I am having a problem with an effect trigger (shadow effect). I did put the trigger to be ismouseover = true. So, when I put the mouse onto a panel (parent), the shadows activate, and it works fine until I start putting some buttons inside the panel (children).
The shadows effect goes off when the mouse is over the children.
So, is there anyway to keep focus on the parents while being focused on the children?
I did try to change the trigger of the effects (from ismouseover to isfocused), but it didn't give any different results.
As said, your design is wrong, then you can remove the trigger and do it manually :
// show or hide shadow effect
procedure TForm2.ShowShadowEffect(AValue: boolean);
begin
if ShadowEffect1.Enabled <> AValue then
ShadowEffect1.Enabled := AValue;
end;
// show when enter on panel
procedure TForm2.Panel1MouseEnter(Sender: TObject);
begin
ShowShadowEffect(True);
end;
// hide when leave the panel
procedure TForm2.Panel1MouseLeave(Sender: TObject);
begin
ShowShadowEffect(False);
end;
// keep visible when over button
procedure TForm2.Button1MouseEnter(Sender: TObject);
begin
ShowShadowEffect(True);
end;
In certain cases my application try to open a certain Form (Form2) automatically after another one (Form1) is shown. I'm using onFormActivate to call ShowModal, but after the second form is shown, it's controls are losing their focus.
To reproduce:
Create a new VCL Applicattion;
Create a second Form and drop a TEdit in it;
On Main Form add an onFormActivate listener;
'
procedure TForm1.FormActivate(Sender: TObject);
begin
Form2.ShowModal;
end;
After run you will see Form2 being shown. But the edit doesn't get the focus.
It works if I comment the MainFormOnTaskbar in the project file.
// Application.MainFormOnTaskbar := True;
But that is not what I'm supposed to change. I would like to understand: Why the TEdit is losing the focus?
OnActivate is triggered while focus is in progress of being shifting around. Interrupting that process is a really bad idea.
If you want the OnActivate event to trigger a ShowModal() call, you should delay it using PostMessage() (or a short TTimer) so the message loop can finish processing the focus shift that is already in progress, and then can perform the ShowModal() when it is safe to do so. For example:
const
WM_SHOWMODAL_FORM2 = WM_APP + 1;
procedure TForm1.FormActivate(Sender: TObject);
begin
PostMessage(Handle, WM_SHOWMODAL_FORM2, 0, 0);
end;
procedure TForm1.WndProc(var Message: TMessage);
begin
if Message.Msg = WM_SHOWMODAL_FORM2 then
Form2.ShowModal
else
inherited;
end;
I just put an instance of TGlyph on a FMX Form and tested this code.
procedure TForm1.FormCreate(Sender: TObject);
begin
Glyph1.OnClick:=myClick;
end;
procedure TForm1.myClick(Sender: TObject);
begin
ShowMessage('test');
end;
Nothing happening when I click the glyph. I know that there is no OnClick event for TGlyph in the Designer IDE. But this TGlyph has derived from TControl which has OnClick. I know that I can use TImage instead of TGlyph but I am just curiuse about that.
You have to set
Glyph1.HitTest := true;
to make it work.
Continue of this topic:
Drop down menu for TButton
I have wrote a generic code for DropDown memu with any TControl, but for some reason it dose not work as expected with TPanel:
var
TickCountMenuClosed: Cardinal = 0;
LastPopupControl: TControl;
type
TDropDownMenuHandler = class
public
class procedure MouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
end;
TControlAccess = class(TControl);
class procedure TDropDownMenuHandler.MouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
if LastPopupControl <> Sender then Exit;
if (Button = mbLeft) and not ((TickCountMenuClosed + 100) < GetTickCount) then
begin
if GetCapture <> 0 then SendMessage(GetCapture, WM_CANCELMODE, 0, 0);
ReleaseCapture;
// SetCapture(0);
if Sender is TGraphicControl then Abort;
end;
end;
procedure RegisterControlDropMenu(Control: TControl; PopupMenu: TPopupMenu);
begin
TControlAccess(Control).OnMouseDown := TDropDownMenuHandler.MouseDown;
end;
procedure DropMenuDown(Control: TControl; PopupMenu: TPopupMenu);
var
APoint: TPoint;
begin
LastPopupControl := Control;
RegisterControlDropMenu(Control, PopupMenu);
APoint := Control.ClientToScreen(Point(0, Control.ClientHeight));
PopupMenu.PopupComponent := Control;
PopupMenu.Popup(APoint.X, APoint.Y);
TickCountMenuClosed := GetTickCount;
end;
This works well with TButton and with TSpeedButton and with any TGraphicControl (like TImage or TSpeedButton etc) as far as I can tell.
BUT does not work as expected with TPanel
procedure TForm1.Button1Click(Sender: TObject);
begin
DropMenuDown(Sender as TControl, PopupMenu1);
end;
procedure TForm1.Panel1Click(Sender: TObject);
begin
DropMenuDown(Sender as TControl, PopupMenu1); // Does not work!
end;
procedure TForm1.SpeedButton1Click(Sender: TObject);
begin
DropMenuDown(Sender as TControl, PopupMenu1);
end;
procedure TForm1.Image1Click(Sender: TObject);
begin
DropMenuDown(Sender as TControl, PopupMenu1);
end;
Seems like TPanel is not respecting ReleaseCapture; and not even Abort in the event TDropDownMenuHandler.MouseDown. What can I do to make this work with TPanel and other controls? What am I missing?
