Add test cases for BalanceSeekBar

Bug: 123722274
Test: Manual
      make RunSettingsRoboTests ROBOTEST_FILTER=BalanceSeekBar

Change-Id: Ie6b560b2f92d78a0d3bd7ddb0e0d0a85c7803827

tests/robotests/src/com/android/settings/accessibility/BalanceSeekBarTest.java

@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2019 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.settings.accessibility;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.widget.SeekBar;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+@RunWith(RobolectricTestRunner.class)
+public class BalanceSeekBarTest {
+    // Fix the maximum process value to 200 for testing the BalanceSeekBar.
+    // It affects the SeekBar value of center(100) and snapThreshold(200 * SNAP_TO_PERCENTAGE).
+    private static final int MAX_PROGRESS_VALUE = 200;
+
+    private Context mContext;
+    private AttributeSet mAttrs;
+    private BalanceSeekBar mSeekBar;
+    private BalanceSeekBar.OnSeekBarChangeListener mProxySeekBarListener;
+    private SeekBar.OnSeekBarChangeListener mockSeekBarChangeListener;
+
+    @Before
+    public void setUp() {
+        mContext = RuntimeEnvironment.application;
+        mSeekBar = new BalanceSeekBar(mContext, mAttrs);
+        mProxySeekBarListener = mSeekBar.getProxySeekBarListener();
+        mockSeekBarChangeListener = mock(SeekBar.OnSeekBarChangeListener.class);
+        mSeekBar.setOnSeekBarChangeListener(mockSeekBarChangeListener);
+    }
+
+    @Test
+    public void onStartTrackingTouch_shouldInvokeMethod() {
+        mProxySeekBarListener.onStartTrackingTouch(mSeekBar);
+
+        verify(mockSeekBarChangeListener, times(1)).onStartTrackingTouch(mSeekBar);
+    }
+
+    @Test
+    public void onStopTrackingTouch_shouldInvokeMethod() {
+        mProxySeekBarListener.onStopTrackingTouch(mSeekBar);
+
+        verify(mockSeekBarChangeListener, times(1)).onStopTrackingTouch(mSeekBar);
+    }
+
+    @Test
+    public void onProgressChanged_shouldInvokeMethod() {
+        // Assign the test value of SeekBar progress
+        mProxySeekBarListener.onProgressChanged(mSeekBar, MAX_PROGRESS_VALUE, true);
+
+        verify(mockSeekBarChangeListener, times(1)).onProgressChanged(eq(mSeekBar),
+                eq(MAX_PROGRESS_VALUE), eq(true));
+    }
+
+    @Test
+    public void setMaxTest_shouldSetValue() {
+        mSeekBar.setMax(MAX_PROGRESS_VALUE);
+
+        assertThat(getBalanceSeekBarCenter(mSeekBar)).isEqualTo(MAX_PROGRESS_VALUE / 2);
+        assertThat(getBalanceSeekBarSnapThreshold(mSeekBar)).isEqualTo(
+                MAX_PROGRESS_VALUE * BalanceSeekBar.SNAP_TO_PERCENTAGE);
+    }
+
+    @Test
+    public void setProgressTest_shouldSnapToCenter() {
+        // Assign the test value of SeekBar progress within the threshold (94-106 in this case).
+        final int progressWithinThreshold = 102;
+        mSeekBar.setMax(MAX_PROGRESS_VALUE);
+        mSeekBar.setProgress(progressWithinThreshold + 10); //set progress which is over threshold.
+        mProxySeekBarListener.onProgressChanged(mSeekBar, progressWithinThreshold, true);
+
+        assertThat(mSeekBar.getProgress()).isEqualTo(getBalanceSeekBarCenter(mSeekBar));
+    }
+
+    @Test
+    public void setProgressTest_shouldMaintainInputValue() {
+        // Assign the test value of SeekBar progress without the threshold.
+        final int progressWithoutThreshold = 107;
+        mSeekBar.setMax(MAX_PROGRESS_VALUE);
+        mSeekBar.setProgress(progressWithoutThreshold);
+        mProxySeekBarListener.onProgressChanged(mSeekBar, progressWithoutThreshold, true);
+
+        assertThat(mSeekBar.getProgress()).isEqualTo(progressWithoutThreshold);
+    }
+
+    // method to get the center from BalanceSeekBar for testing setMax().
+    private int getBalanceSeekBarCenter(BalanceSeekBar seekBar) {
+        return seekBar.getMax() / 2;
+    }
+
+    // method to get the snapThreshold from BalanceSeekBar for testing setMax().
+    private float getBalanceSeekBarSnapThreshold(BalanceSeekBar seekBar) {
+        return seekBar.getMax() * BalanceSeekBar.SNAP_TO_PERCENTAGE;
+    }
+}