Java tutorial
/** * Copyright (C) 2015 ogaclejapan * Copyright (C) 2013 The Android Open Source Project * * 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.socialinfotech.tabbar.smart; import android.content.Context; import android.content.res.ColorStateList; import android.content.res.TypedArray; import android.graphics.Typeface; import android.os.Build; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.util.AttributeSet; import android.util.DisplayMetrics; 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.socialinfotech.tabbar.R; /** * 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.app.Fragment}, {@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...)} and {@link #setDividerColors(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. * <p> * Forked from Google Samples > SlidingTabsBasic > * <a href="https://developer.android.com/samples/SlidingTabsBasic/src/com.example.android.common/view/SlidingTabLayout.html">SlidingTabLayout</a> */ public class SmartTabLayout 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); /** * @return return the color of the divider drawn to the right of {@code position}. */ int getDividerColor(int position); } /** * Create the custom tabs in the tab layout. Set with * {@link #setCustomTabView(TabProvider)} */ public interface TabProvider { /** * @return Return the View of {@code position} for the Tabs */ View createTabView(ViewGroup container, int position, PagerAdapter adapter); } private static final boolean DEFAULT_DISTRIBUTE_EVENLY = false; private static final int TITLE_OFFSET_DIPS = 24; private static final int TAB_VIEW_PADDING_DIPS = 16; private static final boolean TAB_VIEW_TEXT_ALL_CAPS = true; private static final int TAB_VIEW_TEXT_SIZE_SP = 12; private static final int TAB_VIEW_TEXT_COLOR = 0xFC000000; private static final int TAB_VIEW_TEXT_MIN_WIDTH = 0; private int mTitleOffset; private boolean mTabViewTextAllCaps; private ColorStateList mTabViewTextColors; private float mTabViewTextSize; private int mTabViewTextHorizontalPadding; private int mTabViewTextMinWidth; private ViewPager mViewPager; private ViewPager.OnPageChangeListener mViewPagerPageChangeListener; private TabProvider mTabProvider; private boolean mDistributeEvenly; protected final SmartTabStrip mTabStrip; public SmartTabLayout(Context context) { this(context, null); } public SmartTabLayout(Context context, AttributeSet attrs) { this(context, attrs, 0); } public SmartTabLayout(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); final DisplayMetrics dm = getResources().getDisplayMetrics(); final float density = dm.density; boolean textAllCaps = TAB_VIEW_TEXT_ALL_CAPS; ColorStateList textColors; float textSize = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, TAB_VIEW_TEXT_SIZE_SP, dm); int textHorizontalPadding = (int) (TAB_VIEW_PADDING_DIPS * density); int textMinWidth = (int) (TAB_VIEW_TEXT_MIN_WIDTH * density); boolean distributeEvenly = DEFAULT_DISTRIBUTE_EVENLY; int customTabLayoutId = NO_ID; int customTabTextViewId = NO_ID; TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.stl_SmartTabLayout, defStyle, 0); textAllCaps = a.getBoolean(R.styleable.stl_SmartTabLayout_stl_defaultTabTextAllCaps, textAllCaps); textColors = a.getColorStateList(R.styleable.stl_SmartTabLayout_stl_defaultTabTextColor); textSize = a.getDimension(R.styleable.stl_SmartTabLayout_stl_defaultTabTextSize, textSize); textHorizontalPadding = a.getDimensionPixelSize( R.styleable.stl_SmartTabLayout_stl_defaultTabTextHorizontalPadding, textHorizontalPadding); textMinWidth = a.getDimensionPixelSize(R.styleable.stl_SmartTabLayout_stl_defaultTabTextMinWidth, textMinWidth); customTabLayoutId = a.getResourceId(R.styleable.stl_SmartTabLayout_stl_customTabTextLayoutId, customTabLayoutId); customTabTextViewId = a.getResourceId(R.styleable.stl_SmartTabLayout_stl_customTabTextViewId, customTabTextViewId); distributeEvenly = a.getBoolean(R.styleable.stl_SmartTabLayout_stl_distributeEvenly, distributeEvenly); a.recycle(); mTitleOffset = (int) (TITLE_OFFSET_DIPS * density); mTabViewTextAllCaps = textAllCaps; mTabViewTextColors = (textColors != null) ? textColors : ColorStateList.valueOf(TAB_VIEW_TEXT_COLOR); mTabViewTextSize = textSize; mTabViewTextHorizontalPadding = textHorizontalPadding; mTabViewTextMinWidth = textMinWidth; mDistributeEvenly = distributeEvenly; if (customTabLayoutId != NO_ID) { setCustomTabView(customTabLayoutId, customTabTextViewId); } mTabStrip = new SmartTabStrip(context, attrs); if (distributeEvenly && mTabStrip.isIndicatorAlwaysInCenter()) { throw new UnsupportedOperationException( "'distributeEvenly' and 'indicatorAlwaysInCenter' both use does not support"); } addView(mTabStrip, LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); if (mTabStrip.isIndicatorAlwaysInCenter() && getChildCount() > 0) { int left = (w - mTabStrip.getChildMeasuredWidthAt(0)) / 2; int right = (w - mTabStrip.getChildMeasuredWidthAt(getChildCount() - 1)) / 2; setPadding(left, getPaddingTop(), right, getPaddingBottom()); setClipToPadding(false); } } /** * Set the behavior of the Indicator scrolling feedback. * * @param interpolator {@link SmartTabIndicationInterpolator} */ public void setIndicationInterpolator(SmartTabIndicationInterpolator interpolator) { mTabStrip.setIndicationInterpolator(interpolator); } /** * Set the custom {@link TabColorizer} to be used. * * If you only require simple customisation then you can use * {@link #setSelectedIndicatorColors(int...)} and {@link #setDividerColors(int...)