Java tutorial
/* * Copyright (C) 2011 The Android Open Source Project * Copyright (C) 2011 Jake Wharton * * 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.zhuo.tong.view.pager_indicator; import static android.view.ViewGroup.LayoutParams.MATCH_PARENT; import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT; import java.util.List; import android.content.Context; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.support.v4.view.ViewPager.OnPageChangeListener; import android.util.AttributeSet; import android.view.View; import android.view.ViewGroup; import android.widget.HorizontalScrollView; import android.widget.LinearLayout; import android.widget.TextView; import com.zhuo.tong.R; /** * ?????? * ViewPager.OnPageChangeListener? * page?setOnPageChangeListener * * ? * setViewPagerHaveTitlesetTabssetViewPagerHaveTitle? * tabviewtagadaptertitletitleEMPTY_TITLE * * setTabsview??tag???viewpagerviewpager * * ?????? */ public class TabPagerIndicator extends HorizontalScrollView implements IPagerIndicator { /** titletitle */ private static final CharSequence EMPTY_TITLE = ""; private boolean viewPagerHaveTitle; private boolean HaveUserTag; /** * ???tab??? * Interface for a callback when the selected tab has been reselected. */ public interface OnTabReselectedListener { /** * Callback when the selected tab has been reselected. * ???? * @param position Position of the current center item. */ void onTabReselected(int position); } private OnTabReselectedListener mTabReselectedListener; private final OnClickListener mTabClickListener = new OnClickListener() { public void onClick(View view) { if (viewPagerHaveTitle && !HaveUserTag) { TabView tabView = (TabView) view; final int oldSelected = mViewPager.getCurrentItem(); final int newSelected = tabView.getIndex(); setCurrentItem(newSelected); if (oldSelected == newSelected && mTabReselectedListener != null) { mTabReselectedListener.onTabReselected(newSelected); } } else if (HaveUserTag) { setCurrentItem(view); if (view == mTabLayout.getChildAt(mSelectedTabIndex) && mTabReselectedListener != null) { mTabReselectedListener.onTabReselected(mSelectedTabIndex); } } } }; /** * ??tab??? * @param listener */ public void setOnTabReselectedListener(OnTabReselectedListener listener) { mTabReselectedListener = listener; } private final DividerLinearLayout mTabLayout; private ViewPager mViewPager; private ViewPager.OnPageChangeListener mListener; private int mMaxTabWidth; private int mSelectedTabIndex; public TabPagerIndicator(Context context) { this(context, null); } public TabPagerIndicator(Context context, AttributeSet attrs) { super(context, attrs); setHorizontalScrollBarEnabled(false); // mTabLayout = (LinearLayout) LayoutInflater.from(context).inflate(R.layout.tabpager_dividerlinearlayout, this); mTabLayout = new DividerLinearLayout(context, attrs); addView(mTabLayout, new ViewGroup.LayoutParams(WRAP_CONTENT, MATCH_PARENT)); } /** * ???tag(????tag)2??4 * @param num */ public void setTabNumVisible(int num) { final int childCount = mTabLayout.getChildCount(); if (num < 0 || num > childCount) { } } @Override public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { final int widthMode = MeasureSpec.getMode(widthMeasureSpec); final boolean lockedExpanded = widthMode == MeasureSpec.EXACTLY; //?View??????match_parent0dptrue setFillViewport(lockedExpanded); final int childCount = mTabLayout.getChildCount(); if (childCount > 1 && (widthMode == MeasureSpec.EXACTLY || widthMode == MeasureSpec.AT_MOST)) { if (childCount > 2) {//4 mMaxTabWidth = (int) (MeasureSpec.getSize(widthMeasureSpec) * 0.4f); } else { mMaxTabWidth = MeasureSpec.getSize(widthMeasureSpec) / 2; } } else { mMaxTabWidth = -1; } final int oldWidth = getMeasuredWidth(); super.onMeasure(widthMeasureSpec, heightMeasureSpec); final int newWidth = getMeasuredWidth(); if (lockedExpanded && oldWidth != newWidth) { // Recenter the tab display if we're at a new (scrollable) size. setCurrentItem(mSelectedTabIndex); } } /*******************************Tab??************************************/ private Runnable mTabSelector; private boolean UserTagbind; private void animateToTab(final int position) { final View tabView = mTabLayout.getChildAt(position); if (mTabSelector != null) { removeCallbacks(mTabSelector); } mTabSelector = new Runnable() { public void run() { final int scrollPos = tabView.getLeft() - (getWidth() - tabView.getWidth()) / 2; smoothScrollTo(scrollPos, 0); /*scrollTo ?? smoothScrollTo scrollTo?? smoothScrollTo? ? scrollView.scrollTo(0, 0); scrollView.smoothScrollTo(0, 0); ??*/ mTabSelector = null; } }; post(mTabSelector); } @Override public void onAttachedToWindow() { super.onAttachedToWindow(); if (mTabSelector != null) { // Re-post the selector we saved post(mTabSelector);//Runnable????? } } @Override public void onDetachedFromWindow() { super.onDetachedFromWindow(); if (mTabSelector != null) { removeCallbacks(mTabSelector); } } /*******************************Tab??