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.melvin.android.base.common.ui; 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.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.HorizontalScrollView; import android.widget.LinearLayout; import android.widget.TextView; import com.uucun.android.utils.r.RFileUtil; /** * This widget implements the dynamic action bar tab behavior that can change * across different configurations or circumstances. */ public class TabPageIndicator extends HorizontalScrollView implements PageIndicator { Runnable mTabSelector; private OnClickListener mTabClickListener = new OnClickListener() { public void onClick(View view) { int index = (Integer) view.getTag(); mViewPager.setCurrentItem(index); if (custClickListener != null) custClickListener.clickTab(index); } }; private CustClickListener custClickListener = null; private LinearLayout mTabLayout; private ViewPager mViewPager; private ViewPager.OnPageChangeListener mListener; private LayoutInflater mInflater; int mMaxTabWidth; private int mSelectedTabIndex; private Context mContext; public TabPageIndicator(Context context) { this(context, null); mContext = context; } public void setCustClickListener(CustClickListener listener) { custClickListener = listener; } public interface CustClickListener { public void clickTab(int index); } public TabPageIndicator(Context context, AttributeSet attrs) { super(context, attrs); mContext = context; setHorizontalScrollBarEnabled(false); setSmoothScrollingEnabled(true); setHorizontalFadingEdgeEnabled(false); setHorizontalScrollBarEnabled(false); mInflater = LayoutInflater.from(context); mTabLayout = new LinearLayout(getContext()); addView(mTabLayout, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.MATCH_PARENT)); } 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) * 0.2f); } 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); } public void onAttachedToWindow() { super.onAttachedToWindow(); if (mTabSelector != null) { // Re-post the selector we saved post(mTabSelector); } } public void onDetachedFromWindow() { super.onDetachedFromWindow(); if (mTabSelector != null) { removeCallbacks(mTabSelector); } } private void addTab(String text, int index) { // Workaround for not being able to pass a defStyle on pre-3.0 RFileUtil fileUtil = RFileUtil.getInstance(this.mContext); int layoutid = fileUtil.getLayoutValue("tab_item_layout"); LinearLayout linear = (LinearLayout) mInflater.inflate(layoutid, null); linear.setFocusable(true); linear.setOnClickListener(mTabClickListener); TextView vv = (TextView) linear.findViewById(android.R.id.text1); vv.setText(text); linear.setTag(index); mTabLayout.addView(linear, new LinearLayout.LayoutParams(0, LayoutParams.MATCH_PARENT, 1)); } public void onPageScrollStateChanged(int arg0) { if (mListener != null) { mListener.onPageScrollStateChanged(arg0); } } public void onPageScrolled(int arg0, float arg1, int arg2) { if (mListener != null) { mListener.onPageScrolled(arg0, arg1, arg2); } } public void onPageSelected(int arg0) { setCurrentItem(arg0); if (mListener != null) { mListener.onPageSelected(arg0); } } public void setViewPager(ViewPager view) { final PagerAdapter adapter = view.getAdapter(); if (adapter == null) { throw new IllegalStateException("ViewPager does not have adapter instance."); } if (!(adapter instanceof TitleProvider)) { throw new IllegalStateException( "ViewPager adapter must implement TitleProvider to be used with TitlePageIndicator."); } mViewPager = view; view.setOnPageChangeListener(this); notifyDataSetChanged(); } public void notifyDataSetChanged() { mTabLayout.removeAllViews(); TitleProvider adapter = (TitleProvider) mViewPager.getAdapter(); final int count = ((PagerAdapter) adapter).getCount(); for (int i = 0; i < count; i++) { addTab(adapter.getTitle(i), i); } if (mSelectedTabIndex > count) { mSelectedTabIndex = count - 1; } setCurrentItem(mSelectedTabIndex); requestLayout(); } public void setViewPager(ViewPager view, int initialPosition) { setViewPager(view); setCurrentItem(initialPosition); } public void setCurrentItem(int item) { if (mViewPager == null) { throw new IllegalStateException("ViewPager has not been bound."); } mSelectedTabIndex = item; final int tabCount = mTabLayout.getChildCount(); for (int i = 0; i < tabCount; i++) { View child = mTabLayout.getChildAt(i); boolean isSelected = (i == item); child.setSelected(isSelected); if (isSelected) { animateToTab(item); } } } public void setOnPageChangeListener(OnPageChangeListener listener) { mListener = listener; } }