{ boxprocs unit

  Copyright (C) 2005-2017 Lagunov Aleksey alexs75@yandex.ru and Lazarus team
  original conception from rx library for Delphi (c)

  This library is free software; you can redistribute it and/or modify it
  under the terms of the GNU Library General Public License as published by
  the Free Software Foundation; either version 2 of the License, or (at your
  option) any later version with the following modification:

  As a special exception, the copyright holders of this library give you
  permission to link this library with independent modules to produce an
  executable, regardless of the license terms of these independent modules,and
  to copy and distribute the resulting executable under terms of your choice,
  provided that you also meet, for each linked independent module, the terms
  and conditions of the license of that module. An independent module is a
  module which is not derived from or based on this library. If you modify
  this library, you may extend this exception to your version of the library,
  but you are not obligated to do so. If you do not wish to do so, delete this
  exception statement from your version.

  This program is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
  for more details.

  You should have received a copy of the GNU Library General Public License
  along with this library; if not, write to the Free Software Foundation,
  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
}

unit rxboxprocs;

{$I rx.inc}

interface

uses Classes, Controls, StdCtrls;
const
  LB_ERR = -1;
  
procedure BoxMoveSelectedItems(SrcList, DstList: TWinControl);
procedure BoxMoveAllItems(SrcList, DstList: TWinControl);
procedure BoxDragOver(List: TWinControl; Source: TObject;
  X, Y: Integer; State: TDragState; var Accept: Boolean; Sorted: Boolean);
procedure BoxMoveFocusedItem(List: TWinControl; DstIndex: Integer);

procedure BoxMoveSelected(List: TWinControl; Items: TStrings);
procedure BoxSetItem(List: TWinControl; Index: Integer);
function BoxGetFirstSelection(List: TWinControl): Integer;
function BoxCanDropItem(List: TWinControl; X, Y: Integer;
  var DragIndex: Integer): Boolean;

implementation

uses LCLIntf, Graphics;

function BoxItems(List: TWinControl): TStrings;
begin
  if List is TCustomListBox then
    Result := TCustomListBox(List).Items
{  else if List is TRxCustomListBox then
    Result := TRxCustomListBox(List).Items}
  else Result := nil;
end;

function BoxGetSelected(List: TWinControl; Index: Integer): Boolean;
begin
  if List is TCustomListBox then
  begin
    if TCustomListBox(List).MultiSelect then
      Result := TCustomListBox(List).Selected[Index]
    else
      Result := TCustomListBox(List).ItemIndex = Index
  end
{  else if List is TRxCustomListBox then
    Result := TRxCustomListBox(List).Selected[Index]}
  else Result := False;
end;

procedure BoxSetSelected(List: TWinControl; Index: Integer; Value: Boolean);
begin
  if List is TCustomListBox then
    TCustomListBox(List).Selected[Index] := Value
{  else if List is TRxCustomListBox then
    TRxCustomListBox(List).Selected[Index] := Value;}
end;

function BoxGetItemIndex(List: TWinControl): Integer;
begin
  if List is TCustomListBox then
    Result := TCustomListBox(List).ItemIndex
{  else if List is TRxCustomListBox then
    Result := TRxCustomListBox(List).ItemIndex}
  else Result := -1;
end;

{.$IFNDEF WIN32}
function BoxGetCanvas(List: TWinControl): TCanvas;
begin
  if List is TCustomListBox then
    Result := TCustomListBox(List).Canvas
{  else if List is TRxCustomListBox then
    Result := TRxCustomListBox(List).Canvas }
  else Result := nil;
end;
{.$ENDIF}

procedure BoxSetItemIndex(List: TWinControl; Index: Integer);
begin
  if List is TCustomListBox then
    TCustomListBox(List).ItemIndex := Index
{  else if List is TRxCustomListBox then
    TRxCustomListBox(List).ItemIndex := Index;}
end;

function BoxMultiSelect(List: TWinControl): Boolean;
begin
  if List is TCustomListBox then
    Result := TListBox(List).MultiSelect
{  else if List is TRxCustomListBox then
    Result := TRxCheckListBox(List).MultiSelect}
  else Result := False;
end;

function BoxSelCount(List: TWinControl): Integer;
begin
  if List is TCustomListBox then
    Result := TCustomListBox(List).SelCount
{  else if List is TRxCustomListBox then
    Result := TRxCustomListBox(List).SelCount}
  else Result := 0;
end;

function BoxItemAtPos(List: TWinControl; Pos: TPoint;
  Existing: Boolean): Integer;
begin
  if List is TCustomListBox then
    Result := TCustomListBox(List).ItemAtPos(Pos, Existing)
{  else if List is TRxCustomListBox then
    Result := TRxCustomListBox(List).ItemAtPos(Pos, Existing)}
  else Result := LB_ERR;
end;

function BoxItemRect(List: TWinControl; Index: Integer): TRect;
begin
  if List is TCustomListBox then
    Result := TCustomListBox(List).ItemRect(Index)
{  else if List is TRxCustomListBox then
    Result := TRxCustomListBox(List).ItemRect(Index)}
  else FillChar(Result, SizeOf(Result), 0);
end;

procedure BoxMoveSelected(List: TWinControl; Items: TStrings);
var
  I: Integer;
begin
  if BoxItems(List) = nil then Exit;
  I := 0;
  while I < BoxItems(List).Count do begin
    if BoxGetSelected(List, I) then begin
      Items.AddObject(BoxItems(List).Strings[I], BoxItems(List).Objects[I]);
      BoxItems(List).Delete(I);
    end
    else Inc(I);
  end;
end;

