java - 我需要在屏幕底部的ArcMenu mainImage。 OnMeasure不允许它出现在屏幕底部

我正在尝试将mainImg放到屏幕底部。

 /*
 * Copyright (C) 2012 Capricorn
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

在ArcLayout OnMeasure中，如果我将大小更改为0，它将降低但动画消失。
如何更改OnMeasure以使img降到屏幕底部，并且高度应向上调整？请帮忙!

package com.example.splashscreen;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.Animation;
import android.view.animation.AnimationSet;
import android.view.animation.Interpolator;
import android.view.animation.LinearInterpolator;
import android.view.animation.OvershootInterpolator;
import android.view.animation.RotateAnimation;
import android.view.animation.Animation.AnimationListener;

/**
 * A Layout that arranges its children around its center. The arc can be set by
 * calling {@link #setArc(float, float) setArc()}. You can override the method
 * {@link #onMeasure(int, int) onMeasure()}, otherwise it is always
 * WRAP_CONTENT.
 *
 * @author Capricorn
 *
 */
public class ArcLayout extends ViewGroup {
    /**
     * children will be set the same size.
     */
    private int mChildSize;

    private int mChildPadding = 5;

    private int mLayoutPadding = 10;

    public static final float DEFAULT_FROM_DEGREES = 270.0f;

    public static final float DEFAULT_TO_DEGREES = 360.0f;

    private float mFromDegrees = DEFAULT_FROM_DEGREES;

    private float mToDegrees = DEFAULT_TO_DEGREES;

    private static final int MIN_RADIUS = 150;

    /* the distance between the layout's center and any child's center */
    private int mRadius;

    private boolean mExpanded = false;

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

    public ArcLayout(Context context, AttributeSet attrs) {
        super(context, attrs);

        if (attrs != null) {
            TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.ArcLayout, 0, 0);
            mFromDegrees = a.getFloat(R.styleable.ArcLayout_fromDegrees, DEFAULT_FROM_DEGREES);
            mToDegrees = a.getFloat(R.styleable.ArcLayout_toDegrees, DEFAULT_TO_DEGREES);
            mChildSize = Math.max(a.getDimensionPixelSize(R.styleable.ArcLayout_childSize, 0), 0);

            a.recycle();
        }
    }

    private static int computeRadius(final float arcDegrees, final int childCount, final int childSize,
            final int childPadding, final int minRadius) {
        if (childCount < 2) {
            return minRadius;
        }

        final float perDegrees = arcDegrees / (childCount - 1);
        final float perHalfDegrees = perDegrees / 2;
        final int perSize = childSize + childPadding;

        final int radius = (int) ((perSize / 2) / Math.sin(Math.toRadians(perHalfDegrees)));

        return Math.max(radius, minRadius);
    }

    private static Rect computeChildFrame(final int centerX, final int centerY, final int radius, final float degrees,
            final int size) {

        final double childCenterX = centerX + radius * Math.cos(Math.toRadians(degrees));
        final double childCenterY = centerY + radius * Math.sin(Math.toRadians(degrees));

        return new Rect((int) (childCenterX - size / 2), (int) (childCenterY),
                (int) (childCenterX + size / 2), (int) (childCenterY + size ));
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        final int radius = mRadius = computeRadius(Math.abs(mToDegrees - mFromDegrees), getChildCount(), mChildSize,
                mChildPadding, MIN_RADIUS);
        final int size = radius * 2 + mChildSize + mChildPadding + mLayoutPadding * 2;

        setMeasuredDimension(size, size);

        final int count = getChildCount();
        for (int i = 0; i < count; i++) {
            getChildAt(i).measure(MeasureSpec.makeMeasureSpec(mChildSize, MeasureSpec.EXACTLY),
                    MeasureSpec.makeMeasureSpec(mChildSize, MeasureSpec.EXACTLY));
        }
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        final int centerX = getWidth() / 2;
        final int centerY = getHeight() / 2;
        final int radius = mExpanded ? mRadius : 0;

        final int childCount = getChildCount();
        final float perDegrees = (mToDegrees - mFromDegrees) / (childCount - 1);

        float degrees = mFromDegrees;
        for (int i = 0; i < childCount; i++) {
            Rect frame = computeChildFrame(centerX, centerY, radius, degrees, mChildSize);
            degrees += perDegrees;
            getChildAt(i).layout(frame.left, frame.top, frame.right, frame.bottom);
        }
    }

