TabLayout底部线和底部指示器 自定义属性，修改系统TabLayout源码实现
先上图：
Gif图做的有问题，先将就用吧
公司项项目需要实现一个带底部指示器的tab，第一时间想到的就是TabLayout，可是TabLayout的指示器是是固定长度，不能自定义，而我们的项目指示器大概也就20个dp ,显然不符合要求，然后就各种百度，看了好几篇资料，都是通过反射修改器长度，然而长度是能修改，但是最小长度不能小于tab的text宽度，代码如下
public static void setIndicator(Context context, TabLayout tabs, int leftDip, int rightDip) {
Class tabLayout = tabs.getClass();
Field tabStrip = null;
try {
tabStrip = tabLayout.getDeclaredField("mTabStrip");
} catch (NoSuchFieldException e) {
e.printStackTrace();
}
tabStrip.setAccessible(true);
LinearLayout ll_tab = null;
try {
ll_tab = (LinearLayout) tabStrip.get(tabs);
} catch (IllegalAccessException e) {
e.printStackTrace();
}
int left = (int) (getDisplayMetrics(context).density * leftDip);
int right = (int) (getDisplayMetrics(context).density * rightDip);
for (int i = 0; i < ll_tab.getChildCount(); i++) {
View child = ll_tab.getChildAt(i);
child.setPadding(0, 0, 0, 0);
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.MATCH_PARENT, 1);
params.leftMargin = left;
params.rightMargin = right;
child.setLayoutParams(params);
child.invalidate();
}
}参考链接：https://blog.csdn.net/hedong_77/article/details/52972032
刚才也说了指示器大概20dp显然不符合要求，然后就想了一下找个第三方的库算了,去Github找了FlycoTabLayout，看了下各方面都比较满意，这下不用担心了照着撸一个，Fuck!!!!Fuck!!!!Fuck!!!!Fuck!!!!这个最少支持三个tab我们的有两个的有多个的，没办法了只能靠自己了。也参考了几中写法，最后决定从源码下手,这样的好处就是完美兼容TabLayout而不是像动画什么的都需要自己写
第一步： 找到源码
然后找到这四个类和系统定义的属性copy至你的工程下
以下这是我的工程，我为了避免和desigh库冲突，把这些库放到了com报下，当然你也可以选择不引入系统的design包，按照系统的包结构将其放到java包下或者app包下，还有就是这四个类都可以整合进Tablayout中，我这里没有进行整合。
第二步： 修改TabLayout源码
1.先扩展TabLayout的属性，原则是在保留原有属性的原则上修改values.xml
2.TabLayout.java部分,有分割线的部分是修改部分，代码就不一一解释了，注释都有，用法也是最基本的自定义View，这里只是简单的扩展了底部线和线性指示器，当然想要方形的指示器，指定宽高就行了，如果要实现三角形或者是圆形的指示器则需要在draw方法自己去画，还可以给指示器做粘性动画，这里只是抛砖引玉，想要其他效果你们可以自行脑补
/*
* Copyright (C) 2015 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.android.support.design.widget;
import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.ColorStateList;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.database.DataSetObserver;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.support.annotation.ColorInt;
import android.support.annotation.DrawableRes;
import android.support.annotation.IntDef;
import android.support.annotation.LayoutRes;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.annotation.RestrictTo;
import android.support.annotation.StringRes;
import android.support.design.R;
import android.support.v4.util.Pools;
import android.support.v4.view.GravityCompat;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.PointerIconCompat;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.TextViewCompat;
import android.support.v7.app.ActionBar;
import android.support.v7.content.res.AppCompatResources;
import android.support.v7.widget.TooltipCompat;
import android.text.Layout;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.SoundEffectConstants;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.widget.HorizontalScrollView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Iterator;
import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP;
import static android.support.v4.view.ViewPager.SCROLL_STATE_DRAGGING;
import static android.support.v4.view.ViewPager.SCROLL_STATE_IDLE;
import static android.support.v4.view.ViewPager.SCROLL_STATE_SETTLING;
//import android.support.design.widget
/**
* TabLayout provides a horizontal layout to display tabs.
