1374959 - (photon) Support detecting Australis/Photon at runtime in Java frontend

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: General, enhancement)

Description

[Jing-wei Wu [:jwu]]

We would like to detect current skin is Australis or Photon at runtime, then we can do something like this:

```
if (isPhotonSkin()) {
    ... // Display Photon specific visual refresh.
} else {
    ... // Execute original visual behavior.
}
```

The benefit of this change is that we can keep single Java source for both Australis and Photon. This branch should only live in 56 and will be removed after Photon is ready.

Also this detection method should be both work on mach and gradle:
1. for mach, we use `--enable-photon` to enable Photon, the Java source should also aware of this config, and
2. for gradle, we use ProductFlavor to switch Australis and Photon, the Java source should have same behavior according to it.

Comment 1

[Jing-wei Wu [:jwu]]

Attachment: Bug 1374959 - Support skin(Australis/Photon) detection at runtime.

The SKIN field in SkinConfig.java has different value in Australis and Photon, and we can use mach/gradle
to select which class we want at build time. In Java we can use its method to detect skin at runtime.

```
if (SkinConfig.isPhoton()) {
    ... // Execute Photon specific visual refresh.
}
```

Review commit: https://reviewboard.mozilla.org/r/151284/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/151284/

Comment 2

[Nevin Chen(Not active on Bugzilla)]

Comment on attachment 8879878 [details]
Bug 1374959 - Support skin(Australis/Photon) detection at runtime.

https://reviewboard.mozilla.org/r/151284/#review156150

We are eventually moving all of these into BuildConfig. Nick may has a plan for it. 
To me it's a work around for Photon. But we can use a follow up bug to remove it after above happend.

Comment 3

[Max Liu [:maliu]]

Comment on attachment 8879878 [details]
Bug 1374959 - Support skin(Australis/Photon) detection at runtime.

https://reviewboard.mozilla.org/r/151284/#review156250

Comment 4

[Nick Alexander :nalexander [he/him]]

Comment on attachment 8879878 [details]
Bug 1374959 - Support skin(Australis/Photon) detection at runtime.

https://reviewboard.mozilla.org/r/151284/#review156276

I'm fine with this as is, but in general, we want to be strongly informed by what the Gradle standard is.  In this case, `skin` is a Gradle `flavorDimension`, which turns up in the (Gradle-only) generated build configuration as a `String FLAVOR_skin`, like:
```
/**
 * Automatically generated file. DO NOT MODIFY
 */
package org.mozilla.gecko;

public final class BuildConfig {
  public static final boolean DEBUG = false;
  public static final String APPLICATION_ID = "org.mozilla.fennec_nalexander";
  public static final String BUILD_TYPE = "release";
  public static final String FLAVOR = "officialAustralis";
  public static final int VERSION_CODE = 2015495284;
  public static final String VERSION_NAME = "56.0a1";
  public static final String FLAVOR_audience = "official";
  public static final String FLAVOR_skin = "australis";
  // Fields from default config.
  public static final String BUILD_DIR = "/Users/nalexander/Mozilla/gecko/objdir-droid-compile/gradle/build/mobile/android/app";
}
```
So the integers you defined are, in my opinion "better" -- but it'll be harder to get rid of `SkinConfig` and just switch on `BuildConfig.FLAVOR_skin` in the future.

As I say, roll on -- but please figure out what Gradle does for these types of questions, or work with me to figure it out, so that we keep the path to "all Gradle, all the time" open.

Comment 5

[Jing-wei Wu [:jwu]]

Two reasons we choose this solution:

1. So far We still have to support both mach and gradle, but mach doesn't recognize BuildConfig and constant values in AppConstants don't change when we switch between different flavors. If we just have to support gradle in the future, BuildConig will be the best choice.


2. This runtime detection is just a workaround to support both Australis and Photon, `SkinConfig` should be removed ASAP when we don't have to support Australis. Use two simple Java files might cost least effort that I can think of.

Comment 6

[Julian Chu [:walkingice]]

Comment on attachment 8879878 [details]
Bug 1374959 - Support skin(Australis/Photon) detection at runtime.

https://reviewboard.mozilla.org/r/151284/#review156558

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/62908c27accf
Support skin(Australis/Photon) detection at runtime. r=maliu,nalexander,nechen,walkingice

Comment 8

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/62908c27accf