Java tutorial
/* * Copyright 2014 Google Inc. All rights reserved. * * 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.starshow.app.view; import android.content.Context; import android.graphics.Color; import android.graphics.Typeface; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.util.AttributeSet; import android.util.SparseArray; import android.util.TypedValue; import android.view.Gravity; 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.xfdream.soft.starshow.R; import java.util.ArrayList; import java.util.List; /** * ?ViewPager???????? * ?? * ? {@link android.app.Activity} {@link android.support.v4.app.Fragment} * {@link #setViewPager(ViewPager)} ??ViewPager * <p/> * ?? * ? {@link #setSelectedIndicatorColors(int...)} ?? * ?? {@link TabColorizer} ???? * <p/> * ??? {@link #setCustomTabView(int, int)} ??LayoutId */ public class SlidingTabLayout extends HorizontalScrollView { /** * ? * {@link #setCustomTabColorizer(TabColorizer)}? */ public interface TabColorizer { /** * @return ? {@code position} */ int getIndicatorColor(int position); int getIndicatorHeight(); /** * @return return the color of the divider drawn to the right of {@code position}. */ int getDividerColor(int position); } private static final int TITLE_OFFSET_DIPS = 24; private static final int TAB_VIEW_PADDING_DIPS = 16; private static final int TAB_VIEW_TEXT_SIZE_SP = 12; private int mTitleOffset; private int mTabViewLayoutId; private int mTabViewTextViewId; private boolean mDistributeEvenly; private ViewPager mViewPager; private SparseArray<String> mContentDescriptions = new SparseArray<String>(); private ViewPager.OnPageChangeListener mViewPagerPageChangeListener; private final SlidingTabStrip mTabStrip; private int frgCount; private List<TextView> textViewList = new ArrayList<>(); private int tabTitleTextSize = 12; private int selectedTitleTextColor = Color.BLACK; private int unselectedTitleTextColor = Color.BLACK; private int selectedTitleBgColor = Color.WHITE; private int unselectedTitleBgColor = Color.WHITE; private int selectedTitleBg = 0; private int unselectedTitleBg = 0; public SlidingTabLayout(Context context) { this(context, null); } public SlidingTabLayout(Context context, AttributeSet attrs) { this(context, attrs, 0); } public SlidingTabLayout(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); // Disable the Scroll Bar setHorizontalScrollBarEnabled(false); // Make sure that the Tab Strips fills this View setFillViewport(true); mTitleOffset = (int) (TITLE_OFFSET_DIPS * getResources().getDisplayMetrics().density); mTabStrip = new SlidingTabStrip(context); addView(mTabStrip, LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT); } public void setTitleTextColor(int selectedTitleTextColor, int unselectedTitleTextColor) { this.selectedTitleTextColor = selectedTitleTextColor; this.unselectedTitleTextColor = unselectedTitleTextColor; } public void setTitleBgColor(int selectedTitleBgColor, int unselectedTitleBgColor) { this.selectedTitleBgColor = selectedTitleBgColor; this.unselectedTitleBgColor = unselectedTitleBgColor; } public void setTabTitleTextSize(int tabTitleTextSize) { this.tabTitleTextSize = tabTitleTextSize; } /** * {@link TabColorizer} * ? * {@link #setSelectedIndicatorColors(int...)} * ? */ public void setCustomTabColorizer(TabColorizer tabColorizer) { mTabStrip.setCustomTabColorizer(tabColorizer); } /** * ?? */ public void setDistributeEvenly(boolean distributeEvenly) { mDistributeEvenly = distributeEvenly; } /** * ? * * ???? */ public void setSelectedIndicatorColors(int... colors) { mTabStrip.setSelectedIndicatorColors(colors); } public void setSelectedIndicatorHeight(int height) { mTabStrip.setSelectedIndicatorHeight(height); } public void setDividerColors(int... colors) { mTabStrip.setDividerColors(colors); } //1f public void setDividerHeight(float height) { mTabStrip.setDividerHeight(height); } /** * Set the {@link ViewPager.OnPageChangeListener}. When using {@link SlidingTabLayout} you are * required to set any {@link ViewPager.OnPageChangeListener} through this method. This is so * that the layout can update it's scroll position correctly. * * @see ViewPager#setOnPageChangeListener(ViewPager.OnPageChangeListener) */ public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) { mViewPagerPageChangeListener = listener; } /** * Set the custom layout to be inflated for the tab views. * * @param layoutResId Layout id to be inflated * @param textViewId id of the {@link TextView} in the inflated view */ public void setCustomTabView(int layoutResId, int textViewId) { mTabViewLayoutId = layoutResId; mTabViewTextViewId = textViewId; } /** * Sets the associated view pager. Note that the assumption here is that the pager content * (number of tabs and tab titles) does not change after this call has been made. */ public void setViewPager(ViewPager viewPager) { mTabStrip.removeAllViews(); mViewPager = viewPager; if (viewPager != null) { populateTabStrip(); viewPager.addOnPageChangeListener(new InternalViewPagerListener()); } } /** * Create a default view to be used for tabs. This is called if a custom tab view is not set via * {@link #setCustomTabView(int, int)}. */ protected TextView createDefaultTabView(Context context) { TextView textView = new TextView(context); textView.setBackgroundColor(getResources().getColor(R.color.white)); textView.setGravity(Gravity.CENTER); textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, TAB_VIEW_TEXT_SIZE_SP); textView.setTypeface(Typeface.DEFAULT_BOLD); textView.