[Test Week] Add ViewOnDrawExecutorTest

/*

 * Copyright (C) 2024 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.launcher3.util

import android.view.View

import android.view.ViewTreeObserver

import androidx.test.ext.junit.runners.AndroidJUnit4

import com.android.launcher3.Launcher

import com.android.launcher3.Workspace

import com.android.launcher3.pageindicators.PageIndicator

import java.util.function.Consumer

import org.junit.Before

import org.junit.Test

import org.junit.runner.RunWith

import org.mockito.Mock

import org.mockito.Mockito.verify

import org.mockito.Mockito.`when`

import org.mockito.MockitoAnnotations

import org.mockito.kotlin.reset

import org.mockito.kotlin.same

import org.mockito.kotlin.verifyZeroInteractions

@RunWith(AndroidJUnit4::class)

class ViewOnDrawExecutorTest<T> where T : View, T : PageIndicator {

    @Mock private lateinit var runnable: Runnable

    @Mock private lateinit var consumer: Consumer<ViewOnDrawExecutor>

    @Mock private lateinit var launcher: Launcher

    @Mock private lateinit var workspace: Workspace<T>

    @Mock private lateinit var rootView: View

    @Mock private lateinit var viewTreeObserver: ViewTreeObserver

    private lateinit var underTest: ViewOnDrawExecutor

    private lateinit var runnableList: RunnableList

    @Before

    fun setup() {

        MockitoAnnotations.initMocks(this)

        runnableList = RunnableList()

        runnableList.add(runnable)

        underTest = ViewOnDrawExecutor(runnableList, consumer)

        `when`(launcher.workspace).thenReturn(workspace)

        `when`(workspace.rootView).thenReturn(rootView)

        `when`(workspace.viewTreeObserver).thenReturn(viewTreeObserver)

    }

    @Test

    fun attachToLauncher_alreadyAttachedToWindow() {

        `when`(workspace.isAttachedToWindow).thenReturn(true)

        underTest.attachTo(launcher)

        verify(workspace).addOnAttachStateChangeListener(same(underTest))

        verify(viewTreeObserver).addOnDrawListener(same(underTest))

        verify(rootView).invalidate()

    }

    @Test

    fun attachToLauncher_notAttachedToWindow() {

        `when`(workspace.isAttachedToWindow).thenReturn(false)

        underTest.attachTo(launcher)

        verify(workspace).addOnAttachStateChangeListener(same(underTest))

        verifyZeroInteractions(viewTreeObserver)

        verifyZeroInteractions(rootView)

    }

    @Test

    fun onViewAttachedToWindow_registerObserver() {

        `when`(workspace.isAttachedToWindow).thenReturn(false)

        underTest.attachTo(launcher)

        underTest.onViewAttachedToWindow(rootView)

        verify(viewTreeObserver).addOnDrawListener(same(underTest))

        verify(rootView).invalidate()

    }

    @Test

    fun complete_then_onViewAttachedToWindow_registerObserver() {

        underTest.markCompleted()

        reset(viewTreeObserver)

        reset(rootView)

        underTest.onViewAttachedToWindow(rootView)

        verifyZeroInteractions(viewTreeObserver)

        verifyZeroInteractions(rootView)

    }

    @Test

    fun onDraw_postRunnable() {

        underTest.attachTo(launcher)

        underTest.onDraw()

        verify(workspace).post(same(underTest))

    }

    @Test

    fun run_before_onDraw_noOp() {

        underTest.run()

        verifyZeroInteractions(runnable)

        verifyZeroInteractions(viewTreeObserver)

        verifyZeroInteractions(workspace)

        verifyZeroInteractions(consumer)

    }

    @Test

    fun first_run_executeRunnable() {

        underTest.attachTo(launcher)

        underTest.onDraw()

        underTest.run()

        verify(runnable).run()

        verify(viewTreeObserver).removeOnDrawListener(same(underTest))

        verify(workspace).removeOnAttachStateChangeListener(same(underTest))

        verify(consumer).accept(same(underTest))

    }

    @Test

    fun second_run_noOp() {

        underTest.attachTo(launcher)

        underTest.onDraw()

        underTest.run()

        reset(runnable)

        reset(viewTreeObserver)

        reset(workspace)

        reset(consumer)

        underTest.run()

        verifyZeroInteractions(runnable)

        verifyZeroInteractions(viewTreeObserver)

        verifyZeroInteractions(workspace)

        verifyZeroInteractions(consumer)

    }

    @Test

    fun markCompleted_viewNotAttached() {

        underTest.markCompleted()

        verify(runnable).run()

        verify(consumer).accept(underTest)

        verifyZeroInteractions(workspace)

    }

    @Test

    fun markCompleted_viewAttached() {

        underTest.attachTo(launcher)

        underTest.markCompleted()

        verify(runnable).run()

        verify(consumer).accept(underTest)

        verify(workspace).removeOnAttachStateChangeListener(same(underTest))

        verify(viewTreeObserver).removeOnDrawListener(same(underTest))

    }

    @Test

    fun cancel_notRun() {

        underTest.cancel()

        verifyZeroInteractions(runnable)

        verify(consumer).accept(underTest)

        verifyZeroInteractions(workspace)

    }

}