回答編集履歴

修正

2022/01/05 16:50

投稿

jimbe

スコア12659

test CHANGED Viewed

@@ -8,7 +8,7 @@
 回答にしちゃったので、ついでに AndroidStudio のタブのプロジェクト雛形から、タイトルを修正・保存 (SharedPreferences) するコードを作りました。
-タブは TagLayout 、ビューページャは ViewPager2 、バインディングは嫌いなので外しています^^;
+タブは TagLayout 、ビューページャは ViewPager2 、ダイアログはフラグメント、バインディングは嫌いなので外しています^^;

コード追加

2022/01/05 16:50

投稿

jimbe

スコア12659

test CHANGED Viewed

@@ -1 +1,511 @@
 変更をどこかに保存して、再起動時にそれを読んで設定すれば良いのではと思います。
+----
+回答にしちゃったので、ついでに AndroidStudio のタブのプロジェクト雛形から、タイトルを修正・保存 (SharedPreferences) するコードを作りました。
+タブは TagLayout 、ビューページャは ViewPager2 、バインディングは嫌いなので外しています^^;
+MainActivity.java
+```java
+package com.teratail.q375388;
+import android.content.SharedPreferences;
+import android.os.Bundle;
+import android.view.*;
+import com.google.android.material.tabs.*;
+import androidx.appcompat.app.*;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.viewpager2.widget.ViewPager2;
+import com.teratail.q375388.ui.main.*;
+public class MainActivity extends AppCompatActivity implements View.OnLongClickListener, TabTitleChangeDialogFragment.Listener {
+  private SharedPreferences sharedPreferences;
+  private TabLayout tabLayout;
+  private PageViewModel pageViewModel;
+  @Override
+  protected void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    setContentView(R.layout.activity_main);
+    sharedPreferences = getSharedPreferences("TabTitles", MODE_PRIVATE);
+    pageViewModel = new ViewModelProvider(this).get(PageViewModel.class);
+    pageViewModel.restoreTabTitles(sharedPreferences, new String[]{
+        getString(R.string.tab_text_1), getString(R.string.tab_text_2)
+    });
+    ViewPager2 viewPager = findViewById(R.id.pager);
+    viewPager.setAdapter(new SectionsStateAdapter(this));
+    tabLayout = findViewById(R.id.tablayout);
+    new TabLayoutMediator(tabLayout, viewPager, (tab, position) -> tab.setText(pageViewModel.getTabTitle(position))).attach();
+    for(int i=0; i<tabLayout.getTabCount(); i++) {
+      View view = tabLayout.getTabAt(i).view;
+      view.setTag(i);
+      view.setOnLongClickListener(this);
+    }
+  }
+  @Override
+  public boolean onLongClick(View v) {
+    int tabIndex = (Integer)v.getTag();
+    String title = pageViewModel.getTabTitle(tabIndex);
+    TabTitleChangeDialogFragment dialog = TabTitleChangeDialogFragment.newInstance(tabIndex, title);
+    dialog.show(getSupportFragmentManager(), "TabTitleChangeDialogFragment");
+    return true;
+  }
+  @Override
+  public void onTabTitleChange(TabTitleChangeDialogFragment dialog) {
+    String title = dialog.getTitle();
+    int tabIndex = dialog.getTabIndex();
+    tabLayout.getTabAt(tabIndex).setText(title); //ここでタブの名前を変更
+    pageViewModel.setTabTitle(tabIndex, title);
+    pageViewModel.saveTabTitles(sharedPreferences);
+  }
+}
+```
+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.Q375388.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/tablayout"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content" />
+  </com.google.android.material.appbar.AppBarLayout>
+  <androidx.viewpager2.widget.ViewPager2
+      android:id="@+id/pager"
+      android:layout_width="match_parent"
+      android:layout_height="match_parent" />
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
+```
+ui.main.PageViewModel.java
+```java
+package com.teratail.q375388.ui.main;
+import android.content.SharedPreferences;
+import androidx.lifecycle.ViewModel;
+public class PageViewModel extends ViewModel {
+  private String[] tabTitles;
+  public String getTabTitle(int index) { return tabTitles[index]; }
+  public void setTabTitle(int index, String title) { tabTitles[index] = title; }
+  public void restoreTabTitles(SharedPreferences sharedPreferences, String[] defaultTitles) {
+    tabTitles = new String[defaultTitles.length];
+    if(sharedPreferences == null) {
