浮动动作按钮动画

Question

当一个 fab 出现时，它使用缩放动画制作动画，当它隐藏时，它使用缩放动画。

所以，它是一个放大和缩小的动画。

如何制作这个动画？

Answer 1

从@Zielony 的回答中，我做到了我想要的地方。

以下是正确应用效果的代码。

scale_fab_in.xml

<?xml version="1.0" encoding="utf-8"?>
<scale xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="500"
    android:fromXScale="0"
    android:fromYScale="0"
    android:pivotX="50%"
    android:pivotY="50%"
    android:toXScale="1"
    android:toYScale="1"
    android:interpolator="@android:interpolator/overshoot"/>

scale_fab_out.xml

<?xml version="1.0" encoding="utf-8"?>
<scale xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="400"
    android:fromXScale="1"
    android:fromYScale="1"
    android:pivotX="50%"
    android:pivotY="50%"
    android:toXScale="0"
    android:toYScale="0"
    android:interpolator="@android:interpolator/overshoot"/>

编辑 2/16/2016 - 另一种方法：

将下面的代码放在您的 FAB 代码或任何其他视图中。

//global
    private static final int FAB_ANIM_DURATION = 200;

public void hide() {
        // Only use scale animation if FAB is visible
        if (getVisibility() == View.VISIBLE) {
            // Pivots indicate where the animation begins from
            float pivotX = getPivotX() + getTranslationX();
            float pivotY = getPivotY() + getTranslationY();

            // Animate FAB shrinking
            ScaleAnimation anim = new ScaleAnimation(1, 0, 1, 0, pivotX, pivotY);
            anim.setDuration(FAB_ANIM_DURATION);
            anim.setInterpolator(getInterpolator());
            startAnimation(anim);
        }
        setVisibility(View.INVISIBLE);
    }


    public void show() {
        show(0, 0);
    }

    public void show(float translationX, float translationY) {

        // Set FAB's translation
        setTranslation(translationX, translationY);

        // Only use scale animation if FAB is hidden
        if (getVisibility() != View.VISIBLE) {
            // Pivots indicate where the animation begins from
            float pivotX = getPivotX() + translationX;
            float pivotY = getPivotY() + translationY;

            ScaleAnimation anim;
            // If pivots are 0, that means the FAB hasn't been drawn yet so just use the
            // center of the FAB
            if (pivotX == 0 || pivotY == 0) {
                anim = new ScaleAnimation(0, 1, 0, 1, Animation.RELATIVE_TO_SELF, 0.5f,
                        Animation.RELATIVE_TO_SELF, 0.5f);
            } else {
                anim = new ScaleAnimation(0, 1, 0, 1, pivotX, pivotY);
            }

            // Animate FAB expanding
            anim.setDuration(FAB_ANIM_DURATION);
            anim.setInterpolator(getInterpolator());
            startAnimation(anim);
        }
        setVisibility(View.VISIBLE);
    }

    private void setTranslation(float translationX, float translationY) {
        if (Build.VERSION.SDK_INT >= VERSION_CODES.HONEYCOMB_MR1) {
            animate().setInterpolator(getInterpolator()).setDuration(FAB_ANIM_DURATION)
                    .translationX(translationX).translationY(translationY);
        }
    }

    private Interpolator getInterpolator() {
        return AnimationUtils.loadInterpolator(getContext(), R.interpolator.fab_interpolator);
    }


<item name="fab_interpolator" type="interpolator">@android:interpolator/decelerate_cubic</item>

Answer 2

按钮只是使用 OvershootInterpolator 从 0 缩放到 1。应该是这样的：

ScaleAnimation anim = new ScaleAnimation(0,1,0,1);
anim.setFillBefore(true);
anim.setFillAfter(true);
anim.setFillEnabled(true);
anim.setDuration(300);
anim.setInterpolator(new OvershootInterpolator());
fab.startAnimation(anim);

http://developer.android.com/reference/android/view/animation/OvershootInterpolator.html

Answer 3

您可以使用此方法对任何视图进行动画放大。如果你反转 0 和 1，你会得到按比例缩小的动画

 public static void scale(View view, long delay) {
        view.setScaleX(0);
        view.setScaleY(0);
        view.animate()
                .scaleX(1)
                .scaleY(1)
                .setDuration(500)
                .setStartDelay(delay)
                .setInterpolator(new OvershootInterpolator())
                .start();
    }

Answer 4

就我而言，这种类型的缩放动画在设置startOffset 值时看起来更好。这对我很有用：

<scale xmlns:android="http://schemas.android.com/apk/res/android"
       android:duration="400"
       android:fillBefore="true"
       android:fillAfter="true"
       android:fillEnabled="true"
       android:startOffset="500"
       android:fromXScale="0"
       android:fromYScale="0"
       android:pivotX="50%"
       android:pivotY="50%"
       android:toXScale="1"
       android:toYScale="1"
       android:interpolator="@android:interpolator/overshoot"/>

Answer 5

使用下面的代码可以得到同样的效果。

    ScaleAnimation anim = new ScaleAnimation(0, 1, 0, 1, 50, 50);
    anim.setFillBefore(true);
    anim.setFillAfter(true);
    anim.setFillEnabled(true);
    anim.setDuration(400);
    anim.setInterpolator(new OvershootInterpolator());
    imageView.startAnimation(anim);

Answer 6

假设请求是为 FloatingActionButton 调整大小设置动画，我首先将 Animation 子类化为一般处理 View（改编自 @987654321 的 Kotlin @)...

open class ResizeAnimation(
    private val view: View,
    private val toHeight: Float,
    private val fromHeight: Float,
    private val toWidth: Float,
    private val fromWidth: Float,
    duration: Long
) : Animation() {

    init {
        this.duration = duration
    }

    override fun applyTransformation(
        interpolatedTime: Float,
        t: Transformation?
    ) {
        val height = (toHeight - fromHeight) * interpolatedTime + fromHeight
        val width = (toWidth - fromWidth) * interpolatedTime + fromWidth
        val layoutParams = view.layoutParams
        layoutParams.height = height.toInt()
        layoutParams.width = width.toInt()
        view.requestLayout()
    }
}

...为了处理 FloatingActionButton，我将 _ResizeAnimation_ 子类化（主要是为了更新浮动操作按钮的 customSize 属性）...

class FabResizeAnimation(
    private val view: FloatingActionButton,
    private val toSize: Float,
    private val fromSize: Float,
    duration: Long
) : ResizeAnimation(
    view,
    toSize,
    fromSize,
    toSize,
    fromSize,
    duration
) {

    override fun applyTransformation(
        interpolatedTime: Float,
        t: Transformation?
    ) {
        val fabSize = ((toSize - fromSize) * interpolatedTime + fromSize).toInt()
        view.customSize = fabSize
        super.applyTransformation(interpolatedTime, t)
    }
}

...用法...

    val animation = FabResizeAnimation(fab, 800.0f, 100.0f, 2000)
    fab.startAnimation(animation)