Add collection-like extensions to ClipData.

src/androidTest/java/androidx/core/content/ClipDataTest.kt

@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2018 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 androidx.core.content
+
+import android.content.ClipData
+import android.content.ClipDescription
+import androidx.testutils.assertThrows
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertSame
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class ClipDataTest {
+
+    private val clip = ClipData("", arrayOf(ClipDescription.MIMETYPE_TEXT_PLAIN), ClipData.Item(""))
+
+    @Test fun get() {
+        clip.addItem(ClipData.Item(""))
+        clip.addItem(ClipData.Item(""))
+
+        for (index in 0 until clip.itemCount) {
+            assertSame(clip.getItemAt(index), clip[index])
+        }
+        assertThrows<IndexOutOfBoundsException> {
+            clip[-1]
+        }
+        assertThrows<IndexOutOfBoundsException> {
+            clip[clip.itemCount]
+        }
+    }
+
+    @Test fun contains() {
+        val item1 = ClipData.Item("")
+        assertFalse(item1 in clip)
+        clip.addItem(item1)
+        assertTrue(item1 in clip)
+
+        val item2 = ClipData.Item("")
+        assertFalse(item2 in clip)
+        clip.addItem(item2)
+        assertTrue(item2 in clip)
+    }
+
+    @Test fun plusAssign() {
+        val items = listOf(ClipData.Item(""), ClipData.Item(""))
+        val expectedSize = clip.itemCount + items.size
+
+        items.forEach {
+            clip += it
+            assertSame(clip.getItemAt(clip.itemCount - 1), it)
+        }
+        assertEquals(clip.itemCount, expectedSize)
+    }
+
+    @Test fun size() {
+        assertEquals(clip.itemCount, clip.size)
+        clip.addItem(ClipData.Item(""))
+        assertEquals(clip.itemCount, clip.size)
+        clip.addItem(ClipData.Item(""))
+        assertEquals(clip.itemCount, clip.size)
+    }
+
+    @Test fun forEach() {
+        clip.addItem(ClipData.Item(""))
+        clip.addItem(ClipData.Item(""))
+
+        var iterations = 0
+        clip.forEach {
+            assertSame(clip.getItemAt(iterations), it)
+            iterations++
+        }
+        assertEquals(clip.itemCount, iterations)
+    }
+
+    @Test fun forEachIndexed() {
+        clip.addItem(ClipData.Item(""))
+        clip.addItem(ClipData.Item(""))
+
+        var iterations = 0
+        clip.forEachIndexed { index, item ->
+            assertEquals(iterations, index)
+            assertSame(clip.getItemAt(iterations), item)
+            iterations++
+        }
+        assertEquals(clip.itemCount, iterations)
+    }
+
+    @Test fun iterator() {
+        clip.addItem(ClipData.Item(""))
+        clip.addItem(ClipData.Item(""))
+        val iterator = clip.iterator()
+
+        for (index in 0 until clip.itemCount) {
+            assertTrue(iterator.hasNext())
+            assertSame(clip.getItemAt(index), iterator.next())
+        }
+        assertFalse(iterator.hasNext())
+        assertThrows<IndexOutOfBoundsException> {
+            iterator.next()
+        }
+    }
+
+    @Test fun iteratorForEach() {
+        clip.addItem(ClipData.Item(""))
+        clip.addItem(ClipData.Item(""))
+
+        var iterations = 0
+        for (item in clip) {
+            assertSame(clip.getItemAt(iterations), item)
+            iterations++
+        }
+        assertEquals(clip.itemCount, iterations)
+    }
+
+    @Test fun items() {
+        clip.addItem(ClipData.Item(""))
+        clip.addItem(ClipData.Item(""))
+
+        var iterations = 0
+        clip.items.forEachIndexed { index, item ->
+            assertEquals(iterations, index)
+            assertSame(clip.getItemAt(iterations), item)
+            iterations++
+        }
+        assertEquals(clip.itemCount, iterations)
+    }
+
+}

src/main/java/androidx/core/content/ClipData.kt

@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+@file:Suppress("NOTHING_TO_INLINE")
+
+package androidx.core.content
+
+import android.content.ClipData
+
+/**
+ * Returns the item at [index].
+ *
+ * @throws IndexOutOfBoundsException if index is less than 0 or greater than or equal to the count.
+ */
+operator fun ClipData.get(index: Int): ClipData.Item {
+    return if (index < 0 || index >= itemCount)
+        throw IndexOutOfBoundsException("Index: $index, Size: $itemCount")
+    else getItemAt(index)
+}
+
+/** Returns `true` if [item] is found in this clip. */
+inline operator fun ClipData.contains(item: ClipData.Item): Boolean {
+    for (index in 0 until itemCount) {
+        if (getItemAt(index) == item) {
+            return true
+        }
+    }
+    return false
+}
+
+/**
+ * Adds [item] to this clip.
+ *
+ * @see ClipData.addItem
+ */
+inline operator fun ClipData.plusAssign(item: ClipData.Item) = addItem(item)
+
+/** Returns the number of items in this clip data. */
+inline val ClipData.size get() = itemCount
+
+/** Performs the given action on each item in this clip data. */
+inline fun ClipData.forEach(action: (item: ClipData.Item) -> Unit) {
+    for (index in 0 until itemCount) {
+        action(getItemAt(index))
+    }
+}
+
+/** Performs the given action on each item in this clip data, providing its sequential index. */
+inline fun ClipData.forEachIndexed(action: (index: Int, item: ClipData.Item) -> Unit) {
+    for (index in 0 until itemCount) {
+        action(index, getItemAt(index))
+    }
+}
+
+/** Returns a [Iterator] over the items in this clip. */
+operator fun ClipData.iterator() = object : Iterator<ClipData.Item> {
+    private var index = 0
+    override fun hasNext() = index < itemCount
+    override fun next() = getItemAt(index++) ?: throw IndexOutOfBoundsException()
+}
+
+/** Returns a [Sequence] over the items in this clip. */
+val ClipData.items: Sequence<ClipData.Item>
+    get() = object : Sequence<ClipData.Item> {
+        override fun iterator() = [email protected]()
+    }