Add ArraysCompatUtils.binarySearch

Until API version 9, java.util.Arrays.binarySearch(int[], int, int,
int) doesn't exist.

Change-Id: Ife0ed4fbac642eda069e7b6f6b8dd30e0cd5fdee

1 files changed, 103 insertions, 0 deletions

diff --git a/tests/src/com/android/inputmethod/compat/ArraysCompatUtilsTests.java b/tests/src/com/android/inputmethod/compat/ArraysCompatUtilsTests.java
new file mode 100644
index 000000000..93681b616
--- /dev/null
+++ b/tests/src/com/android/inputmethod/compat/ArraysCompatUtilsTests.java
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2011 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.inputmethod.compat;
+
+import android.test.AndroidTestCase;
+
+public class ArraysCompatUtilsTests extends AndroidTestCase {
+    // See {@link tests.api.java.util.ArraysTest}.
+    private static final int ARRAY_SIZE = 100;
+    private final int[] mIntArray = new int[ARRAY_SIZE];
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+        for (int counter = 0; counter < ARRAY_SIZE; counter++) {
+            mIntArray[counter] = counter;
+        }
+    }
+
+    public void testEmptyArray() {
+        final int index = ArraysCompatUtils.binarySearch(mIntArray, 0, 0, 0);
+        assertEquals("empty", ~0, index);
+        final int compat = ArraysCompatUtils.compatBinarySearch(mIntArray, 0, 0, 0);
+        assertEquals("empty compat", ~0, compat);
+    }
+
+    public void testEmptyRangeArray() {
+        final int mid = ARRAY_SIZE / 3;
+        final int index = ArraysCompatUtils.binarySearch(mIntArray, mid, mid, 1);
+        assertEquals("empty", ~mid, index);
+        final int compat = ArraysCompatUtils.compatBinarySearch(mIntArray, mid, mid, 1);
+        assertEquals("empty compat", ~mid, compat);
+    }
+
+    public void testFind() {
+        for (int counter = 0; counter < ARRAY_SIZE; counter++) {
+            final int index = ArraysCompatUtils.binarySearch(mIntArray, 0, ARRAY_SIZE, counter);
+            assertEquals("found", counter, index);
+        }
+        for (int counter = 0; counter < ARRAY_SIZE; counter++) {
+            final int compat = ArraysCompatUtils.compatBinarySearch(
+                    mIntArray, 0, ARRAY_SIZE, counter);
+            assertEquals("found compat", counter, compat);
+        }
+    }
+
+    public void testFindNegative() {
+        final int offset = ARRAY_SIZE / 2;
+        for (int counter = 0; counter < ARRAY_SIZE; counter++) {
+            mIntArray[counter] -= offset;
+        }
+        for (int counter = 0; counter < ARRAY_SIZE; counter++) {
+            final int index = ArraysCompatUtils.binarySearch(
+                    mIntArray, 0, ARRAY_SIZE, counter - offset);
+            assertEquals("found", counter, index);
+        }
+        for (int counter = 0; counter < ARRAY_SIZE; counter++) {
+            final int compat = ArraysCompatUtils.compatBinarySearch(
+                    mIntArray, 0, ARRAY_SIZE, counter - offset);
+            assertEquals("found compat", counter, compat);
+        }
+    }
+
+    public void testNotFountAtTop() {
+        final int index = ArraysCompatUtils.binarySearch(mIntArray, 0, ARRAY_SIZE, -1);
+        assertEquals("not found top", ~0, index);
+        final int compat = ArraysCompatUtils.compatBinarySearch(
+                    mIntArray, 0, ARRAY_SIZE, -1);
+        assertEquals("not found top compat", ~0, compat);
+    }
+
+    public void testNotFountAtEnd() {
+        final int index = ArraysCompatUtils.binarySearch(mIntArray, 0, ARRAY_SIZE, ARRAY_SIZE);
+        assertEquals("not found end", ~ARRAY_SIZE, index);
+        final int compat = ArraysCompatUtils.compatBinarySearch(
+                    mIntArray, 0, ARRAY_SIZE, ARRAY_SIZE);
+        assertEquals("not found end compat", ~ARRAY_SIZE, compat);
+    }
+
+    public void testNotFountAtMid() {
+        final int mid = ARRAY_SIZE / 3;
+        mIntArray[mid] = mIntArray[mid + 1];
+        final int index = ArraysCompatUtils.binarySearch(mIntArray, 0, ARRAY_SIZE, mid);
+        assertEquals("not found mid", ~mid, index);
+        final int compat = ArraysCompatUtils.compatBinarySearch(
+                    mIntArray, 0, ARRAY_SIZE, mid);
+        assertEquals("not found mid compat", ~mid, compat);
+    }
+}