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Add generic type DeviceAnnotation<AnnotationT,TargetT>
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- used for hardware annotations.
- AnnotationT is the type of the annotation
- TargetT is the target value constraint
- typechecking and application is done internally
- the lambdas are back!
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@penguinencounter
penguinencounter committed Jul 5, 2024
1 parent a9b08ac commit 20ecd51
Showing 1 changed file with 72 additions and 34 deletions.
106 changes: 72 additions & 34 deletions TeamCode/src/main/java/org/firstinspires/ftc/teamcode/hardware/HardwareMapper.java
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Original file line number Diff line number Diff line change
Expand Up @@ -4,12 +4,80 @@
import com.qualcomm.robotcore.hardware.DcMotorSimple;
import com.qualcomm.robotcore.hardware.HardwareMap;

import java.lang.annotation.Annotation;
import java.lang.reflect.Field;

/**
* Annotation processor for hardware map things.
*/
public abstract class HardwareMapper {
/**
* Represents an annotation processor for hardware devices.
* Internals are a bit of a mess right now.
* <p> </p>
* HardwareName is hardcoded because it provides the value of the field.
*/
static final class DeviceAnnotation<AnnotationT extends Annotation, TargetT> {
private final Class<AnnotationT> annotationClass;
private final Class<TargetT> targetClass;
private final Action<AnnotationT, TargetT> action;

@FunctionalInterface
interface Action<AnnotationT extends Annotation, TargetType> {
void use(AnnotationT annotation, TargetType target);
}

DeviceAnnotation(Class<AnnotationT> annotationClass, Class<TargetT> targetClass, Action<AnnotationT, TargetT> action) {
this.annotationClass = annotationClass;
this.targetClass = targetClass;
this.action = action;
}

private boolean check(Field t, Object value) {
if (!t.isAnnotationPresent(annotationClass)) return false;
AnnotationT annotation = t.getAnnotation(annotationClass);
if (annotation == null)
throw new NullPointerException("Annotation is null! (isAnnotationPresent is true but getAnnotation returned null)");
if (!targetClass.isAssignableFrom(value.getClass())) {
throw new ClassCastException("Annotation " + annotationClass.getName() + " can only be used on " + targetClass.getName() + " (or subclasses)");
}
return true;
}

void use(Field t, Object value) {
if (!check(t, value)) return;
AnnotationT annotation = t.getAnnotation(annotationClass);
if (annotation == null)
throw new NullPointerException("Annotation disappeared between check and use");
action.use(annotation, targetClass.cast(value));
}
}

static final DeviceAnnotation<Reversed, DcMotorSimple> reversed =
new DeviceAnnotation<>(
Reversed.class,
DcMotorSimple.class,
(annotation, target) -> target.setDirection(DcMotorSimple.Direction.REVERSE)
);

static final DeviceAnnotation<ZeroPower, DcMotor> zeroPower =
new DeviceAnnotation<>(
ZeroPower.class,
DcMotor.class,
(annotation, target) -> target.setZeroPowerBehavior(annotation.value())
);

static final DeviceAnnotation<AutoClearEncoder, DcMotor> autoClearEncoder =
new DeviceAnnotation<>(
AutoClearEncoder.class,
DcMotor.class,
(annotation, target) -> {
DcMotor.RunMode current = target.getMode();
target.setMode(DcMotor.RunMode.STOP_AND_RESET_ENCODER);
target.setMode(current);
}
);

public HardwareMapper(HardwareMap map) {
Field[] fields = this.getClass().getDeclaredFields();
for (Field field : fields) {
Expand All @@ -22,47 +90,17 @@ public HardwareMapper(HardwareMap map) {
Object result = map.tryGet(targetType, field.getName());

if (result == null) {
throw new RuntimeException(
"Hardware: '" +
field.getName() + "' not found, expected type " +
targetType.getName() + " for field " +
field.getName() + " in " + this.getClass().getName()
);
throw new RuntimeException("Hardware: '" + field.getName() + "' not found, expected type " + targetType.getName() + " for field " + field.getName() + " in " + this.getClass().getName());
}
try {
field.set(this, result);
} catch (IllegalAccessException e) {
throw new RuntimeException("Field " + field.getName() + " assign failed: " + result.getClass().getName() + " to " + field.getType().getName());
}

if (field.isAnnotationPresent(Reversed.class)) {
if (targetType.isAssignableFrom(DcMotorSimple.class)) {
DcMotorSimple motor = (DcMotorSimple) result;
motor.setDirection(DcMotorSimple.Direction.REVERSE);
} else {
throw new RuntimeException("@Reversed annotation can only be used on DcMotorSimple (or subclasses)");
}
}
if (field.isAnnotationPresent(ZeroPower.class)) {
if (targetType.isAssignableFrom(DcMotor.class)) {
DcMotor motor = (DcMotor) result;
ZeroPower zeroPower = field.getAnnotation(ZeroPower.class);
if (zeroPower == null) throw new RuntimeException("ZeroPower annotation is null?!");
motor.setZeroPowerBehavior(zeroPower.value());
} else {
throw new RuntimeException("@ZeroPower annotation can only be used on DcMotor (or subclasses)");
}
}
if (field.isAnnotationPresent(AutoClearEncoder.class)) {
if (targetType.isAssignableFrom(DcMotor.class)) {
DcMotor motor = (DcMotor) result;
DcMotor.RunMode current = motor.getMode();
motor.setMode(DcMotor.RunMode.STOP_AND_RESET_ENCODER);
motor.setMode(current);
} else {
throw new RuntimeException("@AutoClearEncoder annotation can only be used on DcMotor (or subclasses)");
}
}
reversed.use(field, result);
zeroPower.use(field, result);
autoClearEncoder.use(field, result);
} catch (IllegalArgumentException e) {
throw new RuntimeException("Field " + field.getName() + " typecast failed");
} finally {
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