Dear all, I'm constructing a rudimentary webview library for Pharo with UFFI (available here [https://github.com/eftomi/Pharo-Webview](https://github.com/eftomi/Pharo-Webview "https://github.com/eftomi/Pharo-Webview")). For now, the basic things work under Windows. Iâm using âa tiny cross-platform webview libraryâ available at [https://github.com/webview/webview](https://github.com/webview/webview "https://github.com/webview/webview"). One of the functions in the dll allows to register a C function to act as a callback and that can be used as a function in javascript, which is convenient for webview presenter - main program communication. This function has the signature: ``` extern void webview_bind(webview_t w, const char *name, void (*fn)(const char *seq, const char *req, void *arg), void *arg); ``` fn is the callback function. Is there any way to make a ffiCall description of this kind of signature, where fn would be an address of the callback in Pharo? Thanks and best wishes,\ Tomaz
Found the solution! Here it is, if somebody needs the description. The webview_bind() function in DLL that expects to get a pointer to the function in Pharo can be called like this: ``` WebViewLibrary >> bind: webview name: aString callback: aFFICallback arguments: aByteString ``` ``` ^ self ffiCall: #(void webview_bind(void * webview, const char * aString, FFICallback aFFICallback, void * aByteString)) ``` Before doing the actual call, the callback should be made according to fn signature: ``` doIt := FFICallback ``` ``` signature: #( void (const char *seq, const char *req, void * arg) ) ``` ``` block: [ :seq :req :arg | ``` ``` âdo the stuffâ ``` ``` ]. ``` And the call is then made as: ``` WebViewLibrary new bind: webview name: 'newJsFunctionName' callback: doIt arguments: args. ``` The next challenge is, of course, threading ... Best wishes,\ Tomaz
Thanks for sharing the solution mate :) I don't know if you are aware, but you can also ask questions on Pharo's discord. Though it's easier to go through the history of conversations by email. Cheers, Harald Le mar. 7 déc. 2021 à 04:53, <tomazz.turk@gmail.com> a écrit :
Found the solution! Here it is, if somebody needs the description.
The webview_bind() function in DLL that expects to get a pointer to the function in Pharo can be called like this:
WebViewLibrary >> bind: webview name: aString callback: aFFICallback arguments: aByteString
^ self ffiCall: #(void webview_bind(void * webview, const char * aString, FFICallback aFFICallback, void * aByteString))
Before doing the actual call, the callback should be made according to fn signature:
doIt := FFICallback
signature: #( void (const char *seq, const char *req, void * arg) )
block: [ :seq :req :arg |
âdo the stuffâ
].
And the call is then made as:
WebViewLibrary new bind: webview name: 'newJsFunctionName' callback: doIt arguments: args.
The next challenge is, of course, threading ...
Best wishes, Tomaz
participants (2)
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Harald VICAIRE -
tomazz.turk＠gmail.com