This closes #1129, make cell support inheritance columns/rows style

Correct cells style in merge range
Fix incorrect style ID returned on getting cell style in some cases
Unit test updated and simplified code

cell.go

@@ -200,12 +200,12 @@ func (f *File) setCellTimeFunc(sheet, axis string, value time.Time) error {
 	if err != nil {
 		return err
 	}
-	cellData, col, _, err := f.prepareCell(ws, sheet, axis)
+	cellData, col, row, err := f.prepareCell(ws, sheet, axis)
 	if err != nil {
 		return err
 	}
 	ws.Lock()
-	cellData.S = f.prepareCellStyle(ws, col, cellData.S)
+	cellData.S = f.prepareCellStyle(ws, col, row, cellData.S)
 	ws.Unlock()
 
 	var isNum bool
@@ -214,10 +214,7 @@ func (f *File) setCellTimeFunc(sheet, axis string, value time.Time) error {
 		return err
 	}
 	if isNum {
-		err = f.setDefaultTimeStyle(sheet, axis, 22)
-		if err != nil {
-			return err
-		}
+		_ = f.setDefaultTimeStyle(sheet, axis, 22)
 	}
 	return err
 }
@@ -254,13 +251,13 @@ func (f *File) SetCellInt(sheet, axis string, value int) error {
 	if err != nil {
 		return err
 	}
-	cellData, col, _, err := f.prepareCell(ws, sheet, axis)
+	cellData, col, row, err := f.prepareCell(ws, sheet, axis)
 	if err != nil {
 		return err
 	}
 	ws.Lock()
 	defer ws.Unlock()
-	cellData.S = f.prepareCellStyle(ws, col, cellData.S)
+	cellData.S = f.prepareCellStyle(ws, col, row, cellData.S)
 	cellData.T, cellData.V = setCellInt(value)
 	return err
 }
@@ -279,13 +276,13 @@ func (f *File) SetCellBool(sheet, axis string, value bool) error {
 	if err != nil {
 		return err
 	}
-	cellData, col, _, err := f.prepareCell(ws, sheet, axis)
+	cellData, col, row, err := f.prepareCell(ws, sheet, axis)
 	if err != nil {
 		return err
 	}
 	ws.Lock()
 	defer ws.Unlock()
-	cellData.S = f.prepareCellStyle(ws, col, cellData.S)
+	cellData.S = f.prepareCellStyle(ws, col, row, cellData.S)
 	cellData.T, cellData.V = setCellBool(value)
 	return err
 }
@@ -316,13 +313,13 @@ func (f *File) SetCellFloat(sheet, axis string, value float64, prec, bitSize int
 	if err != nil {
 		return err
 	}
-	cellData, col, _, err := f.prepareCell(ws, sheet, axis)
+	cellData, col, row, err := f.prepareCell(ws, sheet, axis)
 	if err != nil {
 		return err
 	}
 	ws.Lock()
 	defer ws.Unlock()
-	cellData.S = f.prepareCellStyle(ws, col, cellData.S)
+	cellData.S = f.prepareCellStyle(ws, col, row, cellData.S)
 	cellData.T, cellData.V = setCellFloat(value, prec, bitSize)
 	return err
 }
@@ -341,13 +338,13 @@ func (f *File) SetCellStr(sheet, axis, value string) error {
 	if err != nil {
 		return err
 	}
-	cellData, col, _, err := f.prepareCell(ws, sheet, axis)
+	cellData, col, row, err := f.prepareCell(ws, sheet, axis)
 	if err != nil {
 		return err
 	}
 	ws.Lock()
 	defer ws.Unlock()
-	cellData.S = f.prepareCellStyle(ws, col, cellData.S)
+	cellData.S = f.prepareCellStyle(ws, col, row, cellData.S)
 	cellData.T, cellData.V, err = f.setCellString(value)
 	return err
 }
@@ -439,13 +436,13 @@ func (f *File) SetCellDefault(sheet, axis, value string) error {
 	if err != nil {
 		return err
 	}
-	cellData, col, _, err := f.prepareCell(ws, sheet, axis)
+	cellData, col, row, err := f.prepareCell(ws, sheet, axis)
 	if err != nil {
 		return err
 	}
 	ws.Lock()
 	defer ws.Unlock()
-	cellData.S = f.prepareCellStyle(ws, col, cellData.S)
+	cellData.S = f.prepareCellStyle(ws, col, row, cellData.S)
 	cellData.T, cellData.V = setCellDefault(value)
 	return err
 }
@@ -937,14 +934,14 @@ func (f *File) SetCellRichText(sheet, cell string, runs []RichTextRun) error {
 	if err != nil {
 		return err
 	}
-	cellData, col, _, err := f.prepareCell(ws, sheet, cell)
+	cellData, col, row, err := f.prepareCell(ws, sheet, cell)
 	if err != nil {
 		return err
 	}
 	if err := f.sharedStringsLoader(); err != nil {
 		return err
 	}
-	cellData.S = f.prepareCellStyle(ws, col, cellData.S)
+	cellData.S = f.prepareCellStyle(ws, col, row, cellData.S)
 	si := xlsxSI{}
 	sst := f.sharedStringsReader()
 	textRuns := []xlsxR{}
@@ -1133,13 +1130,18 @@ func isTimeNumFmt(format string) bool {
 
