Java tutorial
package co.herxun.impp.view; /* * 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. */ import java.util.ArrayList; import java.util.List; import co.herxun.impp.R; import co.herxun.impp.adapter.FragmentPagerAdapter; import android.content.Context; import android.graphics.Typeface; import android.graphics.drawable.GradientDrawable; import android.os.Build; 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.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.RelativeLayout; 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(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 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(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 = 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 List<CustomTabView> viewList; 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); viewList = new ArrayList<CustomTabView>(); } /** * Set the custom {@link 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) { mTabStrip.setCustomTabColorizer(tabColorizer); } public void setDistributeEvenly(boolean distributeEvenly) { mDistributeEvenly = 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) { mTabStrip.setSelectedIndicatorColors(colors); } /** * 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) { 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)}. */ 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 class CustomTabView extends RelativeLayout { private TextView textView; private BadgeView badgeView; private int id = 1; public CustomTabView(Context context) { super(context); final float scale = getContext().getResources().getDisplayMetrics().density; setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)); int padding = (int) (TAB_VIEW_PADDING_DIPS * getResources().getDisplayMetrics().density); setPadding(0, padding, 0, padding); textView = new TextView(context); textView.setId(id++); textView.setTextSize(TypedValue.COMPLEX_UNIT_DIP, 14); textView.setTextColor(context.getResources().getColor(R.color.no5)); badgeView = new BadgeView(context); badgeView.setTextColor(context.getResources().getColor(R.color.no1)); badgeView.setBadgeColor(context.getResources().getColor(R.color.no13)); RelativeLayout.LayoutParams rlpTextView = new RelativeLayout.LayoutParams(-2, -2); rlpTextView.addRule(RelativeLayout.CENTER_IN_PARENT); addView(textView, rlpTextView); RelativeLayout.LayoutParams rlpBadgeView = new RelativeLayout.LayoutParams(-2, (int) (21 * scale + 0.5f)); rlpBadgeView.addRule(RelativeLayout.RIGHT_OF, textView.getId()); rlpBadgeView.addRule(RelativeLayout.CENTER_VERTICAL); rlpBadgeView.leftMargin = (int) (4 * scale + 0.5f); addView(badgeView, rlpBadgeView); } public void setTitle(CharSequence charSequence) { textView.setText(charSequence); } public void setBadgeCount(int count) { badgeView.setBadgeCount(count); } } private void populateTabStrip() { final FragmentPagerAdapter adapter = (FragmentPagerAdapter) mViewPager.getAdapter(); final View.OnClickListener tabClickListener = new TabClickListener(); for (int i = 0; i < adapter.getCount(); i++) { CustomTabView 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()); tabView = new CustomTabView(getContext()); } // if (tabTitleView == null && TextView.class.isInstance(tabView)) { // tabTitleView = (TextView) tabView; // } if (mDistributeEvenly) { LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) tabView.getLayoutParams(); lp.width = -1; lp.weight = 1; } //tabTitleView.setText(adapter.getPageTitle(i)); tabView.setTitle(adapter.getPageTitle(i)); tabView.setBadgeCount(adapter.getBadgeCount(i)); tabView.setOnClickListener(tabClickListener); String desc = mContentDescriptions.get(i, null); if (desc != null) { tabView.setContentDescription(desc); } mTabStrip.addView(tabView); if (i == mViewPager.getCurrentItem()) { tabView.setSelected(true); } viewList.add(tabView); } } public void refreshAllTab() { final FragmentPagerAdapter adapter = (FragmentPagerAdapter) mViewPager.getAdapter(); for (int i = 0; i < adapter.getCount(); i++) { refreshTab(i); } } public void refreshTab(int position) { final FragmentPagerAdapter adapter = (FragmentPagerAdapter) mViewPager.getAdapter(); viewList.get(position).setTitle(adapter.getPageTitle(position)); viewList.get(position).setBadgeCount(adapter.getBadgeCount(position)); } 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) { 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 View.OnClickListener { @Override public void onClick(View v) { for (int i = 0; i < mTabStrip.getChildCount(); i++) { if (v == mTabStrip.getChildAt(i)) { mViewPager.setCurrentItem(i); return; } } } } }