JavaFX 2 Automatic Column Width

javafx-2

I have a JavaFX 2 table that is displaying contact details for people, lets imagine there are three columns: first name, last name and email address. When my application starts it populates the table with several rows of data about the people already in the system.

The problem is that the column widths are all the same. Most of the time the first and last name is displayed in full but the email address is getting clipped. The user can double click the divider in the header to resize the column but that will become tedious quickly.

Once the table has been pre-populated I would like to programatically resize all the columns to display the data they contain but I can't figure out how to achieve this. I can see that I can call col.setPrefWidth(x) but that doesn't really help as I would have to guess the width.

Best Answer

If your total number of columns are pre-known. You can distribute the column widths among the tableview's width:

nameCol.prefWidthProperty().bind(personTable.widthProperty().divide(4)); // w * 1/4
surnameCol.prefWidthProperty().bind(personTable.widthProperty().divide(2)); // w * 1/2
emailCol.prefWidthProperty().bind(personTable.widthProperty().divide(4)); // w * 1/4

In this code, the width proportions of columns are kept in sync when the tableview is resized, so you don't need to do it manually. Also the surnameCol takes the half space of the tableview's width.

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Delphi – How to save PngImage from clipboard

Based on empirical results confirmed by my colleague having Adobe Photoshop CS 6 13.0 x32 using the following test code points out that it's not possible to save the image from clipboard copied by the Adobe Photoshop without losing transparency simply because it doesn't copy the alpha channel data.

Adobe Photoshop (at least in the version mentioned above) uses 24-bit pixel format for clipboard image data transfer. And, since it is the 24-bit bitmap there can't be an alpha channel. Don't know anyone who has the Adobe Fireworks to verify, but for sure they're using own registered clipboard format to transfer images including the alpha channel between their products.

The CF_BITMAP or CF_DIB formats used by Adobe Photoshop clipboard supposedly supports alpha channel, as some people says (I haven't tried) but that would be true only for 32-bit pixel format, not for the 24-bit pixel format. The only clipboard format, that surely supports transparency, is the CF_DIBV5 but as the others, the image have to be stored in 32-bit pixel format to preserve the alpha channel:

The following code shows the information about the currently copied clipboard content:

uses
  ActiveX;

function GetClipboardFormatString(Format: Word): string;
var
  S: string;
begin
  case Format of
    1: S := 'CF_TEXT';
    2: S := 'CF_BITMAP';
    3: S := 'CF_METAFILEPICT';
    4: S := 'CF_SYLK';
    5: S := 'CF_DIF';
    6: S := 'CF_TIFF';
    7: S := 'CF_OEMTEXT';
    8: S := 'CF_DIB';
    9: S := 'CF_PALETTE';
    10: S := 'CF_PENDATA';
    11: S := 'CF_RIFF';        
    12: S := 'CF_WAVE';
    13: S := 'CF_UNICODETEXT';
    14: S := 'CF_ENHMETAFILE';
    15: S := 'CF_HDROP';
    16: S := 'CF_LOCALE';
    17: S := 'CF_DIBV5';
    $0080: S := 'CF_OWNERDISPLAY';
    $0081: S := 'CF_DSPTEXT';
    $0082: S := 'CF_DSPBITMAP';
    $0083: S := 'CF_DSPMETAFILEPICT';
    $008E: S := 'CF_DSPENHMETAFILE';
    $0200: S := 'CF_PRIVATEFIRST';
    $02FF: S := 'CF_PRIVATELAST';    
    $0300: S := 'CF_GDIOBJFIRST';
    $03FF: S := 'CF_GDIOBJLAST';
  else
    begin      
      SetLength(S, 255);
      SetLength(S, GetClipboardFormatName(Format, PChar(S), 255));      
      if Length(S) = 0 then
        S := 'Unknown, unregistered clipboard format';
      Result := S + ' (' + IntToStr(Format) + ')';
      Exit;
    end;
  end; 
  Result := 'Standard clipboard format (' + S + ')';
end;

function GetClipboardFormats: string;
var
  S: string;
  FormatEtc: TFormatEtc;
  DataObject: IDataObject;
  EnumFormatEtc: IEnumFormatEtc;
begin
  Result := '';
  if Succeeded(OleGetClipboard(DataObject)) then
  begin
    if Succeeded(DataObject.EnumFormatEtc(DATADIR_GET, EnumFormatEtc)) then
    begin
      S := DupeString('-', 65) + sLineBreak +
        'Clipboard data formats: ' + sLineBreak +
        DupeString('-', 65) + sLineBreak;
      while EnumFormatEtc.Next(1, FormatEtc, nil) = S_OK do
        S := S + GetClipboardFormatString(FormatEtc.cfFormat) + sLineBreak;
      Result := S;
    end;
  end;
end;

