First working RowLayout + TextEdit + UnicodeGlyph (display+input), Selection partially implemented

Author: FremyCompany_cp

FC.MathEditor/WpfMathEditor/Classes/ChildrenHelper.vb

@@ -185,11 +185,11 @@
     Private _LocationInParent As Rect
     Public ReadOnly Property LocationInParent As Rect
         Get
-            PerformLayout()
             If This.Parent Is Nothing Then
                 Return SizeRect
             Else
-                Return _LocationInParent 'This.Parent.Export.GetChildLocation(This)
+                This.Parent.Export.PerformLayout()
+                Return _LocationInParent
             End If
         End Get
     End Property
@@ -202,6 +202,7 @@
         Get
             If This.Parent Is Nothing Then Return LocationInParent
 
+            This.Root.Export.PerformLayout()
             Dim L = LocationInParent
             Return FitRect(LocationInParent, This.Parent.Export.SizeRect, This.Parent.Export.LocationInRoot)
 

FC.MathEditor/WpfMathEditor/Classes/ExportHelper.vb

@@ -80,7 +80,7 @@
     End Function
 
     Public Function ProcessChar_FromRight(ByVal InputChar As Integer) As Boolean
-        Return ProcessChar_FromRight(InputChar)
+        Return ProcessChar_FromRight_Internal(InputChar)
     End Function
 
     Public Sub ProcessDelete()

FC.MathEditor/WpfMathEditor/Classes/InputHelper.vb

@@ -89,5 +89,8 @@
         _Children = GetInitialChildrenHelper()
         _Export = GetInitialExportHelper()
         _Input = GetInitialInputHelper()
+        If _Input Is Nothing Then
+            Trace.TraceError("Bug!")
+        End If
     End Sub
 End Class

FC.MathEditor/WpfMathEditor/Classes/MathElement.Input.vb

@@ -9,50 +9,111 @@ Partial Public MustInherit Class MathElement
     '++
 
     Private _Parent As MathElement
-    Public Property Parent As MathElement
+
+    ''' <summary>
+    ''' Returns the element which attached this element.
+    ''' </summary>
+    Public ReadOnly Property Parent As MathElement
         Get
             Return _Parent
         End Get
-        Set(ByVal value As MathElement)
-            If _Parent IsNot Nothing Then
-                ' REMOVING THE CURRENT PARENT
-                If value Is Nothing Then
-                    If Parent.Children.Contains(Me) Then
-                        Throw New InvalidOperationException("Reseting the Parent property wasn't posssible because the parent still claims it owns the current element.")
-                    Else
-
-                        ' Perform some cleanup
-                        _Parent = Nothing
-                        _ParentDocument = Nothing
-                        _Selection = Nothing
-
-                        ' Raise the corresponding event
-                        RaiseEvent RemovedFromParent(Me, EventArgs.Empty)
-
-                    End If
-                Else
-                    ' TODO: Maybe we can check if value is _Parent before throwing
-                    ' For now, we shall not do so, in order to find duplicate
-                    ' code errors
-                    Throw New InvalidOperationException("Unable to modify the parent of an element after it has been set. Use Clone() to get a parent-free copy of this element, or remove it from its current parent.")
-                End If
+    End Property
+
+    ''' <summary>
+    ''' Changes the Parent of NewChild to this element
+    ''' </summary>
+    ''' <param name="NewChild">The element to attach to this element</param>
+    Public Sub Attach(ByVal NewChild As MathElement)
+        If NewChild Is Nothing Then Throw New ArgumentNullException("NewChild", "The Attach method can't be used with a null argument.")
+        NewChild.SetParent(Me)
+    End Sub
+
+    ''' <summary>
+    ''' Reset the Parent of Child to null.
+    ''' </summary>
+    ''' <param name="Child"></param>
+    ''' <remarks></remarks>
+    Public Sub Detach(ByVal Child As MathElement)
+        If Child.Parent Is Me Then Child.ResetParent() _
+            Else Throw New ArgumentException("Child must be a child of this element.")
+    End Sub
+
+    ''' <summary>
+    ''' Changes the value of the Parent property of this element.
+    ''' </summary>
+    ''' <param name="value">The new value for the Parent property</param>
+    ''' <exception cref="InvalidOperationException">This functions throws an InvalidOperationException when this element already have a parent.</exception>
+    ''' <exception cref="ArgumentException">This functions throws an ArgumentException when this element can't have 'value' as parent.</exception>
+    Private Sub SetParent(ByVal value As MathElement)
+        If _Parent IsNot Nothing Then
+
+            If value Is _Parent Then
+
+#If DEBUG Then
+                ' DON'T DO ANYTHING
+                Trace.TraceWarning("Multiple refefinition of the Parent property of an element. Spaghetti code suspected.")
+#End If
+
             Else
-                ' ADDING A NEW PARENT
-                If value.Children.IsValidChild(Me) Then
 
