Support Forums - View Thread

View Thread

The following is the text of the current message along with any replies.

Messages 1 to 10 of 10 total

Tue, Apr 25 2017 7:49 AM	Permanent Link
Matthew Jones	I have two components on a panel. One is a label, the other has the Drag events handled. I'd like the label to be "click transparent", or somehow pass on its clicks to the underlying component. Is this possible? -- Matthew Jones
Tue, Apr 25 2017 9:01 AM	Permanent Link
Michael Dreher	"Matthew Jones" wrote: // I have two components on a panel. One is a label, the other has the Drag events handled. // I'd like the label to be // "click transparent", or somehow pass on its clicks to the // underlying component. Is this possible? TLabel has a FocusControl property for delegating clicks. M. Dreher
Tue, Apr 25 2017 9:56 AM	Permanent Link
Uli Becker	Michael, > TLabel has a FocusControl property for delegating clicks. I don't think FocusControl is able to delegate a click-event. It just passes the focus. And: Panels are not in the list of the FocusControl property. Uli
Tue, Apr 25 2017 10:08 AM	Permanent Link
Matthew Jones	Michael Dreher wrote: > TLabel has a FocusControl property for delegating clicks. Thanks - this needs to be at a lower level I think. -- Matthew Jones
Tue, Apr 25 2017 10:33 AM	Permanent Link
Tim Young [Elevate Software] Elevate Software, Inc. timyoung@elevatesoft.com	Matthew, << I have two components on a panel. One is a label, the other has the Drag events handled. I'd like the label to be "click transparent", or somehow pass on its clicks to the underlying component. Is this possible? >> Sure, but you need to write a descendant control to do so. The method that you need to use is: function ForwardEvent(AParentElement: TElement; ID: Integer; AElement: TElement): Boolean; virtual; in the TInterfaceController class in the WebUI unit. You would use it like this: 1) Check the ID to see if it's a cdClick event 2) If it is, then call the ForwardEvent method to forward the event to the parent control's client element (use Parent.ClientElement, not Parent.Element). 3) If it isn't, then just call the inherited DispatchEvent method. Of course, in general, with such a control you probably just want to forward everything on to the parent control that deals with mouse/touch events. This is much easier, of course: type TMyLabel = class(TLabel) protected function DispatchEvent(ID: Integer; AElement: TElement): Boolean; override; end; implementation function TMyLabel.DispatchEvent(ID: Integer; AElement: TElement): Boolean; begin if Assigned(Parent) and (ID >= cdMouseDown) and (ID <= cdTouchScroll) then Result:=ForwardEvent(Parent.ClientElement,ID,AElement) else Result:=inherited DispatchEvent(ID,AElement); end; If you put that on a form, you'll now notice that the form will now get all of the mouse/touch events originally intended for the label. Also, further explanation about Element vs. ClientElement. ClientElement is a "universal" reference. For control's that don't have a client element (basic panels, labels), the ClientElement property automatically maps to the root Element for the control. For more complex controls (panels, forms) that do have a client element, the ClientElement property will actually map to the client element for the control. The client element always handles interaction with the control, so this makes sure that you're dispatching to the correct element for the control. It's similar to Windows where there are non-client areas (window title/border) that don't receive normal interaction events, and client areas that do. Tim Young Elevate Software www.elevatesoft.com
Tue, Apr 25 2017 11:00 AM	Permanent Link
Matthew Jones	Tim Young [Elevate Software] wrote: > ForwardEvent Thanks - I may look into that, but in this particular case it looks like it would be easier to modify the one underneath anyway to show the text I'm using the label with. Perhaps though this makes sense for a general modification for TLabel, as a property, since that is probably the most common thing people will want to put on top of other things. Not important though. -- Matthew Jones
Thu, Apr 27 2017 9:08 AM	Permanent Link
Tim Young [Elevate Software] Elevate Software, Inc. timyoung@elevatesoft.com	Matthew, << Thanks - I may look into that, but in this particular case it looks like it would be easier to modify the one underneath anyway to show the text I'm using the label with. >> Easier ? It's 10 lines of code, and I provided the code. All you need to do is put it in the unit of your choosing and pop it on the component palette via Library/Add Component. Tim Young Elevate Software www.elevatesoft.com
Thu, Apr 27 2017 9:14 AM	Permanent Link
Matthew Jones	Tim Young [Elevate Software] wrote: > Easier ? It's 10 lines of code, and I provided the code. All you need to do is put it in the unit of your choosing and pop it on the component palette via Library/Add Component. Hmm, I didn't realise it was complete, but it still needs me to add a new component etc. Silly question: Can I create such a component at run time? I used to do that a lot in Delphi to save installing components - just put a placeholder, create the replacement by copying properties, and then delete the placeholder. That would be a nice way forward. -- Matthew Jones
Thu, Apr 27 2017 9:41 AM	Permanent Link
Tim Young [Elevate Software] Elevate Software, Inc. timyoung@elevatesoft.com	Matthew, << Hmm, I didn't realise it was complete, but it still needs me to add a new component etc. Silly question: Can I create such a component at run time? I used to do that a lot in Delphi to save installing components - just put a placeholder, create the replacement by copying properties, and then delete the placeholder. That would be a nice way forward. >> You're over-thinking this, and applying Delphi's issues with managing packages to EWB. Did you actually try to add the control ? It will literally take about 30 seconds, front to back: 1) Add Component 2) Give it a name (TMyLabel) 3) Type in what unit it is in 4) Click on OK You don't even need an icon. Tim Young Elevate Software www.elevatesoft.com
Thu, Apr 27 2017 10:04 AM	Permanent Link
Matthew Jones	Tim Young [Elevate Software] wrote: > Matthew, > > << Hmm, I didn't realise it was complete, but it still needs me to add a new component etc. Silly question: Can I create such a component at run time? I used to do that a lot in Delphi to save installing components - just put a placeholder, create the replacement by copying properties, and then delete the placeholder. That would be a nice way forward. >> > > You're over-thinking this, and applying Delphi's issues with managing packages to EWB. Yes, but can I do it the way I suggest? That is, just reference the unit and create it manually? I guess so - no reason not to. -- Matthew Jones