Implement step 7.4.5: Unequal column widths

Author: davidnmbond

PanoramicData.Render.Test/UnequalColumnWidthTests.cs

@@ -0,0 +1,77 @@
+namespace PanoramicData.Render.Test;
+
+using AwesomeAssertions;
+using DocumentFormat.OpenXml.Wordprocessing;
+using Xunit;
+
+public sealed class UnequalColumnWidthTests
+{
+	[Fact]
+	public void Paginate_UsesExplicitUnequalColumnWidthsForPlacements()
+	{
+		var section = new SectionInfo
+		{
+			ColumnCount = 2,
+			ColumnsEqualWidth = false,
+			Columns =
+			[
+				new SectionColumnDefinition(3000, 360),
+				new SectionColumnDefinition(6000, 0)
+			]
+		};
+		var blocks = new[]
+		{
+			MakeBlock(12000f),
+			MakeBlock(1000f),
+		};
+
+		var result = PageBuilder.Paginate(blocks, section);
+
+		result.Should().ContainSingle();
+		result[0].BlockPlacements.Should().HaveCount(2);
+		result[0].BlockPlacements[0].ColumnIndex.Should().Be(0);
+		result[0].BlockPlacements[0].XTwips.Should().Be(1440f);
+		result[0].BlockPlacements[0].ContentWidthTwips.Should().Be(3000f);
+		result[0].BlockPlacements[1].ColumnIndex.Should().Be(1);
+		result[0].BlockPlacements[1].XTwips.Should().Be(4800f);
+		result[0].BlockPlacements[1].ContentWidthTwips.Should().Be(6000f);
+	}
+
+	[Fact]
+	public void Paginate_UsesRemainingWidthForUnspecifiedExplicitColumns()
+	{
+		var section = new SectionInfo
+		{
+			ColumnCount = 3,
+			ColumnsEqualWidth = false,
+			ColumnSpacingTwips = 240,
+			Columns =
+			[
+				new SectionColumnDefinition(2000, 360),
+				new SectionColumnDefinition(0, 240)
+			]
+		};
+		var blocks = new[]
+		{
+			MakeBlock(12000f),
+			MakeBlock(12000f),
+			MakeBlock(1000f),
+		};
+
+		var result = PageBuilder.Paginate(blocks, section);
+
+		result.Should().ContainSingle();
+		result[0].BlockPlacements.Should().HaveCount(3);
+		result[0].BlockPlacements[0].ContentWidthTwips.Should().Be(2000f);
+		result[0].BlockPlacements[1].ContentWidthTwips.Should().Be(3380f);
+		result[0].BlockPlacements[2].ContentWidthTwips.Should().Be(3380f);
+		result[0].BlockPlacements[1].XTwips.Should().Be(3800f);
+		result[0].BlockPlacements[2].XTwips.Should().Be(7420f);
+	}
+
+	private static LayoutBlock MakeBlock(float heightTwips)
+	{
+		var para = new ParagraphBlock { SourceElement = new Paragraph() };
+		return new LayoutBlock(para, heightTwips);
+	}
+}

PanoramicData.Render/PageBuilder.cs

@@ -873,12 +873,60 @@ private static IReadOnlyList<ColumnRegion> ComputeColumnRegions(SectionInfo sect
 	{
 		var contentLeft = section.MarginLeft;
 		var contentWidth = MathF.Max(0f, section.PageWidth - section.MarginLeft - section.MarginRight);
-		var columnCount = Math.Max(1, section.ColumnCount);
+		var columnCount = Math.Max(1, Math.Max(section.ColumnCount, section.Columns.Count));
 		if (columnCount == 1)
 		{
 			return [new ColumnRegion(contentLeft, contentWidth)];
 		}
 