-                    ' Perform the change
-                    _Parent = value
+                ' REMOVE THE CURRENT PARENT, AND RETRY
+                Try
 
-                    ' Raise the corresponding event
-                    RaiseEvent AttachedToParent(Me, EventArgs.Empty)
+                    ResetParent()
+                    SetParent(value)
+
+                Catch ex As Exception
+
+                    Throw New InvalidOperationException("Unable to modify the parent of an element after it has been added to a children list. Please remove this element from its parent, or use the Clone() function to get a parent-free copy of this element.", ex)
+
+                End Try
 
-                Else
-                    Throw New ArgumentException("This element is not recognised as a valid child of its new parent.", "Parent")
-                End If
             End If
-        End Set
-    End Property
 
+        Else
+
+            ' ADD THE NEW PARENT
+            If value.Children.CanContains(Me) Then
+
+                ' Perform the change
+                _Parent = value
+
+                ' Raise the corresponding event
+                RaiseEvent AttachedToParent(Me, EventArgs.Empty)
+
+            Else
+                Throw New ArgumentException("This element is not recognised as a valid child of its new parent.", "Parent")
+            End If
+
+        End If
+    End Sub
+
+    ''' <summary>
+    ''' Resets the Parent property for this element.
+    ''' </summary>
+    Private Sub ResetParent()
+
+        If Parent.Children.Contains(Me) Then
+
+            Throw New InvalidOperationException("Reseting the Parent property wasn't posssible because the parent still claims it owns the current element.")
+
+        Else
+
+            ' Perform some cleanup
+            _Parent = Nothing
+            _ParentDocument = Nothing
+            _Selection = Nothing
+
+            ' Raise the corresponding event
+            RaiseDetachedFromParent()
+
+        End If
+
+    End Sub
+
+    ''' <summary>
+    ''' Returns the last element in the Parent chain. If this element is hosted in a document, this function returns the same as ParentDocument.
+    ''' </summary>
     Public ReadOnly Property Root As MathElement
         Get
             If _ParentDocument IsNot Nothing Then Return _ParentDocument
@@ -62,6 +123,10 @@ Partial Public MustInherit Class MathElement
     End Property
 
     Private _ParentDocument As MathDocument
+
+    ''' <summary>
+    ''' Returns the document that host this element, or Nothing if this element is not currently hosted.
+    ''' </summary>
     Public ReadOnly Property ParentDocument As MathDocument
         Get
 
@@ -134,7 +199,6 @@ Partial Public MustInherit Class MathElement
     Protected _Children As ChildrenHelper
     Public ReadOnly Property Children As ChildrenHelper
         Get
-            If _Children Is Nothing Then _Children = Nothing
             Return _Children
         End Get
     End Property
@@ -244,18 +308,64 @@ Partial Public MustInherit Class MathElement
 
     ' TODO: RemovedFromParent
     Public Event AttachedToParent As EventHandler
+    Public Sub RaiseAttachedToParent()
+        RaiseEvent AttachedToParent(Me, EventArgs.Empty)
+    End Sub
+
+    Public Event AddedToParent As EventHandler
+    Public Sub RaiseAddedToParent()
+        RaiseEvent AddedToParent(Me, EventArgs.Empty)
+    End Sub
+
     Public Event RemovedFromParent As EventHandler
+    Public Sub RaiseRemovedFromParent()
+        RaiseEvent RemovedFromParent(Me, EventArgs.Empty)
+    End Sub
+
+    Public Event DetachedFromParent As EventHandler
+    Public Sub RaiseDetachedFromParent()
+        RaiseEvent DetachedFromParent(Me, EventArgs.Empty)
+    End Sub
+
+    Public Event DetachedFromDocument As EventHandler
+    Public Sub RaiseDetachedFromDocument()
+        RaiseEvent DetachedFromDocument(Me, EventArgs.Empty)
+    End Sub
 
     Public Event ChildAdded As EventHandler(Of TreeEventArgs)
+    Public Sub RaiseChildAdded(ByVal Child As MathElement)
+        RaiseEvent ChildAdded(Me, New TreeEventArgs(Child))
+    End Sub
+
     Public Event ChildRemoved As EventHandler(Of TreeEventArgs)
+    Public Sub RaiseChildRemoved(ByVal Child As MathElement)
+        RaiseEvent ChildRemoved(Me, New TreeEventArgs(Child))
+    End Sub
 
