unit JKFootpanel;

interface
uses
	Windows, Messages, SysUtils, Classes,Graphics, Controls, Forms, Dialogs,
  	ExtCtrls, dbctrls, stdctrls, db, ADODB, ComCtrls;

type
   TEditorstyle = (TsDbMemo,TsDBcombox,Tsdbedit);

type
  TJKFootpanel = class(TPanel)
  private
    { Private declarations }
    FLeft: Integer;
    FTop: Integer;
    maxTextLen: Integer;
    maxLabelLen: Integer;
    FScrollBox: TScrollBox; {滚动控件}
    FLineHeight: Integer;
    FEditorstyle:Teditorstyle;
    FTitleVisible :Boolean;
    //数据数组控件，动态生成
    MemoEditors :array of TDBMemo;
    comEditors :array of TDBCombobox;
    edEditors :array of TDBedit;
    Labels :array of TLAbel;  //字段标题，动态生成
    FDataSource :TDataSource; // 数据源
    FColumns :Integer; //显示列数
    procedure FreeEditors; //释放数据输入控件的内存
    procedure AKeyDown(Sender :TObject; var Key: Word; Shift:TShiftState);
    procedure AKeyPress(Sender :TObject; var Key: Char);
    function comEditor(Index :Integer):TDBComboBox;
    function edEditor(Index :Integer):TDBedit;
    function MemoEditor(Index :Integer): TDBMemo;
  protected
    { Protected declarations }

  public
      constructor Create(AOwner :TComponent); override;
      destructor Destroy; override;
    	procedure Setedit(Value :TEditorstyle);
    	procedure ClearHits(ItemIndex :Integer);
    	procedure AddHits(ItemIndex :Integer; Hits :array of string);
      Function CreateEditors(DS :TDataSource; ColCount :Integer) :integer;  //创建各字段的数据输入控件

    { Public declarations }
    published

    	property LimitLeft :Integer read FLeft write FLeft default 10;
    	property LimitTop :Integer read FTop write FTop default 10;
    	property Editorstyle :TEditorstyle read FEditorstyle write FEditorstyle default Tsdbedit;
    	property EditorWidth :Integer read maxTextLen write maxTextLen  default 100;
    	property TitleWidth :Integer read maxLabelLen write maxLabelLen  default 100;
    	property LineHeight :Integer read FLineHeight write FLineHeight  default 15;
    	property TitleVisible :Boolean read FTitleVisible write FTitleVisible default True;
    	property DataSource :TDataSource read FDataSource write FDataSource; //数据源
      property Columns :Integer read FColumns write FColumns default 4;//表列数

    { Published declarations }
  end;

procedure Register;

implementation

constructor TJKFootpanel.Create(AOwner: TComponent);
begin
  Inherited Create(AOWner);
  FLeft :=16;
  FTop := 10;
  maxTextLen := 100;
  maxLabelLen := 100;
  FLineHeight := 15;
  FTitleVisible := True;
  Editorstyle := Tsdbedit;
end;


procedure Register;
begin
  RegisterComponents('Data Controls', [TJKFootpanel]);
end;


procedure TJKFootpanel.Setedit(Value : TEditorstyle);
begin
  	if FEditorstyle <> Value then
   begin
   	FEditorstyle := Value;
   	Invalidate;
   end;
end;

{ 为第I字段增加提示信息的方法}
procedure TJKFootpanel.AddHits(ItemIndex:
Integer; Hits: array of string);
var
  m,n,i: Integer;
begin
	if FEditorstyle = TsDBcombox then
 	begin
   	n := Length(comEditors);
    	m := Length(Hits);
   	if ItemIndex< n then
      for i:=0 to m-1 do
        	comEditors[ItemIndex].Items.Add(Hits[i]);
	end
  	else if FEditorstyle = TsDBEdit then
  	begin
   	n := Length(edEditors);
    	m := Length(Hits);
   	if ItemIndex< n then
      for i:=0 to m-1 do
      	edEditors[ItemIndex].Hint:= Hits[i];
   end
  	else if FEditorstyle = TsDBMemo then
  	begin
   	n := Length(memoEditors);
    	m := Length(Hits);
   	if ItemIndex< n then
      for i:=0 to m-1 do
      	memoEditors[ItemIndex].Hint:= Hits[i];
   end;
end;

