Add code fixer for tab order

Handle scenarios without docking, e.g. all controls that have misaligned
`TabIndex` vs z-order aren't docked.

There are three distinct scenarios when it comes to re-ordering statements:

1. Move down by one, or swap neighbouring statements - in this case we
need to swap the leading trivia before we switch.

2. Move down by more than one position - we need to swap leading trivia
with the statement directly below the statement we are moving, and update
the trivia for the moved statement with the leading trivia of the statement
above which we're inserting.

3. Move up - we need to swap the leading trivia for the moved statement
with the leading trivia of the statement above which we're inserting, and
update that statement's trivia with the leading trivia of the statement
directly below it.

Author: RussKie

src/WindowsForms.Analyzers/ControlTabOrderAnalyzer.cs

@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics;
+using System.Linq;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Diagnostics;
@@ -100,6 +101,8 @@ private void CodeBlockAction(OperationBlockAnalysisContext context)
                     return;
                 }
 
+                Dictionary<string, List<Location>> containerProperties = BuildContainerAddLocations(calculatedContext.ContainerAddLocations);
+
                 // _controlsAddIndex dictionary, which looks something like this:
                 //
                 //      [this.Controls.Add]   : new List { button3, this.button1 }
@@ -111,42 +114,99 @@ private void CodeBlockAction(OperationBlockAnalysisContext context)
                 //      [this.button1:1]
                 //      [label2:0]
                 Dictionary<string, int> flatControlsAddIndex = new();
-                foreach (string key in calculatedContext.ControlsAddIndex.Keys)
+                Dictionary<string, string> containersByControl = new();
+                foreach (string containerName in calculatedContext.ControlsAddIndex.Keys)
                 {
-                    for (int i = 0; i < calculatedContext.ControlsAddIndex[key].Count; i++)
+                    for (int i = 0; i < calculatedContext.ControlsAddIndex[containerName].Count; i++)
                     {
-                        string controlName = calculatedContext.ControlsAddIndex[key][i];
+                        string controlName = calculatedContext.ControlsAddIndex[containerName][i];
                         flatControlsAddIndex[controlName] = i;
+
+                        containersByControl[controlName] = containerName;
                     }
                 }
 
                 // Verify explicit TabIndex is the same as the "add order"
-                foreach (string key in calculatedContext.ControlsTabIndex.Keys)
+                foreach (string controlName in calculatedContext.ControlsTabIndex.Keys)
                 {
-                    if (!flatControlsAddIndex.ContainsKey(key))
+                    if (!flatControlsAddIndex.ContainsKey(controlName))
                     {
                         // TODO: assert, diagnostics, etc.
                         continue;
                     }
 
-                    int tabIndex = calculatedContext.ControlsTabIndex[key];
-                    int addIndex = flatControlsAddIndex[key];
+                    int tabIndex = calculatedContext.ControlsTabIndex[controlName];
+                    int addIndex = flatControlsAddIndex[controlName];
 
                     if (tabIndex == addIndex)
                     {
                         continue;
                     }
 
+                    string containerName = containersByControl[controlName];
+                    Dictionary<string, string?> properties = new();
+                    properties["ZOrder"] = addIndex.ToString();
+                    properties["TabIndex"] = tabIndex.ToString();
+
                     var diagnostic = Diagnostic.Create(
                         descriptor: InconsistentTabIndexRuleIdDescriptor,
-                        location: calculatedContext.ControlsAddIndexLocations[key],
-                        properties: new Dictionary<string, string?> { { "ZOrder", addIndex.ToString() }, { "TabIndex", tabIndex.ToString() } }.ToImmutableDictionary(),
-                        key, addIndex, tabIndex);
+                        location: calculatedContext.ControlsAddIndexLocations[controlName],
+                        additionalLocations: containerProperties[containerName],
+                        properties.ToImmutableDictionary(),
+                        controlName, addIndex, tabIndex);
                     context.ReportDiagnostic(diagnostic);
                 }
             }
         }
 
+        private static Dictionary<string, List<Location>> BuildContainerAddLocations(in Dictionary<string, List<Location>> containerAddLocations)
+        {
+            Dictionary<string, List<Location>> containerProperties = new();
+
+            // Check that 'container.Controls.Add(...)' statements are consequitive.
+            // If not - the code has been manually modified, we won't be able to provide an auto-fix.
+            foreach (string containerName in containerAddLocations.Keys)
+            {
+                containerProperties[containerName] = new();
+
+                Location startLine = Location.None;
+                Location endLine = Location.None;
+                List<int> lines = new();
+                foreach (Location location in containerAddLocations[containerName])
+                {
+                    if (startLine == Location.None || startLine.GetLineSpan().StartLinePosition.Line > location.GetLineSpan().StartLinePosition.Line)
+                    {
+                        startLine = location;
+                    }
+
+                    if (endLine.GetLineSpan().StartLinePosition.Line < location.GetLineSpan().StartLinePosition.Line)
+                    {
+                        endLine = location;
+                    }
+
+                    lines.Add(location.GetLineSpan().StartLinePosition.Line);
+                }
+
+                Debug.Assert(startLine != Location.None);
+                Debug.Assert(endLine != Location.None);
+
+                if (startLine == endLine)
+                {
+                    // A single control with an invalid TabIndex
+                }
+                else if (Enumerable.Range(startLine.GetLineSpan().StartLinePosition.Line, endLine.GetLineSpan().StartLinePosition.Line - startLine.GetLineSpan().StartLinePosition.Line).Except(lines).Any())
+                {
+                    // 'container.Controls.Add(...)' statements aren't consequitive.
+                }
+                else
+                {
+                    containerProperties[containerName] = containerAddLocations[containerName];
+                }
+            }
+
+            return containerProperties;
+        }
+
         private void ParseControlAddStatements(InvocationExpressionSyntax expressionSyntax, CalculatedAnalysisContext calculatedContext)
         {
             if (!expressionSyntax.Expression.ToString().EndsWith(".Controls.Add"))
@@ -169,7 +229,7 @@ private void ParseControlAddStatements(InvocationExpressionSyntax expressionSynt
 