    /**
     * refers to {@link LayoutAnimationController#getDelayForView(View view)}
     */
    private static long computeStartOffset(final int childCount, final boolean expanded, final int index,
            final float delayPercent, final long duration, Interpolator interpolator) {
        final float delay = delayPercent * duration;
        final long viewDelay = (long) (getTransformedIndex(expanded, childCount, index) * delay);
        final float totalDelay = delay * childCount;

        float normalizedDelay = viewDelay / totalDelay;
        normalizedDelay = interpolator.getInterpolation(normalizedDelay);

        return (long) (normalizedDelay * totalDelay);
    }

    private static int getTransformedIndex(final boolean expanded, final int count, final int index) {
        if (expanded) {
            return count - 1 - index;
        }

        return index;
    }

    private static Animation createExpandAnimation(float fromXDelta, float toXDelta, float fromYDelta, float toYDelta,
            long startOffset, long duration, Interpolator interpolator) {
        Animation animation = new RotateAndTranslateAnimation(0, toXDelta, 0, toYDelta, 0, 720);
        animation.setStartOffset(startOffset);
        animation.setDuration(duration);
        animation.setInterpolator(interpolator);
        animation.setFillAfter(true);

        return animation;
    }

    private static Animation createShrinkAnimation(float fromXDelta, float toXDelta, float fromYDelta, float toYDelta,
            long startOffset, long duration, Interpolator interpolator) {
        AnimationSet animationSet = new AnimationSet(false);
        animationSet.setFillAfter(true);

        final long preDuration = duration / 2;
        Animation rotateAnimation = new RotateAnimation(0, 360, Animation.RELATIVE_TO_SELF, 0.5f,
                Animation.RELATIVE_TO_SELF, 0.5f);
        rotateAnimation.setStartOffset(startOffset);
        rotateAnimation.setDuration(preDuration);
        rotateAnimation.setInterpolator(new LinearInterpolator());
        rotateAnimation.setFillAfter(true);

        animationSet.addAnimation(rotateAnimation);

        Animation translateAnimation = new RotateAndTranslateAnimation(0, toXDelta, 0, toYDelta, 360, 720);
        translateAnimation.setStartOffset(startOffset + preDuration);
        translateAnimation.setDuration(duration - preDuration);
        translateAnimation.setInterpolator(interpolator);
        translateAnimation.setFillAfter(true);

        animationSet.addAnimation(translateAnimation);

        return animationSet;
    }

    private void bindChildAnimation(final View child, final int index, final long duration) {
        final boolean expanded = mExpanded;
        final int centerX = getWidth() / 2;
        final int centerY = getHeight() / 2;
        final int radius = expanded ? 0 : mRadius;

        final int childCount = getChildCount();
        final float perDegrees = (mToDegrees - mFromDegrees) / (childCount - 1);
        Rect frame = computeChildFrame(centerX, centerY, radius, mFromDegrees + index * perDegrees, mChildSize);

        final int toXDelta = frame.left - child.getLeft();
        final int toYDelta = frame.top - child.getTop();

        Interpolator interpolator = mExpanded ? new AccelerateInterpolator() : new OvershootInterpolator(1.5f);
        final long startOffset = computeStartOffset(childCount, mExpanded, index, 0.1f, duration, interpolator);

        Animation animation = mExpanded ? createShrinkAnimation(0, toXDelta, 0, toYDelta, startOffset, duration,
                interpolator) : createExpandAnimation(0, toXDelta, 0, toYDelta, startOffset, duration, interpolator);

        final boolean isLast = getTransformedIndex(expanded, childCount, index) == childCount - 1;
        animation.setAnimationListener(new AnimationListener() {

            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationRepeat(Animation animation) {

            }

            @Override
            public void onAnimationEnd(Animation animation) {
                if (isLast) {
                    postDelayed(new Runnable() {

