回答編集履歴

private 化し忘れ

2021/12/14 10:38

投稿

jimbe

スコア13209

test CHANGED Viewed

@@ -38,7 +38,7 @@
 public class MainActivity extends AppCompatActivity {
-  MainViewModel vm;
+  private MainViewModel vm;

リストコピーに修正

2021/12/14 10:38

投稿

jimbe

スコア13209

test CHANGED Viewed

@@ -328,9 +328,7 @@
-  private List<RawData> rawDataList = new ArrayList<>();
-  private MutableLiveData<List<RawData>> rawDataLiveData = new MutableLiveData<>(Collections.unmodifiableList(rawDataList));
+  private MutableLiveData<List<RawData>> rawDataLiveData = new MutableLiveData<>(Collections.emptyList());
   LiveData<List<RawData>> getValue() {
@@ -342,11 +340,13 @@
   void setValue(long time, float value) {
+    List<RawData> newList = new ArrayList(rawDataLiveData.getValue());
-    rawDataList.add(new RawData(time, value));
+    newList.add(new RawData(time, value));
-    while(rawDataList.size() > DATA_COUNT_MAX) rawDataList.remove(0);
+    while(newList.size() > DATA_COUNT_MAX) newList.remove(0);
-    rawDataLiveData.setValue(rawDataLiveData.getValue());
+    rawDataLiveData.setValue(Collections.unmodifiableList(newList));
   }

nullポインタの可能性とマルチスレッドで危ないかもしれない点を少し修正(本当はcopyか...)