             // this is something like "this.Controls.Add" or "panel1.Controls.Add", but good enough for our intents and purposes
             ExpressionSyntax? syntax = expressionSyntax.Expression;
-            string container = syntax.ToString();
+            string containerName = syntax.ToString();
 
             // Transform "Controls.Add" statements into a map. E.g.:
             //
@@ -182,13 +242,20 @@ private void ParseControlAddStatements(InvocationExpressionSyntax expressionSynt
             //      [this.Controls.Add]   : new List { button3, this.button1 }
             //      [panel1.Controls.Add] : new List { label2 }
 
-            if (!calculatedContext.ControlsAddIndex.ContainsKey(container))
+            if (!calculatedContext.ControlsAddIndex.ContainsKey(containerName))
+            {
+                calculatedContext.ControlsAddIndex[containerName] = new List<string>();
+            }
+
+            calculatedContext.ControlsAddIndex[containerName].Add(controlName);
+            calculatedContext.ControlsAddIndexLocations[controlName] = syntax.Parent!.Parent!.GetLocation(); // e.g.: 'this.Controls.Add(button3);'
+
+            if (!calculatedContext.ContainerAddLocations.ContainsKey(containerName))
             {
-                calculatedContext.ControlsAddIndex[container] = new List<string>();
+                calculatedContext.ContainerAddLocations[containerName] = new();
             }
 
-            calculatedContext.ControlsAddIndex[container].Add(controlName);
-            calculatedContext.ControlsAddIndexLocations[controlName] = syntax.Parent!.Parent!.GetLocation();
+            calculatedContext.ContainerAddLocations[containerName].Add(calculatedContext.ControlsAddIndexLocations[controlName]);
         }
 
         private void ParseTabIndexAssignments(AssignmentExpressionSyntax expressionSyntax, OperationBlockAnalysisContext context, CalculatedAnalysisContext calculatedContext)
@@ -246,6 +313,8 @@ private sealed class CalculatedAnalysisContext
             // Contains the list of fields and local controls in order those are added to parent controls.
             public Dictionary<string, List<string>> ControlsAddIndex { get; } = new();
             public Dictionary<string, Location> ControlsAddIndexLocations { get; } = new();
+
+            public Dictionary<string, List<Location>> ContainerAddLocations { get; } = new();
         }
     }
 }

src/WindowsForms.CodeFixes/CodeFixResources.Designer.cs

@@ -1,64 +1,6 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!-- 
-    Microsoft ResX Schema 
-    
-    Version 2.0
-    
-    The primary goals of this format is to allow a simple XML format 
-    that is mostly human readable. The generation and parsing of the 
-    various data types are done through the TypeConverter classes 
-    associated with the data types.
-    
-    Example:
-    
-    ... ado.net/XML headers & schema ...
-    <resheader name="resmimetype">text/microsoft-resx</resheader>
-    <resheader name="version">2.0</resheader>
-    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
-    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
-    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
-    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
-    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
-        <value>[base64 mime encoded serialized .NET Framework object]</value>
-    </data>
-    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
-        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
-        <comment>This is a comment</comment>
-    </data>
-                
-    There are any number of "resheader" rows that contain simple 
-    name/value pairs.
-    
-    Each data row contains a name, and value. The row also contains a 
-    type or mimetype. Type corresponds to a .NET class that support 
-    text/value conversion through the TypeConverter architecture. 
-    Classes that don't support this are serialized and stored with the 
-    mimetype set.
-    
-    The mimetype is used for serialized objects, and tells the 
-    ResXResourceReader how to depersist the object. This is currently not 
-    extensible. For a given mimetype the value must be set accordingly:
-    
-    Note - application/x-microsoft.net.object.binary.base64 is the format 
-    that the ResXResourceWriter will generate, however the reader can 
-    read any of the formats listed below.
-    
-    mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with 
-            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
-            : and then encoded with base64 encoding.
-    
-    mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with 
-            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
-            : and then encoded with base64 encoding.
 
-    mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array 
-            : using a System.ComponentModel.TypeConverter
-            : and then encoded with base64 encoding.
-    -->
   <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
     <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
     <xsd:element name="root" msdata:IsDataSet="true">
@@ -117,8 +59,8 @@
   <resheader name="writer">
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
-  <data name="CodeFixTitle" xml:space="preserve">
-    <value>Make uppercase</value>
-    <comment>The title of the code fix.</comment>
+  <data name="ControlTabOrderAnalyzerCodeFixTitle" xml:space="preserve">
+    <value>Match Z-order to TabIndex</value>
+    <comment>The title of the code fix. {Locked="TabIndex"}.</comment>
   </data>
-</root>
+</root>