Hans-Peter Diettrich wrote

Can somebody explain the purpose of e.g. WindowProc, WndProc and MainWndProc, in the LCL?

Delphi compatibility. AFAIK WndProc works for messages >= WM_USER

In Delphi MainWndProc calls the handler assigned to WindowProc, enclosed in try-finally and try-except blocks. WindowProc typically is initialized with WndProc. Why is this implemented differently in the LCL, and how?

I remember that some people did not like how this worked in Delphi so it didn't work like that, then we had a define to pass messages >= WM_USER to WndProc. I think the define later got changed into always active. I don't remember anyone asking for messages < WM_USER, so probably till now they are not passed to WndProc. I'm just typing from memory, so I could be wrong in parts of this.

Can somebody explain the purpose of e.g. WindowProc, WndProc and MainWndProc, in the LCL?

What's the purpose of TWinControl.MainWndProc, when it's never called or used otherwise, does nothing, and is not virtual?

In Delphi MainWndProc calls the handler assigned to WindowProc, enclosed in try-finally and try-except blocks. WindowProc typically is initialized with WndProc. Why is this implemented differently in the LCL, and how?

DoDi

Hans-Peter Diettrich wrote

WndProc can preprocess *any* kind of messages, which must be handled in a non-standard way in a specific control, e.g. the TripleClick messages. WndProc finally calls Dispatch, to invoke the implemented message handler of the control, or DefaultHandler for all messages without assigned handlers.

You can wait some days to see if anyone is against the change and if not (Vincent didn't like this as far as I remember, so it would be good to hear from him). If there is no answer in 1 week then you can send a patch to bug tracker where this can then be further discussed.

I also don't understand the parallel or different WM..., LM..., CM... and CN... message IDs. Is that separation related to messages handled (or not handled) by widgets or by the LCL? Or have the LM... message IDs been added only to prevent cyclic unit references?

LM messages are sent from the LCL-Widgetsets to the LCL, so they are cross-platform. WM messages are only for Windows. I don't know what CM/CN messages are.

2011/10/19 Felipe Monteiro de Carvalho :

Since I hardly do any win32 programming for Lazarus anymore, I hardly have to say anything anymore.

What I was against, is letting all windows messages bubble up from the win32 widgetset interface into the LCL. I am more a proponent of only passing those messages to the LCL what are handled by the LCL, not all and very messages that the win32 widget generate.

I cannot remember having said about what the LCL should handle messages.

Vincent

WndProc can preprocess *any* kind of messages, which must be handled in a non-standard way in a specific control, e.g. the TripleClick messages. WndProc finally calls Dispatch, to invoke the implemented message handler of the control, or DefaultHandler for all messages without assigned handlers.

I fear that Delphi compatibility is broken, when MainWndProc does nothing. When it is not removed, it should do what Delphi does, so that it can be used in code ported from Delphi. Otherwise it should be removed, together with WindowProc, so that every attempt to use it will result in compiler errors.

I also don't understand the parallel or different WM..., LM..., CM... and CN... message IDs. Is that separation related to messages handled (or not handled) by widgets or by the LCL? Or have the LM... message IDs been added only to prevent cyclic unit references?

DoDi

Since no message IDs exist for other platforms, I'd assume that the LM messages are equivalent to the WM IDs. But why new names for old names?

DoDi

What I was against, is letting all windows messages bubble up from the win32 widgetset interface into the LCL. I am more a proponent of only passing those messages to the LCL what are handled by the LCL, not all and very messages that the win32 widget generate.

IMO such a separation already exists. The WM messges are sent *to* (Windows) widgets, like widget-specific EM (Edit), BM (Button) etc. messages. A widget itself sends back *notification* messages (EN, BN...), for use in an application or in the VCL/LCL.

DoDi

2011/10/19 Hans-Peter Diettrich :

No, IIRC, currently every message that gets into the win32 message handlers, is passed to the LCL.

Vincent

Where do all the messages originate in the non-Windows widgetsets? Aren't these generated by the widgetsets?
Any hints where I could find out more about details?

DoDi

Hans-Peter Diettrich wrote

Since no message IDs exist for other platforms, I'd assume that the LM messages are equivalent to the WM IDs. But why new names for old names?

Can you give some examples of new names? Or you just complain about LM_ and WM_ prefixes?

Prefixes are different to show that message can be not the same as windows passed it. So it just warns developer that it not exact windows message.

Best regards,
Paul Ishenin

I e.g. wonder about method names like WMNotify, associated with an LM_NOTIFY message ID.

Prefixes are different to show that message can be not the same as windows passed it. So it just warns developer that it not exact windows message.

This would be an acceptable explanation.

DoDi