Java tutorial
/******************************************************************************* * Copyright 2011, 2012 Chris Banes. * <p> * 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 * <p> * http://www.apache.org/licenses/LICENSE-2.0 * <p> * 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 library.internal; import android.annotation.SuppressLint; import android.content.Context; import android.graphics.Matrix; import android.graphics.drawable.Drawable; import android.support.v4.content.ContextCompat; import android.view.View; import android.view.animation.Animation; import android.view.animation.Animation.AnimationListener; import android.view.animation.AnimationUtils; import android.view.animation.Interpolator; import android.view.animation.LinearInterpolator; import android.view.animation.RotateAnimation; import android.widget.FrameLayout; import android.widget.ImageView; import android.widget.ImageView.ScaleType; import app.gdpi.library.R; import library.PullToRefreshBase; @SuppressLint("ViewConstructor") public class IndicatorLayout extends FrameLayout implements AnimationListener { static final int DEFAULT_ROTATION_ANIMATION_DURATION = 150; private Animation mInAnim, mOutAnim; private ImageView mArrowImageView; private final Animation mRotateAnimation, mResetRotateAnimation; public IndicatorLayout(Context context, PullToRefreshBase.Mode mode) { super(context); mArrowImageView = new ImageView(context); Drawable arrowD = ContextCompat.getDrawable(context, R.drawable.indicator_arrow); mArrowImageView.setImageDrawable(arrowD); final int padding = getResources().getDimensionPixelSize(R.dimen.indicator_internal_padding); mArrowImageView.setPadding(padding, padding, padding, padding); addView(mArrowImageView); int inAnimResId, outAnimResId; switch (mode) { case PULL_FROM_END: inAnimResId = R.anim.slide_in_from_bottom; outAnimResId = R.anim.slide_out_to_bottom; setBackgroundResource(R.drawable.indicator_bg_bottom); // Rotate Arrow so it's pointing the correct way mArrowImageView.setScaleType(ScaleType.MATRIX); Matrix matrix = new Matrix(); matrix.setRotate(180f, arrowD.getIntrinsicWidth() / 2f, arrowD.getIntrinsicHeight() / 2f); mArrowImageView.setImageMatrix(matrix); break; default: case PULL_FROM_START: inAnimResId = R.anim.slide_in_from_top; outAnimResId = R.anim.slide_out_to_top; setBackgroundResource(R.drawable.indicator_bg_top); break; } mInAnim = AnimationUtils.loadAnimation(context, inAnimResId); mInAnim.setAnimationListener(this); mOutAnim = AnimationUtils.loadAnimation(context, outAnimResId); mOutAnim.setAnimationListener(this); final Interpolator interpolator = new LinearInterpolator(); mRotateAnimation = new RotateAnimation(0, -180, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f); mRotateAnimation.setInterpolator(interpolator); mRotateAnimation.setDuration(DEFAULT_ROTATION_ANIMATION_DURATION); mRotateAnimation.setFillAfter(true); mResetRotateAnimation = new RotateAnimation(-180, 0, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f); mResetRotateAnimation.setInterpolator(interpolator); mResetRotateAnimation.setDuration(DEFAULT_ROTATION_ANIMATION_DURATION); mResetRotateAnimation.setFillAfter(true); } public final boolean isVisible() { Animation currentAnim = getAnimation(); if (null != currentAnim) { return mInAnim == currentAnim; } return getVisibility() == View.VISIBLE; } public void hide() { startAnimation(mOutAnim); } public void show() { mArrowImageView.clearAnimation(); startAnimation(mInAnim); } @Override public void onAnimationEnd(Animation animation) { if (animation == mOutAnim) { mArrowImageView.clearAnimation(); setVisibility(View.GONE); } else if (animation == mInAnim) { setVisibility(View.VISIBLE); } clearAnimation(); } @Override public void onAnimationRepeat(Animation animation) { // NO-OP } @Override public void onAnimationStart(Animation animation) { setVisibility(View.VISIBLE); } public void releaseToRefresh() { mArrowImageView.startAnimation(mRotateAnimation); } public void pullToRefresh() { mArrowImageView.startAnimation(mResetRotateAnimation); } }