 // prepareCellStyle provides a function to prepare style index of cell in
 // worksheet by given column index and style index.
-func (f *File) prepareCellStyle(ws *xlsxWorksheet, col, style int) int {
+func (f *File) prepareCellStyle(ws *xlsxWorksheet, col, row, style int) int {
 	if ws.Cols != nil && style == 0 {
 		for _, c := range ws.Cols.Col {
-			if c.Min <= col && col <= c.Max {
-				style = c.Style
+			if c.Min <= col && col <= c.Max && c.Style != 0 {
+				return c.Style
+			}
 		}
 	}
+	for rowIdx := range ws.SheetData.Row {
+		if styleID := ws.SheetData.Row[rowIdx].S; style == 0 && styleID != 0 {
+			return styleID
+		}
 	}
 	return style
 }
@@ -1150,6 +1152,11 @@ func (f *File) mergeCellsParser(ws *xlsxWorksheet, axis string) (string, error)
 	axis = strings.ToUpper(axis)
 	if ws.MergeCells != nil {
 		for i := 0; i < len(ws.MergeCells.Cells); i++ {
+			if ws.MergeCells.Cells[i] == nil {
+				ws.MergeCells.Cells = append(ws.MergeCells.Cells[:i], ws.MergeCells.Cells[i+1:]...)
+				i--
+				continue
+			}
 			ok, err := f.checkCellInArea(axis, ws.MergeCells.Cells[i].Ref)
 			if err != nil {
 				return axis, err
@@ -1170,8 +1177,7 @@ func (f *File) checkCellInArea(cell, area string) (bool, error) {
 		return false, err
 	}
 
-	rng := strings.Split(area, ":")
-	if len(rng) != 2 {
+	if rng := strings.Split(area, ":"); len(rng) != 2 {
 		return false, err
 	}
 	coordinates, err := areaRefToCoordinates(area)

col.go

@@ -592,9 +592,8 @@ func (f *File) positionObjectPixels(sheet string, col, row, x1, y1, width, heigh
 		row++
 	}
 
-	// Initialise end cell to the same as the start cell.
-	colEnd := col
-	rowEnd := row
+	// Initialized end cell to the same as the start cell.
+	colEnd, rowEnd := col, row
 
 	width += x1
 	height += y1
@@ -632,7 +631,7 @@ func (f *File) getColWidth(sheet string, col int) int {
 			return int(convertColWidthToPixels(width))
 		}
 	}
-	// Optimisation for when the column widths haven't changed.
+	// Optimization for when the column widths haven't changed.
 	return int(defaultColWidthPixels)
 }
 
@@ -658,7 +657,7 @@ func (f *File) GetColWidth(sheet, col string) (float64, error) {
 			return width, err
 		}
 	}
-	// Optimisation for when the column widths haven't changed.
+	// Optimization for when the column widths haven't changed.
 	return defaultColWidth, err
 }
 
@@ -707,7 +706,7 @@ func (f *File) RemoveCol(sheet, col string) error {
 	return f.adjustHelper(sheet, columns, num, -1)
 }
 
-// convertColWidthToPixels provieds function to convert the width of a cell
+// convertColWidthToPixels provides function to convert the width of a cell
 // from user's units to pixels. Excel rounds the column width to the nearest
 // pixel. If the width hasn't been set by the user we use the default value.
 // If the column is hidden it has a value of zero.

