Update BaseChronometer and ChronometerDelegate with Chronometer source code in API 24

app/src/main/java/com/philliphsu/clock2/BaseChronometer.java

@@ -2,8 +2,6 @@ package com.philliphsu.clock2;
 
 import android.annotation.TargetApi;
 import android.content.Context;
-import android.os.Handler;
-import android.os.Message;
 import android.os.SystemClock;
 import android.util.AttributeSet;
 import android.util.Log;
@@ -34,11 +32,10 @@ public class BaseChronometer extends TextView {
     private boolean mVisible;
     private boolean mStarted;
     private boolean mRunning;
+    private long mTickInterval;
     private OnChronometerTickListener mOnChronometerTickListener;
     private final ChronometerDelegate mDelegate = new ChronometerDelegate();
 
-    private static final int TICK_WHAT = 2;
-
     /**
      * Initialize this Chronometer object.
      * Sets the base to the current time.
@@ -85,6 +82,7 @@ public class BaseChronometer extends TextView {
     private void init() {
         mDelegate.init();
         updateText(SystemClock.elapsedRealtime());
+        mTickInterval = 1000;
     }
 
     /**
@@ -96,6 +94,7 @@ public class BaseChronometer extends TextView {
      */
     public void setCountDown(boolean countDown) {
         mDelegate.setCountDown(countDown);
+        updateText(SystemClock.elapsedRealtime());
     }
 
     /**
@@ -119,7 +118,18 @@ public class BaseChronometer extends TextView {
      */
     public void setShowCentiseconds(boolean showCentiseconds, boolean applySizeSpan) {
         mDelegate.setShowCentiseconds(showCentiseconds, applySizeSpan);
-        init(); // Clear and update the text again
+        // Clear and update the text again. The reason we don't just update the text, as in
+        // setCountDown(), is that if showCentiseconds is true, we will be increasing the
+        // granularity of this time display; the time delta between the first
+        // setting of the base time (when this view is first instantiated), and the next call
+        // to updateText() is, while minuscule, significant enough that there would be some nonzero
+        // centiseconds value initially displayed. By resetting the timer, we minimize
+        // this time delta, and that should display an initial centiseconds value of zero.
+        init();
+        // ----------------------------------------------------------------------------
+        // TOneverDO: Precede init(), because init() resets mTickInterval to 1000.
+        mTickInterval = showCentiseconds ? 10 : 1000;
+        // ----------------------------------------------------------------------------
     }
 
     /**
@@ -268,31 +278,34 @@ public class BaseChronometer extends TextView {
     }
 
     private synchronized void updateText(long now) {
-        setText(mDelegate.formatElapsedTime(now));
+        setText(mDelegate.formatElapsedTime(now, getResources()));
     }
 
     private void updateRunning() {
-        boolean running = mVisible && mStarted;
+        // The isShown() check is new to the Chronometer source in API 24.
+        // It is preventing the chronometer in TimerViewHolder from ticking, so leave it off.
+        boolean running = mVisible && mStarted /*&& isShown()*/;
         if (running != mRunning) {
             if (running) {
                 Log.d(TAG, "Running");
                 updateText(SystemClock.elapsedRealtime());
                 dispatchChronometerTick();
-                mHandler.sendMessageDelayed(Message.obtain(mHandler, TICK_WHAT), 10);
+                postDelayed(mTickRunnable, mTickInterval);
             } else {
                 Log.d(TAG, "Not running anymore");
-                mHandler.removeMessages(TICK_WHAT);
+                removeCallbacks(mTickRunnable);
             }
             mRunning = running;
         }
     }
 
-    private Handler mHandler = new Handler() {
-        public void handleMessage(Message m) {
+    private final Runnable mTickRunnable = new Runnable() {
+        @Override
+        public void run() {
             if (mRunning) {
                 updateText(SystemClock.elapsedRealtime());
                 dispatchChronometerTick();
-                sendMessageDelayed(Message.obtain(this, TICK_WHAT), 10);
+                postDelayed(mTickRunnable, mTickInterval);
             }
         }
     };

app/src/main/java/com/philliphsu/clock2/timers/ChronometerDelegate.java

@@ -1,5 +1,6 @@
 package com.philliphsu.clock2.timers;
 
+import android.content.res.Resources;
 import android.os.SystemClock;
 import android.text.SpannableString;
 import android.text.Spanned;
@@ -8,6 +9,8 @@ import android.text.format.DateUtils;
 import android.text.style.RelativeSizeSpan;
 import android.util.Log;
 
+import com.philliphsu.clock2.R;
+
 import java.util.Formatter;
 import java.util.IllegalFormatException;
 import java.util.Locale;
@@ -77,10 +80,18 @@ public final class ChronometerDelegate {
         return mFormat;
     }
 
-    public CharSequence formatElapsedTime(long now) {
+    public CharSequence formatElapsedTime(long now, Resources resources) {
         mNow = now;
-        long millis = mCountDown ? mBase - now : now - mBase;
-        String text = DateUtils.formatElapsedTime(mRecycle, millis / 1000);
+        long seconds = mCountDown ? mBase - now : now - mBase;
+        boolean negative = false;
+        if (seconds < 0) {
+            seconds = -seconds;
+            negative = true;
+        }
+        String text = DateUtils.formatElapsedTime(mRecycle, seconds / 1000);
+        if (negative) {
+            text = resources.getString(R.string.negative_duration, text);
+        }
 
         Locale loc = Locale.getDefault();
         if (mFormat != null) {
@@ -101,7 +112,7 @@ public final class ChronometerDelegate {
             }
         }
         if (mShowCentiseconds) {
-            long centiseconds = (millis % 1000) / 10;
+            long centiseconds = (seconds % 1000) / 10;
             String centisecondsText = String.format(loc,
                     // TODO: Different locales use different decimal marks.
                     // The two most common are . and ,

app/src/main/java/com/philliphsu/clock2/timers/TimerNotificationService.java

@@ -211,7 +211,7 @@ public class TimerNotificationService extends Service {
     }
 
     private void updateNotification() {
-        CharSequence text = mCountdownDelegate.formatElapsedTime(SystemClock.elapsedRealtime());
+        CharSequence text = mCountdownDelegate.formatElapsedTime(SystemClock.elapsedRealtime(), getResources());
         mNoteBuilder.setContentText(text);
         mNotificationManager.notify(TAG, mTimer.getIntId(), mNoteBuilder.build());
     }

app/src/main/res/values/strings.xml

@@ -1,4 +1,4 @@
-<resources>
+<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
     <string name="app_name">Clock+2</string>
     <string name="action_settings">Settings</string>
     <string name="section_format">Hello World from section: %1$d</string>
@@ -206,4 +206,8 @@
 
     <string name="stopwatch">Stopwatch</string>
     <string name="lap">Lap</string>
+
+    <!-- https://android.googlesource.com/platform/frameworks/base/+/master/core/res/res/values/strings.xml -->
+    <!-- The representation of a time duration when negative. An example is -1:14. This can be used with a countdown timer for example.-->
+    <string name="negative_duration">\u2212<xliff:g id="time" example="1:14">%1$s</xliff:g></string>
 </resources>