*
*
Population of the tabs to display is
* done through {@link Tab} instances. You create tabs via {@link #newTab()}. From there you can
* change the tab's label or icon via {@link Tab#setText(int)} and {@link Tab#setIcon(int)}
* respectively. To display the tab, you need to add it to the layout via one of the
* {@link #addTab(Tab)} methods. For example:
*
* TabLayout tabLayout = ...;
* tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
* tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
* tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
*
* You should set a listener via {@link #setOnTabSelectedListener(OnTabSelectedListener)} to be
* notified when any tab's selection state has been changed.
*
*
You can also add items to TabLayout in your layout through the use of {@link TabItem}.
* An example usage is like so:
*
*
*
*
*
*
*
*
ViewPager integration
*
* If you're using a {@link ViewPager} together
* with this layout, you can call {@link #setupWithViewPager(ViewPager)} to link the two together.
* This layout will be automatically populated from the {@link PagerAdapter}'s page titles.
*
*
* This view also supports being used as part of a ViewPager's decor, and can be added
* directly to the ViewPager in a layout resource file like so:
*
*
*
*
*
*
*
* @attr ref android.support.design.R.styleable#TabLayout_tabPadding
* @attr ref android.support.design.R.styleable#TabLayout_tabPaddingStart
* @attr ref android.support.design.R.styleable#TabLayout_tabPaddingTop
* @attr ref android.support.design.R.styleable#TabLayout_tabPaddingEnd
* @attr ref android.support.design.R.styleable#TabLayout_tabPaddingBottom
* @attr ref android.support.design.R.styleable#TabLayout_tabContentStart
* @attr ref android.support.design.R.styleable#TabLayout_tabBackground
* @attr ref android.support.design.R.styleable#TabLayout_tabMinWidth
* @attr ref android.support.design.R.styleable#TabLayout_tabMaxWidth
* @attr ref android.support.design.R.styleable#TabLayout_tabTextAppearance
* @see Tabs
*/
@ViewPager.DecorView
public class TabLayout extends HorizontalScrollView {
private static final int DEFAULT_HEIGHT_WITH_TEXT_ICON = 72; // dps
static final int DEFAULT_GAP_TEXT_ICON = 8; // dps
private static final int INVALID_WIDTH = -1;
private static final int DEFAULT_HEIGHT = 48; // dps
private static final int TAB_MIN_WIDTH_MARGIN = 56; //dps
static final int FIXED_WRAP_GUTTER_MIN = 16; //dps
static final int MOTION_NON_ADJACENT_OFFSET = 24;
private static final int ANIMATION_DURATION = 300;
private static final Pools.Pool sTabPool = new Pools.SynchronizedPool<>(16);
/**
* Scrollable tabs display a subset of tabs at any given moment, and can contain longer tab
* labels and a larger number of tabs. They are best used for browsing contexts in touch
* interfaces when users don’t need to directly compare the tab labels.
*
* @see #setTabMode(int)
* @see #getTabMode()
*/
public static final int MODE_SCROLLABLE = 0;
/**
* Fixed tabs display all tabs concurrently and are best used with content that benefits from
* quick pivots between tabs. The maximum number of tabs is limited by the view’s width.
* Fixed tabs have equal width, based on the widest tab label.
*
* @see #setTabMode(int)
* @see #getTabMode()
*/
public static final int MODE_FIXED = 1;
private int bottomLineColor;
private int bottomLineHeight;
private int bottomLineWidth;
private int dividerHeight;
private int dividerWidth;
private int bottomLineMode;
/**
* @hide
*/
@RestrictTo(LIBRARY_GROUP)
@IntDef(value = {MODE_SCROLLABLE, MODE_FIXED})
@Retention(RetentionPolicy.SOURCE)
public @interface Mode {
}
/**
* Gravity used to fill the {@link TabLayout} as much as possible. This option only takes effect
* when used with {@link #MODE_FIXED}.
*
* @see #setTabGravity(int)
* @see #getTabGravity()
*/
public static final int GRAVITY_FILL = 0;
/**
* Gravity used to lay out the tabs in the center of the {@link TabLayout}.