************************************/ private void addTab(int index, CharSequence text, int iconResId) { final TabView tabView = new TabView(getContext()); tabView.mIndex = index; tabView.setFocusable(true); tabView.setOnClickListener(mTabClickListener); tabView.setText(text); if (iconResId != 0) { tabView.setCompoundDrawablesWithIntrinsicBounds(iconResId, 0, 0, 0); } mTabLayout.addView(tabView, new LinearLayout.LayoutParams(0, MATCH_PARENT, 1)); } /**ViewPager.OnPageChangeListener?**/ @Override public void onPageScrollStateChanged(int state) { if (mListener != null) { mListener.onPageScrollStateChanged(state); } } @Override public void onPageScrolled(int arg0, float arg1, int arg2) { if (mListener != null) { mListener.onPageScrolled(arg0, arg1, arg2); } } @Override public void onPageSelected(int arg0) { setCurrentItem(arg0); if (mListener != null) { mListener.onPageSelected(arg0); } } /**TabPagerIndicator?**/ @Override public void setViewPagerHaveTitle(ViewPager view) { setViewPager(view, true); } @Override public void setViewPager(ViewPager view) { setViewPager(view, false); } public void setViewPager(ViewPager view, boolean haveTitle) { if (mViewPager == view && !HaveUserTag) { return; } if (mViewPager != null) { mViewPager.setOnPageChangeListener(null); } mViewPager = view; viewPagerHaveTitle = haveTitle; HaveUserTag = !haveTitle; if (viewPagerHaveTitle) { UserTagbind = false; } if (view != null) view.setOnPageChangeListener(this); notifyDataSetChanged(); } @Override public void notifyDataSetChanged() { if (HaveUserTag) { final int count = mTabLayout.getChildCount(); if (mSelectedTabIndex > count) { mSelectedTabIndex = count - 1; } setCurrentItem(mSelectedTabIndex); } else { mTabLayout.removeAllViews(); if (mViewPager != null && viewPagerHaveTitle) { PagerAdapter adapter = mViewPager.getAdapter(); if (adapter != null) { IIconPagerAdapter iconAdapter = null; if (adapter instanceof IIconPagerAdapter) { iconAdapter = (IIconPagerAdapter) adapter; } final int count = adapter.getCount(); for (int i = 0; i < count; i++) { CharSequence title = adapter.getPageTitle(i); if (title == null) { title = EMPTY_TITLE; } int iconResId = 0; if (iconAdapter != null) { iconResId = iconAdapter.getIconResId(i); } addTab(i, title, iconResId); } if (mSelectedTabIndex > count) { mSelectedTabIndex = count - 1; } setCurrentItem(mSelectedTabIndex); } } } requestLayout(); } @Override public void setViewPager(ViewPager view, int initialPosition) { setViewPager(view); setCurrentItem(initialPosition); } /** * Viewpageradaptertitletag? */ @Override public void setViewPagerHaveTitle(ViewPager view, int initialPosition) { setViewPagerHaveTitle(view); setCurrentItem(initialPosition); } @Override public void setCurrentItem(int item) { final int tabCount = mTabLayout.getChildCount(); if (item > tabCount || item < 0) return; if (mViewPager != null && UserTagbind) mViewPager.setCurrentItem(item); mSelectedTabIndex = item; if ((mViewPager != null && viewPagerHaveTitle) || (HaveUserTag && UserTagbind)) { for (int i = 0; i < tabCount; i++) { final View child = mTabLayout.getChildAt(i); final boolean isSelected = (i == item); child.setSelected(isSelected); if (isSelected) { animateToTab(item); } } } } public void setCurrentItem(View currrentTagView) { if (currrentTagView == null || currrentTagView.getVisibility() != View.VISIBLE) return; final int tabCount = mTabLayout.getChildCount(); for (int i = 0; i < tabCount; i++) { final View child = mTabLayout.getChildAt(i); if (currrentTagView == child) { mSelectedTabIndex = i; if (mViewPager != null && UserTagbind) mViewPager.setCurrentItem(i); child.setSelected(true); animateToTab(i); } else { child.setSelected(false); } } } @Override public void setOnPageChangeListener(OnPageChangeListener listener) { mListener = listener; } /** * tag?tag???viewpagerviewpager?true? * ??viewpagertagview * @param views * @param bindViewPager * @return */ public boolean setTabs(List<View> views, boolean bindViewPager) { UserTagbind = false; if (views == null) return UserTagbind; mTabLayout.removeAllViews(); for (View view : views) { view.setOnClickListener(mTabClickListener); mTabLayout.addView(view, new LinearLayout.LayoutParams(0, MATCH_PARENT, 1)); } HaveUserTag = true; if (mViewPager != null) { if (bindViewPager) { mViewPager.setOnPageChangeListener(this); UserTagbind = true; } else { mViewPager.setOnPageChangeListener(null); } } notifyDataSetChanged(); return UserTagbind; } public void setUserTagbind(boolean userTagbind) { if (mViewPager != null && HaveUserTag && userTagbind) { UserTagbind = true; mViewPager.setOnPageChangeListener(this); } else { UserTagbind = false; mViewPager.setOnPageChangeListener(null); } } public boolean getUserTagbind() { return UserTagbind; } private class TabView extends TextView { private int mIndex; public TabView(Context context) { super(context, null, R.attr.PagerIndicatorStyle); } @Override public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); // Re-measure if we went beyond our maximum size. if (mMaxTabWidth > 0 && getMeasuredWidth() > mMaxTabWidth) { super.onMeasure(MeasureSpec.makeMeasureSpec(mMaxTabWidth, MeasureSpec.EXACTLY), heightMeasureSpec); } } public int getIndex() { return mIndex; } } }