2021/12/13 18:53

投稿

jimbe

スコア13209

test CHANGED Viewed

@@ -2,6 +2,8 @@
 MPAndroidChart の仕様を確認していませんので、 setEntries のデータの更新部分が(MPAndroidChart を分かっている人からすると)ダメかもしれません。
+ViewPager を ViewPager2 にしています。
 MainActivity.java
@@ -12,65 +14,447 @@
+import android.os.*;
+import android.util.Log;
+import com.google.android.material.tabs.*;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.viewpager2.widget.ViewPager2;
+import java.util.Random;
+public class MainActivity extends AppCompatActivity {
+  MainViewModel vm;
+  @Override
+  protected void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    setContentView(R.layout.activity_main);
+    vm = new ViewModelProvider(this).get(MainViewModel.class);
+    ViewPager2 viewPager2 = findViewById(R.id.view_pager2);
+    viewPager2.setAdapter(new MainPagerAdapter(this));
+    TabLayout tabLayout = findViewById(R.id.tab_layout);
+    new TabLayoutMediator(tabLayout, viewPager2,
+            (tab,position) -> tab.setText(MainPagerAdapter.TAB_TITLES[position]) //タブタイトル
+    ).attach();
+    feedMultiple();
+  }
+  @Override
+  protected void onDestroy() {
+    super.onDestroy();
+    if (thread != null) thread.interrupt();
+  }
+  private Thread thread;
+  void feedMultiple() {
+    if (thread != null) thread.interrupt();
+    Handler handler = new Handler(getMainLooper());
+    thread = new Thread(new Runnable() {
+      Random random = new Random();
+      @Override
+      public void run() {
+        Log.d("","start.");
+        for (int i=0; i<MainViewModel.DATA_COUNT_MAX*2; i++) {
+          long time = System.currentTimeMillis();
+          float value = (float)(Math.random()*40);
+          handler.post(() -> vm.setValue(time, value));
+          try {
+            Thread.sleep(1000);
+          } catch (InterruptedException e) {
+            break;
+          }
+        }
+        Log.d("","end.");
+      }
+    });
+    thread.start();
+  }
+}
+```
+res/layout/activity_main.xml
+```xml
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.coordinatorlayout.widget.CoordinatorLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".MainActivity">
+  <com.google.android.material.appbar.AppBarLayout
+      android:layout_width="match_parent"
+      android:layout_height="wrap_content"
+      android:theme="@style/Theme.Q371702.AppBarOverlay">
+    <TextView
+        android:id="@+id/title"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:gravity="center"
+        android:minHeight="?actionBarSize"
+        android:padding="@dimen/appbar_padding"
+        android:text="@string/app_name"
+        android:textAppearance="@style/TextAppearance.Widget.AppCompat.Toolbar.Title" />
+    <com.google.android.material.tabs.TabLayout
+        android:id="@+id/tab_layout"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content" />
+  </com.google.android.material.appbar.AppBarLayout>
+  <androidx.viewpager2.widget.ViewPager2
+      android:id="@+id/view_pager2"
+      android:layout_width="match_parent"
+      android:layout_height="match_parent"
+      app:layout_behavior="@string/appbar_scrolling_view_behavior" />
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
+```
+MainPagerAdapter.java
+```java
+package com.teratail.q371702;
+import androidx.annotation.*;
+import androidx.fragment.app.*;
+import androidx.viewpager2.adapter.FragmentStateAdapter;
+public class MainPagerAdapter extends FragmentStateAdapter {
+  static final String TAB_TITLES[] = new String[]{"TAB A","TAB B","Graph"};
+  public MainPagerAdapter(FragmentActivity fa) {
+    super(fa);
+  }
+  @NonNull
+  @Override
+  public Fragment createFragment(int position) {
+    switch(position) {
+      default: return new DummyFragment();
+      case 0: return new ControlFragment();
+      case 2: return new GraphFragment();
+    }
+  }
+  @Override
+  public int getItemCount() {
+    return TAB_TITLES.length;
+  }
+}
+```
+MainViewModel.java
+```java
+package com.teratail.q371702;
+import androidx.lifecycle.*;
+import java.util.*;
+class RawData {
+  final long time;
+  final float value;
+  RawData(long time, float value) {
+    this.time = time;
+    this.value = value;
+  }
+}
+public class MainViewModel extends ViewModel {
+  static final int DATA_COUNT_MAX = 120;
+  private List<RawData> rawDataList = new ArrayList<>();
+  private MutableLiveData<List<RawData>> rawDataLiveData = new MutableLiveData<>(Collections.unmodifiableList(rawDataList));
+  LiveData<List<RawData>> getValue() {
+    return rawDataLiveData;
