带有 CollapsingToolbarLayout 的布局之间的 FloatingActionButton

Question

我想在两个具有不同高度的布局之间添加一个浮动操作按钮，以获得如下效果：

这是我的布局，但可能过于复杂：

<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"
    android:theme="@style/AppTheme.NoActionBar">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar_layout"
        android:layout_width="match_parent"
        android:layout_height="250dp"
        android:fitsSystemWindows="true"
        android:theme="@style/ThemeOverlay.AppCompat.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="@color/color_primary"
            app:scrimAnimationDuration="300"
            app:titleEnabled="false"
            app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed">

            <ImageView
                android:id="@+id/trailer"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical"
                android:fitsSystemWindows="true"
                tools:ignore="ContentDescription" />

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

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

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

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

            <android.support.constraint.ConstraintLayout
                android:layout_width="match_parent"
                android:layout_height="150dp"
                android:background="@color/color_primary"
                android:elevation="16.0dp">

                <com.est.streamcorn.views.AspectRatioImageView
                    android:id="@+id/image"
                    android:layout_width="150dp"
                    android:layout_height="wrap_content"
                    app:layout_constraintTop_toTopOf="parent"
                    app:layout_constraintBottom_toBottomOf="parent"
                    android:scaleType="centerInside"
                    android:theme="@style/MoviePosterImage"
                    tools:ignore="ContentDescription"
                    app:elevation="6dp"/>

                <android.support.design.widget.FloatingActionButton
                    android:id="@+id/play"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:clickable="true"
                    android:focusable="true"
                    android:elevation="6dp"
                    app:srcCompat="@drawable/player_action_play"
                    app:layout_constraintTop_toBottomOf="parent"
                    app:layout_constraintBottom_toBottomOf="parent"
                    app:layout_constraintEnd_toEndOf="parent"/>

                <TextView
                    android:id="@+id/title"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    app:layout_constraintTop_toBottomOf="parent"
                    app:layout_constraintStart_toEndOf="@id/image"/>

                <TextView
                    android:id="@+id/link1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    app:layout_constraintTop_toBottomOf="@id/title"
                    app:layout_constraintStart_toEndOf="@id/image"/>

            </android.support.constraint.ConstraintLayout>

            <android.support.constraint.ConstraintLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent">

                <TextView
                    android:id="@+id/text2"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </android.support.constraint.ConstraintLayout>

        </LinearLayout>

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

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

我发现的所有示例都将浮动按钮锚定到协调器布局，但我希望像 NestedScrollView 中的其他元素一样将其固定。 Mybe 有没有更好的方法来完成不同的颜色和高度而不需要两种不同的布局？

Answer 1

最后我做到了：

这是布局：

<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"
    android:background="@color/colorPrimaryReverse"
    android:theme="@style/AppTheme.NoActionBar">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar_layout"
        android:layout_width="match_parent"
        android:layout_height="220dp"
        android:fitsSystemWindows="true"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar">

        <com.est.streamcorn.views.CustomCollapsingToolbarLayout
            android:id="@+id/collapsing_toolbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:scrimAnimationDuration="250"
            app:titleEnabled="false"
            app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed">

            <ImageView
                android:id="@+id/trailer"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical"
                android:scaleType="centerCrop"
                tools:ignore="ContentDescription"
                android:fitsSystemWindows="true"
                app:layout_collapseMode="parallax"/>

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

                <TextView
                    android:id="@+id/toolbar_title"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:singleLine="true"
                    android:ellipsize="end"
                    android:layout_marginEnd="5dp"
                    style="@style/TextAppearance.AppCompat.Widget.ActionBar.Title" />

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

        </com.est.streamcorn.views.CustomCollapsingToolbarLayout>

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

    <android.support.v4.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:behavior_overlapTop="40dp"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" >

        <android.support.design.widget.CoordinatorLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <android.support.design.widget.FloatingActionButton
                android:id="@+id/play"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:clickable="true"
                android:focusable="true"
                android:layout_margin="20dp"
                app:elevation="6dp"
                app:srcCompat="@drawable/player_action_play"
                app:backgroundTint="@color/colorAccent"
                app:layout_anchor="@id/header"
                app:layout_anchorGravity="bottom|right|end"/>

            <android.support.v7.widget.CardView
                android:id="@+id/image_container"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="15dp"
                app:cardElevation="6dp"
                app:cardCornerRadius="6dp"
                app:layout_anchor="@id/header"
                app:layout_anchorGravity="top|left|start">

                <com.est.streamcorn.views.AspectRatioImageView
                    android:id="@+id/image"
                    android:layout_width="110dp"
                    android:layout_height="wrap_content"
                    android:scaleType="centerCrop"
                    tools:ignore="ContentDescription"
                    app:aspectRatio="@dimen/movie_poster_aspect_ratio" />

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

            <FrameLayout
                android:id="@+id/header"
                android:layout_width="match_parent"
                android:layout_height="170dp"
                android:background="@android:color/transparent"
                android:elevation="4.0dp">

