CoordinatorLayout简述

作为Android的控件, CoordinatorLayout已经加入最新的HelloWorld项目中, 也是Material风格的重要组件, 协调(Coordinate)其他组件, 实现联动. 那么让我们来看看这个动画效果怎么用吧?

1. 准备

首先新建HelloWorld项目.

在项目的build.gradle文件中, 引入头像控件库和CardView库, 在本例中会使用.

    compile 'de.hdodenhof:circleimageview:1.3.0'    compile 'com.android.support:cardview-v7:23.1.0'    compile 'com.jakewharton:butterknife:7.0.1'

2. 页面

在activity_main.xml中, 保留CoordinatorLayout和AppBarLayout, 重新编写页面.

android:fitsSystemWindows="true" 这句也需要去掉, 本例需要保留最上面的状态栏(status bar), 这个属性会导致重叠, 默认false.

activity_main.xml代码

<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=".MainActivity">    <android.support.design.widget.AppBarLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:theme="@style/AppTheme.AppBarOverlay">    </android.support.design.widget.AppBarLayout></android.support.design.widget.CoordinatorLayout>

修改主题颜色, 粉色符合风格

    <color name="colorPrimary">#FFCCCC</color>    <color name="colorPrimaryDark">#FF00FF</color>

在AppBarLayout中, 添加CollapsingToolbarLayout控件, CollapsingToolbar会滚动消失, 被ToolBar替换, 实现滚动动画.

        <android.support.design.widget.CollapsingToolbarLayout            android:layout_width="match_parent"            android:layout_height="450dp"            app:layout_scrollFlags="scroll|exitUntilCollapsed|snap">        </android.support.design.widget.CollapsingToolbarLayout>

app:layout_scrollFlags的属性, scroll滑动, exitUntilCollapsed退出到最小, snap自动滑动动画, 定义CollapsingToolbarLayout的滑动属性.

CollapsingToolbarLayout划分两部分, 一部分大图, 一部分文字.

            <ImageView                android:layout_width="match_parent"                android:layout_height="300dp"                android:scaleType="centerCrop"                android:src="@drawable/large"                app:layout_collapseMode="parallax" />            <FrameLayout                android:layout_width="match_parent"                android:layout_height="150dp"                android:layout_gravity="bottom|center_horizontal"                android:background="@color/colorPrimary"                app:layout_collapseMode="parallax">                <LinearLayout                    android:layout_width="wrap_content"                    android:layout_height="wrap_content"                    android:orientation="vertical"                    android:layout_gravity="center">                    <TextView                        android:layout_width="wrap_content"                        android:layout_height="wrap_content"                        android:layout_gravity="center_horizontal"                        android:gravity="bottom|center"                        android:text="@string/person_name"                        android:textColor="@android:color/white"                        android:textSize="30sp" />                    <TextView                        android:layout_width="wrap_content"                        android:layout_height="wrap_content"                        android:layout_gravity="center_horizontal"                        android:layout_marginTop="4dp"                        android:text="@string/person_title"                        android:textColor="@android:color/white"/>                </LinearLayout>            </FrameLayout>

app:layout_collapseMode="parallax"折叠时的视差效果, 自动滑动.

效果

添加NestedScrollView, 文字的滚动视图.

    <android.support.v4.widget.NestedScrollView        android:layout_width="match_parent"        android:layout_height="match_parent"        android:scrollbars="none"        app:behavior_overlapTop="30dp"        app:layout_behavior="@string/appbar_scrolling_view_behavior">        <android.support.v7.widget.CardView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_margin="8dp"            app:cardElevation="8dp"            app:contentPadding="16dp">            <TextView                android:layout_width="match_parent"                android:layout_height="wrap_content"                android:lineSpacingExtra="8dp"                android:text="@string/person_intro"/>        </android.support.v7.widget.CardView>    </android.support.v4.widget.NestedScrollView>

app:behavior_overlapTop="30dp", The amount that the scrolling view should overlap the bottom of any AppBarLayout. 使ScrollView压在AppBarLayout上面一段长度.

添加ToolBar, 滚动结束的效果图.

