Android UI- PullToRrefresh自定义下拉刷新动画

Android UI- PullToRrefresh自定义下拉刷新动画

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本篇博文要给大家分享的是如何使用修改开源项目PullToRrefresh下拉刷新的动画，来满足我们开发当中特定的需求，我们比较常见的一种下拉刷新样式可能是以下这种：

就是下拉列表的时候两个箭头上下翻转，更改日期文本和刷新状态，这种是最普遍的一种模式。

另外一种是旋转动画，就是刷新的时候一个圈不停的旋转，类似南方周末阅读器（注：是小巫公司的一个产品，各位多多支持O(∩_∩)O）：

github地址：https://github.com/devilWwj/Android-PullToRefresh

下载下来之后，import到工作空间，导入到目标项目中去，不清楚如何导入关联项目的童鞋请自行百度。

我这里要实现的一种效果是下拉刷新时播放一个帧动画

增加动画列表：

<?xml version="1.0" encoding="utf-8"?>
<!-- 
	根标签为animation-list，其中oneshot代表着是否只展示一遍，设置为false会不停的循环播放动画
	根标签下，通过item标签对动画中的每一个图片进行声明
	android:duration 表示展示所用的该图片的时间长度
 -->
<animation-list
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:oneshot="false"
  >
  	<item android:drawable="@drawable/loading1" android:duration="150"></item>
  	<item android:drawable="@drawable/loading2" android:duration="150"></item>
  	<item android:drawable="@drawable/loading3" android:duration="150"></item>
  	<item android:drawable="@drawable/loading4" android:duration="150"></item>
</animation-list>

修改下拉刷新布局：

/PullToRefresh/res/layout/pull_to_refresh_header_simple.xml

<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android" >

    <FrameLayout
        android:id="@+id/fl_inner"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="@dimen/header_footer_top_bottom_padding"
        android:paddingLeft="@dimen/header_footer_left_right_padding"
        android:paddingRight="@dimen/header_footer_left_right_padding"
        android:paddingTop="@dimen/header_footer_top_bottom_padding" >

        <FrameLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal" >

            <ImageView
                android:id="@+id/pull_to_refresh_image"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                android:src="@drawable/loading1"
                 />

        </FrameLayout>

    </FrameLayout>

</merge>

增加自定义的加载布局

/PullToRefresh/src/com/handmark/pulltorefresh/library/internal/TweenAnimLoadingLayout.java

package com.handmark.pulltorefresh.library.internal;

import com.handmark.pulltorefresh.library.R;
import com.handmark.pulltorefresh.library.PullToRefreshBase.Mode;
import com.handmark.pulltorefresh.library.PullToRefreshBase.Orientation;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.drawable.AnimationDrawable;
import android.graphics.drawable.Drawable;
import android.view.View;

/**
 * @date 2015/1/8
 * @author wuwenjie
 * @desc 帧动画加载布局
 */
public class TweenAnimLoadingLayout extends LoadingLayout {

	private AnimationDrawable animationDrawable;

	public TweenAnimLoadingLayout(Context context, Mode mode,
			Orientation scrollDirection, TypedArray attrs) {
		super(context, mode, scrollDirection, attrs);
		// 初始化
		mHeaderImage.setImageResource(R.drawable.refresh_anim);
		animationDrawable = (AnimationDrawable) mHeaderImage.getDrawable();
	}
	// 默认图片
	@Override
	protected int getDefaultDrawableResId() {
		return R.drawable.loading1;
	}
	
	@Override
	protected void onLoadingDrawableSet(Drawable imageDrawable) {
		// NO-OP
	}
	
	@Override
	protected void onPullImpl(float scaleOfLayout) {
		// NO-OP
	}
	// 下拉以刷新
	@Override
	protected void pullToRefreshImpl() {
		// NO-OP
	}
	// 正在刷新时回调
	@Override
	protected void refreshingImpl() {
		// 播放帧动画
		animationDrawable.start();
	}
	// 释放以刷新
	@Override
	protected void releaseToRefreshImpl() {
		// NO-OP
	}
	// 重新设置
	@Override
	protected void resetImpl() {
		mHeaderImage.setVisibility(View.VISIBLE);
		mHeaderImage.clearAnimation();
	}

}

我们只要修改开源项目中的LodingLayout代码：

/PullToRefresh/src/com/handmark/pulltorefresh/library/internal/LoadingLayout.java