                        @Override
                        public void run() {
                            onAllAnimationsEnd();
                        }
                    }, 0);
                }
            }
        });

        child.setAnimation(animation);
    }

    public boolean isExpanded() {
        return mExpanded;
    }

    public void setArc(float fromDegrees, float toDegrees) {
        if (mFromDegrees == fromDegrees && mToDegrees == toDegrees) {
            return;
        }

        mFromDegrees = fromDegrees;
        mToDegrees = toDegrees;

        requestLayout();
    }

    public void setChildSize(int size) {
        if (mChildSize == size || size < 0) {
            return;
        }

        mChildSize = size;

        requestLayout();
    }

    /**
     * switch between expansion and shrinkage
     *
     * @param showAnimation
     */
    public void switchState(final boolean showAnimation) {
        if (showAnimation) {
            final int childCount = getChildCount();
            for (int i = 0; i < childCount; i++) {
                bindChildAnimation(getChildAt(i), i, 300);
            }
        }

        mExpanded = !mExpanded;

        if (!showAnimation) {
            requestLayout();
        }

        invalidate();
    }

    private void onAllAnimationsEnd() {
        final int childCount = getChildCount();
        for (int i = 0; i < childCount; i++) {
            getChildAt(i).clearAnimation();
        }

        requestLayout();
    }
}

最佳答案

如您在下面的daCapricorn comment中看到的，报告了类似的问题。

他提供了有关可能解决方案的详细信息:

在xml中设置android:layout_alignParentBottom =“true”和android:layout_alignParentLeft =“true”并以编程方式计算marginBottom和marginLeft(它们应为负数)。 marginBottom =(ArcMenu的高度centerIcon的高度)/2，marginLeft =(ArcMenu的宽度-centerIcon的宽度)/2。

这里的主要思想是将所需的边距设置为负值(我的情况是右下)。
我设法通过计算所需的边距marginBottom =-(((ArcMenu的高度centerIcon的高度)/2)，marginRight =-(((ArcMenu的宽度-centerIcon的宽度)/2)解决了这个问题。

我没有在库代码的ArcLayout.java的onMeasure内部执行此操作，而是在我的 Activity 中执行了以下操作。

在我的 Activity 的布局中，根据需要设置layout_alignParent:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:arc="http://schemas.android.com/apk/res-auto"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <com.capricorn.ArcMenu
         android:layout_alignParentBottom="true"
         android:layout_alignParentRight="true"
         android:id="@+id/arc_menu"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         arc:childSize="@dimen/menuChildSize"
         arc:fromDegrees="180"
         arc:toDegrees="270" />

</RelativeLayout>

在我的 Activity 中:

ArcMenu arcMenu; // the arc menu
FrameLayout controlLayout; // the frame layout of the control from library
int arcWidth, arcHeight; // arc menu measurments to be calculated , required for margins
int controlLayoutWidth, controlLayoutHeight; // controlLayout measurments to be calculated , required for margins
boolean isArcMeasureReady, isControlLayoutMeasureReady; // determine if measurements are ready if so apply the margins with the following runnable
Runnable runnable = new Runnable() {

    @Override
    public void run() {
        if (isArcMeasureReady && isControlLayoutMeasureReady) {
            RelativeLayout.LayoutParams params = (LayoutParams) arcMenu // your container LayoutParmas , mine is RelativeLayout
                    .getLayoutParams();
            int rightMargin = -((arcWidth - crossWidth) / 2);
            int bottomMargin = -((arcHeight - crossHeight) / 2);
            params.setMargins(0, 0, rightMargin, bottomMargin);
            arcMenu.setLayoutParams(params);
        }
    }
};

我的onCreate:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    isArcMeasureReady = isControlLayoutMeasureReady = false;
    controlLayout = (FrameLayout) findViewById(com.capricorn.R.id.control_layout);
    ...

    ViewTreeObserver viewTreeObserverControlLayout = controlLayout.getViewTreeObserver();
    if (viewTreeObserverControlLayout.isAlive()) {
        viewTreeObserverControlLayout
                .addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
                    @Override
                    public void onGlobalLayout() {
                        controlLayout.getViewTreeObserver()
                                .removeGlobalOnLayoutListener(this);
                        controlLayoutWidth = controlLayout.getWidth();
                        controlLayoutHeight = controlLayout.getHeight();
                        isControlLayoutMeasureReady = true;

                        runOnUiThread(runnable);

                    }
                });
    }

    ViewTreeObserver viewTreeObserver = arcMenu.getViewTreeObserver();
    if (viewTreeObserver.isAlive()) {
        viewTreeObserver
                .addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
                    @Override
                    public void onGlobalLayout() {
                        arcMenu.getViewTreeObserver()
                                .removeGlobalOnLayoutListener(this);
                        arcWidth = arcMenu.getWidth();
                        arcHeight = arcMenu.getHeight();
                        isArcMeasureReady = true;

                        runOnUiThread(runnable);
                    }
                });
    }

我在多个设备上对此进行了测试，它的效果很好，因为计算是动态的。

希望这有助于享受这个家伙的很棒的小部件daCapricorn