+		if (!section.ColumnsEqualWidth && section.Columns.Count > 0)
+		{
+			var totalFixedWidth = 0f;
+			var totalExplicitSpacing = 0f;
+			var unresolvedColumnCount = 0;
+
+			for (var i = 0; i < columnCount; i++)
+			{
+				var definition = i < section.Columns.Count ? section.Columns[i] : default;
+				if (definition.WidthTwips > 0)
+				{
+					totalFixedWidth += definition.WidthTwips;
+				}
+				else
+				{
+					unresolvedColumnCount++;
+				}
+
+				if (i < columnCount - 1)
+				{
+					totalExplicitSpacing += i < section.Columns.Count
+						? MathF.Max(0f, definition.SpaceAfterTwips)
+						: MathF.Max(0f, section.ColumnSpacingTwips);
+				}
+			}
+
+			var remainingWidth = MathF.Max(0f, contentWidth - totalFixedWidth - totalExplicitSpacing);
+			var fallbackWidth = unresolvedColumnCount > 0 ? remainingWidth / unresolvedColumnCount : 0f;
+			var explicitResult = new ColumnRegion[columnCount];
+			var explicitX = (float)contentLeft;
+
+			for (var i = 0; i < columnCount; i++)
+			{
+				var definition = i < section.Columns.Count ? section.Columns[i] : default;
+				var width = definition.WidthTwips > 0 ? definition.WidthTwips : fallbackWidth;
+				explicitResult[i] = new ColumnRegion(explicitX, MathF.Max(0f, width));
+				if (i < columnCount - 1)
+				{
+					var spacingAfter = i < section.Columns.Count
+						? MathF.Max(0f, definition.SpaceAfterTwips)
+						: MathF.Max(0f, section.ColumnSpacingTwips);
+					explicitX += MathF.Max(0f, width) + spacingAfter;
+				}
+			}
+
+			return explicitResult;
+		}
+
 		var spacing = MathF.Max(0f, section.ColumnSpacingTwips);
 		var totalSpacing = spacing * (columnCount - 1);
 		var columnWidth = MathF.Max(0f, (contentWidth - totalSpacing) / columnCount);

docs/plans/current-status.md

@@ -10,18 +10,18 @@ Phase 7: Advanced Features — **IN PROGRESS**
 
 ## Current Step
 
-Step 7.4.4 — balanced columns — **COMPLETE**
+Step 7.4.5 — unequal column widths — **COMPLETE**
 
-Completed balanced-column support for the last page of a section:
-- Added a final-page rebalance pass in `PageBuilder` that redistributes remaining multi-column content using existing line-splitting support
-- Balanced splittable content across columns on the last page while leaving earlier pages greedily filled
-- Preserved explicit column-break behavior by skipping last-page balancing when a block carries an explicit column-break directive
+Completed unequal-width column support:
+- Updated `PageBuilder.ComputeColumnRegions` to honor parsed explicit column widths and per-column spacing when a section uses non-equal columns
+- Distributed remaining content width across unspecified explicit columns as a fallback so partially specified column sets still paginate sensibly
+- Added focused placement coverage for fully explicit unequal columns and mixed explicit-plus-fallback column widths
 
-1785 tests passing (1782 → 1785, +3 balanced-column tests).
+1787 tests passing (1785 → 1787, +2 unequal-width column tests).
 
 ## Next Step
 
-Step 7.4.5 — handle unequal column widths
+Step 7.4.6 — integrate column layout with floating objects and wrapping within a column
 
 ## Last Commit
 

docs/plans/phase-7-advanced-features.md

@@ -49,7 +49,7 @@ Implement the remaining document features needed for high-fidelity rendering of
 - [x] 7.4.2 — Implement column flow: text fills the first column, then overflows to the next
 - [x] 7.4.3 — Handle column breaks (`<w:br w:type="column"/>`)
 - [x] 7.4.4 — Handle balanced columns (distribute content evenly, typically on the last page of a section)
-- [ ] 7.4.5 — Handle unequal column widths
+- [x] 7.4.5 — Handle unequal column widths
 - [ ] 7.4.6 — Integrate column layout with floating objects: wrapping within a column
 - [ ] 7.4.7 — Unit tests: verify column flow and break positions