GridPrinter: Add options to center grid on page horizontally and/or vertically.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@8606 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/gridprinter/source/gridprn.pas

@@ -23,6 +23,9 @@ type
 
   TGridPrnHeaderFooterSection = (hfsLeft, hfsCenter, hfsRight);
 
+  TGridPrnOption = (gpoCenterHor, gpoCenterVert);
+  TGridPrnOptions = set of TGridPrnOption;
+
   TGridPrnOrder = (poRowsFirst, poColsFirst);
 
   TGridPrnOutputDevice = (odPrinter, odPreview);
@@ -109,6 +112,7 @@ type
     FFooter: TGridPrnHeaderFooter;
     FMargins: TGridPrnMargins;
     FMonochrome: Boolean;
+    FOptions: TGridPrnOptions;
     FPadding: Integer;
     FPageHeight: Integer;
     FPageWidth: Integer;
@@ -144,6 +148,7 @@ type
     procedure SetGrid(AValue: TCustomGrid);
     procedure SetGridLineColor(AValue: TColor);
     procedure SetGridLineWidth(AValue: Double);
+    procedure SetOptions(AValue: TGridPrnOptions);
     procedure SetOrientation(AValue: TPrinterOrientation);
   protected
     FFactorX: Double;              // Multiply to convert screen to printer/preview pixels
@@ -174,6 +179,8 @@ type
     FFixedCols: Integer;
     FFixedRows: Integer;
     FPrinting: Boolean;
+    procedure CalcFixedColPos(AStartCol, AEndCol: Integer; var ALeft, ARight: Integer);
+    procedure CalcFixedRowPos(AStartRow, AEndRow: Integer; var ATop, ABottom: Integer);
     procedure DoPrepareCanvas(ACol, ARow: Integer); virtual;
     procedure DoUpdatePreview; virtual;
     procedure Execute(ACanvas: TCanvas);
@@ -191,12 +198,12 @@ type
     procedure PrintCell(ACanvas: TCanvas; ACol, ARow: Integer; ARect: TRect); virtual;
     procedure PrintCheckbox(ACanvas: TCanvas; {%H-}ACol, {%H-}ARow: Integer; ARect: TRect;
       ACheckState: TCheckboxstate); virtual;
-    procedure PrintColHeaders(ACanvas: TCanvas; ACol1, ACol2: Integer);
+    procedure PrintColHeaders(ACanvas: TCanvas; ACol1, ACol2, Y: Integer);
     procedure PrintFooter(ACanvas: TCanvas);
     procedure PrintHeader(ACanvas: TCanvas);
-    procedure PrintGridLines(ACanvas: TCanvas; AFirstCol, AFirstRow, XEnd, YEnd: Integer);
+    procedure PrintGridLines(ACanvas: TCanvas; AStartCol, AStartRow, AEndCol, AEndRow, XEnd, YEnd: Integer);
     procedure PrintPage(ACanvas: TCanvas; AStartCol, AStartRow, AEndCol, AEndRow: Integer);
-    procedure PrintRowHeader(ACanvas: TCanvas; ARow: Integer; Y: Double);
+    procedure PrintRowHeader(ACanvas: TCanvas; ARow: Integer; X, Y: Double);
     procedure ScaleColWidths(AFactor: Double);
     procedure ScaleRowHeights(AFactor: Double);
     procedure SelectFont(ACanvas: TCanvas; AFont: TFont);
@@ -234,6 +241,7 @@ type
     property Header: TGridPrnHeaderFooter read FHeader write FHeader;
     property Margins: TGridPrnMargins read FMargins write FMargins;
     property Monochrome: Boolean read FMonochrome write FMonochrome default false;
+    property Options: TGridPrnOptions read FOptions write SetOptions default [];
     property Orientation: TPrinterOrientation read GetOrientation write SetOrientation stored IsOrientationStored;
     property PrintOrder: TGridPrnOrder read FPrintOrder write FPrintOrder default poRowsFirst;
     property ShowPrintDialog: TGridPrnDialog read FShowPrintDialog write FShowPrintDialog default gpdNone;
@@ -565,6 +573,61 @@ begin
   inherited;
 end;
 