procedure TJKFootpanel.AKeyPress(Sender: TObject; var Key: Char);
begin
   if (Sender is TDBComboBox) or (Sender is TDBedit) or (Sender is TDBMemo) then
   if Key=#13 then
   	(Owner as TForm).Perform(WM_NEXTDLGCTL, 0, 0);
end;

procedure TJKFootpanel.ClearHits(ItemIndex: Integer);
var
  n: Integer;
begin
 	if FEditorstyle = TsDBcombox then
  	begin
   	n := Length(comEditors);
   	if ItemIndex< n then comEditors[ItemIndex].Items.Clear;
   end
   else if FEditorstyle = TsDBEdit then
   begin
      n := Length(edEditors);
      if ItemIndex< n then edEditors[ItemIndex].Hint:='';;
   end
   else if FEditorstyle = TsDBMemo then
   begin
      n := Length(MemoEditors);
      if ItemIndex< n then MemoEditors[ItemIndex].Hint:='';;
   end;

end;

{ 创建各字段的数据输入控件的方法}
Function TJKFootpanel.CreateEditors(DS: TDataSource; ColCount: Integer):Integer ;
var
  i, n, RowCount: Integer;
  TextHeight: Integer;
begin
   result := 120;
   if DataSource = nil then exit;
   if not DataSource.DataSet.Active then exit;
   Columns := ColCount;
   if Columns = 0 then exit;
   n := DataSource.DataSet.fieldCount;
   if n > 0 then
  	begin
      DataSource.DataSet.DisableControls;
      if maxLabelLen < maxTextLen then
      	maxTextLen := maxLabelLen;
    	
    	{ 计算最大的标题长度及显示长度}
    	DataSource.DataSet.First;
    	{ 计算高度}
    	TextHeight := Canvas.TextHeight(DataSource.DataSet.Fields[0].DisplayLabel) + FLineHeight; //10;
    	{ 计算行列数}
      if Columns > n then
         Columns := n
      else
         Columns := ColCount;

    	RowCount := n div Columns;
    	if n mod Columns <> 0 then inc(RowCount);
    	{ 分配内存}
    	FreeEditors;
    	SetLength(Labels,n);
    	if FEditorstyle = TsDBcombox then
    		SetLength(comEditors,n)
    	else if FEditorstyle = TsDBEdit then
    		SetLength(edEditors,n)
    	else
    		SetLength(MemoEditors,n);

    	{ 创建滚动盒}
    	FScrollBox := TScrollBox.Create(Owner);
      FScrollBox.Visible := False;
    	FScrollBox.Parent := Self;
    	FScrollBox.Align := alClient;
      //FScrollBox.Color  := clSkyBlue;
      FScrollBox.OnDblClick := OnDblClick;
    	{ 创建编辑}
    	for i := 0 to n - 1 do
    	begin
      	{ 创建标题}
      	Labels[i] := TLabel.Create(Owner);
         Labels[i].visible := TitleVisible;
      	Labels[i].Parent := FScrollBox;
      	Labels[i].Caption := DataSource.DataSet.Fields[i].FieldName;
      	Labels[i].Left := FLeft + (maxLabelLen + 16) * (i div RowCount)+ 2;  //+maxTextLen
         if FEditorstyle = TsDBMemo then
         begin
         	Labels[i].Width := maxLabelLen;
      		Labels[i].Top := FTop + (i mod RowCount) * (TextHeight*2+4) + 12;
         end
         else
         begin
            Labels[i].Width := maxLabelLen;
            Labels[i].Top := FTop + (i mod RowCount) * (TextHeight*1 +12)
         end;

