Merge "Change the status bar clock's measuring scheme" into tm-dev am: e1e006e131

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18374715

Change-Id: Ia691ab6e1b5764a89f1c3e2e346488e239d3c899
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

packages/SystemUI/src/com/android/systemui/statusbar/policy/Clock.java

@@ -103,6 +103,10 @@ public class Clock extends TextView implements
     private boolean mShowSeconds;
     private Handler mSecondsHandler;
 
+    // Fields to cache the width so the clock remains at an approximately constant width
+    private int mCharsAtCurrentWidth = -1;
+    private int mCachedWidth = -1;
+
     /**
      * Color to be set on this {@link TextView}, when wallpaperTextColor is <b>not</b> utilized.
      */
@@ -302,6 +306,32 @@ public class Clock extends TextView implements
         setContentDescription(mContentDescriptionFormat.format(mCalendar.getTime()));
     }
 
+    /**
+     * In order to avoid the clock growing and shrinking due to proportional fonts, we want to
+     * cache the drawn width at a given number of characters (removing the cache when it changes),
+     * and only use the biggest value. This means that the clock width with grow to the maximum
+     * size over time, but reset whenever the number of characters changes (or the configuration
+     * changes)
+     */
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+
+        int chars = getText().length();
+        if (chars != mCharsAtCurrentWidth) {
+            mCharsAtCurrentWidth = chars;
+            mCachedWidth = getMeasuredWidth();
+            return;
+        }
+
+        int measuredWidth = getMeasuredWidth();
+        if (mCachedWidth > measuredWidth) {
+            setMeasuredDimension(mCachedWidth, getMeasuredHeight());
+        } else {
+            mCachedWidth = measuredWidth;
+        }
+    }
+
     @Override
     public void onTuningChanged(String key, String newValue) {
         if (CLOCK_SECONDS.equals(key)) {

packages/SystemUI/tests/src/com/android/systemui/statusbar/policy/ClockTest.kt

@@ -0,0 +1,130 @@
+/*
+ * 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.statusbar.policy
+
+import android.testing.AndroidTestingRunner
+import android.testing.TestableLooper
+import android.view.View.MeasureSpec.UNSPECIFIED
+import android.view.View.MeasureSpec.makeMeasureSpec
+import android.view.ViewGroup.LayoutParams.WRAP_CONTENT
+import android.widget.LinearLayout
+import androidx.test.filters.SmallTest
+import com.android.systemui.SysuiTestCase
+import org.junit.Before
+import org.junit.runner.RunWith
+
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+
+@SmallTest
+@RunWith(AndroidTestingRunner::class)
+@TestableLooper.RunWithLooper
+class ClockTest : SysuiTestCase() {
+    private lateinit var clockView: Clock
+
+    @Before
+    fun setUp() {
+        allowTestableLooperAsMainThread()
+        TestableLooper.get(this).runWithLooper {
+            val container = LinearLayout(context)
+            val lp = LinearLayout.LayoutParams(1000, WRAP_CONTENT)
+            container.layoutParams = lp
+            clockView = Clock(context, null)
+            container.addView(clockView)
+            measureClock()
+        }
+    }
+
+    @Test
+    fun testWidthDoesNotDecrease_sameCharLength() {
+        // GIVEN time is narrow
+        clockView.text = ONE_3
+        measureClock()
+        val width1 = clockView.measuredWidth
+
+        // WHEN the text changes to be wider characters
+        clockView.text = ZERO_3
+        measureClock()
+        val width2 = clockView.measuredWidth
+
+        // THEN the width should be wider (or equals when using monospace font)
+        assertThat(width2).isAtLeast(width1)
+    }
+
+    @Test
+    fun testWidthDoesNotDecrease_narrowerFont_sameNumberOfChars() {
+        // GIVEN time is wide
+        clockView.text = ZERO_3
+        measureClock()
+        val width1 = clockView.measuredWidth
+
+        // WHEN the text changes to a narrower font
+        clockView.text = ONE_3
+        measureClock()
+        val width2 = clockView.measuredWidth
+
+        // THEN the width should not have decreased, and they should in fact be the same
+        assertThat(width2).isEqualTo(width1)
+    }
+
+    @Test
+    fun testWidthIncreases_whenCharsChanges() {
+        // GIVEN wide 3-char text
+        clockView.text = ZERO_3
+        measureClock()
+        val width1 = clockView.measuredWidth
+
+        // WHEN text changes to 4-char wide text
+        clockView.text = ZERO_4
+        measureClock()
+        val width2 = clockView.measuredWidth
+
+        // THEN the text field is wider
+        assertThat(width2).isGreaterThan(width1)
+    }
+
+    @Test
+    fun testWidthDecreases_whenCharsChange_longToShort() {
+        // GIVEN wide 4-char text
+        clockView.text = ZERO_4
+        measureClock()
+        val width1 = clockView.measuredWidth
+
+        // WHEN number of characters changes to a narrow 3-char text
+        clockView.text = ONE_3
+        measureClock()
+        val width2 = clockView.measuredWidth
+
+        // THEN the width can shrink, because number of chars changed
+        assertThat(width2).isLessThan(width1)
+    }
+
+    private fun measureClock() {
+        clockView.measure(
+                makeMeasureSpec(0, UNSPECIFIED),
+                makeMeasureSpec(0, UNSPECIFIED)
+        )
+    }
+}
+
+/**
+ * In a non-monospace font, it is expected that "0:00" is wider than "1:11"
+ */
+private const val ZERO_3 = "0:00"
+private const val ZERO_4 = "00:00"
+private const val ONE_3 = "1:11"
+private const val ONE_4 = "11:11"