[go-nuts] Re: Gomobile Reverse Bindings: Cannot import any android packages
I'm running into an issue with reverse bindings similar to this.
My project structure is like:
mobile/
└── pkg
└── example
├── android
│ └── javatest.go
└── testmobile.go
*testmobile.go:*
package example
import (
"mobile/pkg/example/android"
)
func SystemCurrentTimeMillis() int64 {
return android.SystemCurrentTimeMillis()
}
*android.go:*
package android
import (
"Java/java/lang/Float"
"Java/java/lang/System"
)
func SystemCurrentTimeMillis() int64 {
return System.CurrentTimeMillis()
}
func FloatMin() float32 {
return Float.MIN_VALUE
}
When I run gomobile bind on the top-level example package, it fails:
mobile/pkg/example/android/javatest.go:4:2: could not import
Java/java/lang/Float (cannot find package "Java/java/lang/Float" in any of:
If I run gomobile on the android directory, it works. Is it expected that
the above imports should work, or does gomobile bind only work on one
package?
Thanks,
-Kelly
On Thursday, April 25, 2019 at 6:43:19 PM UTC-4, Mark Bauermeister wrote:
>
> Ok. I fixed it.
>
> For anybody interested, here's how I solved it.
>
> On the Go side, I extended my exported function by adding "ctx
> content.Context" as a parameter (i e "func Hello(ctx content.Context).
> On the Java side, I'm then passing the mobile context as follows (this is
> a React Native app, so it's bound to different from regular Android apps):
>
> Context ctx = getReactApplicationContext();
> Mobile.hello(ctx);
>
>
> I can then access the application context from the Go side.
>
> Now one thing that would be interesting still is whether/how I can reverse
> bind "com.facebook.react.bridge.ReactContextBaseJavaModule" on the Go side
> directly,
> so I can call "getReactApplicationContext()" directly from the Go side
> rather than pass the context in from Java.
>
> I know there's "-classpath" but how does it actually work for external
> Java libraries?
>
> On Wednesday, 24 April 2019 15:27:31 UTC+2, Mark Bauermeister wrote:
>>
>> Yea. Turns out that was indeed the issue. I tried accessing a method that
>> didn't actually exist.
>>
>> Unfortunately, your code doesn't work either. It leads to a segmentation
>> violation/nil pointer error.
>> I suspect one needs to somehow get the right context from the Java side.
>> Question is how.
>>
>> I already tried an OnCreate override func, but that one is somehow never
>> called.
>>
>> On Wednesday, 24 April 2019 15:08:02 UTC+2, ma...@eliasnaur.com wrote:
>>>
>>>
>>>
>>> On Wednesday, April 24, 2019 at 2:34:34 PM UTC+2, Mark Bauermeister
>>> wrote:
I'm currently experimenting with Gomobile Reverse Bindings (my hope is
to eventually be able to call getFilesDir(), so I can save my SQLite3 DB
on
mobile) and it is, quite literally, driving me insane.
I've followed the sparse information available, was able to
successfully work with 'import "Java/java/lang/System" and call
"System.currentTimeMillis()".
Now I'm trying to import "Java/android/content" and it fails outright,
stating that the package "Java/android/content" cannot be found.
What is the correct import path for Android packages, or is there
something else I need to do that I'm missing?
>>>
>>> Note that reverse binding packages will only be generated if you use a
>>> type from it; importing is unfortunately not enough.
>>>
>>> Perhaps
>>>
>>> import "Java/android/content"
>>>
>>> var ctx content.Context
>>> ctx.GetFilesDir()
>>>
>>> is enough to get further.
>>>
>>> The reverse bindings are very fickle, sorry.