+  }
+  void setValue(long time, float value) {
+    rawDataList.add(new RawData(time, value));
+    while(rawDataList.size() > DATA_COUNT_MAX) rawDataList.remove(0);
+    rawDataLiveData.setValue(rawDataLiveData.getValue());
+  }
+}
+```
+GraphFragment.java
+```java
+package com.teratail.q371702;
+import android.graphics.Color;
 import android.os.Bundle;
+import android.view.LayoutInflater;
-import android.util.Log;
+import android.view.View;
+import android.view.ViewGroup;
+import androidx.annotation.NonNull;
-import com.google.android.material.tabs.*;
+import androidx.annotation.Nullable;
-import androidx.appcompat.app.AppCompatActivity;
+import androidx.fragment.app.Fragment;
 import androidx.lifecycle.ViewModelProvider;
+import com.github.mikephil.charting.charts.LineChart;
+import com.github.mikephil.charting.components.XAxis;
+import com.github.mikephil.charting.components.YAxis;
+import com.github.mikephil.charting.components.YAxis.AxisDependency;
+import com.github.mikephil.charting.data.Entry;
+import com.github.mikephil.charting.data.LineData;
-import androidx.viewpager2.widget.ViewPager2;
+import com.github.mikephil.charting.data.LineDataSet;
+import com.github.mikephil.charting.formatter.ValueFormatter;
+import com.github.mikephil.charting.utils.ColorTemplate;
+import java.text.SimpleDateFormat;
-import java.util.Random;
+import java.util.*;
-public class MainActivity extends AppCompatActivity {
+public class GraphFragment extends Fragment {
-  MainViewModel vm;
+  private MainViewModel mainViewModel;
+  private LineChart chart;
+  private static class DateXAxisFormatter extends ValueFormatter {
+    private SimpleDateFormat sdf = new SimpleDateFormat("MM:dd:ss");
+    private List<Long> xAxis = new ArrayList<>();
+    void clear() { xAxis.clear(); }
+    void add(long time) { xAxis.add(time); }
+    @Override
+    public String getFormattedValue(float value){
+      int i = (int)value;
+      if(i < 0 || xAxis.size() <= i) return "-"; //ガード
+      return sdf.format(new Date(xAxis.get(i)));
+    }
+  }
+  private DateXAxisFormatter dateXAxisFormatter = new DateXAxisFormatter();
   @Override
-  protected void onCreate(Bundle savedInstanceState) {
+  public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-    super.onCreate(savedInstanceState);
-    setContentView(R.layout.activity_main);
+    return inflater.inflate(R.layout.fragment_graph, container, false);
-    vm = new ViewModelProvider(this).get(MainViewModel.class);
-    ViewPager2 viewPager2 = findViewById(R.id.view_pager2);
-    viewPager2.setAdapter(new MainPagerAdapter(this));
-    TabLayout tabLayout = findViewById(R.id.tab_layout);
-    new TabLayoutMediator(tabLayout, viewPager2,
-            (tab,position) -> tab.setText(MainPagerAdapter.TAB_TITLES[position]) //タブタイトル
-    ).attach();
-    feedMultiple();
   }
@@ -78,59 +462,155 @@
   @Override
-  protected void onDestroy() {
-    super.onDestroy();
-    if (thread != null) thread.interrupt();
-  }
-  private Thread thread;
-  void feedMultiple() {
-    if (thread != null) thread.interrupt();
-    thread = new Thread(new Runnable() {
-      Random random = new Random();
-      @Override
-      public void run() {
-        Log.d("","start.");
-        for (int i=0; i<120*2; i++) {
-          vm.postValue(System.currentTimeMillis(), (float)(Math.random()*40));
-          try {
-            Thread.sleep(1000);
-          } catch (InterruptedException e) {
-            break;
-          }
-        }
-        Log.d("","end.");
+  public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+    super.onViewCreated(view, savedInstanceState);
+    mainViewModel = new ViewModelProvider(requireActivity()).get(MainViewModel.class);
+    mainViewModel.getValue().observe(getViewLifecycleOwner(), rawDataList -> setEntries(rawDataList));
+    chart = view.findViewById(R.id.line_chart);
+    initChart();
+  }
+  public void initChart(){
+    chart.getDescription().setEnabled(true);
+    chart.setTouchEnabled(true);
+    chart.setDragEnabled(true);
+    chart.setScaleEnabled(true);
+    chart.setDrawGridBackground(false);
+    chart.setPinchZoom(true);
+    chart.setBackgroundColor(Color.LTGRAY);
+    LineData data = new LineData();
+    data.setValueTextColor(Color.WHITE);
+    chart.setData(data);
+    XAxis xl = chart.getXAxis();
+    xl.setTextColor(Color.WHITE);
+    xl.setDrawGridLines(false);
+    xl.setAvoidFirstLastClipping(true);
+    xl.setEnabled(true);
+    xl.setValueFormatter(dateXAxisFormatter); //X軸のラベルを時刻にする