/*******************************************************************************
 * Copyright 2011, 2012 Chris Banes.
 *
 * 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.
 *******************************************************************************/
package com.handmark.pulltorefresh.library.internal;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.ColorStateList;
import android.content.res.TypedArray;
import android.graphics.Typeface;
import android.graphics.drawable.AnimationDrawable;
import android.graphics.drawable.Drawable;
import android.text.TextUtils;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Interpolator;
import android.view.animation.LinearInterpolator;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ProgressBar;
import android.widget.TextView;

import com.handmark.pulltorefresh.library.ILoadingLayout;
import com.handmark.pulltorefresh.library.PullToRefreshBase.Mode;
import com.handmark.pulltorefresh.library.PullToRefreshBase.Orientation;
import com.handmark.pulltorefresh.library.R;

@SuppressLint("ViewConstructor")
public abstract class LoadingLayout extends FrameLayout implements ILoadingLayout {

	static final String LOG_TAG = "PullToRefresh-LoadingLayout";

	static final Interpolator ANIMATION_INTERPOLATOR = new LinearInterpolator();

	private FrameLayout mInnerLayout;

	protected final ImageView mHeaderImage;
	protected final ProgressBar mHeaderProgress;

	private boolean mUseIntrinsicAnimation;

	private final TextView mHeaderText;
	private final TextView mSubHeaderText;

	protected final Mode mMode;
	protected final Orientation mScrollDirection;

	private CharSequence mPullLabel;
	private CharSequence mRefreshingLabel;
	private CharSequence mReleaseLabel;
	

	public LoadingLayout(Context context, final Mode mode, final Orientation scrollDirection, TypedArray attrs) {
		super(context);
		mMode = mode;
		mScrollDirection = scrollDirection;

		switch (scrollDirection) {
			case HORIZONTAL:
				LayoutInflater.from(context).inflate(R.layout.pull_to_refresh_header_horizontal, this);
				break;
			case VERTICAL:
			default:
//				LayoutInflater.from(context).inflate(R.layout.pull_to_refresh_header_vertical, this);
				// 修改代码
				LayoutInflater.from(context).inflate(R.layout.pull_to_refresh_header_simple, this); 
				break;
		}

		mInnerLayout = (FrameLayout) findViewById(R.id.fl_inner);
		mHeaderText = (TextView) mInnerLayout.findViewById(R.id.pull_to_refresh_text);
		mHeaderProgress = (ProgressBar) mInnerLayout.findViewById(R.id.pull_to_refresh_progress);
		mSubHeaderText = (TextView) mInnerLayout.findViewById(R.id.pull_to_refresh_sub_text);
		mHeaderImage = (ImageView) mInnerLayout.findViewById(R.id.pull_to_refresh_image);
		

		FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams) mInnerLayout.getLayoutParams();

		switch (mode) {
			case PULL_FROM_END:
				lp.gravity = scrollDirection == Orientation.VERTICAL ? Gravity.TOP : Gravity.LEFT;

				// Load in labels
				mPullLabel = context.getString(R.string.pull_to_refresh_from_bottom_pull_label);
				mRefreshingLabel = context.getString(R.string.pull_to_refresh_from_bottom_refreshing_label);
				mReleaseLabel = context.getString(R.string.pull_to_refresh_from_bottom_release_label);
				break;

			case PULL_FROM_START:
			default:
				lp.gravity = scrollDirection == Orientation.VERTICAL ? Gravity.BOTTOM : Gravity.RIGHT;

				// Load in labels
				mPullLabel = context.getString(R.string.pull_to_refresh_pull_label);
				mRefreshingLabel = context.getString(R.string.pull_to_refresh_refreshing_label);
				mReleaseLabel = context.getString(R.string.pull_to_refresh_release_label);
				break;
		}

		if (attrs.hasValue(R.styleable.PullToRefresh_ptrHeaderBackground)) {
			Drawable background = attrs.getDrawable(R.styleable.PullToRefresh_ptrHeaderBackground);
			if (null != background) {
				ViewCompat.setBackground(this, background);
			}
		}

