lint/libs/lint-checks/src/main/java/com/android/tools/lint/checks/RangeConstraint.java

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.android.tools.lint.checks;

import static com.android.tools.lint.checks.AnnotationDetector.FLOAT_RANGE_ANNOTATION;
import static com.android.tools.lint.checks.AnnotationDetector.INT_RANGE_ANNOTATION;
import static com.android.tools.lint.checks.AnnotationDetector.SIZE_ANNOTATION;

import com.android.annotations.NonNull;
import com.android.annotations.Nullable;
import com.android.tools.lint.client.api.JavaEvaluator;
import com.intellij.psi.PsiAnnotation;
import com.intellij.psi.PsiModifierListOwner;
import org.jetbrains.uast.UAnnotation;
import org.jetbrains.uast.java.JavaUAnnotation;

public abstract class RangeConstraint {

    @Nullable
    public static RangeConstraint create(@NonNull UAnnotation annotation) {
        String qualifiedName = annotation.getQualifiedName();
        if (qualifiedName == null) {
            return null;
        }

        if (INT_RANGE_ANNOTATION.isEquals(qualifiedName)) {
            return IntRangeConstraint.create(annotation);
        } else if (FLOAT_RANGE_ANNOTATION.isEquals(qualifiedName)) {
            return FloatRangeConstraint.create(annotation);
        } else if (SIZE_ANNOTATION.isEquals(qualifiedName)) {
            return SizeConstraint.create(annotation);
        }

        return null;
    }

    @Nullable
    public static RangeConstraint create(
            @NonNull PsiModifierListOwner owner, @NonNull JavaEvaluator evaluator) {
        for (PsiAnnotation annotation : evaluator.getAllAnnotations(owner, false)) {
            RangeConstraint constraint = create(JavaUAnnotation.wrap(annotation));
            // Pick first; they're mutually exclusive
            if (constraint != null) {
                return constraint;
            }
        }

        return null;
    }

    /**
     * Checks whether the given range is compatible with this one. We err on the side of caution.
     * E.g. if we have
     *
     * <pre>
     *    method(x)
     * </pre>
     *
     * and the parameter declaration says that x is between 0 and 10, and then we have a parameter
     * which is known to be in the range 5 to 15, here we consider this a compatible range; we don't
     * flag this as an error. If however, the ranges don't overlap, *then* we complain.
     */
    @Nullable
    public Boolean contains(@NonNull RangeConstraint other) {
        return null;
    }
}