Add a TestableAlertDialog

This makes it easier to test classes that create and show an
`AlertDialog`. If using `AlertDialog.Builder`, extra work is needed to
use this.

Test: atest TestableAlertDialogTest
Bug: 260731518
Change-Id: I027cc96cbbaff569b2df33fcdcef0ad50800f56d

packages/SystemUI/tests/src/com/android/systemui/util/TestableAlertDialogTest.kt

@@ -0,0 +1,333 @@
+/*
+ * Copyright (C) 2022 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.systemui.util
+
+import android.content.DialogInterface
+import android.content.DialogInterface.BUTTON_NEGATIVE
+import android.content.DialogInterface.BUTTON_NEUTRAL
+import android.content.DialogInterface.BUTTON_POSITIVE
+import android.testing.AndroidTestingRunner
+import android.testing.TestableLooper
+import androidx.test.filters.SmallTest
+import com.android.systemui.SysuiTestCase
+import com.android.systemui.util.mockito.any
+import com.android.systemui.util.mockito.mock
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.anyInt
+import org.mockito.Mockito.inOrder
+import org.mockito.Mockito.never
+import org.mockito.Mockito.verify
+
+@SmallTest
+@RunWith(AndroidTestingRunner::class)
+@TestableLooper.RunWithLooper
+class TestableAlertDialogTest : SysuiTestCase() {
+
+    @Test
+    fun dialogNotShowingWhenCreated() {
+        val dialog = TestableAlertDialog(context)
+
+        assertThat(dialog.isShowing).isFalse()
+    }
+
+    @Test
+    fun dialogShownDoesntCrash() {
+        val dialog = TestableAlertDialog(context)
+
+        dialog.show()
+    }
+
+    @Test
+    fun dialogShowing() {
+        val dialog = TestableAlertDialog(context)
+
+        dialog.show()
+
+        assertThat(dialog.isShowing).isTrue()
+    }
+
+    @Test
+    fun showListenerCalled() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnShowListener = mock()
+        dialog.setOnShowListener(listener)
+
+        dialog.show()
+
+        verify(listener).onShow(dialog)
+    }
+
+    @Test
+    fun showListenerRemoved() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnShowListener = mock()
+        dialog.setOnShowListener(listener)
+        dialog.setOnShowListener(null)
+
+        dialog.show()
+
+        verify(listener, never()).onShow(any())
+    }
+
+    @Test
+    fun dialogHiddenNotShowing() {
+        val dialog = TestableAlertDialog(context)
+
+        dialog.show()
+        dialog.hide()
+
+        assertThat(dialog.isShowing).isFalse()
+    }
+
+    @Test
+    fun dialogDismissNotShowing() {
+        val dialog = TestableAlertDialog(context)
+
+        dialog.show()
+        dialog.dismiss()
+
+        assertThat(dialog.isShowing).isFalse()
+    }
+
+    @Test
+    fun dismissListenerCalled_ifShowing() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnDismissListener = mock()
+        dialog.setOnDismissListener(listener)
+
+        dialog.show()
+        dialog.dismiss()
+
+        verify(listener).onDismiss(dialog)
+    }
+
+    @Test
+    fun dismissListenerNotCalled_ifNotShowing() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnDismissListener = mock()
+        dialog.setOnDismissListener(listener)
+
+        dialog.dismiss()
+
+        verify(listener, never()).onDismiss(any())
+    }
+
+    @Test
+    fun dismissListenerRemoved() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnDismissListener = mock()
+        dialog.setOnDismissListener(listener)
+        dialog.setOnDismissListener(null)
+
+        dialog.show()
+        dialog.dismiss()
+
+        verify(listener, never()).onDismiss(any())
+    }
+
+    @Test
+    fun cancelListenerCalled_showing() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnCancelListener = mock()
+        dialog.setOnCancelListener(listener)
+
+        dialog.show()
+        dialog.cancel()
+
+        verify(listener).onCancel(dialog)
+    }
+
+    @Test
+    fun cancelListenerCalled_notShowing() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnCancelListener = mock()
+        dialog.setOnCancelListener(listener)
+
+        dialog.cancel()
+
+        verify(listener).onCancel(dialog)
+    }
+
+    @Test
+    fun dismissCalledOnCancel_showing() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnDismissListener = mock()
+        dialog.setOnDismissListener(listener)
+
+        dialog.show()
+        dialog.cancel()
+
+        verify(listener).onDismiss(dialog)
+    }
+
+    @Test
