TImageEnMView.AddThumbButtons

Declaration

procedure AddThumbButtons(Count: Integer;
                          Width, Height: Integer;
                          GetButtonEvent: TIEGetButtonEvent;
                          ButtonClickEvent: TIEButtonClickEvent;
                          Position : TIEMCheckboxPos = iecpAutomatic;
                          AlignVert: Boolean = False;
                          HMargin: Integer = 4; VMargin: Integer = 4;
                          Spacing: Integer = 4);

Description

Draw buttons over the thumbnail that the user can click to adjust the image.

Note:
◼Any existing buttons are cleared
◼Buttons do not take the control's enabled state into account, or handle their own enabled state. In your events, supply a different image for disabled state, and check whether enabled before processing a click event
◼To display a hint when hovering over the button use OnGetHint
◼Add spacing to avoid drawing over the thumbnail using LeftGap or RightGap
◼Buttons will auto-hide if there is not enough space to show them

Parameter	Description
Count	Number of buttons to draw
Width, Height	Size of the button (in pixels)
GetButtonEvent	Event where you provide an image to use for the button
ButtonClickEvent	Event that will fire when a button is clicked (by the left mouse button)
Position	Position of the buttons
VertAlign	Align multiple buttons vertically, instead of horizontally
HMargin, VMargin	Spacing between edge-most button and the side of the thumbnail
Spacing	Spacing between buttons

Demo

Demos\Multi\ThumbButtons\ThumbButtons.dpr

Example

procedure TMainForm.FormCreate(Sender: TObject);
begin
  // Add Three buttons at top right of thumbnail
  ImageEnMView1.AddThumbButtons( 3,
                                 ImageList1.Width, ImageList1.Height,
                                 GetThumbButton,
                                 ThumbButtonClick,
                                 iecpTopRight );
end;

function TMainForm.ThumbButtonEnabled(ButtonIndex: Integer) : Boolean;
begin
  Result := ImageEnMView1.Enabled;
  if ( ButtonIndex = 0 ) and not ShowPreviewAvailable() then
    Result := False
  else
  if ( ButtonIndex = 1 ) and not FixColorAvailable() then
    Result := False
  else
  if ( ButtonIndex = 2 ) and not SaveImageAvailable() then
    Result := False;
end;

procedure TMainForm.GetThumbButton(Sender: TObject; ThumbIndex, ButtonIndex: Integer; var Bitmap: TIEBitmap);
var
  imgIndex: Integer;
  ico: TIcon;
begin
  // Get bitmap from TImageList
  imgIndex := ButtonIndex;
  if not ThumbButtonEnabled( ButtonIndex ) then
    inc( imgIndex, 3 );

  // Can do this if don't need alpha transparency
  // ImageList1.GetBitmap( imgIndex, Bitmap.VclBitmap );

  ico := TIcon.create;
  TImageList( ImageList1 ).GetIcon( imgIndex , ico );
  Bitmap.Assign( ico );
  ico.Free;
end;

procedure TMainForm.ThumbButtonClick(Sender: TObject; ThumbIndex, ButtonIndex: Integer);
begin
  if not ThumbButtonEnabled( ButtonIndex ) then
    exit;

  if ButtonIndex = 0 then
    ShowPreview( ThumbIndex )
  else
  if ButtonIndex = 1 then
    FixColor( ThumbIndex )
  else
  if ButtonIndex = 2 then
    SaveImage( ThumbIndex );
end;

TImageEnMView.AddThumbButtons