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 kr.ac.kookmin.cs.firstcoin.order.fragment; import android.annotation.SuppressLint; 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; /** * To be used with ViewPager to provide a tab indicator component which give * constant feedback as to the user's scroll progress. * <p> * To use the component, simply add it to your view hierarchy. Then in your * {@link android.app.Activity} or {@link android.support.v4.app.Fragment} call * {@link #setViewPager(android.support.v4.view.ViewPager)} providing it the * ViewPager this layout is being used for. * <p> * The colors can be customized in two ways. The first and simplest is to * provide an array of colors via {@link #setSelectedIndicatorColors(int...)}. * The alternative is via the * {@link kr.ac.kookmin.cs.firstcoin.orderfragment.tekinarslan.material.sample.SlidingTabLayout.TabColorizer} * interface which provides you complete control over which color is used for * any individual position. * <p> * The views used as tabs can be customized by calling * {@link #setCustomTabView(int, int)}, providing the layout ID of your custom * layout. */ public class SlidingTabLayout extends HorizontalScrollView { /** * Allows complete control over the colors drawn in the tab layout. Set with * {@link #setCustomTabColorizer(kr.ac.kookmin.cs.firstcoin.orderfragment.tekinarslan.material.sample.SlidingTabLayout.TabColorizer)} * . */ public interface TabColorizer { /** * @return return the color of the indicator used when {@code position} * is selected. */ int getIndicatorColor(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 = 16; private int titleOffset; private int tabViewLayoutId; private int tabViewTextViewId; private boolean distributeEvenly; private ViewPager viewPager; private SparseArray<String> contentDescriptions = new SparseArray<String>(); private ViewPager.OnPageChangeListener viewPagerPageChangeListener; private final SlidingTabStrip tabStrip; 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); titleOffset = (int) (TITLE_OFFSET_DIPS * getResources().getDisplayMetrics().density); tabStrip = new SlidingTabStrip(context); addView(tabStrip, LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT); } /** * Set the custom * {@link kr.ac.kookmin.cs.firstcoin.orderfragment.tekinarslan.material.sample.SlidingTabLayout.TabColorizer} to * be used. * * If you only require simple custmisation then you can use * {@link #setSelectedIndicatorColors(int...)} to achieve similar effects. */ public void setCustomTabColorizer(TabColorizer tabColorizer) { tabStrip.setCustomTabColorizer(tabColorizer); } public void setDistributeEvenly(boolean distributeEvenly) { this.distributeEvenly = distributeEvenly; } /** * Sets the colors to be used for indicating the selected tab. These colors * are treated as a circular array. Providing one color will mean that all * tabs are indicated with the same color. */ public void setSelectedIndicatorColors(int... colors) { tabStrip.setSelectedIndicatorColors(colors); } /** * Set the {@link android.support.v4.view.ViewPager.OnPageChangeListener}. * When using {@link kr.ac.kookmin.cs.firstcoin.orderfragment.tekinarslan.material.sample.SlidingTabLayout} you * are required to set any * {@link android.support.v4.view.ViewPager.OnPageChangeListener} through * this method. This is so that the layout can update it's scroll position * correctly. * * @see android.support.v4.view.ViewPager#setOnPageChangeListener(android.support.v4.view.ViewPager.OnPageChangeListener) */ public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) { viewPagerPageChangeListener = 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 android.widget.TextView} in the inflated view */ public void setCustomTabView(int layoutResId, int textViewId) { tabViewLayoutId = layoutResId; tabViewTextViewId = 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) { tabStrip.removeAllViews(); this.viewPager = viewPager; if (viewPager != null) { viewPager.setOnPageChangeListener(new InternalViewPagerListener()); populateTabStrip(); } } /** * 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)}. */ @SuppressLint("NewApi") protected TextView createDefaultTabView(Context context) { TextView textView = new TextView(context); 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 = viewPager.getAdapter(); final OnClickListener tabClickListener = new TabClickListener(); for (int i = 0; i < adapter.getCount(); i++) { View tabView = null; TextView tabTitleView = null; if (tabViewLayoutId != 0) { // If there is a custom tab view layout id set, try and inflate // it tabView = LayoutInflater.from(getContext()).inflate(tabViewLayoutId, tabStrip, false); tabTitleView = (TextView) tabView.findViewById(tabViewTextViewId); } if (tabView == null) { tabView = createDefaultTabView(getContext()); } if (tabTitleView == null && TextView.class.isInstance(tabView)) { tabTitleView = (TextView) tabView; } if (distributeEvenly) { LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) tabView.getLayoutParams(); lp.width = 0; lp.weight = 1; } tabTitleView.setText(adapter.getPageTitle(i)); tabTitleView.setTextColor(Color.parseColor("#00a470")); tabView.setOnClickListener(tabClickListener); String desc = contentDescriptions.get(i, null); if (desc != null) { tabView.setContentDescription(desc); } tabStrip.addView(tabView); if (i == viewPager.getCurrentItem()) { tabView.setSelected(true); } } } public void setContentDescription(int i, String desc) { contentDescriptions.put(i, desc); } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); if (viewPager != null) { scrollToTab(viewPager.getCurrentItem(), 0); } } private void scrollToTab(int tabIndex, int positionOffset) { final int tabStripChildCount = tabStrip.getChildCount(); if (tabStripChildCount == 0 || tabIndex < 0 || tabIndex >= tabStripChildCount) { return; } View selectedChild = tabStrip.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 -= titleOffset; } scrollTo(targetScrollX, 0); } } private class InternalViewPagerListener implements ViewPager.OnPageChangeListener { private int mScrollState; @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { int tabStripChildCount = tabStrip.getChildCount(); if ((tabStripChildCount == 0) || (position < 0) || (position >= tabStripChildCount)) { return; } tabStrip.onViewPagerPageChanged(position, positionOffset); View selectedTitle = tabStrip.getChildAt(position); int extraOffset = (selectedTitle != null) ? (int) (positionOffset * selectedTitle.getWidth()) : 0; scrollToTab(position, extraOffset); if (viewPagerPageChangeListener != null) { viewPagerPageChangeListener.onPageScrolled(position, positionOffset, positionOffsetPixels); } } @Override public void onPageScrollStateChanged(int state) { mScrollState = state; if (viewPagerPageChangeListener != null) { viewPagerPageChangeListener.onPageScrollStateChanged(state); } } @Override public void onPageSelected(int position) { if (mScrollState == ViewPager.SCROLL_STATE_IDLE) { tabStrip.onViewPagerPageChanged(position, 0f); scrollToTab(position, 0); } for (int i = 0; i < tabStrip.getChildCount(); i++) { tabStrip.getChildAt(i).setSelected(position == i); } if (viewPagerPageChangeListener != null) { viewPagerPageChangeListener.onPageSelected(position); } } } private class TabClickListener implements OnClickListener { @Override public void onClick(View v) { for (int i = 0; i < tabStrip.getChildCount(); i++) { if (v == tabStrip.getChildAt(i)) { viewPager.setCurrentItem(i); return; } } } } }