another fix for showHeaderOnEveryPage (#264)

* Update PDFCalculations.swift
account for space.header and space.footer in page margins calculations
* Update PDFTableObject.swift
- if table has a header that repeats on everypage, make sure the cells are shifted by headerHeight and adjust the position of the size wrt minOffset. also add table padding to the surrounding cells
- fixed the spacing between the first row and the table header on rest of the pages (after firstpage)
* Update PDFTableObjectSpec.swift
Co-authored-by: Philip Niedertscheider <dev@philpri.me>

Documentation/Usage.md

@@ -95,6 +95,9 @@ All values are in dots and are rendered using 72 DPI (dots per inch), as this is
 
 You can also used the predefined formats. For details please refer to the source file [PDFPageFormat.swift](https://github.com/techprimate/TPPDF/blob/master/Source/PDFPageFormat.swift)
 
+Keep in mind that the `space.header` is only applied, if there is at least one element in a header container.
+The same applies to the `space.footer` for footer containers and elements.
+
 If you need your page in landscape format, use the `landscapeSize` variable.
 
 ![Layout](../resources/layout.png)
@@ -820,4 +823,4 @@ If you want to enable a debug overlay, set the flag `debug` of the `PDFGenerator
 let document: PDFDocument
 let generator = PDFDocumentGenerator(document: document)
 generator.debug = true
-```
+```

Source/Internal/Graphics/PDFContext.swift

@@ -32,21 +32,18 @@ public class PDFContext {
 
     internal func beginPDFPage(_ pageInfo: CFDictionary?) {
         // Do not create page immediately, instead invoke it as soon as necessary
-        print("beginPDFPage")
         delayedCommands.append(.beginPDFPage(pageConfig: pageInfo))
         currentPageContainsDrawnContent = false
         hasActivePage = true
     }
 
     internal func endPDFPage() {
-        print("endPDFPage")
         applyDelayedCommands()
         cgContext.endPDFPage()
         hasActivePage = false
     }
 
     internal func closePDF() {
-        print("closePDFPage")
         applyDelayedCommands()
         cgContext.closePDF()
         hasActivePage = false
@@ -61,33 +58,28 @@ public class PDFContext {
     // MARK: - Translation
 
     internal func translateBy(x: CGFloat, y: CGFloat) {
-        print("translateBy")
         delayedCommands.append(.translateBy(x: x, y: y))
     }
 
     internal func scaleBy(x: CGFloat, y: CGFloat) {
-        print("scaleBy")
         delayedCommands.append(.scaleBy(x: x, y: y))
     }
 
     // MARK: - Drawing
 
     internal func drawPath(using mode: CGPathDrawingMode) {
-        print("drawPath")
         applyDelayedCommands()
         cgContext.drawPath(using: mode)
         currentPageContainsDrawnContent = true
     }
 
     internal func drawPDFPage(_ page: CGPDFPage) {
-        print("drawPDFPage")
         applyDelayedCommands()
         cgContext.drawPDFPage(page)
         currentPageContainsDrawnContent = true
     }
 
     internal func draw(image: CGImage, in frame: CGRect, flipped: Bool) {
-        print("draw(image:)")
         applyDelayedCommands()
         cgContext.draw(image: image, in: frame, flipped: flipped)
         currentPageContainsDrawnContent = true
@@ -96,7 +88,6 @@ public class PDFContext {
     // MARK: - Colors
 
     internal func setFillColor(_ color: CGColor) {
-        print("setFillColor")
         applyDelayedCommands()
         cgContext.setFillColor(color)
         currentPageContainsDrawnContent = true
@@ -105,42 +96,36 @@ public class PDFContext {
     // MARK: - Paths
 
     internal func beginPath() {
-        print("beginPath")
         applyDelayedCommands()
         cgContext.beginPath()
         currentPageContainsDrawnContent = true
     }
 
     internal func addPath(_ path: CGPath) {
-        print("addPath")
         applyDelayedCommands()
         cgContext.addPath(path)
         currentPageContainsDrawnContent = true
     }
 
     internal func setLineDash(phase: CGFloat, lengths: [CGFloat]) {
-        print("setLineDash")
         applyDelayedCommands()
         cgContext.setLineDash(phase: phase, lengths: lengths)
         currentPageContainsDrawnContent = true
     }
 
     internal func setLineCap(_ cap: CGLineCap) {
-        print("setLineCap")
         applyDelayedCommands()
         cgContext.setLineCap(cap)
         currentPageContainsDrawnContent = true
     }
 
     internal func setLineWidth(_ width: CGFloat) {
-        print("setLineWidth")
         applyDelayedCommands()
         cgContext.setLineWidth(width)
         currentPageContainsDrawnContent = true
     }
 
     internal func setStrokeColor(_ color: CGColor) {
-        print("setStrokeColor")
         applyDelayedCommands()
         cgContext.setStrokeColor(color)
         currentPageContainsDrawnContent = true
@@ -149,13 +134,11 @@ public class PDFContext {
     // MARK: - State
 