>>>
>>> - elias
>>>
>>
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[go-nuts] Re: Gomobile Reverse Bindings: Cannot import any android packages
Ok. I fixed it. For anybody interested, here's how I solved it. On the Go side, I extended my exported function by adding "ctx content.Context" as a parameter (i e "func Hello(ctx content.Context). On the Java side, I'm then passing the mobile context as follows (this is a React Native app, so it's bound to different from regular Android apps): Context ctx = getReactApplicationContext(); Mobile.hello(ctx); I can then access the application context from the Go side. Now one thing that would be interesting still is whether/how I can reverse bind "com.facebook.react.bridge.ReactContextBaseJavaModule" on the Go side directly, so I can call "getReactApplicationContext()" directly from the Go side rather than pass the context in from Java. I know there's "-classpath" but how does it actually work for external Java libraries? On Wednesday, 24 April 2019 15:27:31 UTC+2, Mark Bauermeister wrote: > > Yea. Turns out that was indeed the issue. I tried accessing a method that > didn't actually exist. > > Unfortunately, your code doesn't work either. It leads to a segmentation > violation/nil pointer error. > I suspect one needs to somehow get the right context from the Java side. > Question is how. > > I already tried an OnCreate override func, but that one is somehow never > called. > > On Wednesday, 24 April 2019 15:08:02 UTC+2, ma...@eliasnaur.com wrote: >> >> >> >> On Wednesday, April 24, 2019 at 2:34:34 PM UTC+2, Mark Bauermeister wrote: >>> >>> I'm currently experimenting with Gomobile Reverse Bindings (my hope is >>> to eventually be able to call getFilesDir(), so I can save my SQLite3 DB on >>> mobile) and it is, quite literally, driving me insane. >>> I've followed the sparse information available, was able to successfully >>> work with 'import "Java/java/lang/System" and call >>> "System.currentTimeMillis()". >>> >>> Now I'm trying to import "Java/android/content" and it fails outright, >>> stating that the package "Java/android/content" cannot be found. >>> >>> What is the correct import path for Android packages, or is there >>> something else I need to do that I'm missing? >>> >> >> Note that reverse binding packages will only be generated if you use a >> type from it; importing is unfortunately not enough. >> >> Perhaps >> >> import "Java/android/content" >> >> var ctx content.Context >> ctx.GetFilesDir() >> >> is enough to get further. >> >> The reverse bindings are very fickle, sorry. >> >> - elias >> > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[go-nuts] Re: Gomobile Reverse Bindings: Cannot import any android packages
Yea. Turns out that was indeed the issue. I tried accessing a method that didn't actually exist. Unfortunately, your code doesn't work either. It leads to a segmentation violation/nil pointer error. I suspect one needs to somehow get the right context from the Java side. Question is how. I already tried an OnCreate override func, but that one is somehow never called. On Wednesday, 24 April 2019 15:08:02 UTC+2, ma...@eliasnaur.com wrote: > > > > On Wednesday, April 24, 2019 at 2:34:34 PM UTC+2, Mark Bauermeister wrote: >> >> I'm currently experimenting with Gomobile Reverse Bindings (my hope is to >> eventually be able to call getFilesDir(), so I can save my SQLite3 DB on >> mobile) and it is, quite literally, driving me insane. >> I've followed the sparse information available, was able to successfully >> work with 'import "Java/java/lang/System" and call >> "System.currentTimeMillis()". >> >> Now I'm trying to import "Java/android/content" and it fails outright, >> stating that the package "Java/android/content" cannot be found. >> >> What is the correct import path for Android packages, or is there >> something else I need to do that I'm missing? >> > > Note that reverse binding packages will only be generated if you use a > type from it; importing is unfortunately not enough. > > Perhaps > > import "Java/android/content" > > var ctx content.Context > ctx.GetFilesDir() > > is enough to get further. > > The reverse bindings are very fickle, sorry. > > - elias > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[go-nuts] Re: Gomobile Reverse Bindings: Cannot import any android packages
On Wednesday, April 24, 2019 at 2:34:34 PM UTC+2, Mark Bauermeister wrote: > > I'm currently experimenting with Gomobile Reverse Bindings (my hope is to > eventually be able to call getFilesDir(), so I can save my SQLite3 DB on > mobile) and it is, quite literally, driving me insane. > I've followed the sparse information available, was able to successfully > work with 'import "Java/java/lang/System" and call > "System.currentTimeMillis()". > > Now I'm trying to import "Java/android/content" and it fails outright, > stating that the package "Java/android/content" cannot be found. > > What is the correct import path for Android packages, or is there > something else I need to do that I'm missing? > Note that reverse binding packages will only be generated if you use a type from it; importing is unfortunately not enough. Perhaps import "Java/android/content" var ctx content.Context ctx.GetFilesDir() is enough to get further. The reverse bindings are very fickle, sorry. - elias -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