                <android.support.constraint.ConstraintLayout
                    android:layout_width="match_parent"
                    android:layout_height="130dp"
                    android:background="@color/colorPrimaryReverse"
                    android:orientation="vertical"
                    android:layout_gravity="bottom"
                    android:layout_marginBottom="0dp"
                    android:paddingEnd="0dp"
                    android:paddingStart="135dp">

                    <TextView
                        android:id="@+id/title"
                        android:layout_width="0dp"
                        android:layout_height="wrap_content"
                        android:layout_marginBottom="5dp"
                        android:ellipsize="end"
                        android:maxLines="2"
                        android:singleLine="false"
                        android:textAppearance="@style/MovieDetail.Title"
                        app:layout_constraintBottom_toTopOf="@id/text1"
                        app:layout_constraintStart_toStartOf="parent"
                        app:layout_constraintEnd_toStartOf="@id/download"
                        app:layout_constraintHorizontal_weight="0"
                        tools:text="The Martian - A Test Movie As Placeholder" />

                    <TextView
                        android:id="@+id/text1"
                        android:layout_width="0dp"
                        android:layout_height="wrap_content"
                        android:ellipsize="end"
                        android:singleLine="true"
                        android:textAppearance="@style/MovieDetail.Text1"
                        app:layout_constraintBottom_toTopOf="@id/text2"
                        app:layout_constraintStart_toStartOf="parent"
                        app:layout_constraintEnd_toStartOf="@id/download"
                        android:layout_marginBottom="5dp"
                        tools:text="2015" />

                    <TextView
                        android:id="@+id/text2"
                        android:layout_width="0dp"
                        android:layout_height="wrap_content"
                        android:ellipsize="end"
                        android:singleLine="true"
                        android:textAppearance="@style/MovieDetail.Text2"
                        app:layout_constraintBottom_toBottomOf="parent"
                        app:layout_constraintStart_toStartOf="parent"
                        app:layout_constraintEnd_toStartOf="@id/download"
                        android:layout_marginBottom="15dp"
                        tools:text="141 minutes" />

                    <android.support.design.widget.FloatingActionButton
                        android:id="@+id/download"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginEnd="20dp"
                        android:background="@android:color/transparent"
                        app:layout_constraintBottom_toBottomOf="@id/title"
                        app:layout_constraintTop_toTopOf="@id/title"
                        app:layout_constraintEnd_toEndOf="parent"
                        app:backgroundTint="@android:color/transparent"
                        app:borderWidth="0dp"
                        app:elevation="0dp"
                        app:srcCompat="@drawable/ic_download"
                        tools:ignore="ContentDescription" />

                </android.support.constraint.ConstraintLayout>

            </FrameLayout>

            <LinearLayout
                android:id="@+id/content"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_marginTop="150dp"
                android:background="@color/backgroundColorReverse"
                android:orientation="vertical"
                android:paddingEnd="15dp"
                android:paddingStart="15dp"
                android:paddingTop="60dp">

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginBottom="10dp"
                    android:textSize="16sp"
                    android:textAllCaps="true"
                    android:textColor="@color/textColorPrimaryReverse"
                    android:text="@string/description" />

                <TextView
                    android:id="@+id/description"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"/>
            </LinearLayout>

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

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

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

自定义视图：

public class CustomCollapsingToolbarLayout extends CollapsingToolbarLayout {

    private Boolean previousShowing = true;

    public static interface Listener {
        public void onContentScrimAnimationStarted(boolean showing);
    }

    private Listener mListener;

    public CustomCollapsingToolbarLayout(Context context) {
        super(context);
    }

    public CustomCollapsingToolbarLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomCollapsingToolbarLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    public void setScrimsShown(boolean shown, boolean animate) {
        super.setScrimsShown(shown, animate);
        if (animate && mListener != null && shown != previousShowing) {
            mListener.onContentScrimAnimationStarted(shown);
            previousShowing = shown;
        }
    }

    public void setListener(Listener listener) {
        mListener = listener;
    }
}

在活动OnCreate：

    setSupportActionBar(toolbar);
    getSupportActionBar().setTitle("");
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setDisplayShowHomeEnabled(true);

    TypedValue tv = new TypedValue();
    getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true);
    final int actionBarHeight = getResources().getDimensionPixelSize(tv.resourceId);
    collapsingToolbarLayout.setScrimVisibleHeightTrigger(actionBarHeight + 100);
    collapsingToolbarLayout.setListener(showing -> {
        if(showing){
            toolbarTitle.setVisibility(View.VISIBLE);
            toolbarTitle.animate().alpha(1).setDuration(250);
        }
        else{
            toolbarTitle.setVisibility(View.INVISIBLE);
            toolbarTitle.animate().alpha(0).setDuration(250);
        }
    });

仅当您希望在展开CollapsingToolbarLayout 时使标题消失时才需要自定义视图。对于布局，它可能不是一个好的解决方案，但它很流畅。欢迎提出更好的想法。