Problem minimizing print preview window

rbuser

I have an end-user reporting app set up using RB7.03 and Delphi 5. If I
print a report to the screen, then minimize the print preview window and
then click on my application in the taskbar I get the Report Explorer
window. At this point I am stuck because the print preview window is the
active window but it's not visible. Nothing I do will bring it back. I'm
forced to terminate my application to get out of this. Is this a RB bug or
is it something I'm doing? I can consistently make it do this.

Michael Gregg

nardmoseley

This is an issue related to Delphi applications and many Windows apps in
general. They do not always activate themselves properly when switching
between apps using the task bar. I believe Borland is trying to improving
the VCL to handle this better in future versions.

When Alt + Tab is used to switch between apps, this is never an problem -
the app is always restored properly. As a test try using Alt + Tab and
observe what happens.

You can implement an Application.OnActivate event-handler to work improve
the default behavior.

1. Assign the event-handler sometime after the application starts up.

Application.OnActivate := ehApplicationActivate;


2. Add the following code to the event-handler method

procedure TmyEndUserSolution.ehApplicationActivate(Sender: TObject);
begin

if Screen.ActiveForm.WindowState = wsMinimized then
Screen.ActiveForm.WindowState := wsMaximized;

Screen.ActiveForm.BringToFront;

end;




--
Nard Moseley
Digital Metaphors Corporation
www.digital-metaphors.com

rbuser

Michael Gregg wrote:


This may help you:


First, one unit subclasses the report explorer form (remember to
register/unregister it).

type
TgtcRBReportExplorerForm = class(TppReportExplorerForm)
...

constructor TgtcRBReportExplorerForm.Create(aOwner: TComponent);
begin
inherited;

...

// Minimising the designer or explorer is confusing when they are not
in the taskbar.
BorderIcons := BorderIcons - [biMinimize];
end;

procedure TgtcRBReportExplorerForm.CreateParams(var Params:
TCreateParams);
begin
inherited CreateParams(Params);

// We don't want a taskbar icon for the explorer.
Params.ExStyle := Params.ExStyle and not WS_EX_APPWINDOW;
end;


Next, I had to do the same for the designer, in another unit:
(rpt is the data module containing the TppReport, and the
RemoveDesignerTaskIcon is called from an OnIdle event.)

rocedure TdmReport.RemoveDesignerTaskIcon(Sender: TObject);
var
ppd : TppDesigner;
dwExStyle : DWORD;
begin
ppd := rpt.ppReportExplorer.Designer;
if not Assigned(ppd) then
Exit;

// We don't want the designer as an icon in the taskbar. Form
property creates the form.
dwExStyle := GetWindowLong(ppd.Form.Handle, GWL_EXSTYLE);
if dwExStyle <> 0 then
SetWindowLong(ppd.Form.Handle, GWL_EXSTYLE, dwExStyle and not
WS_EX_APPWINDOW);
end;


I think this should be just about it. Got rid of the problem, at least.

-tor

rbuser

First, to answer Nard - yes using Alt-Tab does restore the windows properly.
Secondly, the response offered below refers to another question I had.
Namely, why do the Report Explorer and Report Designer show up as separate
entries on the taskbar? It seems to me that this was not the behavior prior
to version 7. Is there a way to override this without the recoding as shown
below?

Michael Gregg

nardmoseley

RB 6 and RB 7 behave differently in managing the windows and task bar. RB 7
contains some modifications that were meant to improve things. However,
there is still room for more improvement. We will research this and try to
improve things for the next release.


--
Nard Moseley
Digital Metaphors Corporation
www.digital-metaphors.com