[droid] "Uri too long" in WebView.NavigateToString remediation

doc/ReleaseNotes/_ReleaseNotes.md

@@ -101,6 +101,7 @@
     > This change might break the compilation for projects that define duplicate resources in other globally accessible resource dictionaries. Adjustments to remove duplicate resources may be necessary.
 
 ### Bug fixes
+* [#2023](https://github.com/unoplatform/uno/pull/2023) Android WebView.NavigateToString doesn't throw exception even when string is very long.
 * [#2020](https://github.com/unoplatform/uno/pull/2020) `ContentControl` no longer display the datacontext type when ContentTemplate and content are empty
 * [#1987](https://github.com/unoplatform/uno/pull/1987) Missing XML comment warnings are disabled on generated code
 * [#1939](https://github.com/unoplatform/uno/pull/1939) Handles nullables types in XAML file generator

src/SamplesApp/SamplesApp.UITests/Windows_UI_Xaml_Controls/WebViewTests/UnoSamples_Test_NavigateToString.cs

@@ -0,0 +1,45 @@
+using NUnit.Framework;
+using SamplesApp.UITests.TestFramework;
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Uno.UITest.Helpers;
+using Uno.UITest.Helpers.Queries;
+
+namespace SamplesApp.UITests.Windows_UI_Xaml_Controls.WebViewTests
+{
+	[TestFixture]
+	public partial class WebView_Tests : SampleControlUITestBase
+	{
+		[Test]
+		[AutoRetry]
+		[ActivePlatforms(Platform.Android, Platform.iOS)]
+		public void WebView_NavigateToLongString()
+		{
+			Run("UITests.Shared.Windows_UI_Xaml_Controls.WebView.WebView_NavigateToString2");
+
+			_app.WaitForElement(_app.Marked("startButton"));
+
+			TakeScreenshot("Initial");
+
+			var startButton = _app.Marked("startButton");
+			var clickResult = _app.Marked("WebView_NavigateToStringResult");
+
+			// step 1: generate long string
+			_app.Tap(startButton);
+
+			_app.WaitForText(clickResult, "string ready");  // timeout here means: add wait
+
+			// step 2: NavigateTo
+			_app.Tap(startButton);
+			_app.WaitForText(clickResult, "success");   // timeout here means: bug reappear
+
+			TakeScreenshot("AfterSuccess");
+
+		}
+
+	}
+}

src/SamplesApp/UITests.Shared/UITests.Shared.projitems

@@ -1809,6 +1809,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\WebView\WebView_NavigateToString2.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\WebView\WebView_NavigateToUri.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -3615,6 +3619,9 @@
       <DependentUpon>UndefinedHeightListView.xaml</DependentUpon>
     </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\WebView\WebViewViewModel.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\WebView\WebView_NavigateToString2.xaml.cs">
+      <DependentUpon>WebView_NavigateToString2.xaml</DependentUpon>
+    </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Input\CopyToClipboard\CopyToClipboard.xaml.cs">
       <DependentUpon>CopyToClipboard.xaml</DependentUpon>
     </Compile>

src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_NavigateToString2.xaml

@@ -0,0 +1,31 @@
+<UserControl
+	x:Class="UITests.Shared.Windows_UI_Xaml_Controls.WebView.WebView_NavigateToString2"
+	xmlns:controls="using:Uno.UI.Samples.Controls"
+	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+	xmlns:u="using:Uno.UI.Samples.Controls"
+	xmlns:uBehaviors="using:Uno.UI.Samples.Behaviors"
+	xmlns:ios="http://nventive.com/ios"
+	xmlns:win="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+	xmlns:android="http://nventive.com/android"
+	mc:Ignorable="d ios android"
+	d:DesignHeight="2000"
+	d:DesignWidth="400">
+
+	<Grid>
+		<Grid.RowDefinitions>
+			<RowDefinition Height="Auto" />
+			<RowDefinition Height="*" />
+		</Grid.RowDefinitions>
+
+		<StackPanel Background="Honeydew">
+			<TextBox Header="Size of (big) string, in thousands of lines" Text="1000" x:Name="WebView_NavigateToStringSize" InputScope="Number" />
+			<Button Content="generate long string" Click="generateLong_Click" x:Name="startButton" />
+			<TextBlock Text="waiting for NavigationCompleted" x:Name="WebView_NavigateToStringResult" />
+		</StackPanel>
+
+		<WebView Grid.Row="1" Name="webViewControl" />
+	</Grid>
+</UserControl>

src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_NavigateToString2.xaml.cs