+{ Calculates the extent (in printer/preview pixels) of the fixed ccolumns
+  (left edge of first and right edge of last fixed column).
+  Takes care of the optional horizontal centering of the grid. }
+procedure TGridPrinter.CalcFixedColPos(AStartCol, AEndCol: Integer;
+  var ALeft, ARight: Integer);
+var
+  col: Integer;
+  w: Double;
+  fixedColsWidth: Integer;
+begin
+  if (gpoCenterHor in FOptions) then
+  begin
+    // Total width of all fixed columns
+    fixedColsWidth := FFixedColPos - FLeftMargin;
+    w := fixedColsWidth;
+    for col := AStartCol to AEndCol do
+      w := w + FColWidths[col];
+    // w is total column width on this page
+    ALeft := FLeftMargin + round((FPageRect.Width - w) / 2);
+    ARight := ALeft + fixedColsWidth;
+  end else
+  begin
+    ALeft := FLeftMargin;
+    ARight := FFixedColPos;
+  end;
+end;
+
+{ Calculates the extent (in printer/preview pixels) of the fixed rows
+  (top edge of first and bottom edge of last fixed row).
+  Takes care of the optional vertical centering of the grid. }
+procedure TGridPrinter.CalcFixedRowPos(AStartRow, AEndRow: Integer;
+  var ATop, ABottom: Integer);
+var
+  row: Integer;
+  h: Double;
+  fixedRowsHeight: Integer;
+begin
+  if (gpoCenterVert in FOptions) then
+  begin
+    // Total height of all fixed rows
+    fixedRowsheight := FFixedRowPos - FTopMargin;
+    h := fixedRowsHeight;
+    for row := AStartRow to AEndRow do
+      h := h + FRowHeights[row];
+    // h is total row height on this page
+    ATop := FTopMargin + round((FPageRect.Height - h) / 2);
+    ABottom := ATop + fixedRowsHeight;
+  end else
+  begin
+    ATop := FTopMargin;
+    ABottom := FFixedRowPos;
+  end;
+end;
+
+
 function TGridPrinter.CreatePreviewBitmap(APageNo, APercentage: Integer): TBitmap;
 begin
   if FGrid = nil then
@@ -1179,32 +1242,35 @@ end;
 
 { Prints the column headers: at first the fixed column headers, then the
   headers between ACol1 and ACol2. }
-procedure TGridPrinter.PrintColHeaders(ACanvas: TCanvas; ACol1, ACol2: Integer);
+procedure TGridPrinter.PrintColHeaders(ACanvas: TCanvas; ACol1, ACol2, Y: Integer);
 var
   R: TRect;
   col, row: Integer;
-  x, y, x2, y2: Double;
+  x, x2, y1, y2: Double;
+  fixedColsLeft: Integer = 0;
+  fixedColsRight: Integer = 0;
 begin
-  x := FLeftMargin;
+  CalcFixedColPos(ACol1, ACol2, fixedColsLeft, fixedColsRight);
-  y := FTopMargin;
+  x := fixedColsLeft;
+  y1 := Y;
   for row := 0 to FFixedRows-1 do
   begin
-    y2 := FTopMargin + FRowHeights[row];
+    y2 := Y + FRowHeights[row];
     for col := 0 to FFixedCols-1 do
     begin
       x2 := x + FColWidths[col];
-      R := Rect(round(x), round(y), round(x2), round(y2));
+      R := Rect(round(x), round(y1), round(x2), round(y2));
       PrintCell(ACanvas, col, row, R);
       x := x2;
     end;
     for col := ACol1 to ACol2 do
     begin
       x2 := x + FColWidths[col];
-      R := Rect(round(x), round(y), round(x2), round(y2));
+      R := Rect(round(x), round(y1), round(x2), round(y2));
       PrintCell(ACanvas, col, row, R);
       x := x2;
     end;
-    y := y2;
+    y1 := y2;
   end;
 end;
 
@@ -1276,14 +1342,20 @@ begin
 end;
 
 procedure TGridPrinter.PrintGridLines(ACanvas: TCanvas;
-  AFirstCol, AFirstRow, XEnd, YEnd: Integer);
+  AStartCol, AStartRow, AEndCol, AEndRow, XEnd, YEnd: Integer);
 var
   x, y: Double;
   xr, yr: Integer;  // x, y rounded to integer
   col, row: Integer;
   lGrid: TGridAccess;
+  fixedColsLeft: Integer = 0;
+  fixedColsRight: Integer = 0;
+  fixedRowsTop: Integer = 0;
+  fixedRowsBottom: Integer = 0;
 begin
   lGrid := TGridAccess(FGrid);
+  CalcFixedColPos(AStartCol, AEndCol, fixedColsLeft, fixedColsRight);
+  CalcFixedRowPos(AStartRow, AEndRow, fixedRowsTop, fixedRowsBottom);
 