+    fun dialogCancelNotShowing() {
+        val dialog = TestableAlertDialog(context)
+
+        dialog.show()
+        dialog.cancel()
+
+        assertThat(dialog.isShowing).isFalse()
+    }
+
+    @Test
+    fun cancelListenerRemoved() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnCancelListener = mock()
+        dialog.setOnCancelListener(listener)
+        dialog.setOnCancelListener(null)
+
+        dialog.show()
+        dialog.cancel()
+
+        verify(listener, never()).onCancel(any())
+    }
+
+    @Test
+    fun positiveButtonClick() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnClickListener = mock()
+        dialog.setButton(BUTTON_POSITIVE, "", listener)
+
+        dialog.show()
+        dialog.clickButton(BUTTON_POSITIVE)
+
+        verify(listener).onClick(dialog, BUTTON_POSITIVE)
+    }
+
+    @Test
+    fun positiveButtonListener_noCalledWhenClickOtherButtons() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnClickListener = mock()
+        dialog.setButton(BUTTON_POSITIVE, "", listener)
+
+        dialog.show()
+        dialog.clickButton(BUTTON_NEUTRAL)
+        dialog.clickButton(BUTTON_NEGATIVE)
+
+        verify(listener, never()).onClick(any(), anyInt())
+    }
+
+    @Test
+    fun negativeButtonClick() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnClickListener = mock()
+        dialog.setButton(BUTTON_NEGATIVE, "", listener)
+
+        dialog.show()
+        dialog.clickButton(BUTTON_NEGATIVE)
+
+        verify(listener).onClick(dialog, DialogInterface.BUTTON_NEGATIVE)
+    }
+
+    @Test
+    fun negativeButtonListener_noCalledWhenClickOtherButtons() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnClickListener = mock()
+        dialog.setButton(BUTTON_NEGATIVE, "", listener)
+
+        dialog.show()
+        dialog.clickButton(BUTTON_NEUTRAL)
+        dialog.clickButton(BUTTON_POSITIVE)
+
+        verify(listener, never()).onClick(any(), anyInt())
+    }
+
+    @Test
+    fun neutralButtonClick() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnClickListener = mock()
+        dialog.setButton(BUTTON_NEUTRAL, "", listener)
+
+        dialog.show()
+        dialog.clickButton(BUTTON_NEUTRAL)
+
+        verify(listener).onClick(dialog, BUTTON_NEUTRAL)
+    }
+
+    @Test
+    fun neutralButtonListener_noCalledWhenClickOtherButtons() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnClickListener = mock()
+        dialog.setButton(BUTTON_NEUTRAL, "", listener)
+
+        dialog.show()
+        dialog.clickButton(BUTTON_POSITIVE)
+        dialog.clickButton(BUTTON_NEGATIVE)
+
+        verify(listener, never()).onClick(any(), anyInt())
+    }
+
+    @Test
+    fun sameClickListenerCalledCorrectly() {
+        val dialog = TestableAlertDialog(context)
+        val listener: DialogInterface.OnClickListener = mock()
+        dialog.setButton(BUTTON_POSITIVE, "", listener)
+        dialog.setButton(BUTTON_NEUTRAL, "", listener)
+        dialog.setButton(BUTTON_NEGATIVE, "", listener)
+
+        dialog.show()
+        dialog.clickButton(BUTTON_POSITIVE)
+        dialog.clickButton(BUTTON_NEGATIVE)
+        dialog.clickButton(BUTTON_NEUTRAL)
+
+        val inOrder = inOrder(listener)
+        inOrder.verify(listener).onClick(dialog, BUTTON_POSITIVE)
+        inOrder.verify(listener).onClick(dialog, BUTTON_NEGATIVE)
+        inOrder.verify(listener).onClick(dialog, BUTTON_NEUTRAL)
+    }
+
+    @Test(expected = IllegalArgumentException::class)
+    fun clickBadButton() {
+        val dialog = TestableAlertDialog(context)
+
+        dialog.clickButton(10000)
+    }
+
+    @Test
+    fun clickButtonDismisses_positive() {
+        val dialog = TestableAlertDialog(context)
+
+        dialog.show()
+        dialog.clickButton(BUTTON_POSITIVE)
+
+        assertThat(dialog.isShowing).isFalse()
+    }
+
+    @Test
+    fun clickButtonDismisses_negative() {
+        val dialog = TestableAlertDialog(context)
+
+        dialog.show()
+        dialog.clickButton(BUTTON_NEGATIVE)
+
+        assertThat(dialog.isShowing).isFalse()
+    }
+
+    @Test
+    fun clickButtonDismisses_neutral() {
+        val dialog = TestableAlertDialog(context)
+
+        dialog.show()
+        dialog.clickButton(BUTTON_NEUTRAL)
+
+        assertThat(dialog.isShowing).isFalse()
+    }
+}

packages/SystemUI/tests/utils/src/com/android/systemui/util/TestableAlertDialog.kt