+    YAxis leftAxis = chart.getAxisLeft();
+    leftAxis.setTextColor(Color.WHITE);
+    leftAxis.setAxisMaximum(100f);
+    leftAxis.setAxisMinimum(0f);
+    leftAxis.setDrawGridLines(true);
+    YAxis rightAxis = chart.getAxisRight();
+    rightAxis.setEnabled(false);
+  }
+  public void setEntries(List<RawData> rawDataList) {
+    LineData data = chart.getData();
+    if(data != null) {
+      data.clearValues();
+      data.addDataSet(createSet());
+      dateXAxisFormatter.clear();
+      for(int i=0; i<rawDataList.size(); i++) {
+        RawData rawData = rawDataList.get(i);
+        dateXAxisFormatter.add(rawData.time);
+        data.addEntry(new Entry(i, rawData.value), 0);
       }
+      data.notifyDataChanged();
+      chart.notifyDataSetChanged();
+      chart.setVisibleXRangeMaximum(MainViewModel.DATA_COUNT_MAX);
+      chart.moveViewToX(data.getEntryCount());
-    });
+    }
+  }
+  private LineDataSet createSet() {
+    LineDataSet set = new LineDataSet(null, "Dynamic Data");
+    set.setAxisDependency(AxisDependency.LEFT);
+    set.setColor(ColorTemplate.getHoloBlue());
+    set.setCircleColor(Color.WHITE);
-    thread.start();
+    set.setLineWidth(2f);
+    set.setCircleRadius(4f);
+    set.setFillAlpha(65);
+    set.setFillColor(ColorTemplate.getHoloBlue());
+    set.setHighLightColor(Color.rgb(244, 117, 117));
+    set.setValueTextColor(Color.WHITE);
+    set.setValueTextSize(9f);
+    set.setDrawValues(false);
+    return set;
   }
@@ -138,498 +618,24 @@
 ```
-res/layout/activity_main.xml
+res/layout/fragment_graph.xml
 ```xml
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.coordinatorlayout.widget.CoordinatorLayout
+<com.github.mikephil.charting.charts.LineChart
     xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/line_chart"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    tools:context=".MainActivity">
-  <com.google.android.material.appbar.AppBarLayout
-      android:layout_width="match_parent"
-      android:layout_height="wrap_content"
-      android:theme="@style/Theme.Q371702.AppBarOverlay">
-    <TextView
-        android:id="@+id/title"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:gravity="center"
-        android:minHeight="?actionBarSize"
-        android:padding="@dimen/appbar_padding"
-        android:text="@string/app_name"
-        android:textAppearance="@style/TextAppearance.Widget.AppCompat.Toolbar.Title" />
-    <com.google.android.material.tabs.TabLayout
-        android:id="@+id/tab_layout"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content" />
+    android:layout_height="match_parent" />
-  </com.google.android.material.appbar.AppBarLayout>
-  <androidx.viewpager2.widget.ViewPager2
-      android:id="@+id/view_pager2"
-      android:layout_width="match_parent"
-      android:layout_height="match_parent"
-      app:layout_behavior="@string/appbar_scrolling_view_behavior" />
-</androidx.coordinatorlayout.widget.CoordinatorLayout>
 ```
-MainPagerAdapter.java
-```java
-package com.teratail.q371702;
-import androidx.annotation.*;
-import androidx.fragment.app.*;
-import androidx.viewpager2.adapter.FragmentStateAdapter;
-public class MainPagerAdapter extends FragmentStateAdapter {
-  static final String TAB_TITLES[] = new String[]{"TAB A","TAB B","Graph"};
-  public MainPagerAdapter(FragmentActivity fa) {
-    super(fa);
-  }
-  @NonNull
-  @Override
-  public Fragment createFragment(int position) {
-    switch(position) {
-      default: return new DummyFragment();
-      case 0: return new ControlFragment();
-      case 2: return new GraphFragment();
-    }
-  }
-  @Override
-  public int getItemCount() {
-    return TAB_TITLES.length;
-  }
-}
-```
-MainViewModel.java
-```java
-package com.teratail.q371702;
-import androidx.lifecycle.*;
-import java.util.*;
-class RawData {
-  final long time;
-  final float value;
-  RawData(long time, float value) {
-    this.time = time;
-    this.value = value;
-  }
-}
-public class MainViewModel extends ViewModel {
-  static final int DATA_COUNT_MAX = 120;
-  private List<RawData> rawDataList = new ArrayList<>();
-  private MutableLiveData<List<RawData>> rawDataLiveData = new MutableLiveData<>();
-  LiveData<List<RawData>> getValue() {
-    return rawDataLiveData;
-  }
-  void postValue(long time, float value) {
-    rawDataList.add(new RawData(time, value));
-    while(rawDataList.size() > DATA_COUNT_MAX) rawDataList.remove(0);
-    rawDataLiveData.postValue(Collections.unmodifiableList(rawDataList)); //UIスレッドで実行させる