    <android.support.v7.widget.Toolbar        android:layout_width="match_parent"        android:layout_height="?attr/actionBarSize"        android:background="@color/colorPrimary"        app:layout_anchor="@id/main_fl_title"        app:theme="@style/ThemeOverlay.AppCompat.Dark">        <LinearLayout            android:layout_width="wrap_content"            android:layout_height="match_parent"            android:orientation="horizontal">            <Space                android:layout_width="@dimen/image_final_width"                android:layout_height="@dimen/image_final_width" />            <TextView                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:gravity="center_vertical"                android:text="@string/person_name"                android:textColor="@android:color/white"                android:textSize="20sp"/>        </LinearLayout>    </android.support.v7.widget.Toolbar>

ToolBar是工具栏, 滑动完成时, 在最上部显示. Space预留头像的位置.

圆形头像CircleImageView显示(使用第三方库)

    <de.hdodenhof.circleimageview.CircleImageView        android:layout_width="120dp"        android:layout_height="120dp"        android:layout_gravity="center"        android:src="@drawable/small"        app:border_color="@android:color/white"        app:border_width="2dp"        app:layout_behavior=".AvatarImageBehavior" />

头像控件的滑动行为是自定义的类, 具体行为参考注释. 判断起始和终止位置, child和dependency视图联动, 这里是图像视图和Toolbar联动.

/** * 图片控件位置动画 * * @author wangchenlong */@SuppressWarnings("unused")public class AvatarImageBehavior extends CoordinatorLayout.Behavior<CircleImageView> {    private final static float MIN_AVATAR_PERCENTAGE_SIZE = 0.3f;    private final static int EXTRA_FINAL_AVATAR_PADDING = 80;    private int mStartYPosition; // 起始的Y轴位置    private int mFinalYPosition; // 结束的Y轴位置    private int mStartHeight; // 开始的图片高度    private int mFinalHeight; // 结束的图片高度    private int mStartXPosition; // 起始的X轴高度    private int mFinalXPosition; // 结束的X轴高度    private float mStartToolbarPosition; // Toolbar的起始位置    private final Context mContext;    private float mAvatarMaxSize;    public AvatarImageBehavior(Context context, AttributeSet attrs) {        mContext = context;        init();    }    private void init() {        bindDimensions();    }    private void bindDimensions() {        mAvatarMaxSize = mContext.getResources().getDimension(R.dimen.image_width);    }    @Override    public boolean layoutDependsOn(CoordinatorLayout parent, CircleImageView child, View dependency) {        // 依赖Toolbar控件        return dependency instanceof Toolbar;    }    @Override    public boolean onDependentViewChanged(CoordinatorLayout parent, CircleImageView child, View dependency) {        // 初始化属性        shouldInitProperties(child, dependency);        // 最大滑动距离: 起始位置-状态栏高度        final int maxScrollDistance = (int) (mStartToolbarPosition - getStatusBarHeight());        // 滑动的百分比        float expandedPercentageFactor = dependency.getY() / maxScrollDistance;        // Y轴距离        float distanceYToSubtract = ((mStartYPosition - mFinalYPosition)                * (1f - expandedPercentageFactor)) + (child.getHeight() / 2);        // X轴距离        float distanceXToSubtract = ((mStartXPosition - mFinalXPosition)                * (1f - expandedPercentageFactor)) + (child.getWidth() / 2);        // 高度减小        float heightToSubtract = ((mStartHeight - mFinalHeight) * (1f - expandedPercentageFactor));        // 图片位置        child.setY(mStartYPosition - distanceYToSubtract);        child.setX(mStartXPosition - distanceXToSubtract);        // 图片大小        CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) child.getLayoutParams();        lp.width = (int) (mStartHeight - heightToSubtract);        lp.height = (int) (mStartHeight - heightToSubtract);        child.setLayoutParams(lp);        return true;    }    /**     * 初始化动画值     *     * @param child      图片控件     * @param dependency ToolBar     */    private void shouldInitProperties(CircleImageView child, View dependency) {        // 图片控件中心        if (mStartYPosition == 0)            mStartYPosition = (int) (child.getY() + (child.getHeight() / 2));        // Toolbar中心        if (mFinalYPosition == 0)            mFinalYPosition = (dependency.getHeight() / 2);        // 图片高度        if (mStartHeight == 0)            mStartHeight = child.getHeight();        // Toolbar缩略图高度        if (mFinalHeight == 0)            mFinalHeight = mContext.getResources().getDimensionPixelOffset(R.dimen.image_final_width);        // 图片控件水平中心        if (mStartXPosition == 0)            mStartXPosition = (int) (child.getX() + (child.getWidth() / 2));        // 边缘+缩略图宽度的一半        if (mFinalXPosition == 0)            mFinalXPosition = mContext.getResources().getDimensionPixelOffset(R.dimen.abc_action_bar_content_inset_material) + (mFinalHeight / 2);        // Toolbar的起始位置        if (mStartToolbarPosition == 0)            mStartToolbarPosition = dependency.getY() + (dependency.getHeight() / 2);    }    // 获取状态栏高度    public int getStatusBarHeight() {        int result = 0;        int resourceId = mContext.getResources().getIdentifier("status_bar_height", "dimen", "android");        if (resourceId > 0) {            result = mContext.getResources().getDimensionPixelSize(resourceId);        }        return result;    }}