   // Print inner grid lines
   ACanvas.Pen.EndCap := pecFlat;
@@ -1294,22 +1366,22 @@ begin
   begin
     ACanvas.Pen.Width := GetGridLineWidthVert;
     col := 1;
-    x := FLeftMargin;
+    x := fixedColsLeft;
     while col < lGrid.FixedCols do
     begin
       x := x + FColWidths[col-1];
       xr := round(x);
-      ACanvas.Line(xr, FTopMargin, xr, YEnd);
+      ACanvas.Line(xr, fixedRowsTop, xr, YEnd);
       inc(col);
     end;
-    col := AFirstCol;
+    col := AStartCol;
-    x := FFixedColPos;
+    x := fixedColsRight;
     xr := round(x);
     while (xr < XEnd) and (col < lGrid.ColCount) do
     begin
       x := x + FColWidths[col];
       xr := round(x);
-      ACanvas.Line(xr, FTopMargin, xr, FFixedRowPos);
+      ACanvas.Line(xr, fixedRowsTop, xr, fixedRowsBottom);
       inc(col);
     end;
   end;
@@ -1317,14 +1389,14 @@ begin
   if (goVertLine in lGrid.Options) then
   begin
     ACanvas.Pen.Width := GetGridLineWidthVert;
-    col := AFirstCol;
+    col := AStartCol;
-    x := FFixedColPos;
+    x := fixedColsRight;
     xr := round(x);
     while (xr < XEnd) and (col < FColCount) do
     begin
       x := x + FColWidths[col];
       xr := round(x);
-      ACanvas.Line(xr, FFixedRowPos, xr, YEnd);
+      ACanvas.Line(xr, fixedRowsBottom, xr, YEnd);
       inc(col);
     end;
   end;
@@ -1333,23 +1405,23 @@ begin
   begin
     ACanvas.Pen.Width := GetGridLineWidthHor;
     row := 1;
-    y := FTopMargin;
+    y := fixedRowsTop;
     yr := round(y);
     while row < lGrid.FixedRows do
     begin
       y := y + FRowHeights[row];
       yr := round(y);
-      ACanvas.Line(FLeftMargin, yr, XEnd, yr);
+      ACanvas.Line(fixedColsLeft, yr, XEnd, yr);
       inc(row);
     end;
-    row := AFirstRow;
+    row := AStartRow;
-    y := FFixedRowPos;
+    y := fixedRowsBottom;
     yr := round(y);
     while (yr < YEnd) and (row < FRowCount) do
     begin
       y := y + FRowHeights[row];
       yr := round(y);
-      ACanvas.Line(FLeftMargin, yr, FFixedColPos, yr);
+      ACanvas.Line(fixedColsLeft, yr, fixedColsRight, yr);
       inc(row);
     end;
   end;
@@ -1357,14 +1429,14 @@ begin
   if (goHorzLine in lGrid.Options) then
   begin
     ACanvas.Pen.Width := GetGridLineWidthHor;
-    row := AFirstRow;
+    row := AStartRow;
-    y := FFixedRowPos;
+    y := fixedRowsBottom;
     yr := round(y);
     while (yr < YEnd) and (row < FRowCount) do
     begin
       y := y + FRowHeights[row];
       yr := round(y);
-      ACanvas.Line(FFixedColPos, yr, XEnd, yr);
+      ACanvas.Line(fixedColsRight, yr, XEnd, yR);
       inc(row);
     end;
   end;
@@ -1374,10 +1446,10 @@ begin
   ACanvas.Pen.Style := psSolid;
   ACanvas.Pen.Color := GetPenColor(FFixedLineColor);
   ACanvas.Pen.Width := GetFixedLineWidthHor;
-  ACanvas.Line(FLeftMargin, FFixedRowPos, XEnd, FFixedRowPos);
+  ACanvas.Line(fixedColsLeft, fixedRowsBottom, XEnd, fixedRowsBottom);
   // ... vertical
   ACanvas.Pen.Width := GetFixedLineWidthVert;
-  ACanvas.Line(FFixedColPos, FTopMargin, FFixedColPos, YEnd);
+  ACanvas.Line(fixedColsRight, fixedRowsTop, fixedColsRight, YEnd);
 
