CollapsingToolbarLayoutのスクロールが停止するのを防ぐ方法

Question

CoordinatorLayoutでは、スクロールが一番上になると停止します。したがって、ユーザーは画像を見るために再びスクロールする必要があります。イメージが完全に表示されるまでスクロールを続けることは可能ですか？

<android.support.design.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" 
android:fitsSystemWindows="true" 
tools:context="com.example.murat.coordinatorlayouttest.ScrollingActivity"> 

<android.support.design.widget.AppBarLayout 
    android:id="@+id/app_bar" 
    android:layout_width="match_parent" 
    android:layout_height="@dimen/app_bar_height" 
    android:fitsSystemWindows="true" 
    android:theme="@style/AppTheme.AppBarOverlay"> 

    <android.support.design.widget.CollapsingToolbarLayout 
     android:id="@+id/collapsing_toolbar" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:fitsSystemWindows="true" 
     app:contentScrim="?attr/colorPrimary" 
     app:expandedTitleMarginEnd="64dp" 
     app:expandedTitleMarginStart="48dp" 
     app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed"> 

     <android.support.v7.widget.Toolbar 
      android:id="@+id/toolbar" 
      android:layout_width="match_parent" 
      android:layout_height="?attr/actionBarSize" 
      app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed"/> 
     <ImageView 
      android:src="@drawable/poster" 
      app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:scaleType="centerCrop" 
      app:layout_collapseMode="parallax" 
      android:minHeight="200dp"/> 

    </android.support.design.widget.CollapsingToolbarLayout> 
</android.support.design.widget.AppBarLayout> 

<include layout="@layout/content_scrolling" /> 

Answer 1

あなたはNestedScrollViewの高さを計算する必要があります。最初にxmlレイアウトを更新し、ツールバーでこれらのプロパティを追加し、<includelayout="@layout/content_scrolling" />がNestedScrollViewで、スクロール表示の動作があることを確認します。

app:layout_scrollFlags="scroll|exitUntilCollapsed" 
app:layout_collapseMode="pin" 

アクティビティにこれらのグローバル変数を定義します。

private int screenHeight; 
    private int linearLayoutHeight; 
    private int toolbarHeight_org; 
    private int toolbarHeight; 

が活動のonCreateメソッドでこれを行います

screenHeight = getScreenHeight(this); 

    TypedValue typedValue = new TypedValue(); 
    getTheme().resolveAttribute(R.attr.colorPrimary, typedValue, true); 
    final int colorPrimary = typedValue.data; 

    final Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 
    getSupportActionBar().setDisplayHomeAsUpEnabled(true); 

    AppBarLayout appbar = (AppBarLayout) findViewById(R.id.appbar); 
    final CoordinatorLayout.LayoutParams appbarLayoutParams = (CoordinatorLayout.LayoutParams)appbar.getLayoutParams(); 

    final ViewGroup.LayoutParams toolbarLayoutParams = toolbar.getLayoutParams(); 
    if (toolbarLayoutParams != null) { 
     toolbarHeight_org = toolbarLayoutParams.height; 
     toolbarHeight = toolbarLayoutParams.height; 
    } 

    final CollapsingToolbarLayout collapsingToolbar = 
      (CollapsingToolbarLayout) findViewById(R.id.collapsing_toolbar); 
    collapsingToolbar.setTitle(cheeseName); 

    collapsingToolbar.setContentScrimColor(colorPrimary); 
    collapsingToolbar.setExpandedTitleTextAppearance(R.style.ExpandedTitleTextAppearance); 
    //collapsingToolbar.setCollapsedTitleTextAppearance(R.style.CollapsedTitleTextAppearance); 

    final LinearLayout linearLayout = (LinearLayout) findViewById(R.id.linearLayout1); 
    ViewTreeObserver observer = linearLayout.getViewTreeObserver(); 
    observer.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() { 
     @Override 
     public void onGlobalLayout() { 
      linearLayoutHeight = linearLayout.getHeight(); 
      if (linearLayoutHeight + toolbarHeight < screenHeight) { 
       if (toolbarLayoutParams != null) { 
        toolbarLayoutParams.height = screenHeight - linearLayoutHeight - 20; 
        if (toolbarLayoutParams.height < toolbarHeight_org) { 
         toolbarLayoutParams.height = toolbarHeight_org; 
        } 

