Fix remaining TextView issues

Terminal.Gui/Views/TextInput/TextView/TextView.Movement.cs

@@ -296,7 +296,7 @@ private bool MoveRight ()
         {
             CurrentColumn++;
 
-            if (CurrentColumn >= currentLine.Count || TextModel.CursorColumn (TextModel.CellsToStringList (currentLine), CurrentColumn, TabWidth, out _, out _) >= Viewport.Width)
+            if (CurrentColumn >= currentLine.Count || TextModel.CursorColumn (TextModel.CellsToStringList (currentLine), CurrentColumn, TabWidth, out _, out _) >= Viewport.X + Viewport.Width)
             {
                 SetNeedsDraw ();
             }
@@ -393,6 +393,11 @@ private bool MoveWordLeft ()
             CurrentRow = newPos.Value.row;
         }
 
+        if (CurrentRow < Viewport.Y || CurrentColumn < Viewport.X || CurrentColumn >= Viewport.X + Viewport.Width)
+        {
+            SetNeedsDraw ();
+        }
+
         DoNeededAction ();
 
         return true;
@@ -408,6 +413,11 @@ private bool MoveWordRight ()
             CurrentRow = newPos.Value.row;
         }
 
+        if (CurrentRow >= Viewport.Y + Viewport.Height || CurrentColumn >= Viewport.X + Viewport.Width || CurrentColumn < Viewport.X)
+        {
+            SetNeedsDraw ();
+        }
+
         DoNeededAction ();
 
         return true;

Terminal.Gui/Views/TextInput/TextView/TextView.Scrolling.cs

@@ -115,7 +115,7 @@ private void AdjustViewport ()
             }
             need = true;
         }
-        else if (!_wordWrap && (CurrentColumn - Viewport.X + 1 > Viewport.Width || dSize.size + 1 >= Viewport.Width))
+        else if (!_wordWrap && (CurrentColumn - Viewport.X + 1 > Viewport.Width || dSize.size - Viewport.X + 1 >= Viewport.Width))
         {
             Viewport = Viewport with { X = TextModel.CalculateLeftColumn (line, Viewport.X, CurrentColumn, Viewport.Width, TabWidth) };
             need = true;
@@ -140,11 +140,6 @@ private void AdjustViewport ()
             Viewport = Viewport with { Y = Math.Min (Math.Max (CurrentRow - Viewport.Height + 1, 0), CurrentRow) };
             need = true;
         }
-        else if (!WordWrap && Viewport.Y > 0 && CurrentRow - Viewport.Height + 1 < Viewport.Y)
-        {
-            Viewport = Viewport with { Y = Math.Max (Viewport.Y - 1, 0) };
-            need = true;
-        }
 