     Public Class TreeEventArgs : Inherits EventArgs
-
         Public Property Argument As MathElement
         Public Sub New(ByVal Argument As MathElement)
             Me.Argument = Argument
         End Sub
-
     End Class
 
+    Private Sub MathElement_ChildAdded(ByVal sender As Object, ByVal e As TreeEventArgs) Handles Me.ChildAdded
+        e.Argument.RaiseAddedToParent()
+    End Sub
+
+    Private Sub MathElement_ChildRemoved(ByVal sender As Object, ByVal e As TreeEventArgs) Handles Me.ChildRemoved
+        e.Argument.RaiseRemovedFromParent()
+    End Sub
+
+    Private Sub MathElement_DetachedFromDocument(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.DetachedFromDocument
+        _ParentDocument = Nothing
+        _Selection = Nothing
+    End Sub
+
+    Private Sub MathElement_DetachedFromParent(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.DetachedFromParent
+        RaiseDetachedFromDocument()
+        For Each Child In Children
+            Child.RaiseDetachedFromDocument()
+        Next
+    End Sub
 End Class

FC.MathEditor/WpfMathEditor/Classes/MathElement.XmlTree.vb

@@ -1,4 +1,5 @@
 Partial Public Class SelectionHelper
+    Implements IEnumerable(Of MathElement)
 
     Private This As MathDocument
     Public Sub New(ByVal This As MathDocument)
@@ -39,7 +40,6 @@
         SetSelection(CommonAncestror, NewChild, SelectionEnd)
     End Sub
 
-
     Private Sub SetSelection(ByVal StartPoint As Selection, ByVal EndPoint As Selection)
 
         ' Compute _Selection
@@ -207,4 +207,11 @@
         RTL = -1
     End Enum
 
+    Public Function GetEnumerator() As System.Collections.Generic.IEnumerator(Of MathElement) Implements System.Collections.Generic.IEnumerable(Of MathElement).GetEnumerator
+        Return GetSelectedElements().GetEnumerator()
+    End Function
+
+    Private Function GetGenericEnumerator() As System.Collections.IEnumerator Implements System.Collections.IEnumerable.GetEnumerator
+        Return GetEnumerator()
+    End Function
 End Class

FC.MathEditor/WpfMathEditor/Classes/SelectionHelper.vb

@@ -130,6 +130,7 @@
     <Compile Include="TextEdit\TextEdit.vb" />
     <Compile Include="TextEdit\TextEditChildrenHelper.vb" />
     <Compile Include="TextEdit\TextEditInputHelper.vb" />
+    <Compile Include="TextEdit\TextEditExportHelper.vb" />
     <Compile Include="UserControl\GlyphDisplayer.xaml.vb">
       <DependentUpon>GlyphDisplayer.xaml</DependentUpon>
     </Compile>

FC.MathEditor/WpfMathEditor/EquationEditor.vbproj

@@ -20,10 +20,6 @@
         Return InvalidCall()
     End Function
 
-    Public Overrides Function Contains(ByVal Element As MathElement) As Boolean
-        Return False
-    End Function
-
     Public Overrides Function IndexOf(ByVal Element As MathElement) As Integer
         Return -1
     End Function
@@ -72,4 +68,14 @@
         InvalidCall()
     End Sub
 
+    Protected Overrides Function Contains_Internal(ByVal Element As MathElement) As Boolean
+        Return False
+    End Function
+
+    Public Overrides ReadOnly Property Last As MathElement
+        Get
+            Return Nothing
+        End Get
+    End Property
+
 End Class

FC.MathEditor/WpfMathEditor/Glyphs/GlyphChildrenHelper.vb

@@ -46,7 +46,6 @@
     End Function
 
     Protected Overrides Function GetInitialInputHelper() As InputHelper
-        ' TODO: InputHelper for UnicodeGlyph!
-        Return Nothing
+        Return New UnicodeGlyphInputHelper(Me)
     End Function
 End Class

FC.MathEditor/WpfMathEditor/Glyphs/UnicodeGlyph.vb

@@ -1,5 +1,11 @@
-Public Class UnicodeGlyphInputHelper
+Public Class UnicodeGlyphInputHelper : Inherits InputHelper
 
+    Public Sub New(ByVal This As UnicodeGlyph)
+        MyBase.New(This)
+    End Sub
 
+    Public Overrides Function ProcessChar_Internal(ByVal InputChar As Integer) As Boolean
+        Return False
+    End Function
 
 End Class