添加需要使用的id, activity_main.xml如下

<?xml version="1.0" encoding="utf-8"?><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="false"    tools:context=".MainActivity">    <android.support.design.widget.AppBarLayout        android:id="@+id/main_abl_app_bar"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">        <android.support.design.widget.CollapsingToolbarLayout            android:layout_width="match_parent"            android:layout_height="450dp"            app:layout_scrollFlags="scroll|exitUntilCollapsed|snap">            <ImageView                android:id="@+id/main_iv_placeholder"                android:layout_width="match_parent"                android:layout_height="300dp"                android:scaleType="centerCrop"                android:src="@drawable/large"                app:layout_collapseMode="parallax" />            <FrameLayout                android:id="@+id/main_fl_title"                android:layout_width="match_parent"                android:layout_height="150dp"                android:layout_gravity="bottom|center_horizontal"                android:background="@color/colorPrimary"                app:layout_collapseMode="parallax">                <LinearLayout                    android:id="@+id/main_ll_title_container"                    android:layout_width="wrap_content"                    android:layout_height="wrap_content"                    android:layout_gravity="center"                    android:orientation="vertical">                    <TextView                        android:layout_marginTop="@dimen/title_margin"                        android:layout_width="wrap_content"                        android:layout_height="wrap_content"                        android:layout_gravity="center_horizontal"                        android:gravity="bottom|center"                        android:text="@string/person_name"                        android:textColor="@android:color/white"                        android:textSize="30sp"/>                    <TextView                        android:layout_width="wrap_content"                        android:layout_height="wrap_content"                        android:layout_gravity="center_horizontal"                        android:layout_marginTop="4dp"                        android:text="@string/person_title"                        android:textColor="@android:color/white" />                </LinearLayout>            </FrameLayout>        </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:scrollbars="none"        app:behavior_overlapTop="30dp"        app:layout_behavior="@string/appbar_scrolling_view_behavior">        <android.support.v7.widget.CardView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_margin="8dp"            app:cardElevation="8dp"            app:contentPadding="16dp">            <TextView                android:layout_width="match_parent"                android:layout_height="wrap_content"                android:lineSpacingExtra="8dp"                android:text="@string/person_intro" />        </android.support.v7.widget.CardView>    </android.support.v4.widget.NestedScrollView>    <android.support.v7.widget.Toolbar        android:id="@+id/main_tb_toolbar"        android:layout_width="match_parent"        android:layout_height="?attr/actionBarSize"        android:background="@color/colorPrimary"        app:layout_anchor="@id/main_fl_title"        app:theme="@style/ThemeOverlay.AppCompat.Dark">        <LinearLayout            android:layout_width="wrap_content"            android:layout_height="match_parent"            android:orientation="horizontal">            <Space                android:layout_width="@dimen/image_final_width"                android:layout_height="@dimen/image_final_width" />            <TextView                android:id="@+id/main_tv_title"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_marginLeft="8dp"                android:gravity="center_vertical"                android:text="@string/person_name"                android:textColor="@android:color/white"                android:textSize="20sp"                android:visibility="invisible"/>        </LinearLayout>    </android.support.v7.widget.Toolbar>    <de.hdodenhof.circleimageview.CircleImageView        android:layout_width="@dimen/image_width"        android:layout_height="@dimen/image_width"        android:layout_gravity="center"        android:src="@drawable/small"        app:border_color="@android:color/white"        app:border_width="2dp"        app:layout_behavior=".AvatarImageBehavior" /></android.support.design.widget.CoordinatorLayout>