*
* @see #setTabGravity(int)
* @see #getTabGravity()
*/
public static final int GRAVITY_CENTER = 1;
/**
* @hide
*/
@RestrictTo(LIBRARY_GROUP)
@IntDef(flag = true, value = {GRAVITY_FILL, GRAVITY_CENTER})
@Retention(RetentionPolicy.SOURCE)
public @interface TabGravity {
}
/**
* Callback interface invoked when a tab's selection state changes.
*/
public interface OnTabSelectedListener {
/**
* Called when a tab enters the selected state.
*
* @param tab The tab that was selected
*/
public void onTabSelected(Tab tab);
/**
* Called when a tab exits the selected state.
*
* @param tab The tab that was unselected
*/
public void onTabUnselected(Tab tab);
/**
* Called when a tab that is already selected is chosen again by the user. Some applications
* may use this action to return to the top level of a category.
*
* @param tab The tab that was reselected.
*/
public void onTabReselected(Tab tab);
}
private final ArrayList mTabs = new ArrayList<>();
private Tab mSelectedTab;
private final SlidingTabStrip mTabStrip;
int mTabPaddingStart;
int mTabPaddingTop;
int mTabPaddingEnd;
int mTabPaddingBottom;
int mTabTextAppearance;
ColorStateList mTabTextColors;
float mTabTextSize;
float mTabTextMultiLineSize;
final int mTabBackgroundResId;
int mTabMaxWidth = Integer.MAX_VALUE;
private final int mRequestedTabMinWidth;
private final int mRequestedTabMaxWidth;
private final int mScrollableTabMinWidth;
private int mContentInsetStart;
int mTabGravity;
int mMode;
private OnTabSelectedListener mSelectedListener;
private final ArrayList mSelectedListeners = new ArrayList<>();
private OnTabSelectedListener mCurrentVpSelectedListener;
private ValueAnimator mScrollAnimator;
ViewPager mViewPager;
private PagerAdapter mPagerAdapter;
private DataSetObserver mPagerAdapterObserver;
private TabLayoutOnPageChangeListener mPageChangeListener;
private AdapterChangeListener mAdapterChangeListener;
private boolean mSetupViewPagerImplicitly;
// Pool we use as a simple RecyclerBin
private final Pools.Pool mTabViewPool = new Pools.SimplePool<>(12);
public TabLayout(Context context) {
this(context, null);
}
public TabLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public TabLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
ThemeUtils.checkAppCompatTheme(context);
// Disable the Scroll Bar
setHorizontalScrollBarEnabled(false);
// Add the TabStrip
mTabStrip = new SlidingTabStrip(context);
// super.addView(mTabStrip, 0, new LayoutParams(
// LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT));
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.TabLayout,
defStyleAttr, R.style.Widget_Design_TabLayout);
//*****************************自定义部分 START*****************************
bottomLineMode = a.getInt(R.styleable.TabLayout_bottomLineMode, 0);
if (bottomLineMode == 1) {
bottomLineColor = a.getInt(R.styleable.TabLayout_bottomLineColor, getResources().getColor(android.R.color.darker_gray));
bottomLineHeight = a.getDimensionPixelSize(R.styleable.TabLayout_bottomLineHeight, 0);
bottomLineWidth = a.getDimensionPixelSize(R.styleable.TabLayout_bottomLineWidth, 0);
LinearLayout linearLayout = new LinearLayout(context);
linearLayout.setOrientation(LinearLayout.VERTICAL);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 0);
layoutParams.weight = 1;
layoutParams.gravity = Gravity.CENTER;
mTabStrip.setBottomLineColor(bottomLineColor);
linearLayout.addView(mTabStrip, layoutParams);
super.addView(linearLayout, 0, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.MATCH_PARENT));
} else {
