动画旋转箭头，源码

 很久没更新文章了，到时候在经常浏览别人的技术文章。

现在分享一个简单实现箭头旋转指向动画。虽然在actionbar里面实现很简单，但自己还是用代码写了。供大家分享。

转发请著名： http://androidmaster.iteye.com/blog/2335021

 

DrawerArrowDrawable.java

 

package com.jinwowo.android.widget;

import android.animation.ValueAnimator;
import android.animation.ValueAnimator.AnimatorUpdateListener;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PathMeasure;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.util.Log;
import android.view.animation.DecelerateInterpolator;

import com.jinwowo.android.R;

public abstract class DrawerArrowDrawable extends Drawable {
	private static final float ARROW_HEAD_ANGLE = (float) Math.toRadians(45.0D); // 箭头的角度
	protected float mBarGap; // 菜单 按钮两条线之间的间隔
	protected float mBarSize; // 菜单 按钮线的长度
	protected float mBarThickness; // 菜单按钮 线的宽度
	protected float mMiddleArrowSize; // 箭头按钮 中间那条线的长度
	protected final Paint mPaint = new Paint();
	protected final Path mPath = new Path();
	protected float mProgress;
	protected float cmProgress;
	protected int mSize;
	protected float mVerticalMirror = 1f;
	protected float mTopBottomArrowSize;// 箭头 按钮的上下部分的长度
	protected Context context;

	public DrawerArrowDrawable(Context context) {
		this.context = context;
		this.mPaint.setAntiAlias(true);// 设置抗锯齿
		this.mPaint.setColor(context.getResources().getColor(R.color.white)); // 设置画笔的颜色为白色
		this.mSize = context.getResources().getDimensionPixelSize(R.dimen.ldrawer_drawableSize);
		this.mBarSize = context.getResources().getDimensionPixelSize(R.dimen.ldrawer_barSize);
		this.mTopBottomArrowSize = context.getResources().getDimensionPixelSize(R.dimen.ldrawer_topBottomBarArrowSize);
		this.mBarThickness = context.getResources().getDimensionPixelSize(R.dimen.ldrawer_thickness);
		this.mBarGap = context.getResources().getDimensionPixelSize(R.dimen.ldrawer_gapBetweenBars);
		this.mMiddleArrowSize = context.getResources().getDimensionPixelSize(R.dimen.ldrawer_middleBarArrowSize);
		this.mPaint.setStyle(Paint.Style.STROKE);
		// 设置两条线相交时候 相交部分的处理
		this.mPaint.setStrokeJoin(Paint.Join.ROUND);
		this.mPaint.setStrokeCap(Paint.Cap.SQUARE);
		// 设置画笔线的宽度
		this.mPaint.setStrokeWidth(this.mBarThickness);
	}

	// 此方法是用来进行动画转换的时候差值的 第三个参数是进度
	protected float lerp(float paramFloat1, float paramFloat2, float paramFloat3) {
		return paramFloat1 + paramFloat3 * (paramFloat2 - paramFloat1);
	}

	PathMeasure mpMeasure;

	public void draw(Canvas canvas) {
		Rect localRect = getBounds();
		float f1 = lerp(this.mBarSize, this.mTopBottomArrowSize, this.mProgress);
		float f2 = lerp(this.mBarSize, this.mMiddleArrowSize, this.mProgress);
		float f3 = lerp(0.0F, this.mBarThickness / 2.0F, this.mProgress);
		float f4 = lerp(0.0F, ARROW_HEAD_ANGLE, this.mProgress);
		float f5 = 0.0F;
		float f6 = 180.0F;
		float f7 = lerp(f5, f6, this.mProgress);
		float f8 = lerp(this.mBarGap + this.mBarThickness, 0.0F, this.mProgress);
		this.mPath.rewind();
		float f9 = -f2 / 2.0F;
		this.mPath.moveTo(f9 + f3, 0.0F);
		this.mPath.rLineTo(f2 - f3, 0.0F);
		float f10 = (float) Math.round(f1 * Math.cos(f4));
		float f11 = (float) Math.round(f1 * Math.sin(f4));
		this.mPath.moveTo(f9, f8);
		this.mPath.rLineTo(f10, f11);
		this.mPath.moveTo(f9, -f8);
		this.mPath.rLineTo(f10, -f11);
		this.mPath.moveTo(0.0F, 0.0F);

		this.mPath.close();
		canvas.save();
		if (!isLayoutRtl())
			canvas.rotate(180.0F, localRect.centerX(), localRect.centerY());
		canvas.rotate(f7 * mVerticalMirror, localRect.centerX(), localRect.centerY());
		canvas.translate(localRect.centerX(), localRect.centerY());
		canvas.drawPath(this.mPath, this.mPaint);
		canvas.restore();
	}

	// 开启路径动画
	public void startPathAnim() {
		if (mProgress == cmProgress) {
			return;
		}
		// 0 － getLength()
		ValueAnimator valueAnimator = ValueAnimator.ofFloat(0, 10);
		valueAnimator.setDuration(1000);
		// 减速插值器
		valueAnimator.setInterpolator(new DecelerateInterpolator());
		valueAnimator.addUpdateListener(new AnimatorUpdateListener() {

			@Override
			public void onAnimationUpdate(ValueAnimator animation) {
				float value = (Float) animation.getAnimatedValue();
				if (cmProgress == 1) {
					mProgress = value / 10f;
					invalidateSelf();
				} else { // 0
					mProgress = 1 - value / 10f;
					invalidateSelf();
				}
				Log.e("TAG", value + "");
				// 获取当前点坐标封装到mCurrentPosition
				// mpMeasure.getPosTan(value, mCurrentPosition, null);
				// postInvalidate();
				// invalidateSelf();
			}
		});
		valueAnimator.start();

	}

	public int getIntrinsicHeight() {
		return this.mSize;
	}

	public int getIntrinsicWidth() {
		return this.mSize;
	}

	public void setAlpha(int alpha) {
		this.mPaint.setAlpha(alpha);
	}

	@Override
	public int getOpacity() {
		return PixelFormat.TRANSLUCENT;
	}

	public abstract boolean isLayoutRtl();

	public void setColorFilter(ColorFilter colorFilter) {
		this.mPaint.setColorFilter(colorFilter);
	}

	public void setVerticalMirror(boolean mVerticalMirror) {
		this.mVerticalMirror = mVerticalMirror ? 1 : -1;
	}

	/**
	 * 实现旋转动画。
	 * 
	 * @param paramFloat
	 *            0 .1
	 */
	public void setProgress(float paramFloat) {
		// this.mProgress = paramFloat;
		this.cmProgress = paramFloat;
		// invalidateSelf();
		startPathAnim();
	}

	public void setColor(int resourceId) {
		this.mPaint.setColor(context.getResources().getColor(resourceId));
	}
}

 

调用方法：imgUserHead为ImageView

final DrawerArrowDrawable drawable = new DrawerArrowDrawable(this.getCurtentActivity()) {

					@Override
					public boolean isLayoutRtl() {
						return false;
					}
				};
				imgUserHead.setImageDrawable(drawable);
				imgUserHead.setOnClickListener(new OnClickListener() {
					boolean isclick = false;

					@Override
					public void onClick(View arg0) {
						isclick = !isclick;
						if (isclick) {
							drawable.setProgress(0f);
						} else {
							drawable.setProgress(1f);
						}
					}
				});

 效果图：

 

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