//		if (attrs.hasValue(R.styleable.PullToRefresh_ptrHeaderTextAppearance)) {
//			TypedValue styleID = new TypedValue();
//			attrs.getValue(R.styleable.PullToRefresh_ptrHeaderTextAppearance, styleID);
//			setTextAppearance(styleID.data);
//		}
//		if (attrs.hasValue(R.styleable.PullToRefresh_ptrSubHeaderTextAppearance)) {
//			TypedValue styleID = new TypedValue();
//			attrs.getValue(R.styleable.PullToRefresh_ptrSubHeaderTextAppearance, styleID);
//			setSubTextAppearance(styleID.data);
//		}
//
//		// Text Color attrs need to be set after TextAppearance attrs
//		if (attrs.hasValue(R.styleable.PullToRefresh_ptrHeaderTextColor)) {
//			ColorStateList colors = attrs.getColorStateList(R.styleable.PullToRefresh_ptrHeaderTextColor);
//			if (null != colors) {
//				setTextColor(colors);
//			}
//		}
//		if (attrs.hasValue(R.styleable.PullToRefresh_ptrHeaderSubTextColor)) {
//			ColorStateList colors = attrs.getColorStateList(R.styleable.PullToRefresh_ptrHeaderSubTextColor);
//			if (null != colors) {
//				setSubTextColor(colors);
//			}
//		}

		// Try and get defined drawable from Attrs
		Drawable imageDrawable = null;
		if (attrs.hasValue(R.styleable.PullToRefresh_ptrDrawable)) {
			imageDrawable = attrs.getDrawable(R.styleable.PullToRefresh_ptrDrawable);
		}

		// Check Specific Drawable from Attrs, these overrite the generic
		// drawable attr above
		switch (mode) {
			case PULL_FROM_START:
			default:
				if (attrs.hasValue(R.styleable.PullToRefresh_ptrDrawableStart)) {
					imageDrawable = attrs.getDrawable(R.styleable.PullToRefresh_ptrDrawableStart);
				} else if (attrs.hasValue(R.styleable.PullToRefresh_ptrDrawableTop)) {
					Utils.warnDeprecation("ptrDrawableTop", "ptrDrawableStart");
					imageDrawable = attrs.getDrawable(R.styleable.PullToRefresh_ptrDrawableTop);
				}
				break;

			case PULL_FROM_END:
				if (attrs.hasValue(R.styleable.PullToRefresh_ptrDrawableEnd)) {
					imageDrawable = attrs.getDrawable(R.styleable.PullToRefresh_ptrDrawableEnd);
				} else if (attrs.hasValue(R.styleable.PullToRefresh_ptrDrawableBottom)) {
					Utils.warnDeprecation("ptrDrawableBottom", "ptrDrawableEnd");
					imageDrawable = attrs.getDrawable(R.styleable.PullToRefresh_ptrDrawableBottom);
				}
				break;
		}

		// If we don't have a user defined drawable, load the default
		if (null == imageDrawable) {
			imageDrawable = context.getResources().getDrawable(getDefaultDrawableResId());
		}

		// Set Drawable, and save width/height
		setLoadingDrawable(imageDrawable);

		reset();
	}

	public final void setHeight(int height) {
		ViewGroup.LayoutParams lp = getLayoutParams();
		lp.height = height;
		requestLayout();
	}

	public final void setWidth(int width) {
		ViewGroup.LayoutParams lp = getLayoutParams();
		lp.width = width;
		requestLayout();
	}

	public final int getContentSize() {
		switch (mScrollDirection) {
			case HORIZONTAL:
				return mInnerLayout.getWidth();
			case VERTICAL:
			default:
				return mInnerLayout.getHeight();
		}
	}

	public final void hideAllViews() {
//		if (View.VISIBLE == mHeaderText.getVisibility()) {
//			mHeaderText.setVisibility(View.INVISIBLE);
//		}
//		if (View.VISIBLE == mHeaderProgress.getVisibility()) {
//			mHeaderProgress.setVisibility(View.INVISIBLE);
//		}
//		if (View.VISIBLE == mHeaderImage.getVisibility()) {
//			mHeaderImage.setVisibility(View.INVISIBLE);
//		}
//		if (View.VISIBLE == mSubHeaderText.getVisibility()) {
//			mSubHeaderText.setVisibility(View.INVISIBLE);
//		}
	}

	public final void onPull(float scaleOfLayout) {
		if (!mUseIntrinsicAnimation) {
			onPullImpl(scaleOfLayout);
		}
	}

	public final void pullToRefresh() {
//		if (null != mHeaderText) {
//			mHeaderText.setText(mPullLabel);
//		}

		// Now call the callback
		pullToRefreshImpl();
	}

	public final void refreshing() {
		if (null != mHeaderText) {
			mHeaderText.setText(mRefreshingLabel);
		}

		if (mUseIntrinsicAnimation) {
			((AnimationDrawable) mHeaderImage.getDrawable()).start();
		} else {
			// Now call the callback
			refreshingImpl();
		}

