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.zhongsou.souyue.ui.indicator; import android.annotation.SuppressLint; import android.content.Context; import android.graphics.Color; import android.graphics.drawable.ColorDrawable; 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.Gravity; import android.view.View; import android.view.ViewGroup; import android.widget.HorizontalScrollView; import android.widget.LinearLayout; import android.widget.TextView; import com.zhongsou.souyue.R; import com.zhongsou.souyue.activity.SubscribeListActivity.TabPagerAdapter; import static android.view.ViewGroup.LayoutParams.MATCH_PARENT; /** * This widget implements the dynamic action bar tab behavior that can change * across different configurations or circumstances. */ public class SuberPageIndicator extends HorizontalScrollView implements PageIndicator { /** Title text used when no title is provided by the adapter. */ private static final CharSequence EMPTY_TITLE = ""; /** * 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 Runnable mTabSelector; private final OnClickListener mTabClickListener = new OnClickListener() { public void onClick(View view) { TabView tabView = (TabView) view; final int oldSelected = mViewPager.getCurrentItem(); final int newSelected = tabView.getIndex(); mViewPager.setCurrentItem(newSelected); if (oldSelected == newSelected && mTabReselectedListener != null) { mTabReselectedListener.onTabReselected(newSelected); } } }; private final IcsLinearLayout mTabLayout; private ViewPager mViewPager; private ViewPager.OnPageChangeListener mListener; private int mMaxTabWidth; private int mSelectedTabIndex; private OnTabReselectedListener mTabReselectedListener; public SuberPageIndicator(Context context) { this(context, null); } public SuberPageIndicator(Context context, AttributeSet attrs) { super(context, attrs); setHorizontalScrollBarEnabled(false); mTabLayout = new IcsLinearLayout(context, R.attr.vpiTabPageIndicatorStyle); //5.05 mTabLayout.setDividerDrawable(new ColorDrawable(Color.TRANSPARENT)); addView(mTabLayout, new ViewGroup.LayoutParams(MATCH_PARENT, (int) getResources().getDimension(R.dimen.space_35))); } public void setOnTabReselectedListener(OnTabReselectedListener listener) { mTabReselectedListener = listener; } @Override public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { final int widthMode = MeasureSpec.getMode(widthMeasureSpec); final boolean lockedExpanded = widthMode == MeasureSpec.EXACTLY; setFillViewport(lockedExpanded); final int childCount = mTabLayout.getChildCount(); if (childCount > 1 && (widthMode == MeasureSpec.EXACTLY || widthMode == MeasureSpec.AT_MOST)) { if (childCount > 2) { 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); } } 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); mTabSelector = null; } }; post(mTabSelector); } @Override public void onAttachedToWindow() { super.onAttachedToWindow(); if (mTabSelector != null) { // Re-post the selector we saved post(mTabSelector); } } @Override public void onDetachedFromWindow() { super.onDetachedFromWindow(); if (mTabSelector != null) { removeCallbacks(mTabSelector); } } 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(0, iconResId, 0, 0); }*/ LinearLayout.LayoutParams parmas = new LinearLayout.LayoutParams(0, MATCH_PARENT, 1); parmas.gravity = Gravity.CENTER_HORIZONTAL; tabView.setGravity(Gravity.CENTER); mTabLayout.addView(tabView, parmas); } @Override public void onPageScrollStateChanged(int arg0) { if (mListener != null) { mListener.onPageScrollStateChanged(arg0); } } @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); } } @Override public void setViewPager(ViewPager view) { if (mViewPager == view) { return; } if (mViewPager != null) { mViewPager.setOnPageChangeListener(null); } final PagerAdapter adapter = view.getAdapter(); if (adapter == null) { throw new IllegalStateException("ViewPager does not have adapter instance."); } mViewPager = view; view.setOnPageChangeListener(this); notifyDataSetChanged(); } public void notifyDataSetChanged() { mTabLayout.removeAllViews(); PagerAdapter adapter = mViewPager.getAdapter(); TabPagerAdapter iconAdapter = null; if (adapter instanceof PagerAdapter) { iconAdapter = (TabPagerAdapter) 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); } @Override public void setCurrentItem(int item) { if (mViewPager == null) { throw new IllegalStateException("ViewPager has not been bound."); } mSelectedTabIndex = item; mViewPager.setCurrentItem(item); final int tabCount = mTabLayout.getChildCount(); for (int i = 0; i < tabCount; i++) { final TextView child = (TextView) mTabLayout.getChildAt(i); final boolean isSelected = (i == item); if (isSelected) { //?. child.setTextColor(Color.parseColor("#da4644")); child.setBackgroundResource(R.drawable.suberlist_indicator_underline); } else { //????? child.setTextColor(getResources().getColor(R.color.middark_black)); child.setBackgroundColor(Color.TRANSPARENT); } child.setSelected(isSelected); if (isSelected) { animateToTab(item); } } } @Override public void setOnPageChangeListener(OnPageChangeListener listener) { mListener = listener; } private class TabView extends TextView { private int mIndex; @SuppressLint("NewApi") public TabView(Context context) { super(context, null, R.attr.vpiTabPageIndicatorStyle); this.setGravity(Gravity.CENTER_HORIZONTAL); this.setLayoutDirection(TEXT_DIRECTION_INHERIT); } @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; } } }