Hello,
Since we upgraded from EQ 6 to VCL 13.2.5, we have a strange issue with CxgridDBTableView, ONLY if Tdataset.AfterScroll contains code that takes time and contains application.processmessages. Grid scrolls uncontrolled and Scrollbar button stays in pressed state, until BOF or EOF is reached.
With EQ 6, we did not have this issue.
Iv there a way to stop Grid View Scrolling from TDataset.AfterScroll?
Regards, Ronald
We have fixed the issue described in this ticket and will include the fix in our next maintenance update. To apply this solution before the official update, request a hotfix by clicking the corresponding link for product versions you require.
Note: Hotfixes may be unavailable for beta versions and updates that are about to be released.
Please try the following fix in addition to the VCL 13.2.6 changes:
DelphicxGridCustomView.pas:
procedure TcxGridSite.WndProc(var Message: TMessage);
function IsUnwantedMouseMessage: Boolean;
begin
if Locked then
begin
case Message.Msg of
WM_MOUSEFIRST..WM_MOUSELAST, WM_MOUSEHOVER, WM_MOUSELEAVE:
begin
Result := True;
if (Message.Msg = WM_LBUTTONUP) and (ScrollBarsManager <> nil) and ScrollBarsManager.IsCapture then
ScrollBarsManager.HandleMessage(Message);
end;
else
Result := False;
end;
end
else
Result := False;
end;
begin
if IsUnwantedMouseMessage then
Exit;
Controller.WndProc(Message);
inherited WndProc(Message);
end;
cxControls.pas:
TcxControlScrollBarsManager = class(TcxIUnknownObject,
IcxMouseTrackingCaller, IcxMouseTrackingCaller2)
private
FIsCapture: Boolean;
FHotScrollBar: TcxControlScrollBarHelper;
FOwner: TcxControl;
FScrollBars: TList;
function GetScrollBars(AIndex: Integer): TcxControlScrollBarHelper;
procedure SetHotScrollBar(AValue: TcxControlScrollBarHelper);
procedure SetIsCapture(AValue: Boolean);
protected
function ProcessMouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer): Boolean; virtual;
function ProcessMouseMove(Shift: TShiftState; X, Y: Integer): Boolean; virtual;
function ProcessMouseUp(Button: TMouseButton; Shift: TShiftState; X, Y: Integer): Boolean; virtual;
// IcxMouseTrackingCaller
procedure MouseLeave;
// IcxMouseTrackingCaller2
function PtInCaller(const P: TPoint): Boolean;
property HotScrollBar: TcxControlScrollBarHelper read FHotScrollBar write SetHotScrollBar;
property ScrollBars[Index: Integer]: TcxControlScrollBarHelper read GetScrollBars;
public
constructor Create(AOwner: TcxControl); virtual;
destructor Destroy; override;
function HandleMessage(var Message: TMessage): Boolean; virtual;
function IsScrollBarsArea(const APoint: TPoint): Boolean; virtual;
procedure Paint(ACanvas: TcxCanvas); virtual;
procedure RegisterScrollBar(AScrollBar: TcxControlScrollBarHelper);
procedure UnRegisterScrollBar(AScrollBar: TcxControlScrollBarHelper);
property IsCapture: Boolean read FIsCapture write SetIsCapture;
end;
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Additional info: scrolling stops if mouse is moved from button, scrolling continues if mouse is moved over button again (no clicks, only moves).
Hello Ronald,
I was not able to reproduce this behavior. Attached is an example, that operates without the EOF scrolling on my side. Please modify it to illustrate the problem, and attach it to your next message. I am looking forward to hearing from you.
Hi Paulo,
Unfortunately, I am unable to create a small test app. In such cases, problem does not occur. However, this does not mean that issue does not occur.
Is reproduction on your side the only way you can help, or would for instance a TeamViewer session be an option? Reproduction in application is easy.
regards, Ronald
I kindly ask you to provide a small sample project. This will let us examine it on our side and check with different versions of our controls. Here is an algorithm I personally use to localize a problem in a large project. Reset all event handlers in your application (except AfterScroll). If the problem disappears, set them back one by one, and see when the problem returns. If this does not help, remove all controls one by one and test your sample at each step until the problem is gone. As a result, you will have a small sample illustrating the issue.
Hi Paulo,
Please find attached a modified version of gridmodedemo,. I modified tvOrder.DataController.DataSource.DataSet.AfterScroll event procedure so that for each order, an html-file is loaded, which takes time, whicht leads to uncontrolled scrolling.
Reproduction: start exe, open orders for fist car, click on <down> arrow of orders scrollbar and watch the app scrolling until the last order has reached.
In my first message, I linked behavior to application .processmessages, but later, I found that the fact that a scroll handler takes time causes the behavior.
Regards, Ronald
[Attachment is removed by DevExpress because of the private data]
Hello,
Thank you for your sample project. I have reproduced the described behavior without using the HTML editor and forwarded this ticket to our developers for research.