Enhancement for TDPFUITableView( Scroll up/down and check on top/bottom )

[heroes3lover]

Hi, I got problem with loading data to the TDPFUITableView.
I need to load a fixed amount of data to the TDPFUITableView, when it scroll up or down,
Load another. I checked the source and can't find a good way to do this( am I wrong? ).
so I wrote my own code there, hopefully the next version can support similar requirement
and help other guys.

Thanks,
Hao

type

TDPFTableViewScrollBegin = procedure( Sender: TObject) of object;
TDPFTableViewScrollend = procedure( Sender: TObject; sp, tp : CGPoint) of object;

TDPFUITableView = class( TDPFiOSBaseControl )
///***///
private
{$IFDEF IOS}
FOnScrollBegin : TDPFTableViewScrollBegin;
FOnScrollEnd : TDPFTableViewScrollend;
{$ENDIF}
public
{$IFDEF IOS}
CurOffSet : CGPoint;
property OnScrollBegin : TDPFTableViewScrollBegin read FOnScrollBegin write FOnScrollBegin;
property OnScrollEnd : TDPFTableViewScrollend read FOnScrollEnd write FOnScrollEnd;
function BOF :Boolean;
function EOF : Boolean;
{$ENDIF}
///******///
end;

constructor TDPFUITableView.Create( AOwner: TComponent );
begin
//**//
{$IFDEF IOS}
FOnScrollBegin := nil;
FOnScrollEnd := nil;
CurOffSet.x := 0;
CurOffSet.y := 0;
{$ENDIF}
end;

{$IFDEF IOS}
function TDPFUITableView.EOF : Boolean;
var
height : CGFloat;
contentYoffset : CGFloat;
distanceFromBottom : CGFloat;
begin
Result := False;
height := FUITableView.frame.size.height;
contentYoffset := FUITableView.contentOffset.y;
distanceFromBottom := FUITableView.contentSize.height - contentYoffset;
if(distanceFromBottom <= height)then
Result := True;
end;

function TDPFUITableView.BOF : Boolean;
begin
Result :=( CurOffSet.y<=0 );
end;
{$ENDIF}

//**TTableViewDelegate**//
procedure TTableViewDelegate.scrollViewWillBeginDragging( scrollView: UIScrollView );
begin
//**//
FDPFUITableView.CurOffSet := scrollView.contentOffset;
if( Assigned( FDPFUITableView.OnScrollBegin ))then
FDPFUITableView.OnScrollBegin( Self );
//**//
end;

// ------------------------------------------------------------------------------
procedure TTableViewDelegate.scrollViewWillEndDragging( scrollView: UIScrollView; withVelocity: CGPoint; targetContentOffset: CGPoint );
begin
//****//
if( Assigned( FDPFUITableView.OnScrollEnd))then
FDPFUITableView.OnScrollEnd( Self, FDPFUITableView.CurOffSet, scrollView.contentOffset );
FDPFUITableView.CurOffSet := scrollView.contentOffset;
end;

//sample to use the function above

vwItems: TDPFUITableView;

vwItems.OnScrollEnd := ScrollEnd;

procedure TfrmItemSearch.ScrollEnd( Sender : TObject; sp, tp : CGPoint );
begin
if( sp.y>tp.y )then//scroll up
begin
if( vwItems.BOF )then
begin
//do something
end;
end
else//scroll down
begin
if( vwItems.Eof )then
begin
//do something
end;
end;
end;

[heroes3lover]

sorry about the formatting, don't know how to do it.

[Babak Yaghoobi]

Hi, heroes3lover

Both OnScrollBegin, OnScrollEnd events will be added in the next release,

thank you for feedback

regards

[heroes3lover]

Hi Babak,

Is there any better way to know the tableview already scroll up to the begin or down to the end? I saw lots of discussion with XCode then I translate one to Delphi XE4 as above. how to do that without my BOF/EOF code?

Thanks,
Hao