效果

3. 逻辑

在onCreate里面设置滑动逻辑, 设置两个动画: 监听AppBar的滑动, 处理Toolbar和Title的显示; 自动滑动效果.

    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ButterKnife.bind(this);        mTbToolbar.setTitle("");        // AppBar的监听        mAblAppBar.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {            @Override            public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {                int maxScroll = appBarLayout.getTotalScrollRange();                float percentage = (float) Math.abs(verticalOffset) / (float) maxScroll;                handleAlphaOnTitle(percentage);                handleToolbarTitleVisibility(percentage);            }        });        initParallaxValues(); // 自动滑动效果    }

根据滑动百分比, 设置Title和Toolbar的显示与消失, 使用Alpha动画.

    // 处理ToolBar的显示    private void handleToolbarTitleVisibility(float percentage) {        if (percentage >= PERCENTAGE_TO_SHOW_TITLE_AT_TOOLBAR) {            if (!mIsTheTitleVisible) {                startAlphaAnimation(mTvToolbarTitle, ALPHA_ANIMATIONS_DURATION, View.VISIBLE);                mIsTheTitleVisible = true;            }        } else {            if (mIsTheTitleVisible) {                startAlphaAnimation(mTvToolbarTitle, ALPHA_ANIMATIONS_DURATION, View.INVISIBLE);                mIsTheTitleVisible = false;            }        }    }    // 控制Title的显示    private void handleAlphaOnTitle(float percentage) {        if (percentage >= PERCENTAGE_TO_HIDE_TITLE_DETAILS) {            if (mIsTheTitleContainerVisible) {                startAlphaAnimation(mLlTitleContainer, ALPHA_ANIMATIONS_DURATION, View.INVISIBLE);                mIsTheTitleContainerVisible = false;            }        } else {            if (!mIsTheTitleContainerVisible) {                startAlphaAnimation(mLlTitleContainer, ALPHA_ANIMATIONS_DURATION, View.VISIBLE);                mIsTheTitleContainerVisible = true;            }        }    }    // 设置渐变的动画    public static void startAlphaAnimation(View v, long duration, int visibility) {        AlphaAnimation alphaAnimation = (visibility == View.VISIBLE)                ? new AlphaAnimation(0f, 1f)                : new AlphaAnimation(1f, 0f);        alphaAnimation.setDuration(duration);        alphaAnimation.setFillAfter(true);        v.startAnimation(alphaAnimation);    }

自动滑动动画, 当到一定比例时展开或关闭.

    // 设置自动滑动的动画效果    private void initParallaxValues() {        CollapsingToolbarLayout.LayoutParams petDetailsLp =                (CollapsingToolbarLayout.LayoutParams) mIvPlaceholder.getLayoutParams();        CollapsingToolbarLayout.LayoutParams petBackgroundLp =                (CollapsingToolbarLayout.LayoutParams) mFlTitleContainer.getLayoutParams();        petDetailsLp.setParallaxMultiplier(0.9f);        petBackgroundLp.setParallaxMultiplier(0.3f);        mIvPlaceholder.setLayoutParams(petDetailsLp);        mFlTitleContainer.setLayoutParams(petBackgroundLp);    }