         if (need)
         {

Tests/UnitTestsParallelizable/Views/TextView.NavigationTests.cs

@@ -318,4 +318,165 @@ public void CtrlB_Moves_Backward_One_Character ()
         Assert.Equal (Point.Empty, tv.InsertionPoint);
         Assert.False (tv.IsSelecting);
     }
+
+    [Fact]
+    public void CursorRight_At_NearTheEndOfLine_With_ViewportY_Greater_Than_Zero_Does_Not_Scroll_Up ()
+    {
+        // Test that pressing CursorRight at near the end of line does not scroll up if Viewport.Y > 0
+        TextView tv = new ()
+        {
+            Width = 10,
+            Height = 3,
+            Text = "Line1.\nLine2.\nLine3.\nLine4.\nLine5."
+        };
+        tv.BeginInit ();
+        tv.EndInit ();
+
+        // Scroll to second line and set insertion point at near the end of line
+        tv.Viewport = tv.Viewport with { Y = 1 };
+        tv.InsertionPoint = new Point (5, 1);
+        Assert.Equal (new Point (0, 1), tv.Viewport.Location);
+        Assert.Equal (new Point (5, 1), tv.InsertionPoint);
+        Assert.False (tv.WordWrap);
+
+        // Press CursorRight - should not scroll up since we aren't already at first line
+        Assert.True (tv.NewKeyDownEvent (Key.CursorRight));
+        Assert.Equal (new Point (0, 1), tv.Viewport.Location);
+        Assert.Equal (new Point (6, 1), tv.InsertionPoint);
+    }
+
+    [Fact]
+    public void CursorRight_At_BeforeNearTheEndOfLine_With_ViewportX_Greater_Than_Zero_Does_Not_Scroll_Left ()
+    {
+        // Test that pressing CursorRight at neat the end of line does not scroll left if Viewport.X > 0
+        TextView tv = new ()
+        {
+            Width = 10, Height = 3,
+            Text = "Line1 with more long text.\nLine2.\nLine3.\nLine4."
+        };
+        tv.BeginInit ();
+        tv.EndInit ();
+
+        // Scroll to the column 10 and set insertion point at before near the end of line
+        tv.Viewport = tv.Viewport with { X = 10 };
+        tv.InsertionPoint = new Point (17, 0);
+        Assert.Equal (new Point (10, 0), tv.Viewport.Location);
+        Assert.Equal (new Point (17, 0), tv.InsertionPoint);
+        Assert.False (tv.WordWrap);
+        Assert.True (tv.NeedsDraw);
+
+        // Clear NeedsDraw to isolate the effect of CursorRight key press
+        tv.ClearNeedsDraw ();
+        Assert.False (tv.NeedsDraw);
+
+        // Press CursorRight - should not scroll left since we aren't already at the end of the line
+        Assert.True (tv.NewKeyDownEvent (Key.CursorRight));
+        Assert.Equal (new Point (10, 0), tv.Viewport.Location);
+        Assert.Equal (new Point (18, 0), tv.InsertionPoint);
+        Assert.False (tv.NeedsDraw);
+    }
+
+    [Fact]
+    public void CursorRight_With_CtrlKey_Pressed_At_BeforeNearTheEndOfLine_Scrolls_Right_Next_Word ()
+    {
+        // Test that pressing Ctrl+CursorRight at neat the end of line scrolls right to next word
+        TextView tv = new () { Width = 10, Height = 3, Text = "Line1 with more long text.\nLine2.\nLine3.\nLine4." };
+        tv.BeginInit ();
+        tv.EndInit ();
+
+        // Scroll to the column 10 and set insertion point at before near the end of line
+        tv.Viewport = tv.Viewport with { X = 10 };
+        tv.InsertionPoint = new Point (17, 0);
+        Assert.Equal (new Point (10, 0), tv.Viewport.Location);
+        Assert.Equal (new Point (17, 0), tv.InsertionPoint);
+        Assert.True (tv.NeedsDraw);
+
+        // Clear NeedsDraw to isolate the effect of Ctrl+CursorRight key press
+        tv.ClearNeedsDraw ();
+        Assert.False (tv.NeedsDraw);
+
+        // Press Ctrl+CursorRight - should scroll right to next word
+        Assert.True (tv.NewKeyDownEvent (Key.CursorRight.WithCtrl));
+        Assert.Equal (new Point (12, 0), tv.Viewport.Location);