} to achieve * similar effects. */ public void setCustomTabColorizer(TabColorizer tabColorizer) { mTabStrip.setCustomTabColorizer(tabColorizer); } /** * Set the color used for styling the tab text. This will need to be called prior to calling * {@link #setViewPager(ViewPager)} otherwise it will not get set * * @param color to use for tab text */ public void setDefaultTabTextColor(int color) { mTabViewTextColors = ColorStateList.valueOf(color); } /** * Sets the colors used for styling the tab text. This will need to be called prior to calling * {@link #setViewPager(ViewPager)} otherwise it will not get set * * @param colors ColorStateList to use for tab text */ public void setDefaultTabTextColor(ColorStateList colors) { mTabViewTextColors = colors; } /** * Set the same weight for tab */ 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); } /** * Sets the colors to be used for tab dividers. These colors are treated as a circular array. * Providing one color will mean that all tabs are indicated with the same color. */ public void setDividerColors(int... colors) { mTabStrip.setDividerColors(colors); } /** * Set the {@link ViewPager.OnPageChangeListener}. When using {@link SmartTabLayout} 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) { mTabProvider = new SimpleTabProvider(getContext(), layoutResId, textViewId); } /** * Set the custom layout to be inflated for the tab views. * * @param provider {@link TabProvider} */ public void setCustomTabView(TabProvider provider) { mTabProvider = provider; } /** * 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.getAdapter() != null) { viewPager.setOnPageChangeListener(new InternalViewPagerListener()); populateTabStrip(); } } /** * Returns the view at the specified position in the tabs. * @param position the position at which to get the view from * @return the view at the specified position or null if the position does not exist within the tabs */ public View getTabAt(int position) { return mTabStrip.getChildAt(position); } /** * 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(CharSequence title) { TextView textView = new TextView(getContext()); textView.setGravity(Gravity.CENTER); textView.setText(title); textView.setTextColor(mTabViewTextColors); textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTabViewTextSize); textView.setTypeface(Typeface.DEFAULT_BOLD); textView.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.MATCH_PARENT)); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { // If we're running on Honeycomb or newer, then we can use the Theme's // selectableItemBackground to ensure that the View has a pressed state TypedValue outValue = new TypedValue(); getContext().getTheme().resolveAttribute(android.R.attr.selectableItemBackground, outValue, true); textView.setBackgroundResource(outValue.resourceId); } if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) { // If we're running on ICS or newer, enable all-caps to match the Action Bar tab style textView.setAllCaps(mTabViewTextAllCaps); } textView.setPadding(mTabViewTextHorizontalPadding, 0, mTabViewTextHorizontalPadding, 0); if (mTabViewTextMinWidth > 0) { textView.setMinWidth(mTabViewTextMinWidth); } return textView; } private void populateTabStrip() { final PagerAdapter adapter = mViewPager.getAdapter(); final OnClickListener tabClickListener = new TabClickListener(); for (int i = 0; i < adapter.getCount(); i++) { final View tabView = (mTabProvider == null) ? createDefaultTabView(adapter.getPageTitle(i)) : mTabProvider.createTabView(mTabStrip, i, adapter); if (tabView == null) { throw new IllegalStateException("tabView is null."); } if (mDistributeEvenly) { LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) tabView.getLayoutParams(); lp.width = 0; lp.weight = 1; } if (tabView.getParent() != null) ((ViewGroup) tabView.getParent()).removeView(tabView); // <- fix mTabStrip.addView(tabView); tabView.setOnClickListener(tabClickListener); // mTabStrip.addView(tabView); if (i == mViewPager.getCurrentItem()) { tabView.setSelected(true); } } } @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 (mTabStrip.isIndicatorAlwaysInCenter()) { targetScrollX -= (mTabStrip.getChildWidthAt(0) - selectedChild.getWidth()) / 2; } else 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; if (0f < positionOffset && positionOffset < 1f && mTabStrip.isIndicatorAlwaysInCenter()) { int current = mTabStrip.getChildWidthAt(position) / 2; int next = mTabStrip.getChildWidthAt(position + 1) / 2; extraOffset = Math.round(positionOffset * (current + next)); } 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, size = mTabStrip.getChildCount(); i < size; 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; } } } } private static class SimpleTabProvider implements TabProvider { private final LayoutInflater mInflater; private final int mTabViewLayoutId; private final int mTabViewTextViewId; private SimpleTabProvider(Context context, int layoutResId, int textViewId) { mInflater = LayoutInflater.from(context); mTabViewLayoutId = layoutResId; mTabViewTextViewId = textViewId; } @Override public View createTabView(ViewGroup container, int position, PagerAdapter adapter) { View tabView = null; TextView tabTitleView = null; if (mTabViewLayoutId != NO_ID) { tabView = mInflater.inflate(mTabViewLayoutId, container, false); } if (mTabViewTextViewId != NO_ID && tabView != null) { tabTitleView = (TextView) tabView.findViewById(mTabViewTextViewId); } if (tabTitleView == null && TextView.class.isInstance(tabView)) { tabTitleView = (TextView) tabView; } if (tabTitleView != null) { tabTitleView.setText(adapter.getPageTitle(position)); } return tabView; } } }