最终逻辑

public class MainActivity extends AppCompatActivity {    // 控制ToolBar的变量    private static final float PERCENTAGE_TO_SHOW_TITLE_AT_TOOLBAR = 0.9f;    private static final float PERCENTAGE_TO_HIDE_TITLE_DETAILS = 0.3f;    private static final int ALPHA_ANIMATIONS_DURATION = 200;    private boolean mIsTheTitleVisible = false;    private boolean mIsTheTitleContainerVisible = true;    @Bind(R.id.main_iv_placeholder)    ImageView mIvPlaceholder; // 大图片    @Bind(R.id.main_ll_title_container)    LinearLayout mLlTitleContainer; // Title的LinearLayout    @Bind(R.id.main_fl_title)    FrameLayout mFlTitleContainer; // Title的FrameLayout    @Bind(R.id.main_abl_app_bar)    AppBarLayout mAblAppBar; // 整个可以滑动的AppBar    @Bind(R.id.main_tv_toolbar_title)    TextView mTvToolbarTitle; // 标题栏Title    @Bind(R.id.main_tb_toolbar)    Toolbar mTbToolbar; // 工具栏    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ButterKnife.bind(this);        mTbToolbar.setTitle("");        // AppBar的监听        mAblAppBar.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {            @Override            public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {                int maxScroll = appBarLayout.getTotalScrollRange();                float percentage = (float) Math.abs(verticalOffset) / (float) maxScroll;                handleAlphaOnTitle(percentage);                handleToolbarTitleVisibility(percentage);            }        });        initParallaxValues(); // 自动滑动效果    }    // 设置自动滑动的动画效果    private void initParallaxValues() {        CollapsingToolbarLayout.LayoutParams petDetailsLp =                (CollapsingToolbarLayout.LayoutParams) mIvPlaceholder.getLayoutParams();        CollapsingToolbarLayout.LayoutParams petBackgroundLp =                (CollapsingToolbarLayout.LayoutParams) mFlTitleContainer.getLayoutParams();        petDetailsLp.setParallaxMultiplier(0.9f);        petBackgroundLp.setParallaxMultiplier(0.3f);        mIvPlaceholder.setLayoutParams(petDetailsLp);        mFlTitleContainer.setLayoutParams(petBackgroundLp);    }    // 处理ToolBar的显示    private void handleToolbarTitleVisibility(float percentage) {        if (percentage >= PERCENTAGE_TO_SHOW_TITLE_AT_TOOLBAR) {            if (!mIsTheTitleVisible) {                startAlphaAnimation(mTvToolbarTitle, ALPHA_ANIMATIONS_DURATION, View.VISIBLE);                mIsTheTitleVisible = true;            }        } else {            if (mIsTheTitleVisible) {                startAlphaAnimation(mTvToolbarTitle, ALPHA_ANIMATIONS_DURATION, View.INVISIBLE);                mIsTheTitleVisible = false;            }        }    }    // 控制Title的显示    private void handleAlphaOnTitle(float percentage) {        if (percentage >= PERCENTAGE_TO_HIDE_TITLE_DETAILS) {            if (mIsTheTitleContainerVisible) {                startAlphaAnimation(mLlTitleContainer, ALPHA_ANIMATIONS_DURATION, View.INVISIBLE);                mIsTheTitleContainerVisible = false;            }        } else {            if (!mIsTheTitleContainerVisible) {                startAlphaAnimation(mLlTitleContainer, ALPHA_ANIMATIONS_DURATION, View.VISIBLE);                mIsTheTitleContainerVisible = true;            }        }    }    // 设置渐变的动画    public static void startAlphaAnimation(View v, long duration, int visibility) {        AlphaAnimation alphaAnimation = (visibility == View.VISIBLE)                ? new AlphaAnimation(0f, 1f)                : new AlphaAnimation(1f, 0f);        alphaAnimation.setDuration(duration);        alphaAnimation.setFillAfter(true);        v.startAnimation(alphaAnimation);    }}

Github下载地址

这样联动效果就已经显示出来了, 在AppBar中Toolbar和Title之间的关系, 符合Material的风格, 给用户更多的体验. 既然已经集成到HelloWorld中, 说明Android是极力推荐使用CoordinatorLayout这种风格的, 那我们就Enjoy it吧.