@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2022 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.systemui.util
+
+import android.app.AlertDialog
+import android.content.Context
+import android.content.DialogInterface
+import java.lang.IllegalArgumentException
+
+/**
+ * [AlertDialog] that is easier to test. Due to [AlertDialog] being a class and not an interface,
+ * there are some things that cannot be avoided, like the creation of a [Handler] on the main thread
+ * (and therefore needing a prepared [Looper] in the test).
+ *
+ * It bypasses calls to show, clicks on buttons, cancel and dismiss so it all can happen bounded in
+ * the test. It tries to be as close in behavior as a real [AlertDialog].
+ *
+ * It will only call [onCreate] as part of its lifecycle, but not any of the other lifecycle methods
+ * in [Dialog].
+ *
+ * In order to test clicking on buttons, use [clickButton] instead of calling [View.callOnClick] on
+ * the view returned by [getButton] to bypass the internal [Handler].
+ */
+class TestableAlertDialog(context: Context) : AlertDialog(context) {
+
+    private var _onDismissListener: DialogInterface.OnDismissListener? = null
+    private var _onCancelListener: DialogInterface.OnCancelListener? = null
+    private var _positiveButtonClickListener: DialogInterface.OnClickListener? = null
+    private var _negativeButtonClickListener: DialogInterface.OnClickListener? = null
+    private var _neutralButtonClickListener: DialogInterface.OnClickListener? = null
+    private var _onShowListener: DialogInterface.OnShowListener? = null
+    private var _dismissOverride: Runnable? = null
+
+    private var showing = false
+    private var visible = false
+    private var created = false
+
+    override fun show() {
+        if (!created) {
+            created = true
+            onCreate(null)
+        }
+        if (isShowing) return
+        showing = true
+        visible = true
+        _onShowListener?.onShow(this)
+    }
+
+    override fun hide() {
+        visible = false
+    }
+
+    override fun isShowing(): Boolean {
+        return visible && showing
+    }
+
+    override fun dismiss() {
+        if (!showing) {
+            return
+        }
+        if (_dismissOverride != null) {
+            _dismissOverride?.run()
+            return
+        }
+        _onDismissListener?.onDismiss(this)
+        showing = false
+    }
+
+    override fun cancel() {
+        _onCancelListener?.onCancel(this)
+        dismiss()
+    }
+
+    override fun setOnDismissListener(listener: DialogInterface.OnDismissListener?) {
+        _onDismissListener = listener
+    }
+
+    override fun setOnCancelListener(listener: DialogInterface.OnCancelListener?) {
+        _onCancelListener = listener
+    }
+
+    override fun setOnShowListener(listener: DialogInterface.OnShowListener?) {
+        _onShowListener = listener
+    }
+
+    override fun takeCancelAndDismissListeners(
+        msg: String?,
+        cancel: DialogInterface.OnCancelListener?,
+        dismiss: DialogInterface.OnDismissListener?
+    ): Boolean {
+        _onCancelListener = cancel
+        _onDismissListener = dismiss
+        return true
+    }
+
+    override fun setButton(
+        whichButton: Int,
+        text: CharSequence?,
+        listener: DialogInterface.OnClickListener?
+    ) {
+        super.setButton(whichButton, text, listener)
+        when (whichButton) {
+            DialogInterface.BUTTON_POSITIVE -> _positiveButtonClickListener = listener
+            DialogInterface.BUTTON_NEGATIVE -> _negativeButtonClickListener = listener
+            DialogInterface.BUTTON_NEUTRAL -> _neutralButtonClickListener = listener
+            else -> Unit
+        }
+    }
+
+    /**
+     * Click one of the buttons in the [AlertDialog] and call the corresponding listener.
+     *
+     * Button ids are from [DialogInterface].
+     */
+    fun clickButton(whichButton: Int) {
+        val listener =
+            when (whichButton) {
+                DialogInterface.BUTTON_POSITIVE -> _positiveButtonClickListener
+                DialogInterface.BUTTON_NEGATIVE -> _negativeButtonClickListener
+                DialogInterface.BUTTON_NEUTRAL -> _neutralButtonClickListener
+                else -> throw IllegalArgumentException("Wrong button $whichButton")
+            }
+        listener?.onClick(this, whichButton)
+        dismiss()
+    }
+}