      	{ 创建信息显示数据对象}
	 		if FEditorstyle = TsDBcombox then
    		begin
      		comEditors[i] := TDBComboBox.Create(Owner);
      		comEditors[i].Parent := FScrollBox; //Self;
      		comEditors[i].Left := Labels[i].Left; //+ Labels[i].Width;
      		comEditors[i].Width := maxTextLen;
      		comEditors[i].Top := Labels[i].Top+15;
      		comEditors[i].DataSource := DataSource;
      		comEditors[i].DataField := DataSource.DataSet.Fields[i].FieldName;
      		comEditors[i].OnKeyPress := AKeyPress;
      		comEditors[i].OnKeyDown := AKeyDown;
            comEditors[i].Font.Color := ClBlue;
    		end
    		else if FEditorstyle = TsDBEdit then
    		begin
      		edEditors[i] := TDBedit.Create(Owner);
      		edEditors[i].Parent := FScrollBox;
      		edEditors[i].Left := Labels[i].Left; //+ Labels[i].Width;
      		edEditors[i].Width := maxTextLen;
      		edEditors[i].Top := Labels[i].Top+15;
      		edEditors[i].DataSource := DataSource;
      		edEditors[i].DataField := DataSource.DataSet.Fields[i].FieldName;
      		edEditors[i].OnKeyPress := AKeyPress;
      		edEditors[i].OnKeyDown := AKeyDown;
            edEditors[i].Font.Color := ClBlue;

    		end
    		else
    		begin
      		MemoEditors[i] := TDBmemo.Create(Owner);
      		MemoEditors[i].Parent := FScrollBox;
      		MemoEditors[i].Left := Labels[i].Left;
      		MemoEditors[i].Width := maxTextLen;
      		MemoEditors[i].Top := Labels[i].Top+15;
      		MemoEditors[i].DataSource := DataSource;
      		MemoEditors[i].DataField := DataSource.DataSet.Fields[i].FieldName;
      		MemoEditors[i].OnKeyPress := AKeyPress;
      		MemoEditors[i].OnKeyDown := AKeyDown;
            MemoEditors[i].Font.Color := ClBlue;
    		end;
  		end;
      if FEditorstyle = TsDBMemo then
         result := RowCount*TextHeight*4 +20
      else
         result := RowCount*TextHeight*2 +20;
      DataSource.DataSet.EnableControls;
  		FScrollBox.Visible := True;
  end;
end;

destructor TJKFootpanel.Destroy;
begin
  	FreeEditors;
  	Inherited Destroy;
end;

function TJKFootpanel.comEditor(Index: Integer): TDBComboBox;
begin
  	if Index< Length(comEditors) then Result := comEditors[Index]
  	else Result := nil;
end;

function TJKFootpanel.edEditor(Index: Integer): TDBedit;
begin
  	if Index < Length(edEditors) then Result := edEditors[Index]
  	else Result := nil;
end;
function TJKFootpanel.MemoEditor(Index: Integer): TDBMemo;
begin
  	if Index< Length(MemoEditors) then Result := MemoEditors[Index]
  	else Result := nil;
end;

// 内存的释放是要有顺序的！必须以创建的相反的顺序进行！尤其是当组件之间有父子关系时
procedure TJKFootpanel.FreeEditors;
begin
  	if FScrollBox <> nil then
   begin
   	comEditors := nil;
   	edEditors := nil;
   	MemoEditors := nil;
    	FScrollBox.Free;
    	FScrollBox := nil;
  	end;
end;


procedure TJKFootpanel.AKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
begin
{
  if (Sender is TDBComboBox) then
   begin
    	case Key of
      	VK_Next: (Sender as TDBComboBox).DataSource.DataSet.Next;
       	VK_PRIOR: (Sender as TDBComboBox).DataSource.DataSet.Prior;
      end;
  	end
  	else if (Sender is TDBedit) then
   begin
   	case Key of
      	VK_Next: (Sender as TDBedit).DataSource.DataSet.Next;
       	VK_PRIOR: (Sender as TDBedit).DataSource.DataSet.Prior;
      end;
   end
  	else if (Sender is TDBMemo) then
   begin
   	case Key of
      	VK_Next: (Sender as TDBMemo).DataSource.DataSet.Next;
       	VK_PRIOR: (Sender as TDBMemo).DataSource.DataSet.Prior;
      end;
   end;
   }
end;

end.