Merge pull request #62 from rh-mitre-ten/android_fix_suggestions_not_…

…showing_when_search_string_empty Android - display suggestions empty search text
dotMorten · Mar 9, 2020 · 15365ad · 15365ad
2 parents 484b779 + 9b616b6
commit 15365ad
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Showing 4 changed files with 112 additions and 4 deletions.
diff --git a/AutoSuggestBox/Platform/NativeAutoSuggestBox.Android.cs b/AutoSuggestBox/Platform/NativeAutoSuggestBox.Android.cs
@@ -33,6 +33,16 @@ public AndroidAutoSuggestBox(Context context) : base(context)
             Adapter = adapter = new SuggestCompleteAdapter(Context, global::Android.Resource.Layout.SimpleDropDownItem1Line);
         }
 
+        /// <inheritdoc />
+        public override bool EnoughToFilter()
+        {
+            // Setting Threshold = 0 in the constructor does not allow the control to display suggestions when the Text property is null or empty.
+            // This is by design by Android.
+            // See https://stackoverflow.com/questions/2126717/android-autocompletetextview-show-suggestions-when-no-text-entered for details
+            // Overriding this method to always returns true changes this behaviour.
+            return true;
+        }
+
         /// <inheritdoc />
         protected override void OnFocusChanged(bool gainFocus, [GeneratedEnum] FocusSearchDirection direction, Rect previouslyFocusedRect)
         {

diff --git a/SampleApp/SampleApp/SampleApp.csproj b/SampleApp/SampleApp/SampleApp.csproj
@@ -8,10 +8,10 @@
     <PackageReference Include="Xamarin.Forms" Version="3.0.0.446417" />
   </ItemGroup>
 
-  <ItemGroup>
-    <ProjectReference Include="..\..\AutoSuggestBox\dotMorten.Xamarin.Forms.AutoSuggestBox.csproj">
-      <Private>false</Private>
-    </ProjectReference>
+  <ItemGroup>	
+    <ProjectReference Include="..\..\AutoSuggestBox\dotMorten.Xamarin.Forms.AutoSuggestBox.csproj">	
+      <Private>false</Private>	
+    </ProjectReference>	
   </ItemGroup>
 
   <ItemGroup>

diff --git a/SampleApp/SampleApp/Samples/AutoSuggestBoxSamples/PreviousAndSuggested.xaml b/SampleApp/SampleApp/Samples/AutoSuggestBoxSamples/PreviousAndSuggested.xaml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage
+  x:Class="SampleApp.Samples.AutoSuggestBoxSamples.PreviousAndSuggested"
+  xmlns="http://xamarin.com/schemas/2014/forms"
+  xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+  xmlns:dm="clr-namespace:dotMorten.Xamarin.Forms;assembly=dotMorten.Xamarin.Forms.AutoSuggestBox"
+  Padding="20">
+    <ContentPage.Content>
+        <StackLayout>
+            <dm:AutoSuggestBox
+              x:Name="SuggestBox1"
+              Focused="SuggestBox1_OnFocused"
+              PlaceholderText="Scan or type"
+              QuerySubmitted="SuggestBox_QuerySubmitted"
+              TextChanged="SuggestBox_TextChanged" />
+        </StackLayout>
+    </ContentPage.Content>
+</ContentPage>
diff --git a/SampleApp/SampleApp/Samples/AutoSuggestBoxSamples/PreviousAndSuggested.xaml.cs b/SampleApp/SampleApp/Samples/AutoSuggestBoxSamples/PreviousAndSuggested.xaml.cs
@@ -0,0 +1,80 @@
+using dotMorten.Xamarin.Forms;
+using System.Collections.Generic;
+using System.ComponentModel;
+using Xamarin.Forms;
+using Xamarin.Forms.Xaml;
+
+namespace SampleApp.Samples.AutoSuggestBoxSamples
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+    [Description("Previous search and suggested")]
+    [SamplePriority(4)]
+	public partial class PreviousAndSuggested : ContentPage
+	{
+		public PreviousAndSuggested()
+		{
+			InitializeComponent ();
+            Initialize();
+        }
+
+        private List<string> _suggestedSearches;
+        private List<string> _previousSearches;
+
+        private void Initialize()
+        {
+            // suggested searches based on what was typed - normally loaded from some api
+            _suggestedSearches = new List<string>
+            {
+                "suggestion 1",
+                "suggestion 2",
+                "suggestion 3"
+            };
+
+            // a history of searches the user has previous executed
+            _previousSearches = new List<string>
+            {
+                "previous search 1",
+                "previous search 2",
+                "previous search 3",
+            };
+        }
+
+        private void SuggestBox_TextChanged(object sender, AutoSuggestBoxTextChangedEventArgs e)
+        {
+            var box = (AutoSuggestBox)sender;
+            UpdateSuggestionItemSource(box);
+        }
+
+        private void SuggestBox1_OnFocused(object sender, FocusEventArgs e)
+        {
+            var box = (AutoSuggestBox)sender;
+            UpdateSuggestionItemSource(box);
+        }
+
+        private void UpdateSuggestionItemSource(AutoSuggestBox box)
+        {
+            if (box.Text.Length >= 3)
+            {
+                // show suggested searches, presumably loaded from an API
+                box.ItemsSource = _suggestedSearches;
+                box.IsSuggestionListOpen = true;
+            }
+            else if (box.Text.Length == 0)
+            {
+                // show the user's previous searches when they haven't typed anything yet
+                box.ItemsSource = _previousSearches;
+                box.IsSuggestionListOpen = true;
+            }
+            else
+            {
+                box.IsSuggestionListOpen = false;
+                box.ItemsSource = null;
+            }
+        }
+
+        private void SuggestBox_QuerySubmitted(object sender, AutoSuggestBoxQuerySubmittedEventArgs e)
+        {
+            SuggestBox1.Unfocus();
+        }
+    }
+}