`TextFormatter` bugs

[tig]

This API is described as:

    /// <summary>
    ///     Returns the number of columns in the widest line in the list based on the <paramref name="startIndex"/> and
    ///     the <paramref name="length"/>.
    /// </summary>
    /// <remarks>
    ///     This API will return incorrect results if the text includes glyphs who's width is dependent on surrounding
    ///     glyphs (e.g. Arabic).
    /// </remarks>
    /// <param name="lines">The lines.</param>
    /// <param name="startIndex">The start index.</param>
    /// <param name="length">The length.</param>
    /// <param name="tabWidth">The number of columns used for a tab.</param>
    /// <returns>The maximum characters width.</returns>
    public static int GetWidestLineLength (
        List<string> lines,
        int startIndex = -1,
        int length = -1,
        int tabWidth = 0
    )

Based on this, this unit test should pass. It doesn't. The actual width returned is 1.

    [Theory]
    [InlineData (new [] { "0123456789" }, 10)]
    public void GetWidestLineLength_List_GetsWidth (IEnumerable<string> text, int expectedWidth
    )
    {
        Assert.Equal (expectedWidth, TextFormatter.GetWidestLineLength (text.ToList ()));
    }

I'm massively confused. Perhaps the API docs are completely wrong?

@BDisp can you advise?

[BDisp]

I understand your doubt. Maybe you can improve the documentation for this method. In fact, in this case it should return 1, because this method is used for the vertical direction of the text, to obtain the maximum size that a column will occupy in a set of characters. If in a line there is a glyph that occupies two columns then it will return 2. Therefore, it does not return the sum of the column sizes but only the maximum size occupied by a character.

[tig]

I understand your doubt. Maybe you can improve the documentation for this method. In fact, in this case it should return 1, because this method is used for the vertical direction of the text, to obtain the maximum size that a column will occupy in a set of characters. If in a line there is a glyph that occupies two columns then it will return 2. Therefore, it does not return the sum of the column sizes but only the maximum size occupied by a character.

Yeah, I think I see it now. On it...

[tig]

This helped me fix issues here:

    /// <summary>
    ///     Returns the number of columns required to render <paramref name="lines"/> oriented vertically.
    /// </summary>
    /// <remarks>
    ///     This API will return incorrect results if the text includes glyphs who's width is dependent on surrounding
    ///     glyphs (e.g. Arabic).
    /// </remarks>
    /// <param name="lines">The lines.</param>
    /// <param name="startLine">The line in the list to start with (any lines before will be ignored).</param>
    /// <param name="linesCount">The number of lines to process (if less than <c>lines.Count</c>, any lines after will be ignored).</param>
    /// <param name="tabWidth">The number of columns used for a tab.</param>
    /// <returns>The width required.</returns>
    public static int GetColumnsRequiredForVerticalText (
        List<string> lines,
        int startLine = -1,
        int linesCount = -1,
        int tabWidth = 0
    )

This was my bad. I renamed this method way back without really understanding what it did.

[BDisp]

Glad this helped fix the error. What matters is that now you know its purpose and it will certainly be well documented.

[tig]

Is it just me or is vertical text with multiple lines, except when centered horiz, completely broken?

Note, to test this, you have to use this PR which fixes a crash in the scenario and updates the API per above:

#3419

[tig]

While we're at it, perhaps you could help me understand why this test isn't working right

    [SetupFakeDriver]
    [Theory]
    [InlineData ("A", 0, "")]
    [InlineData ("A", 1, "A")]
    [InlineData ("A", 2, "A")]
    [InlineData ("A B", 3, "A B")]
    [InlineData ("A B", 1, "A")]
    [InlineData ("A B", 2, "A")]
    [InlineData ("A B", 3, "A B")]
    [InlineData ("A B", 4, "A B")] // BUGBUG: This should be "A  B"
    [InlineData ("A B", 5, "A B")]// BUGBUG: This should be "A   B"
    [InlineData ("A B", 6, "A B")]// BUGBUG: This should be "A   B"
    [InlineData ("A B", 10, "A B")]// BUGBUG: This should be "A      B"
    [InlineData ("ABC ABC", 10, "ABC ABC")] // BUGBUG: this is wrong
    [InlineData ("ABC ABC", 12, "ABC ABC")]  // BUGBUG: this is wrong
    public void Draw_Horizontal_Justified (string text, int width, string expectedText)
    {
        TextFormatter tf = new ()
        {
            Text = text,
            Alignment = TextAlignment.Justified,
        };
        tf.Draw (new Rectangle (0, 0, width, 1), Attribute.Default, Attribute.Default);

        TestHelpers.AssertDriverContentsWithFrameAre (expectedText, _output);
    }

[BDisp]

Only the ones in the middle vertically are correct. The ones on the sides are incorrect.

[tig]

Only the ones in the middle vertically are correct. The ones on the sides are incorrect.

I was not setting tf.Size. Nevermind.

[tig]

Now, I really did find a bug in TextAlignment.Right when tf.AutoSize = true:

    [SetupFakeDriver]
    [Theory]
    [InlineData ("A", 0, false, "")]
    [InlineData ("A", 1, false, "A")]
    [InlineData ("A", 2, false, " A")]
    [InlineData ("AB", 1, false, "A")]
    [InlineData ("AB", 2, false, "AB")]
    [InlineData ("ABC", 3, false, "ABC")]
    [InlineData ("ABC", 4, false, " ABC")]
    [InlineData ("ABC", 6, false, "   ABC")]

    [InlineData ("A", 0, true, "")]
    [InlineData ("A", 1, true, "A")]
    [InlineData ("A", 2, true, " A")]
    [InlineData ("AB", 1, true, "")] // BUGBUG: This is wrong, it should be "A"
    [InlineData ("AB", 2, true, "AB")]
    [InlineData ("ABC", 3, true, "ABC")]
    [InlineData ("ABC", 4, true, " ABC")]
    [InlineData ("ABC", 6, true, "   ABC")]
    public void Draw_Horizontal_Right (string text, int width, bool autoSize, string expectedText)
    {
        TextFormatter tf = new ()
        {
            Text = text,
            Alignment = TextAlignment.Right,
            AutoSize = autoSize,
        };

        if (!autoSize)
        {
            tf.Size = new Size (width, 1);
        }

        tf.Draw (new Rectangle (Point.Empty, new (width, 1)), Attribute.Default, Attribute.Default);
        TestHelpers.AssertDriverContentsWithFrameAre (expectedText, _output);
    }

[BDisp]

I've also seen that Button doesn't draw the right brackets in justified alignment in some situations. Have you ever noticed this?

[tig]

Now, I really did find a bug in TextAlignment.Right when tf.AutoSize = true:

(This is my bug. nevermind again... I can't repro it on v2_develop).