) => v is UITabBar) as UITabBar;
if (null != tabBar)
{
// Remove bar's shadow & top line
me.originalBackgroundImage = tabBar.BackgroundImage;
tabBar.BackgroundImage = new UIImage();
me.originalShadowImage = tabBar.ShadowImage;
tabBar.ShadowImage = new UIImage();
tabBar.ClipsToBounds = true;
}
if (heightConfig == null)
{
var constraint = me.rendererContainer.TopAnchor.ConstraintEqualTo(container.LayoutMarginsGuide.BottomAnchor, -(nfloat)xfView.HeightRequest);
constraint.SetIdentifier("top_to_bottom");
constraint.Active = true;
}
else
{
if (heightConfig.Mode == TabHeightMode.Absolute)
{
var constraint = me.rendererContainer.TopAnchor.ConstraintEqualTo(container.LayoutMarginsGuide.BottomAnchor, -(nfloat)heightConfig.Value);
constraint.SetIdentifier("top_to_bottom");
constraint.Active = true;
}
else if (null != tabBar)
{
if (heightConfig.Mode == TabHeightMode.RelativeToNativeTabBar)
{
var constraint = me.rendererContainer.HeightAnchor.ConstraintEqualTo(tabBar.HeightAnchor, 1.0f, (nfloat)heightConfig.Value);
constraint.SetIdentifier("relative_height");
constraint.Active = true;
}
else
{
var constraint = me.rendererContainer.HeightAnchor.ConstraintEqualTo(tabBar.HeightAnchor, (nfloat)heightConfig.Value, 0.0f);
constraint.SetIdentifier("proportional_height");
constraint.Active = true;
}
}
}
me.rendererContainer.UpdateBackgroundColor(TabEffect.GetTabBarColor(me.Element).ToUIColor());
}
});
}
protected override void OnElementPropertyChanged(PropertyChangedEventArgs args)
{
base.OnElementPropertyChanged(args);
if (null == rendererContainer || null == Element || null == Container)
{
return;
}
if (args.PropertyName == VisualElement.HeightProperty.PropertyName)
{
var heightConfig = TabEffect.GetCustomTabHeight(Element);
if (null == heightConfig)
{
var contraints = rendererContainer.Constraints;
if (contraints.FirstOrDefault((c) => string.Equals(c.GetIdentifier(), "top_to_bottom")) is NSLayoutConstraint constraint)
{
constraint.Constant = -(nfloat)((VisualElement)Element).HeightRequest;
rendererContainer.UpdateConstraints();
}
}
}
if (args.PropertyName == TabEffect.TabBarColorProperty.PropertyName)
{
rendererContainer.UpdateBackgroundColor(TabEffect.GetTabBarColor(Element).ToUIColor());
}
else if (args.PropertyName == TabEffect.CustomTabHeightProperty.PropertyName)
{
var heightConfig = TabEffect.GetCustomTabHeight(Element);
var contraints = rendererContainer.Constraints;
if (null == heightConfig || heightConfig.Mode == TabHeightMode.Absolute)
{
var value = -(nfloat)(null == heightConfig ? (rendererContainer.FormsView?.HeightRequest ?? 0) : heightConfig.Value);
var found = false;
var shouldStop = false;
foreach (var c in contraints)
{
var id = c.GetIdentifier();
switch (id)
{
case "top_to_bottom":
c.Constant = value;
found = true;
break;
case "relative_height":
case "proportional_height":
rendererContainer.RemoveConstraint(c);
shouldStop = true;
break;
default: break;
}
if (found || shouldStop)
{
break;
}
}
if (false == found)
{
var constraint = rendererContainer.TopAnchor.ConstraintEqualTo(Container.LayoutMarginsGuide.BottomAnchor, value);
constraint.SetIdentifier("top_to_bottom");
constraint.Active = true;
}
}
else
{
var value = (nfloat)heightConfig.Value;
var shouldStop = false;
var needNewConstraint = true;
foreach (var c in contraints)
{
var id = c.GetIdentifier();
switch (id)
{
case "top_to_bottom":
case "proportional_height":
rendererContainer.RemoveConstraint(c);
shouldStop = true;
break;
case "relative_height":
if (heightConfig.Mode == TabHeightMode.RelativeToNativeTabBar)
{
c.Constant = value;
needNewConstraint = false;
}
else
{
rendererContainer.RemoveConstraint(c);
shouldStop = true;
}
break;
default: break;
}
if (!needNewConstraint || shouldStop)
{
break;
}
}
if (needNewConstraint && Container.Subviews?.FirstOrDefault((v) => v is UITabBar) is UITabBar tabBar)
{
if (heightConfig.Mode == TabHeightMode.RelativeToNativeTabBar)
{
var constraint = rendererContainer.HeightAnchor.ConstraintEqualTo(tabBar.HeightAnchor, 1.0f, value);
constraint.SetIdentifier("relative_height");
constraint.Active = true;
}
else
{
var constraint = rendererContainer.HeightAnchor.ConstraintEqualTo(tabBar.HeightAnchor, value, 0.0f);
constraint.SetIdentifier("proportional_height");
constraint.Active = true;
}
}
}
}
}