It's not that TPanel is not respecting ReleaseCapture, it is that the capture is not relevant at all. This is what happens after the popup menu is launched and active, and the control is clicked once again:
The click cancels the modal menu loop, the menu is closed and a mouse down message is posted.
VCL sets a flag within the mouse down message handling [csClicked].
Mouse down event handler is fired, you release the capture.
After the mouse down message returns, posted mouse up message is processed, VCL checks for the flag and clicks the control if it is set.
The click handler pops the menu.
Granted I didn't trace a working example so I can't tell when and how ReleaseCapture is helpful. In any case, it can't help here.
The solution I'd propose is a little different than the current design.
What we want is a second click to not to cause a click. See this part of the code:
procedure DropMenuDown(Control: TControl; PopupMenu: TPopupMenu);
var
APoint: TPoint;
begin
...
PopupMenu.PopupComponent := Control;
PopupMenu.Popup(APoint.X, APoint.Y);
TickCountMenuClosed := GetTickCount;
end;
The second click is in fact what closes the menu, before launching it again through the same handler. It is what causes the PopupMenu.Popup call to return. So what we can tell here is that the mouse button is clicked (either a left button or a double click), but not yet processed by the VCL. That means the message is yet in the queue.
Remove the registration mechanism (mouse down handler hacking) with this approach, it is not needed, and the class itself as a result, and the globals.
procedure DropMenuDown(Control: TControl; PopupMenu: TPopupMenu);
var
APoint: TPoint;
Msg: TMsg;
Wnd: HWND;
ARect: TRect;
begin
APoint := Control.ClientToScreen(Point(0, Control.ClientHeight));
PopupMenu.PopupComponent := Control;
PopupMenu.Popup(APoint.X, APoint.Y);
if (Control is TWinControl) then
Wnd := TWinControl(Control).Handle
else
Wnd := Control.Parent.Handle;
if PeekMessage(Msg, Wnd, WM_LBUTTONDOWN, WM_LBUTTONDBLCLK, PM_NOREMOVE) then begin
ARect.TopLeft := Control.ClientOrigin;
ARect.Right := ARect.Left + Control.Width;
ARect.Bottom := ARect.Top + Control.Height;
if PtInRect(ARect, Msg.pt) then
PeekMessage(Msg, Wnd, WM_LBUTTONDOWN, WM_LBUTTONDBLCLK, PM_REMOVE);
end;
end;
Additionally this doesn't depend on processing timing.
Requirements
If I understand you correctly, then the requirements are:
At the first left mouse button click on a Control, a PopupMenu should be shown beneath the Control.
At the second left mouse button click an that same Control, the shown PopupMenu should be closed.
Realize that, disregarding the implementation of requirement 1 for the moment, requirement 2 happens automatically: when you click outside a PopupMenu, the PopupMenu will close. This concludes to that the implementation of the first should not interfere with the second.
Possible solutions:
Count the clicks on the Control: at the first click, show the PopupMenu and at the second click, do nothing. But this will not work, because the PopupMenu may be closed already by clicks elsewhere and then a second click should actually be the first click.
At the first click, show the PopupMenu. At the second click, determine whether the PopupMenu is still shown. If so, then do nothing. Otherwise, assume a first click. This also will not work, because when a second click is processed, the PopupMenu will be already closed.
At the first click, show the PopupMenu. At the second click, determine whether the PopupMenu is closed sometime during the last couple of milliseconds. If so, then the disappearance is due to this very second click and do nothing. This is the solution you are currently using by utilizing the fact that TPopupMenu.Popup will not return until the PopupMenu is closed.
The current implementation
During the OnClick event of a Control:
The OnMouseDown event of the control is assigned to a custom handler,
The PopupMenu is Shown.
On the second click on the Control:
The time when then PopupMenu was closed is saved (this is still during execution of the previous OnClick event),
The custom OnMouseDown event handler is called,
If the saved time was within the last 100 milliseconds, the mouse capture is released and all execution is aborted.
Note: a possibly already OnMouseDown event setting is not saved and gone!
Why this works for a Button
A TCustomButton handles click events by responding to a by Windows send CN_COMMAND message. That is a specific Windows BUTTON sytem class control characteristic. By canceling the mouse capture mode, this message is not send. Thus the Control's OnClick event is not fired on the second click.
Why this doesn't work for a Panel
A TPanel handles click events by adding the csClickEvents style to its ControlStyle property. This is a specific VCL characteristic. By aborting execution, subsequent code due to the WM_LBUTTONDOWN message is stopped. However, the OnClick event of a TPanel is fired somewhere down its WM_LBUTTONUP message handler, thus the OnClick event is still fired.
Solution for both
Use davea's answer on your other question wherein he simply does nothing if the saved time of the PopupMenu's closing was within the last 100 milliseconds.
I try to make a new project add a TEdit and a TButton.
Set Edit1.Text to 'This is a test message'.
And add an event to the button:
procedure TForm7.Button1Click(Sender: TObject);
begin
Edit1.SelStart := 5;
Edit1.SelLength := 5;
end;
Nothing is selected when I click the button. Can someone explain why and how it should be done to select some part of the text ?
Regards
Roland
It works as expected, but since your button stealed the focus by clicking on it, you're then trying to focus that edit box back again. And by focusing an edit box, all of its text is selected by default. Here's a simple proof, that the text is selected if the edit box has focus while selecting:
procedure TForm1.Button1Click(Sender: TObject);
begin
Edit1.SetFocus;
Edit1.SelStart := 5;
Edit1.SelLength := 5;
end;