//		if (null != mSubHeaderText) {
//			mSubHeaderText.setVisibility(View.GONE);
//		}
	}

	public final void releaseToRefresh() {
//		if (null != mHeaderText) {
//			mHeaderText.setText(mReleaseLabel);
//		}

		// Now call the callback
		releaseToRefreshImpl();
	}

	public final void reset() {
//		if (null != mHeaderText) {
//			mHeaderText.setText(mPullLabel);
//		}
		mHeaderImage.setVisibility(View.VISIBLE);

		if (mUseIntrinsicAnimation) {
			((AnimationDrawable) mHeaderImage.getDrawable()).stop();
		} else {
			// Now call the callback
			resetImpl();
		}

//		if (null != mSubHeaderText) {
//			if (TextUtils.isEmpty(mSubHeaderText.getText())) {
//				mSubHeaderText.setVisibility(View.GONE);
//			} else {
//				mSubHeaderText.setVisibility(View.VISIBLE);
//			}
//		}
	}

	@Override
	public void setLastUpdatedLabel(CharSequence label) {
//		setSubHeaderText(label);
	}

	@Override
	public final void setLoadingDrawable(Drawable imageDrawable) {
		// Set Drawable
		mHeaderImage.setImageDrawable(imageDrawable);
		mUseIntrinsicAnimation = (imageDrawable instanceof AnimationDrawable);

		// Now call the callback
		onLoadingDrawableSet(imageDrawable);
	}

	@Override
	public void setPullLabel(CharSequence pullLabel) {
		mPullLabel = pullLabel;
	}

	@Override
	public void setRefreshingLabel(CharSequence refreshingLabel) {
		mRefreshingLabel = refreshingLabel;
	}

	@Override
	public void setReleaseLabel(CharSequence releaseLabel) {
		mReleaseLabel = releaseLabel;
	}

	@Override
	public void setTextTypeface(Typeface tf) {
		mHeaderText.setTypeface(tf);
	}

	public final void showInvisibleViews() {
//		if (View.INVISIBLE == mHeaderText.getVisibility()) {
//			mHeaderText.setVisibility(View.VISIBLE);
//		}
//		if (View.INVISIBLE == mHeaderProgress.getVisibility()) {
//			mHeaderProgress.setVisibility(View.VISIBLE);
//		}
		if (View.INVISIBLE == mHeaderImage.getVisibility()) {
			mHeaderImage.setVisibility(View.VISIBLE);
		}
//		if (View.INVISIBLE == mSubHeaderText.getVisibility()) {
//			mSubHeaderText.setVisibility(View.VISIBLE);
//		}
	}

	/**
	 * Callbacks for derivative Layouts
	 */

	protected abstract int getDefaultDrawableResId();

	protected abstract void onLoadingDrawableSet(Drawable imageDrawable);

	protected abstract void onPullImpl(float scaleOfLayout);

	protected abstract void pullToRefreshImpl();

	protected abstract void refreshingImpl();

	protected abstract void releaseToRefreshImpl();

	protected abstract void resetImpl();

	private void setSubHeaderText(CharSequence label) {
		if (null != mSubHeaderText) {
			if (TextUtils.isEmpty(label)) {
				mSubHeaderText.setVisibility(View.GONE);
			} else {
				mSubHeaderText.setText(label);

				// Only set it to Visible if we're GONE, otherwise VISIBLE will
				// be set soon
				if (View.GONE == mSubHeaderText.getVisibility()) {
					mSubHeaderText.setVisibility(View.VISIBLE);
				}
			}
		}
	}

	private void setSubTextAppearance(int value) {
		if (null != mSubHeaderText) {
			mSubHeaderText.setTextAppearance(getContext(), value);
		}
	}

	private void setSubTextColor(ColorStateList color) {
		if (null != mSubHeaderText) {
			mSubHeaderText.setTextColor(color);
		}
	}

	private void setTextAppearance(int value) {
		if (null != mHeaderText) {
			mHeaderText.setTextAppearance(getContext(), value);
		}
		if (null != mSubHeaderText) {
			mSubHeaderText.setTextAppearance(getContext(), value);
		}
	}

	private void setTextColor(ColorStateList color) {
		if (null != mHeaderText) {
			mHeaderText.setTextColor(color);
		}
		if (null != mSubHeaderText) {
			mSubHeaderText.setTextColor(color);
		}
	}

}

最后就不要让我提供源码了，笔者这里只是提供一个思路，把刷新的头布局更改为我们的自定义布局就行了。

最终效果是下拉刷新的时候会有一个不停在闪的灯，这里没有录制gif动画，只提供一张截图吧：