+      for(int i=0; i<tabTitles.length; i++) {
+        tabTitles[i] = defaultTitles[i];
+      }
+    } else {
+      for(int i=0; i<tabTitles.length; i++) {
+        tabTitles[i] = sharedPreferences.getString(getPreferencesKey(i), defaultTitles[i]);
+      }
+    }
+  }
+  public void saveTabTitles(SharedPreferences sharedPreferences) {
+    SharedPreferences.Editor editor = sharedPreferences.edit();
+    editor.clear();
+    for(int i=0; i<tabTitles.length; i++) {
+      editor.putString(getPreferencesKey(i), tabTitles[i]);
+    }
+    editor.commit();
+  }
+  private String getPreferencesKey(int i) { return "tab"+(i+1); }
+}
+```
+ui.main.TabTitleChangeDialogFragment.java
+```java
+package com.teratail.q375388.ui.main;
+import android.app.Dialog;
+import android.content.*;
+import android.os.Bundle;
+import android.view.*;
+import android.widget.EditText;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AlertDialog;
+import androidx.fragment.app.*;
+import com.teratail.q375388.R;
+public class TabTitleChangeDialogFragment extends DialogFragment {
+  public interface Listener {
+    void onTabTitleChange(TabTitleChangeDialogFragment dialog);
+  }
+  private static final String ARGS_TAB_INDEX = "TabIndex";
+  private static final String ARGS_TITLE = "Title";
+  public static TabTitleChangeDialogFragment newInstance(int tabIndex, String title) {
+    TabTitleChangeDialogFragment dialog = new TabTitleChangeDialogFragment();
+    Bundle args = new Bundle();
+    args.putInt(ARGS_TAB_INDEX, tabIndex);
+    args.putString(ARGS_TITLE, title);
+    dialog.setArguments(args);
+    return dialog;
+  }
+  private int tabIndex;
+  private String title;
+  private Listener listener;
+  private EditText editText;
+  @Override
+  public void onCreate(@Nullable Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    Bundle args = getArguments();
+    tabIndex = args.getInt(ARGS_TAB_INDEX);
+    title = args.getString(ARGS_TITLE);
+  }
+  public int getTabIndex() { return tabIndex; }
+  public String getTitle() { return editText.getText().toString(); }
+  @Override
+  public void onAttach(Context context) {
+    super.onAttach(context);
+    try {
+      listener = (Listener)context;
+    } catch (ClassCastException e) {
+      throw new ClassCastException(context.toString() + " must implement TabTitleChangeDialogListener");
+    }
+  }
+  @Override
+  public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
+    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
+    LayoutInflater inflater = requireActivity().getLayoutInflater();
+    View inputView = inflater.inflate(R.layout.fragment_tab_title_change_dialog, null);
+    editText = inputView.findViewById(R.id.editText1);
+    editText.setText(title);
+    editText.requestFocus();
+    editText.setSelection(0, title.length());
+    builder.setView(inputView)
+        .setTitle("カテゴリ名変更")
+        .setPositiveButton("変更", new DialogInterface.OnClickListener() {
+          public void onClick(DialogInterface dialog, int id) {
+            listener.onTabTitleChange(TabTitleChangeDialogFragment.this);
+          }
+        })
+        .setNegativeButton("キャンセル", (dialog, id) -> TabTitleChangeDialogFragment.this.getDialog().cancel());
+    return builder.create();
+  }
+}
+```
+res/layout/fragment_tab_title_change_dialog.xml
+```xml
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout
+    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=".ui.main.TabTitleChangeDialogFragment">
+  <EditText
+      android:id="@+id/editText1"
+      android:layout_width="wrap_content"
+      android:layout_height="wrap_content"
+      android:ems="16"
+      android:singleLine="true"
+      app:layout_constraintLeft_toLeftOf="parent"
+      app:layout_constraintTop_toTopOf="parent" />
+</androidx.constraintlayout.widget.ConstraintLayout>
+```