Java tutorial
/* * Copyright (C) 2016 hejunlin * * 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.yuandong.brandviewdemo.widget.brandLooper; import android.animation.Animator; import android.animation.AnimatorInflater; import android.annotation.TargetApi; import android.content.Context; import android.content.res.TypedArray; import android.database.DataSetObserver; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.os.Build; import android.support.annotation.AnimatorRes; import android.support.annotation.DrawableRes; import android.support.v4.view.ViewPager; import android.util.AttributeSet; import android.util.Log; import android.view.Gravity; import android.view.View; import android.view.animation.Interpolator; import android.widget.LinearLayout; import com.yuandong.brandviewdemo.R; import static android.support.v4.view.ViewPager.OnPageChangeListener; public class CircleIndicator extends LinearLayout { private final static int DEFAULT_INDICATOR_WIDTH = 5; private final static String TAG = "CircleIndicator"; private ViewPager mViewpager; private int mIndicatorMargin = -1; private int mIndicatorWidth = -1; private int mIndicatorHeight = -1; private int mAnimatorResId = R.animator.scale_with_alpha; private int mAnimatorReverseResId = 0; private int mIndicatorBackgroundResId = R.drawable.white_radius; private int mIndicatorUnselectedBackgroundResId = R.drawable.white_radius; private Animator mAnimatorOut; private Animator mAnimatorIn; private Animator mImmediateAnimatorOut; private Animator mImmediateAnimatorIn; private int mLastPosition = -1; public CircleIndicator(Context context) { super(context); init(context, null); } public CircleIndicator(Context context, AttributeSet attrs) { super(context, attrs); init(context, attrs); } public CircleIndicator(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(context, attrs); } @TargetApi(Build.VERSION_CODES.LOLLIPOP) public CircleIndicator(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { super(context, attrs, defStyleAttr, defStyleRes); init(context, attrs); } private void init(Context context, AttributeSet attrs) { handleTypedArray(context, attrs); checkIndicatorConfig(context); } private void handleTypedArray(Context context, AttributeSet attrs) { if (attrs == null) { return; } TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.CircleIndicator); mIndicatorWidth = typedArray.getDimensionPixelSize(R.styleable.CircleIndicator_ci_width, -1); mIndicatorHeight = typedArray.getDimensionPixelSize(R.styleable.CircleIndicator_ci_height, -1); mIndicatorMargin = typedArray.getDimensionPixelSize(R.styleable.CircleIndicator_ci_margin, -1); mAnimatorResId = typedArray.getResourceId(R.styleable.CircleIndicator_ci_animator, R.animator.scale_with_alpha); mAnimatorReverseResId = typedArray.getResourceId(R.styleable.CircleIndicator_ci_animator_reverse, 0); mIndicatorBackgroundResId = typedArray.getResourceId(R.styleable.CircleIndicator_ci_drawable, R.drawable.white_radius); mIndicatorUnselectedBackgroundResId = typedArray .getResourceId(R.styleable.CircleIndicator_ci_drawable_unselected, mIndicatorBackgroundResId); int orientation = typedArray.getInt(R.styleable.CircleIndicator_ci_orientation, -1); setOrientation(orientation == VERTICAL ? VERTICAL : HORIZONTAL); int gravity = typedArray.getInt(R.styleable.CircleIndicator_ci_gravity, -1); setGravity(gravity >= 0 ? gravity : Gravity.CENTER); typedArray.recycle(); } /** * Create and configure Indicator in Java code. */ public void configureIndicator(int indicatorWidth, int indicatorHeight, int indicatorMargin) { configureIndicator(indicatorWidth, indicatorHeight, indicatorMargin, R.animator.scale_with_alpha, 0, R.drawable.white_radius, R.drawable.white_radius); } public void configureIndicator(int indicatorWidth, int indicatorHeight, int indicatorMargin, @AnimatorRes int animatorId, @AnimatorRes int animatorReverseId, @DrawableRes int indicatorBackgroundId, @DrawableRes int indicatorUnselectedBackgroundId) { mIndicatorWidth = indicatorWidth; mIndicatorHeight = indicatorHeight; mIndicatorMargin = indicatorMargin; mAnimatorResId = animatorId; mAnimatorReverseResId = animatorReverseId; mIndicatorBackgroundResId = indicatorBackgroundId; mIndicatorUnselectedBackgroundResId = indicatorUnselectedBackgroundId; checkIndicatorConfig(getContext()); } private void checkIndicatorConfig(Context context) { mIndicatorWidth = (mIndicatorWidth < 0) ? dip2px(DEFAULT_INDICATOR_WIDTH) : mIndicatorWidth; mIndicatorHeight = (mIndicatorHeight < 0) ? dip2px(DEFAULT_INDICATOR_WIDTH) : mIndicatorHeight; mIndicatorMargin = (mIndicatorMargin < 0) ? dip2px(DEFAULT_INDICATOR_WIDTH) : mIndicatorMargin; mAnimatorResId = (mAnimatorResId == 0) ? R.animator.scale_with_alpha : mAnimatorResId; mAnimatorOut = createAnimatorOut(context); mImmediateAnimatorOut = createAnimatorOut(context); mImmediateAnimatorOut.setDuration(0); mAnimatorIn = createAnimatorIn(context); mImmediateAnimatorIn = createAnimatorIn(context); mImmediateAnimatorIn.setDuration(0); mIndicatorBackgroundResId = (mIndicatorBackgroundResId == 0) ? R.drawable.white_radius : mIndicatorBackgroundResId; mIndicatorUnselectedBackgroundResId = (mIndicatorUnselectedBackgroundResId == 0) ? mIndicatorBackgroundResId : mIndicatorUnselectedBackgroundResId; } private Animator createAnimatorOut(Context context) { return AnimatorInflater.loadAnimator(context, mAnimatorResId); } private Animator createAnimatorIn(Context context) { Animator animatorIn; if (mAnimatorReverseResId == 0) { animatorIn = AnimatorInflater.loadAnimator(context, mAnimatorResId); animatorIn.setInterpolator(new ReverseInterpolator()); } else { animatorIn = AnimatorInflater.loadAnimator(context, mAnimatorReverseResId); } return animatorIn; } public void setViewPager(ViewPager viewPager) { mViewpager = viewPager; if (mViewpager != null && mViewpager.getAdapter() != null) { mLastPosition = -1; createIndicators(); mViewpager.removeOnPageChangeListener(mInternalPageChangeListener); mViewpager.addOnPageChangeListener(mInternalPageChangeListener); mInternalPageChangeListener.onPageSelected(mViewpager.getCurrentItem()); } } private final OnPageChangeListener mInternalPageChangeListener = new OnPageChangeListener() { @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { Log.e(TAG, "<< onPageScrolled position :" + position + ", positionOffset: " + positionOffset + ", positionOffsetPixels: " + positionOffsetPixels); } @Override public void onPageSelected(int position) { Log.e(TAG, "<< onPageSelected position :" + position); if (mViewpager.getAdapter() == null || mViewpager.getAdapter().getCount() <= 0) { return; } if (mAnimatorIn.isRunning()) { mAnimatorIn.end(); mAnimatorIn.cancel(); } if (mAnimatorOut.isRunning()) { mAnimatorOut.end(); mAnimatorOut.cancel(); } View currentIndicator; if (mLastPosition >= 0 && (currentIndicator = getChildAt(mLastPosition)) != null) { currentIndicator.setBackgroundResource(mIndicatorUnselectedBackgroundResId); mAnimatorIn.setTarget(currentIndicator); mAnimatorIn.start(); } View selectedIndicator = getChildAt(position); if (selectedIndicator != null) { selectedIndicator.setBackgroundResource(mIndicatorBackgroundResId); mAnimatorOut.setTarget(selectedIndicator); mAnimatorOut.start(); } mLastPosition = position; } @Override public void onPageScrollStateChanged(int state) { Log.e(TAG, "<< onPageSelected position :" + state); } }; public DataSetObserver getDataSetObserver() { return mInternalDataSetObserver; } private DataSetObserver mInternalDataSetObserver = new DataSetObserver() { @Override public void onChanged() { super.onChanged(); if (mViewpager == null) { return; } int newCount = mViewpager.getAdapter().getCount(); int currentCount = getChildCount(); if (newCount == currentCount) { // No change return; } else if (mLastPosition < newCount) { mLastPosition = mViewpager.getCurrentItem(); } else { mLastPosition = -1; } createIndicators(); } }; /** * @deprecated User ViewPager addOnPageChangeListener */ @Deprecated public void setOnPageChangeListener(OnPageChangeListener onPageChangeListener) { if (mViewpager == null) { throw new NullPointerException("can not find Viewpager , setViewPager first"); } mViewpager.removeOnPageChangeListener(onPageChangeListener); mViewpager.addOnPageChangeListener(onPageChangeListener); } private void createIndicators() { removeAllViews(); int count = mViewpager.getAdapter().getCount(); if (count <= 0) { return; } int currentItem = mViewpager.getCurrentItem(); for (int i = 0; i < count; i++) { if (currentItem == i) { addIndicator(mIndicatorBackgroundResId, mImmediateAnimatorOut); } else { addIndicator(mIndicatorUnselectedBackgroundResId, mImmediateAnimatorIn); } } } private void addIndicator(@DrawableRes int backgroundDrawableId, Animator animator) { if (animator.isRunning()) { animator.end(); animator.cancel(); } View Indicator = new View(getContext()); Indicator.setBackgroundResource(backgroundDrawableId); addView(Indicator, mIndicatorWidth, mIndicatorHeight); LayoutParams lp = (LayoutParams) Indicator.getLayoutParams(); lp.leftMargin = mIndicatorMargin; lp.rightMargin = mIndicatorMargin; Indicator.setLayoutParams(lp); animator.setTarget(Indicator); animator.start(); } private class ReverseInterpolator implements Interpolator { @Override public float getInterpolation(float value) { return Math.abs(1.0f - value); } } public int dip2px(float dpValue) { final float scale = getResources().getDisplayMetrics().density; return (int) (dpValue * scale + 0.5f); } }