+        Assert.Equal (new Point (21, 0), tv.InsertionPoint);
+        Assert.True (tv.NeedsDraw);
+    }
+
+    [Fact]
+    public void CursorRight_With_CtrlKey_Pressed_At_TheEndOfLine_Scrolls_Left_To_StartOfNextLine ()
+    {
+        // Test that pressing Ctrl+CursorRight at the end of line scrolls right to start of next line
+        TextView tv = new () { Width = 10, Height = 3, Text = "Line1 with more long text.\nLine2.\nLine3.\nLine4." };
+        tv.BeginInit ();
+        tv.EndInit ();
+
+        // Scroll to the column 17 and set insertion point at the end of line
+        tv.Viewport = tv.Viewport with { X = 17 };
+        tv.InsertionPoint = new Point (26, 0);
+        Assert.Equal (new Point (17, 0), tv.Viewport.Location);
+        Assert.Equal (new Point (26, 0), tv.InsertionPoint);
+        Assert.True (tv.NeedsDraw);
+
+        // Clear NeedsDraw to isolate the effect of Ctrl+CursorRight key press
+        tv.ClearNeedsDraw ();
+        Assert.False (tv.NeedsDraw);
+
+        // Press Ctrl+CursorRight - should scroll right to start of next line
+        Assert.True (tv.NewKeyDownEvent (Key.CursorRight.WithCtrl));
+        Assert.Equal (new Point (0, 0), tv.Viewport.Location);
+        Assert.Equal (new Point (0, 1), tv.InsertionPoint);
+        Assert.True (tv.NeedsDraw);
+    }
+
+    [Fact]
+    public void CursorLeft_With_CtrlKey_Pressed_At_BeforeNearTheStartOfLine_Scrolls_Left_Previous_Word ()
+    {
+        // Test that pressing Ctrl+CursorLeft at neat the start of line scrolls left to previous word
+        TextView tv = new () { Width = 10, Height = 3, Text = "Line1 with more long text.\nLine2.\nLine3.\nLine4." };
+        tv.BeginInit ();
+        tv.EndInit ();
+
+        // Scroll to the column 2 and set insertion point at before near the start of line
+        tv.Viewport = tv.Viewport with { X = 2 };
+        tv.InsertionPoint = new Point (4, 0);
+        Assert.Equal (new Point (2, 0), tv.Viewport.Location);
+        Assert.Equal (new Point (4, 0), tv.InsertionPoint);
+        Assert.True (tv.NeedsDraw);
+
+        // Clear NeedsDraw to isolate the effect of Ctrl+CursorLeft key press
+        tv.ClearNeedsDraw ();
+        Assert.False (tv.NeedsDraw);
+
+        // Press Ctrl+CursorLeft - should scroll left to previous word
+        Assert.True (tv.NewKeyDownEvent (Key.CursorLeft.WithCtrl));
+        Assert.Equal (new Point (0, 0), tv.Viewport.Location);
+        Assert.Equal (new Point (0, 0), tv.InsertionPoint);
+        Assert.True (tv.NeedsDraw);
+    }
+
+    [Fact]
+    public void CursorLeft_With_CtrlKey_Pressed_At_TheStartOfLine_Scrolls_Right_To_EndOfPreviousLine ()
+    {
+        // Test that pressing Ctrl+CursorLeft at the start of line scrolls left to end of previous line
+        TextView tv = new () { Width = 10, Height = 3, Text = "Line1 with more long text.\nLine2.\nLine3.\nLine4." };
+        tv.BeginInit ();
+        tv.EndInit ();
+
+        // Scroll to the column 0 and set insertion point at the start of line
+        tv.Viewport = tv.Viewport with { X = 0, Y = 1 };
+        tv.InsertionPoint = new Point (0, 1);
+        Assert.Equal (new Point (0, 1), tv.Viewport.Location);
+        Assert.Equal (new Point (0, 1), tv.InsertionPoint);
+        Assert.True (tv.NeedsDraw);
+
+        // Clear NeedsDraw to isolate the effect of Ctrl+CursorLeft key press
+        tv.ClearNeedsDraw ();
+        Assert.False (tv.NeedsDraw);
+
+        // Press Ctrl+CursorLeft - should scroll left to end of previous line
+        Assert.True (tv.NewKeyDownEvent (Key.CursorLeft.WithCtrl));
+        Assert.Equal (new Point (17, 0), tv.Viewport.Location);
+        Assert.Equal (new Point (26, 0), tv.InsertionPoint);
+        Assert.True (tv.NeedsDraw);
+    }
 }