adjust UI

Gallery.Share/Resources/UI/AdaptedPage.cs

@@ -0,0 +1,148 @@
+using System;
+using Gallery.Services;
+using Gallery.Util;
+using Xamarin.Essentials;
+using Xamarin.Forms;
+
+namespace Gallery.Resources.UI
+{
+    public class AdaptedPage : ContentPage
+    {
+        public static readonly BindableProperty TopMarginProperty = BindableProperty.Create(nameof(TopMargin), typeof(Thickness), typeof(AdaptedPage));
+
+        public Thickness TopMargin
+        {
+            get => (Thickness)GetValue(TopMarginProperty);
+            set => SetValue(TopMarginProperty, value);
+        }
+
+        public event EventHandler Load;
+        public event EventHandler Unload;
+
+        protected static readonly bool isPhone = DeviceInfo.Idiom == DeviceIdiom.Phone;
+
+        public AdaptedPage()
+        {
+            SetDynamicResource(Screen.StatusBarStyleProperty, Theme.Theme.StatusBarStyle);
+            Shell.SetNavBarHasShadow(this, true);
+        }
+
+        public virtual void OnLoad() => Load?.Invoke(this, EventArgs.Empty);
+
+        public virtual void OnUnload() => Unload?.Invoke(this, EventArgs.Empty);
+
+        public virtual void OnOrientationChanged(bool landscape)
+        {
+            var old = TopMargin;
+            Thickness @new;
+            if (Definition.IsFullscreenDevice)
+            {
+                @new = landscape ?
+                    AppShell.NavigationBarOffset :
+                    AppShell.TotalBarOffset;
+            }
+            else if (isPhone)
+            {
+                @new = landscape ?
+                    Definition.TopOffset32 :
+                    AppShell.TotalBarOffset;
+            }
+            else
+            {
+                // iPad
+                @new = AppShell.TotalBarOffset;
+            }
+            if (old != @new)
+            {
+                TopMargin = @new;
+                OnTopMarginChanged(old, @new);
+            }
+        }
+
+        protected virtual void OnTopMarginChanged(Thickness old, Thickness @new) { }
+
+        protected override void OnSizeAllocated(double width, double height)
+        {
+            base.OnSizeAllocated(width, height);
+            OnOrientationChanged(width > height);
+        }
+
+        protected void AnimateToMargin(View element, Thickness margin, bool animate = true)
+        {
+            var m = margin;
+            var start = element.Margin.Top - m.Top;
+            element.Margin = m;
+            element.CancelAnimations();
+            if (start > 0 && animate)
+            {
+                element.Animate("margin", top =>
+                {
+                    element.TranslationY = top;
+                },
+                start, 0,
+#if DEBUG
+                length: 500,
+#else
+                length: 300,
+#endif
+                easing: Easing.SinInOut,
+                finished: (v, r) =>
+                {
+                    element.TranslationY = 0;
+                });
+            }
+            else if (element.TranslationY != 0)
+            {
+                element.TranslationY = 0;
+            }
+        }
+
+        protected void Start(Action action)
+        {
+            if (Tap.IsBusy)
+            {
+                Log.Error($"{GetType()}.tap", "gesture recognizer is now busy...");
+                return;
+            }
+            using (Tap.Start())
+            {
+                action();
+            }
+        }
+
+        private class Tap : IDisposable
+        {
+            public static bool IsBusy
+            {
+                get
+                {
+                    lock (sync)
+                    {
+                        return instance?.isBusy == true;
+                    }
+                }
+            }
+
+            private static readonly object sync = new();
+            private static readonly Tap instance = new();
+
+            private Tap() { }
+
+            public static Tap Start()
+            {
+                lock (sync)
+                {
+                    instance.isBusy = true;
+                }
+                return instance;
+            }
+
+            private bool isBusy = false;
+
+            public void Dispose()
+            {
+                isBusy = false;
+            }
+        }
+    }
+}