-  }
-}
-```
-GraphFragment.java
-```java
-package com.teratail.q371702;
-import android.graphics.Color;
-import android.os.Bundle;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import androidx.fragment.app.Fragment;
-import androidx.lifecycle.ViewModelProvider;
-import com.github.mikephil.charting.charts.LineChart;
-import com.github.mikephil.charting.components.XAxis;
-import com.github.mikephil.charting.components.YAxis;
-import com.github.mikephil.charting.components.YAxis.AxisDependency;
-import com.github.mikephil.charting.data.Entry;
-import com.github.mikephil.charting.data.LineData;
-import com.github.mikephil.charting.data.LineDataSet;
-import com.github.mikephil.charting.formatter.ValueFormatter;
-import com.github.mikephil.charting.utils.ColorTemplate;
-import java.text.SimpleDateFormat;
-import java.util.*;
-public class GraphFragment extends Fragment {
-  private MainViewModel mainViewModel;
-  private LineChart chart;
-  private static class DateXAxisFormatter extends ValueFormatter {
-    private SimpleDateFormat sdf = new SimpleDateFormat("MM:dd:ss");
-    private List<Long> xAxis = new ArrayList<>();
-    void clear() { xAxis.clear(); }
-    void add(long time) { xAxis.add(time); }
-    @Override
-    public String getFormattedValue(float value){
-      int i = (int)value;
-      if(i < 0 || xAxis.size() <= i) return "-"; //ガード
-      return sdf.format(new Date(xAxis.get(i)));
-    }
-  }
-  private DateXAxisFormatter dateXAxisFormatter = new DateXAxisFormatter();
-  @Override
-  public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-    return inflater.inflate(R.layout.fragment_graph, container, false);
-  }
-  @Override
-  public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
-    super.onViewCreated(view, savedInstanceState);
-    mainViewModel = new ViewModelProvider(requireActivity()).get(MainViewModel.class);
-    mainViewModel.getValue().observe(getViewLifecycleOwner(), rawDataList -> setEntries(rawDataList));
-    chart = view.findViewById(R.id.line_chart);
-    initChart();
-  }
-  public void initChart(){
-    chart.getDescription().setEnabled(true);
-    chart.setTouchEnabled(true);
-    chart.setDragEnabled(true);
-    chart.setScaleEnabled(true);
-    chart.setDrawGridBackground(false);
-    chart.setPinchZoom(true);
-    chart.setBackgroundColor(Color.LTGRAY);
-    LineData data = new LineData();
-    data.setValueTextColor(Color.WHITE);
-    chart.setData(data);
-    XAxis xl = chart.getXAxis();
-    xl.setTextColor(Color.WHITE);
-    xl.setDrawGridLines(false);
-    xl.setAvoidFirstLastClipping(true);
-    xl.setEnabled(true);
-    xl.setValueFormatter(dateXAxisFormatter); //X軸のラベルを時刻にする
-    YAxis leftAxis = chart.getAxisLeft();
-    leftAxis.setTextColor(Color.WHITE);
-    leftAxis.setAxisMaximum(100f);
-    leftAxis.setAxisMinimum(0f);
-    leftAxis.setDrawGridLines(true);
-    YAxis rightAxis = chart.getAxisRight();
-    rightAxis.setEnabled(false);
-  }
-  public void setEntries(List<RawData> rawDataList) {
-    LineData data = chart.getData();
-    if(data != null) {
-      data.clearValues();
-      data.addDataSet(createSet());
-      dateXAxisFormatter.clear();
-      for(int i=0; i<rawDataList.size(); i++) {
-        RawData rawData = rawDataList.get(i);
-        dateXAxisFormatter.add(rawData.time);
-        data.addEntry(new Entry(i, rawData.value), 0);
-      }
-      data.notifyDataChanged();
-      chart.notifyDataSetChanged();
-      chart.setVisibleXRangeMaximum(MainViewModel.DATA_COUNT_MAX);
-      chart.moveViewToX(data.getEntryCount());
-    }
-  }
-  private LineDataSet createSet() {
-    LineDataSet set = new LineDataSet(null, "Dynamic Data");
-    set.setAxisDependency(AxisDependency.LEFT);
-    set.setColor(ColorTemplate.getHoloBlue());
-    set.setCircleColor(Color.WHITE);
-    set.setLineWidth(2f);
-    set.setCircleRadius(4f);
-    set.setFillAlpha(65);
-    set.setFillColor(ColorTemplate.getHoloBlue());
-    set.setHighLightColor(Color.rgb(244, 117, 117));
-    set.setValueTextColor(Color.WHITE);
-    set.setValueTextSize(9f);
-    set.setDrawValues(false);
-    return set;
-  }
-}
-```
-res/layout/fragment_graph.xml
-```xml
-<?xml version="1.0" encoding="utf-8"?>
-<com.github.mikephil.charting.charts.LineChart
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    android:id="@+id/line_chart"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent" />
-```
 ※ DummyFragment, ControlFragment のコード・レイアウトは省略