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)); TypedValue outValue = new TypedValue(); getContext().getTheme().resolveAttribute(android.R.attr.selectableItemBackground, outValue, true); textView.setBackgroundResource(outValue.resourceId); textView.setAllCaps(true); int padding = (int) (TAB_VIEW_PADDING_DIPS * getResources().getDisplayMetrics().density); textView.setPadding(padding, padding, padding, padding); return textView; } private void populateTabStrip() { final PagerAdapter adapter = mViewPager.getAdapter(); frgCount = adapter.getCount(); for (int i = 0; i < adapter.getCount(); i++) { View tabView = null; TextView tabTitleView = null; if (mTabViewLayoutId != 0) { // If there is a custom tab view layout id set, try and inflate it tabView = LayoutInflater.from(getContext()).inflate(mTabViewLayoutId, mTabStrip, false); tabTitleView = (TextView) tabView.findViewById(mTabViewTextViewId); } if (tabView == null) { tabView = createDefaultTabView(getContext()); } if (tabTitleView == null && TextView.class.isInstance(tabView)) { tabTitleView = (TextView) tabView; } if (mDistributeEvenly) { LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) tabView.getLayoutParams(); lp.width = 0; lp.weight = 1; } tabTitleView.setText(adapter.getPageTitle(i)); tabTitleView.setTextSize(tabTitleTextSize); tabTitleView.setMaxLines(1); tabView.setOnClickListener(new TabClickListener()); String desc = mContentDescriptions.get(i, null); if (desc != null) { tabView.setContentDescription(desc); } mTabStrip.addView(tabView); if (i == mViewPager.getCurrentItem()) { tabView.setSelected(true); } textViewList.add(tabTitleView); } textViewList.get(0).setTextColor(selectedTitleTextColor); // textViewList.get(0).setBackgroundColor(selectedTitleBgColor); for (int i = 1; i < frgCount; i++) { textViewList.get(i).setTextColor(unselectedTitleTextColor); // textViewList.get(i).setBackgroundColor(unselectedTitleBgColor); } } public void setContentDescription(int i, String desc) { mContentDescriptions.put(i, desc); } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); if (mViewPager != null) { scrollToTab(mViewPager.getCurrentItem(), 0); } } private void scrollToTab(int tabIndex, int positionOffset) { final int tabStripChildCount = mTabStrip.getChildCount(); if (tabStripChildCount == 0 || tabIndex < 0 || tabIndex >= tabStripChildCount) { return; } View selectedChild = mTabStrip.getChildAt(tabIndex); if (selectedChild != null) { int targetScrollX = selectedChild.getLeft() + positionOffset; if (tabIndex > 0 || positionOffset > 0) { // If we're not at the first child and are mid-scroll, make sure we obey the offset targetScrollX -= mTitleOffset; } scrollTo(targetScrollX, 0); } } private class InternalViewPagerListener implements ViewPager.OnPageChangeListener { private int mScrollState; @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { int tabStripChildCount = mTabStrip.getChildCount(); if ((tabStripChildCount == 0) || (position < 0) || (position >= tabStripChildCount)) { return; } mTabStrip.onViewPagerPageChanged(position, positionOffset); View selectedTitle = mTabStrip.getChildAt(position); int extraOffset = (selectedTitle != null) ? (int) (positionOffset * selectedTitle.getWidth()) : 0; scrollToTab(position, extraOffset); if (mViewPagerPageChangeListener != null) { mViewPagerPageChangeListener.onPageScrolled(position, positionOffset, positionOffsetPixels); } } @Override public void onPageScrollStateChanged(int state) { mScrollState = state; if (mViewPagerPageChangeListener != null) { mViewPagerPageChangeListener.onPageScrollStateChanged(state); } } @Override public void onPageSelected(int position) { for (int i = 0; i < frgCount; i++) { if (position == i) { textViewList.get(i).setTextColor(selectedTitleTextColor); // textViewList.get(i).setBackgroundColor(selectedTitleBgColor); } else { textViewList.get(i).setTextColor(unselectedTitleTextColor); // textViewList.get(i).setBackgroundColor(unselectedTitleBgColor); } } if (mScrollState == ViewPager.SCROLL_STATE_IDLE) { mTabStrip.onViewPagerPageChanged(position, 0f); scrollToTab(position, 0); } for (int i = 0; i < mTabStrip.getChildCount(); i++) { mTabStrip.getChildAt(i).setSelected(position == i); } if (mViewPagerPageChangeListener != null) { mViewPagerPageChangeListener.onPageSelected(position); } } } private class TabClickListener implements OnClickListener { @Override public void onClick(View v) { for (int i = 0; i < mTabStrip.getChildCount(); i++) { if (v == mTabStrip.getChildAt(i)) { mViewPager.setCurrentItem(i); return; } } } } }