        int extended_text_size = (int) getResources().getDimension(R.dimen.expanded_text_size); 

        if (appbarLayoutParams.height - toolbarLayoutParams.height <= extended_text_size) { 
         int value = appbarLayoutParams.height - toolbarLayoutParams.height; 
         if (value < 0) { 
          appbarLayoutParams.height = toolbarLayoutParams.height - value + extended_text_size * 3; 
         } else { 
          appbarLayoutParams.height = toolbarLayoutParams.height + extended_text_size * 3; 
         } 
         if (appbarLayoutParams.height >= screenHeight) { 
          appbarLayoutParams.height = screenHeight; 
         } 
        } 

        // collapsingToolbar.setContentScrimColor(getResources().getColor(android.R.color.transparent)); 
        if (toolbarLayoutParams.height > toolbarHeight_org) { 
         collapsingToolbar.setContentScrimColor(ContextCompat.getColor(mContext, android.R.color.transparent)); 
        } 
       } 
      } 
      // Removes the listener if possible 
      ViewTreeObserver viewTreeObserver = linearLayout.getViewTreeObserver(); 
      if (viewTreeObserver.isAlive()) { 
       if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) { 
        linearLayout.getViewTreeObserver().removeGlobalOnLayoutListener(this); 
       } else { 
        linearLayout.getViewTreeObserver().removeOnGlobalLayoutListener(this); 
       } 
      } 
     } 
    }); 
    appbar.setExpanded(true); 
} 

取得画面の高さの方法は、ここで

private int getScreenHeight(Context context) { 
    int measuredHeight; 
    Point size = new Point(); 
    WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); 

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) { 
     wm.getDefaultDisplay().getSize(size); 
     measuredHeight = size.y; 
    } else { 
     Display d = wm.getDefaultDisplay(); 
     measuredHeight = d.getHeight(); 
    } 

    return measuredHeight; 
} 

は親切にこの

に応じてあなたを更新活動の完全なXMLレイアウトであります

<android.support.design.widget.AppBarLayout 
    android:id="@+id/appbar" 
    android:layout_width="match_parent" 
    android:layout_height="@dimen/detail_backdrop_height" 
    android:fitsSystemWindows="true" 
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"> 

    <android.support.design.widget.CollapsingToolbarLayout 
     android:id="@+id/collapsing_toolbar" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:fitsSystemWindows="true" 
     app:contentScrim="?attr/colorPrimary" 
     app:layout_scrollFlags="scroll|exitUntilCollapsed"> 

     <ImageView 
      android:id="@+id/backdrop" 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:fitsSystemWindows="false" 
      android:scaleType="centerCrop" 
      app:layout_collapseMode="parallax" /> 

     <android.support.v7.widget.Toolbar 
      android:id="@+id/toolbar" 
      android:layout_width="match_parent" 
      android:layout_height="?attr/actionBarSize" 
      app:layout_collapseMode="pin" 
      app:popupTheme="@style/ThemeOverlay.AppCompat.Light" /> 

    </android.support.design.widget.CollapsingToolbarLayout> 

</android.support.design.widget.AppBarLayout> 

<android.support.v4.widget.NestedScrollView 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content"    
    app:layout_behavior="@string/appbar_scrolling_view_behavior"> 

    <LinearLayout 
     android:id="@+id/linearLayout1" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:orientation="vertical"> 

     <android.support.v7.widget.CardView 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:layout_margin="@dimen/card_margin"> 

      <LinearLayout 
       style="@style/Widget.CardContent" 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content"> 

       <TextView 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:text="Info" 
        android:textAppearance="@style/TextAppearance.AppCompat.Title" /> 

       <TextView 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:text="@string/cheese_ipsum" /> 

      </LinearLayout> 

     </android.support.v7.widget.CardView> 

    </LinearLayout> 

</android.support.v4.widget.NestedScrollView>