function GetClipboardInfoDIB: string;
var
  S: string;
  ClipboardData: HGLOBAL;
  BitmapInfoHeader: PBitmapInfoHeader;
const
  BI_JPEG = 4;
  BI_PNG = 5;
begin
  Result := '';
  if OpenClipboard(0) then
  try
    ClipboardData := GetClipboardData(CF_DIB);
    if ClipboardData <> 0 then
    begin
      BitmapInfoHeader := GlobalLock(ClipboardData);
      if Assigned(BitmapInfoHeader) then
      try
        S := DupeString('-', 65) + sLineBreak +
          'Clipboard data of CF_DIB format: ' + sLineBreak +
          DupeString('-', 65) + sLineBreak +
          'Width: ' + IntToStr(BitmapInfoHeader.biWidth) + ' px' + sLineBreak +
          'Height: ' + IntToStr(BitmapInfoHeader.biHeight) + ' px' + sLineBreak +
          'Bit depth: ' + IntToStr(BitmapInfoHeader.biBitCount) + ' bpp' + sLineBreak +
          'Compression format: ';
        case BitmapInfoHeader.biCompression of
          BI_RGB:   S := S + 'Uncompressed format (BI_RGB)';
          BI_RLE8: S := S + 'RLE format for bitmaps with 8 bpp (BI_RLE8)';
          BI_RLE4: S := S + 'RLE format for bitmaps with 4 bpp (BI_RLE4)';
          BI_BITFIELDS: S := S + 'Not compressed with color masks (BI_BITFIELDS)';
          BI_JPEG: S := S + 'Compressed using JPEG file format (BI_JPEG)';
          BI_PNG:   S := S + 'Compressed using PNG file format (BI_PNG)';
        end;
        S := S + sLineBreak;
        Result := S;
      finally
        GlobalUnlock(ClipboardData);
      end;      
    end;
  finally
    CloseClipboard;
  end;
end;

function GetClipboardInfoDIBV5: string;
var
  S: string;
  ClipboardData: HGLOBAL;
  BitmapInfoHeader: PBitmapV5Header;
const
  BI_JPEG = 4;
  BI_PNG = 5;
begin
  Result := '';
  if OpenClipboard(0) then
  try
    ClipboardData := GetClipboardData(CF_DIBV5);
    if ClipboardData <> 0 then
    begin
      BitmapInfoHeader := GlobalLock(ClipboardData);
      if Assigned(BitmapInfoHeader) then
      try
        S := DupeString('-', 65) + sLineBreak +
          'Clipboard data of CF_DIBV5 format: ' + sLineBreak +
          DupeString('-', 65) + sLineBreak +
          'Width: ' + IntToStr(BitmapInfoHeader.bV5Width) + ' px' + sLineBreak +
          'Height: ' + IntToStr(BitmapInfoHeader.bV5Height) + ' px' + sLineBreak +
          'Bit depth: ' + IntToStr(BitmapInfoHeader.bV5BitCount) + ' bpp' + sLineBreak +
          'Compression format: ';
        case BitmapInfoHeader.bV5Compression of
          BI_RGB:   S := S + 'Uncompressed format (BI_RGB)';
          BI_RLE8: S := S + 'RLE format for bitmaps with 8 bpp (BI_RLE8)';
          BI_RLE4: S := S + 'RLE format for bitmaps with 4 bpp (BI_RLE4)';
          BI_BITFIELDS: S := S + 'Not compressed with color masks (BI_BITFIELDS)';
          BI_JPEG: S := S + 'Compressed using JPEG file format (BI_JPEG)';
          BI_PNG:   S := S + 'Compressed using PNG file format (BI_PNG)';
        end;
        S := S + sLineBreak;
        Result := S;
      finally
        GlobalUnlock(ClipboardData);
      end;      
    end;
  finally
    CloseClipboard;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  S: string;
begin
  S := GetClipboardFormats;
  if IsClipboardFormatAvailable(CF_DIB) then
    S := S + sLineBreak + GetClipboardInfoDIB;
  if IsClipboardFormatAvailable(CF_DIBV5) then
    S := S + sLineBreak + GetClipboardInfoDIBV5;
  ShowMessage(S);
end;

Output of the above code for transparent image copied into a clipboard by Adobe Photoshop CS 6 13.0 (click to enlarge):

Something useful to read:

Java – How to insert text field to javafx table view header

You don't need to get your hands dirty with the lookup. Just set a graphic on the TableColumn:

TextField headerTextField = new TextField();
Label label = new Label("First Name");
VBox headerGraphic = new VBox();
headerGraphic.setAlignment(Pos.CENTER);
headerGraphic.getChildren().addAll(label, headerTextField);

TableColumn<Person, String> firstNameCol = new TableColumn<>();
firstNameCol.setGraphic(headerGraphic);

Best Answer

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