   // Print outer border lines
   ACanvas.Pen.EndCap := pecRound;
@@ -1385,12 +1457,12 @@ begin
   ACanvas.Pen.Color := GetPenColor(FBorderLineColor);
   // ... horizontal
   ACanvas.Pen.Width := GetBorderLineWidthHor;
-  ACanvas.Line(FLeftMargin, FTopMargin, XEnd, FTopMargin);
+  ACanvas.Line(fixedColsLeft, fixedRowsTop, XEnd, fixedRowsTop);
-  ACanvas.Line(FLeftMargin, YEnd, XEnd, YEnd);
+  ACanvas.Line(fixedColsLeft, YEnd, XEnd, YEnd);
   // ... vertical
   ACanvas.Pen.Width := GetBorderLineWidthVert;
-  ACanvas.Line(FLeftMargin, FTopMargin, FLeftMargin, YEnd);
+  ACanvas.Line(fixedColsLeft, fixedRowsTop, fixedColsLeft, YEnd);
-  ACanvas.Line(XEnd, FTopMargin, XEnd, YEnd);
+  ACanvas.Line(XEnd, fixedRowsTop, XEnd, YEnd);
 end;
 
 procedure TGridPrinter.PrintHeader(ACanvas: TCanvas);
@@ -1466,19 +1538,26 @@ var
   x, y: Double;
   x2, y2: Double;
   row, col: Integer;
+  fixedColsLeft: Integer = 0;
+  fixedColsRight: Integer = 0;
+  fixedRowsTop: Integer = 0;
+  fixedRowsBottom: Integer = 0;
   lastPagePrinted: Boolean;
   R: TRect;
 begin
+  CalcFixedColPos(AStartCol, AEndCol, fixedColsLeft, fixedColsRight);
+  CalcFixedRowPos(AStartRow, AEndRow, fixedRowsTop, fixedRowsBottom);
+
   // Print column headers
-  PrintColHeaders(ACanvas, AStartCol, AEndCol);
+  PrintColHeaders(ACanvas, AStartCol, AEndCol, fixedRowsTop);
 
   // Print grid cells
-  y := FFixedRowPos;
+  y := fixedRowsBottom;
   for row := AStartRow to AEndRow do
   begin
     y2 := y + FRowHeights[row];
-    PrintRowHeader(ACanvas, row, y);
+    PrintRowHeader(ACanvas, row, fixedColsLeft, y);
-    x := FFixedColPos;
+    x := fixedColsRight;
     for col := AStartCol to AEndCol do
     begin
       x2 := x + FColWidths[col];
@@ -1490,7 +1569,7 @@ begin
   end;
 
   // Print cell grid lines
-  PrintGridLines(ACanvas, AStartCol, AStartRow, round(x2), round(y2));
+  PrintGridLines(ACanvas, AStartCol, AStartRow, AEndCol, AEndRow, round(x2), round(y2));
 
   // Print header and footer
   PrintHeader(ACanvas);
@@ -1504,24 +1583,23 @@ end;
 
 { Prints the row headers of the specified row. Row headers are the cells in the
   FixedCols of that row. The row is positioned at the given y coordinate on
-  the canvas. }
+  the canvas. X is the position of the left edge of the grid. }
 procedure TGridPrinter.PrintRowHeader(ACanvas: TCanvas; ARow: Integer;
-  Y: Double);
+  X, Y: Double);
 var
   R: TRect;
   col: Integer;
   y1, y2: Integer;
-  x, x2: Double;
+  x2: Double;
 begin
-  x := FLeftMargin;                    // left side of the row
+  y1 := round(Y);                      // upper edge of the row
-  y1 := round(Y);                      // upper end of the row
+  y2 := round(Y + FRowHeights[ARow]);  // lower edge of the row
-  y2 := round(Y + FRowHeights[ARow]);  // lower end of the row
   for col := 0 to FFixedCols-1 do
   begin
-    x2 := x + FColWidths[col];
+    x2 := X + FColWidths[col];
-    R := Rect(round(x), y1, round(x2), y2);
+    R := Rect(round(X), y1, round(x2), y2);
     PrintCell(ACanvas, col, ARow, R);
-    x := x2;
+    X := x2;
   end;
 end;
 
@@ -1662,6 +1740,15 @@ begin
   end;
 end;
 
+procedure TGridPrinter.SetOptions(AValue: TGridPrnOptions);
+begin
+  if FOptions <> AValue then
+  begin
+    FOptions := AValue;
+    UpdatePreview;
+  end;
+end;
+
 procedure TGridPrinter.SetOrientation(AValue: TPrinterOrientation);
 begin
   if GetOrientation <> AValue then