Compiler Plugin¶
Compose works by transforming all Kotlin functions that are annotated with @Composable and adding code for the Compose Runtime. To do that it uses a Kotlin Compiler Plugin.
For instance, this Composable:
@Composable
fun Hello(name: String) {
Text(name)
}
will be transformed and compiled to Jvm ByteCode. Below you can see the decompiled code as Java code
@Metadata(
mv = {1, 5, 1},
k = 2,
xi = 48,
d1 = {"\u0000\u0010\n\u0000\n\u0002\u0010\u0002\n\u0000\n\u0002\u0010\u000e\n\u0002\b\u0002\u001a\u0015\u0010\u0000\u001a\u00020\u00012\u0006\u0010\u0002\u001a\u00020\u0003H\u0007¢\u0006\u0002\u0010\u0004¨\u0006\u0005"},
d2 = {"Hello", "", "name", "", "(Ljava/lang/String;Landroidx/compose/runtime/Composer;I)V", "app_debug"}
)
public final class GreetingKt {
@Composable
public static final void Hello(@NotNull final String name, @Nullable Composer $composer, final int $changed) {
Intrinsics.checkNotNullParameter(name, "name");
$composer = $composer.startRestartGroup(274849561);
ComposerKt.sourceInformation($composer, "C(Hello)7@166L10:Greeting.kt#tlkiwl");
int $dirty = $changed;
if (($changed & 14) == 0) {
$dirty = $changed | ($composer.changed(name) ? 4 : 2);
}
if (($dirty & 11 ^ 2) == 0 && $composer.getSkipping()) {
$composer.skipToGroupEnd();
} else {
TextKt.Text-fLXpl1I(name, (Modifier)null, 0L, 0L, (FontStyle)null, (FontWeight)null, (FontFamily)null, 0L, (TextDecoration)null, (TextAlign)null, 0L, 0, false, 0, (Function1)null, (TextStyle)null, $composer, 14 & $dirty, 0, 65534);
}
ScopeUpdateScope var4 = $composer.endRestartGroup();
if (var4 != null) {
var4.updateScope((Function2)(new Function2() {
public final void invoke(@Nullable Composer $composer, int $force) {
GreetingKt.Hello(name, $composer, $changed | 1);
}
}));
}
}
}
Where can i find the source code¶
See also:¶
- Leland Richardson(@intelligibabble) started a series about the Compose Compiler https://www.youtube.com/watch?v=bg0R9-AUXQM
- Under the hood of Jetpack Compose — part 2 of 2
- A Hitchhiker’s Guide to Compose Compiler: Composers, Compiler Plugins, and Snapshots
- Explained: Compose Compiler and Runtime
- Using Compose Runtime to create a client library
Last update: August 3, 2022