use snackbars instead of toasts (in most cases)

src/keepass2android-app/Utils/MessagePresenter.cs

@@ -0,0 +1,153 @@
+using Android.OS;
+using Android.Views;
+using Google.Android.Material.Snackbar;
+
+namespace keepass2android.Utils
+{
+    public struct Message
+    {
+        public Message()
+        {
+            Text = null;
+            Severity = MessageSeverity.Info;
+        }
+
+        public string Text { get; set; }
+        public MessageSeverity Severity { get; set; }
+        public bool ShowOnSubsequentScreens { get; set; } = true;
+    }
+    public interface IMessagePresenter
+    {
+        void ShowMessage(Message message);
+
+        List<Message> PendingMessages
+        {
+            get;
+        }
+
+    }
+
+    internal class NonePresenter : IMessagePresenter
+    {
+        public void ShowMessage(Message message)
+        {
+            PendingMessages.Add(message);
+        }
+
+        public List<Message> PendingMessages
+        {
+            get;
+            set;
+        } = new List<Message>();
+    }
+
+
+    internal class ToastPresenter : IMessagePresenter
+    {
+        public void ShowMessage(Message message)
+        {
+            Toast.MakeText(App.Context, message.Text, ToastLength.Long).Show();
+        }
+
+        public List<Message> PendingMessages => new();
+    }
+
+    internal class ChainedSnackbarPresenter: IMessagePresenter
+    {
+        internal ChainedSnackbarPresenter(View anchorView)
+        {
+            this.AnchorView = anchorView;
+            
+        }
+
+        private DateTime nextSnackbarShowTime = DateTime.Now;
+        private List<Message> queuedMessages = new List<Message>();
+
+        public View AnchorView { get; set; }
+
+        private TimeSpan chainingTime = TimeSpan.FromSeconds(1.5);
+        private Snackbar snackbar;
+        private Message lastMessage;
+
+        public void ShowMessage(Message message)
+        {
+            if (DateTime.Now < nextSnackbarShowTime)
+            {
+                var waitDuration = nextSnackbarShowTime - DateTime.Now;
+                nextSnackbarShowTime = nextSnackbarShowTime.Add(chainingTime);
+                
+                new Handler().PostDelayed(() => { ShowNextSnackbar(); }, (long)waitDuration.TotalMilliseconds);
+                if (queuedMessages.Any())
+                {
+                    queuedMessages.Add(message);
+                }
+
+                return;
+            }
+            ShowSnackbarNow(message);
+            nextSnackbarShowTime = DateTime.Now.Add(chainingTime);
+
+        }
+
+        public List<Message> PendingMessages
+        {
+            get
+            {
+                List<Message> pendingMessages = new List<Message>();
+                if (snackbar?.IsShown == true)
+                {
+                    pendingMessages.Add(lastMessage);
+                }
+
+                pendingMessages.AddRange(queuedMessages);
+                return pendingMessages;
+            }
+        }
+
+        private void ShowNextSnackbar()
+        {
+            if (!queuedMessages.Any())
+            {
+                return;
+            }
+
+            ShowSnackbarNow(queuedMessages.First());
+            queuedMessages.RemoveAt(0);
+
+            if (!queuedMessages.Any())
+            {
+                new Handler().PostDelayed(() => { ShowNextSnackbar(); }, (long)chainingTime.TotalMilliseconds);
+            }
+        }
+
+        private void ShowSnackbarNow(Message message)
+        {
+            snackbar = Snackbar
+                .Make(AnchorView, message.Text,
+                    Snackbar.LengthLong);
+            snackbar.SetTextMaxLines(10);
+            if ((int)Build.VERSION.SdkInt >= 23)
+            {
+                if (message.Severity == MessageSeverity.Error)
+                {
+                    snackbar.SetBackgroundTint(App.Context.GetColor(Resource.Color.md_theme_errorContainer));
+                    snackbar.SetTextColor(App.Context.GetColor(Resource.Color.md_theme_onErrorContainer));
+                }
+                else if (message.Severity == MessageSeverity.Warning)
+                {
+                    snackbar.SetBackgroundTint(App.Context.GetColor(Resource.Color.md_theme_inverseSurface));
+                    snackbar.SetTextColor(App.Context.GetColor(Resource.Color.md_theme_inverseOnSurface));
+                }
+                else
+                {
+                    snackbar.SetBackgroundTint(App.Context.GetColor(Resource.Color.md_theme_secondaryContainer));
+                    snackbar.SetTextColor(App.Context.GetColor(Resource.Color.md_theme_onSecondaryContainer));
+                }
+            }
+
+            snackbar.Show();
+            lastMessage = message;
+
+        }
+    }
+}