     internal func saveGState() {
-        print("saveGState")
         applyDelayedCommands()
         cgContext.saveGState()
     }
 
     internal func restoreGState() {
-        print("restoreGState")
         applyDelayedCommands()
         cgContext.restoreGState()
     }
@@ -172,7 +155,6 @@ public class PDFContext {
     }
 
     internal func draw(ctFrame frameRef: CTFrame) {
-        print("draw(ctFrame:)")
         applyDelayedCommands()
         CTFrameDraw(frameRef, cgContext)
         currentPageContainsDrawnContent = true
@@ -181,7 +163,6 @@ public class PDFContext {
     // MARK: - Masking
 
     internal func clip() {
-        print("clip")
         applyDelayedCommands()
         cgContext.clip()
         currentPageContainsDrawnContent = true
@@ -190,7 +171,6 @@ public class PDFContext {
     // MARK: - Metadata
 
     internal func setURL(_ url: CFURL, for rect: CGRect) {
-        print("setURL")
         applyDelayedCommands()
         cgContext.setURL(url, for: rect)
         currentPageContainsDrawnContent = true

Source/Internal/Table/PDFTableObject.swift

@@ -284,19 +284,25 @@ internal class PDFTableObject: PDFRenderObject {
         let startPosition: CGPoint = cells.first?.frames.cell.origin ?? .zero
         var nextPageCells: [PDFTableCalculatedCell] = cells
         var pageEnd = CGPoint.null
+        var headerShift = table.showHeadersOnEveryPage
+
 
         repeat {
             var pageStart = CGPoint.null
 
+            // Calculate top page inset
             var minOffset = PDFCalculations.calculateTopMinimum(for: generator)
+            // Calculate bottom page maximum limit
             let maxOffset = PDFCalculations.calculateBottomMaximum(for: generator)
 
             if !firstPage, let headerCells = headerCells {
                 for item in headerCells {
                     var cellFrame = item.frames.cell
                     var contentFrame = item.frames.content
                     cellFrame.origin.y -= startPosition.y - minOffset
+                    cellFrame.origin.y += table.margin
                     contentFrame.origin.y -= startPosition.y - minOffset
+                    contentFrame.origin.y += table.margin
 
                     pageStart = pageStart == .null ? cellFrame.origin : pageStart
                     pageEnd = CGPoint(x: cellFrame.maxX, y: cellFrame.maxY) + CGPoint(x: table.margin, y: table.margin)
@@ -329,11 +335,18 @@ internal class PDFTableObject: PDFRenderObject {
                 }
                 minOffset +=  headerHeight
             }
+            if !firstPage {
+                // shift the rest of the cells down by headerHeight
+                if headerShift {
+                    nextPageCells = shiftCellsBy(cells: nextPageCells, shiftValue: headerHeight)
+                    headerShift = false
+                }
+                //add table padding around cells
+                nextPageCells = shiftCellsBy(cells: nextPageCells, shiftValue: table.margin)
+            }
 
-            let filterResult = filterCellsOnPage(for: generator,
-                                                 items: nextPageCells,
-                                                 minOffset: minOffset,
-                                                 maxOffset: maxOffset,
+            let filterResult = filterCellsOnPage(for: generator, items: nextPageCells,
+                                                 minOffset: minOffset, maxOffset: maxOffset,
                                                  shouldSplitCellsOnPageBreak: table.shouldSplitCellsOnPageBreak)
             let onPageCells = filterResult.cells
             nextPageCells = filterResult.remainder
@@ -432,7 +445,6 @@ internal class PDFTableObject: PDFRenderObject {
                 if shouldSplitCellsOnPageBreak && cellFrame.minY < maxOffset {
                     result.cells.append(item)
                 }
-                // In any case, if the cell does not fit on the active page entirely, it must be repositioned for further pages
                 var nextPageCell = item
                 if shouldSplitCellsOnPageBreak {
                     nextPageCell.frames.cell.origin.y -= contentHeight
@@ -450,7 +462,22 @@ internal class PDFTableObject: PDFRenderObject {
         }
         return result
     }
-
+
+    internal typealias ShiftedCells = [PDFTableCalculatedCell]
+
+    internal func shiftCellsBy(cells: [PDFTableCalculatedCell], shiftValue: CGFloat) -> ShiftedCells {
+        var shiftedCells: [PDFTableCalculatedCell] = []
+
+        for cell in cells {
+            var shiftedCell = cell
+
+            shiftedCell.frames.cell.origin.y += shiftValue
+            shiftedCell.frames.content.origin.y += shiftValue
+            shiftedCells.append(shiftedCell)
+        }
+        return shiftedCells
+    }
+
     internal func createSliceObject(frame: CGRect, elements: [PDFRenderObject], minOffset: CGFloat, maxOffset: CGFloat) -> PDFSlicedObject {
         let sliceObject = PDFSlicedObject(children: elements, frame: frame)
         if frame.maxY > maxOffset {