@@ -0,0 +1,60 @@
+
+using SamplesApp.Windows_UI_Xaml_Controls.WebView;
+using Uno.UI.Samples.Controls;
+using Windows.UI.Xaml.Controls;
+
+namespace UITests.Shared.Windows_UI_Xaml_Controls.WebView
+{
+	[Uno.UI.Samples.Controls.SampleControlInfo("WebView", "WebView_NavigateToString2", description: "Testing a NavigateToString with a very long string")]
+	public sealed partial class WebView_NavigateToString2 : UserControl
+	{
+		public WebView_NavigateToString2()
+		{
+			this.InitializeComponent();
+		}
+
+		string longString = "";
+
+		private void generateLong_Click(object sender, object e)
+		{
+
+			if (longString.Length < 10)
+			{
+				// generate string
+				WebView_NavigateToStringResult.Text = "generating string";
+
+
+				int linesCount = 0;
+				if (!int.TryParse(WebView_NavigateToStringSize.Text, out linesCount))
+				{
+					return;
+				}
+
+				longString = "<html><body>";
+				for (int i = 0; i < linesCount; i++)
+				{
+					string line = "Linia " + i.ToString() + " ";
+					line = line.PadRight(1000, 'x');
+					longString = longString + "<p>" + line;
+					WebView_NavigateToStringResult.Text = ((int)(i * 100 / linesCount)).ToString();  // percentage, as generating string takes loooong
+				}
+				longString += "</body></html>";
+
+				WebView_NavigateToStringResult.Text = "string ready";
+				startButton.Content = "NavigateTo";
+			}
+			else
+			{
+				// NavigateTo
+				WebView_NavigateToStringResult.Text = "waiting for NavigationCompleted";
+				webViewControl.NavigationCompleted += webViewControl_NavigationCompleted;
+				webViewControl.NavigateToString(longString);
+			}
+		}
+		private void webViewControl_NavigationCompleted(object sender, object args)
+		{
+			WebView_NavigateToStringResult.Text = "success";
+		}
+
+	}
+}

src/Uno.UI/UI/Xaml/Controls/WebView/WebView.Android.cs

@@ -25,8 +25,9 @@ namespace Windows.UI.Xaml.Controls
 	public partial class WebView : Control
 	{
 		private Android.Webkit.WebView _webView;
-
-		protected override void OnApplyTemplate()
+        private bool _wasLoadedFromString;
+
+        protected override void OnApplyTemplate()
 		{
 			base.OnApplyTemplate();
 
@@ -70,7 +71,8 @@ partial void NavigatePartial(Uri uri)
 				return;
 			}
 
-			if (uri.Scheme.Equals("local", StringComparison.OrdinalIgnoreCase))
+            _wasLoadedFromString = false;
+            if (uri.Scheme.Equals("local", StringComparison.OrdinalIgnoreCase))
 			{
 				var path = $"file:///android_asset/{uri.PathAndQuery}";
 				_webView.LoadUrl(path);
@@ -119,7 +121,8 @@ partial void NavigateWithHttpRequestMessagePartial(HttpRequestMessage requestMes
 					element => element.Value.JoinBy(", ")
 				);
 
-			_webView.LoadUrl(uri.AbsoluteUri, headers);
+            _wasLoadedFromString = false;
+            _webView.LoadUrl(uri.AbsoluteUri, headers);
 		}
 
 		partial void NavigateToStringPartial(string text)
@@ -129,7 +132,8 @@ partial void NavigateToStringPartial(string text)
 				return;
 			}
 
-			_webView.LoadData(text, "text/html; charset=utf-8", "utf-8");
+            _wasLoadedFromString = true;
+            _webView.LoadData(text, "text/html; charset=utf-8", "utf-8");
 		}
 
 		//This should be IAsyncOperation<string> instead of Task<string> but we use an extension method to enable the same signature in Win.
@@ -299,11 +303,14 @@ public override void OnPageFinished(Android.Webkit.WebView view, string url)
 				var args = new WebViewNavigationCompletedEventArgs()
 				{
 					IsSuccess = _webViewSuccess,
-					Uri = new Uri(url),
 					WebErrorStatus = _webErrorStatus
 				};
+                if (!_webView._wasLoadedFromString && !string.IsNullOrEmpty(url))
+                {
+                    args.Uri = new Uri(url);
+                }
 
-				_webView.NavigationCompleted?.Invoke(_webView, args);
+                _webView.NavigationCompleted?.Invoke(_webView, args);
 				base.OnPageFinished(view, url);
 			}