function BoxGetFirstSelection(List: TWinControl): Integer;
var
  I: Integer;
begin
  Result := LB_ERR;
  if BoxItems(List) = nil then Exit;
  for I := 0 to BoxItems(List).Count - 1 do begin
    if BoxGetSelected(List, I) then begin
      Result := I;
      Exit;
    end;
  end;
  Result := LB_ERR;
end;

procedure BoxSetItem(List: TWinControl; Index: Integer);
var
  MaxIndex: Integer;
begin
  if BoxItems(List) = nil then Exit;
  with List do begin
    if CanFocus then SetFocus;
    MaxIndex := BoxItems(List).Count - 1;
    if Index = LB_ERR then Index := 0
    else if Index > MaxIndex then Index := MaxIndex;
    if Index >= 0 then begin
      if BoxMultiSelect(List) then BoxSetSelected(List, Index, True)
      else BoxSetItemIndex(List, Index);
    end;
  end;
end;

procedure BoxMoveSelectedItems(SrcList, DstList: TWinControl);
var
  Index, I, NewIndex: Integer;
begin
  Index := BoxGetFirstSelection(SrcList);
  if Index <> LB_ERR then
  begin
    BoxItems(SrcList).BeginUpdate;
    BoxItems(DstList).BeginUpdate;
    try
      I := 0;
      while I < BoxItems(SrcList).Count do
      begin
        if BoxGetSelected(SrcList, I) then
        begin
          NewIndex := BoxItems(DstList).AddObject(BoxItems(SrcList).Strings[I],
            BoxItems(SrcList).Objects[I]);
{          if (SrcList is TRxCheckListBox) and (DstList is TRxCheckListBox) then
          begin
            TRxCheckListBox(DstList).State[NewIndex] :=
              TRxCheckListBox(SrcList).State[I];
          end;}
          BoxItems(SrcList).Delete(I);
        end
        else Inc(I);
      end;
      BoxSetItem(SrcList, Index);
    finally
      BoxItems(SrcList).EndUpdate;
      BoxItems(DstList).EndUpdate;
    end;
  end;
end;

procedure BoxMoveAllItems(SrcList, DstList: TWinControl);
var
  I, NewIndex: Integer;
begin
  for I := 0 to BoxItems(SrcList).Count - 1 do begin
    NewIndex := BoxItems(DstList).AddObject(BoxItems(SrcList)[I],
      BoxItems(SrcList).Objects[I]);
{    if (SrcList is TRxCheckListBox) and (DstList is TRxCheckListBox) then
    begin
      TRxCheckListBox(DstList).State[NewIndex] :=
        TRxCheckListBox(SrcList).State[I];
    end;}
  end;
  BoxItems(SrcList).Clear;
  BoxSetItem(SrcList, 0);
end;

function BoxCanDropItem(List: TWinControl; X, Y: Integer;
  var DragIndex: Integer): Boolean;
var
  Focused: Integer;
begin
  Result := False;
  if (BoxSelCount(List) = 1) or (not BoxMultiSelect(List)) then
  begin
    Focused := BoxGetItemIndex(List);
    if Focused <> LB_ERR then
    begin
      DragIndex := BoxItemAtPos(List, Point(X, Y), True);
      if (DragIndex >= 0) and (DragIndex <> Focused) then
      begin
        Result := True;
      end;
    end;
  end;
end;

procedure BoxDragOver(List: TWinControl; Source: TObject;
  X, Y: Integer; State: TDragState; var Accept: Boolean; Sorted: Boolean);
var
  DragIndex: Integer;
  R: TRect;

procedure DrawItemFocusRect(Idx: Integer);
(*
{$IFDEF WIN32}
  var
    P: TPoint;
    DC: HDC;
{$ENDIF}
  begin
    R := BoxItemRect(List, Idx);
{$IFDEF WIN32}
    P := List.ClientToScreen(R.TopLeft);
    R := Bounds(P.X, P.Y, R.Right - R.Left, R.Bottom - R.Top);
    DC := GetDC(0);
    DrawFocusRect(DC, R);
    ReleaseDC(0, DC);
{$ELSE}
    BoxGetCanvas(List).DrawFocusRect(R);
{$ENDIF}
*)
begin
   BoxGetCanvas(List).DrawFocusRect(R);
end;

begin
  if Source <> List then
    Accept := (Source is TWinControl) { or (Source is TRxCustomListBox) }
  else
  begin
    if Sorted then
      Accept := False
    else
    begin
      Accept := BoxCanDropItem(List, X, Y, DragIndex);
      if ((List.Tag - 1) = DragIndex) and (DragIndex >= 0) then
      begin
        if State = dsDragLeave then
        begin
          DrawItemFocusRect(List.Tag - 1);
          List.Tag := 0;
        end;
      end
      else
      begin
        if List.Tag > 0 then DrawItemFocusRect(List.Tag - 1);
        if DragIndex >= 0 then DrawItemFocusRect(DragIndex);
        List.Tag := DragIndex + 1;
      end;
    end;
  end;
end;

procedure BoxMoveFocusedItem(List: TWinControl; DstIndex: Integer);
begin
  if (DstIndex >= 0) and (DstIndex < BoxItems(List).Count) then
    if (DstIndex <> BoxGetItemIndex(List)) then
    begin
      BoxItems(List).Move(BoxGetItemIndex(List), DstIndex);
      BoxSetItem(List, DstIndex);
    end;
end;

end.