col_test.go

@@ -289,18 +289,24 @@ func TestOutlineLevel(t *testing.T) {
 func TestSetColStyle(t *testing.T) {
 	f := NewFile()
 	assert.NoError(t, f.SetCellValue("Sheet1", "B2", "Hello"))
-	style, err := f.NewStyle(`{"fill":{"type":"pattern","color":["#94d3a2"],"pattern":1}}`)
+	styleID, err := f.NewStyle(`{"fill":{"type":"pattern","color":["#94d3a2"],"pattern":1}}`)
 	assert.NoError(t, err)
 	// Test set column style on not exists worksheet.
-	assert.EqualError(t, f.SetColStyle("SheetN", "E", style), "sheet SheetN is not exist")
+	assert.EqualError(t, f.SetColStyle("SheetN", "E", styleID), "sheet SheetN is not exist")
 	// Test set column style with illegal cell coordinates.
-	assert.EqualError(t, f.SetColStyle("Sheet1", "*", style), newInvalidColumnNameError("*").Error())
-	assert.EqualError(t, f.SetColStyle("Sheet1", "A:*", style), newInvalidColumnNameError("*").Error())
+	assert.EqualError(t, f.SetColStyle("Sheet1", "*", styleID), newInvalidColumnNameError("*").Error())
+	assert.EqualError(t, f.SetColStyle("Sheet1", "A:*", styleID), newInvalidColumnNameError("*").Error())
 
-	assert.NoError(t, f.SetColStyle("Sheet1", "B", style))
+	assert.NoError(t, f.SetColStyle("Sheet1", "B", styleID))
 	// Test set column style with already exists column with style.
-	assert.NoError(t, f.SetColStyle("Sheet1", "B", style))
-	assert.NoError(t, f.SetColStyle("Sheet1", "D:C", style))
+	assert.NoError(t, f.SetColStyle("Sheet1", "B", styleID))
+	assert.NoError(t, f.SetColStyle("Sheet1", "D:C", styleID))
+	ws, ok := f.Sheet.Load("xl/worksheets/sheet1.xml")
+	assert.True(t, ok)
+	ws.(*xlsxWorksheet).SheetData.Row[1].C[2].S = 0
+	cellStyleID, err := f.GetCellStyle("Sheet1", "C2")
+	assert.NoError(t, err)
+	assert.Equal(t, styleID, cellStyleID)
 	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetColStyle.xlsx")))
 }
 

excelize_test.go

@@ -147,6 +147,7 @@ func TestOpenFile(t *testing.T) {
 	assert.NoError(t, f.SetCellValue("Sheet2", "G4", time.Now()))
 
 	assert.NoError(t, f.SetCellValue("Sheet2", "G4", time.Now().UTC()))
+	assert.EqualError(t, f.SetCellValue("SheetN", "A1", time.Now()), "sheet SheetN is not exist")
 	// 02:46:40
 	assert.NoError(t, f.SetCellValue("Sheet2", "G5", time.Duration(1e13)))
 	// Test completion column.

merge.go

@@ -11,7 +11,9 @@
 
 package excelize
 
-import "strings"
+import (
+	"strings"
+)
 
 // Rect gets merged cell rectangle coordinates sequence.
 func (mc *xlsxMergeCell) Rect() ([]int, error) {
@@ -68,7 +70,8 @@ func (f *File) MergeCell(sheet, hCell, vCell string) error {
 		ws.MergeCells = &xlsxMergeCells{Cells: []*xlsxMergeCell{{Ref: ref, rect: rect}}}
 	}
 	ws.MergeCells.Count = len(ws.MergeCells.Cells)
-	return err
+	styleID, _ := f.GetCellStyle(sheet, hCell)
+	return f.SetCellStyle(sheet, hCell, vCell, styleID)
 }
 
 // UnmergeCell provides a function to unmerge a given coordinate area.

rows_test.go

@@ -921,6 +921,9 @@ func TestSetRowStyle(t *testing.T) {
 	assert.EqualError(t, f.SetRowStyle("Sheet1", 1, 1, -1), newInvalidStyleID(-1).Error())
 	assert.EqualError(t, f.SetRowStyle("SheetN", 1, 1, styleID), "sheet SheetN is not exist")
 	assert.NoError(t, f.SetRowStyle("Sheet1", 10, 1, styleID))
+	cellStyleID, err := f.GetCellStyle("Sheet1", "B2")
+	assert.NoError(t, err)
+	assert.Equal(t, styleID, cellStyleID)
 	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetRowStyle.xlsx")))
 }
 

styles.go

@@ -2613,11 +2613,11 @@ func (f *File) GetCellStyle(sheet, axis string) (int, error) {
 	if err != nil {
 		return 0, err
 	}
-	cellData, col, _, err := f.prepareCell(ws, sheet, axis)
+	cellData, col, row, err := f.prepareCell(ws, sheet, axis)
 	if err != nil {
 		return 0, err
 	}
-	return f.prepareCellStyle(ws, col, cellData.S), err
+	return f.prepareCellStyle(ws, col, row, cellData.S), err
 }
 
 // SetCellStyle provides a function to add style attribute for cells by given