ViewGroup.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.MATCH_PARENT);
if (bottomLineMode == 2) {
bottomLineColor = a.getInt(R.styleable.TabLayout_bottomLineColor, getResources().getColor(android.R.color.darker_gray));
bottomLineHeight = a.getDimensionPixelSize(R.styleable.TabLayout_bottomLineHeight, 0);
bottomLineWidth = a.getDimensionPixelSize(R.styleable.TabLayout_bottomLineWidth, 0);
mTabStrip.setBottomLineColor(bottomLineColor);
mTabStrip.setBottomLineHeight(bottomLineHeight);
mTabStrip.setBottomLineWidth(bottomLineWidth);
}
super.addView(mTabStrip, 0, layoutParams);
//View view = new View(context);
//view.setBackgroundColor(bottomLineColor);
//linearLayout.addView(view,new LinearLayout.LayoutParams(bottomLineWidth, bottomLineHeight));
}
mTabStrip.setSelectedIndicatorWidth(a.getDimensionPixelSize(R.styleable.TabLayout_tabIndicatorWidth, 0));
mTabStrip.setSelectedIndicatorColor(a.getColor(R.styleable.TabLayout_tabIndicatorColor, 0));
mTabStrip.setDividerCorlor(a.getColor(R.styleable.TabLayout_dividerColor, getResources().getColor(android.R.color.darker_gray)));
dividerHeight = a.getDimensionPixelSize(R.styleable.TabLayout_dividerHeight, 0);
dividerWidth = a.getDimensionPixelSize(R.styleable.TabLayout_dividerWidth, 0);
mTabStrip.setDividerHeight(dividerHeight);
mTabStrip.setDividerWidth(a.getDimensionPixelSize(R.styleable.TabLayout_dividerWidth, 0));
//*****************************自定义部分 END*****************************
mTabStrip.setSelectedIndicatorHeight(
a.getDimensionPixelSize(R.styleable.TabLayout_tabIndicatorHeight, 0));
mTabStrip.setSelectedIndicatorColor(a.getColor(R.styleable.TabLayout_tabIndicatorColor, 0));
mTabPaddingStart = mTabPaddingTop = mTabPaddingEnd = mTabPaddingBottom = a
.getDimensionPixelSize(R.styleable.TabLayout_tabPadding, 0);
mTabPaddingStart = a.getDimensionPixelSize(R.styleable.TabLayout_tabPaddingStart,
mTabPaddingStart);
mTabPaddingTop = a.getDimensionPixelSize(R.styleable.TabLayout_tabPaddingTop,
mTabPaddingTop);
mTabPaddingEnd = a.getDimensionPixelSize(R.styleable.TabLayout_tabPaddingEnd,
mTabPaddingEnd);
mTabPaddingBottom = a.getDimensionPixelSize(R.styleable.TabLayout_tabPaddingBottom,
mTabPaddingBottom);
mTabTextAppearance = a.getResourceId(R.styleable.TabLayout_tabTextAppearance,
R.style.TextAppearance_Design_Tab);
// Text colors/sizes come from the text appearance first
final TypedArray ta = context.obtainStyledAttributes(mTabTextAppearance,
android.support.v7.appcompat.R.styleable.TextAppearance);
try {
mTabTextSize = ta.getDimensionPixelSize(
android.support.v7.appcompat.R.styleable.TextAppearance_android_textSize, 0);
mTabTextColors = ta.getColorStateList(
android.support.v7.appcompat.R.styleable.TextAppearance_android_textColor);
} finally {
ta.recycle();
}
if (a.hasValue(R.styleable.TabLayout_tabTextColor)) {
// If we have an explicit text color set, use it instead
mTabTextColors = a.getColorStateList(R.styleable.TabLayout_tabTextColor);
}
if (a.hasValue(R.styleable.TabLayout_tabSelectedTextColor)) {
// We have an explicit selected text color set, so we need to make merge it with the
// current colors. This is exposed so that developers can use theme attributes to set
// this (theme attrs in ColorStateLists are Lollipop+)
final int selected = a.getColor(R.styleable.TabLayout_tabSelectedTextColor, 0);
mTabTextColors = createColorStateList(mTabTextColors.getDefaultColor(), selected);
}
mRequestedTabMinWidth = a.getDimensionPixelSize(R.styleable.TabLayout_tabMinWidth,
INVALID_WIDTH);
mRequestedTabMaxWidth = a.getDimensionPixelSize(R.styleable.TabLayout_tabMaxWidth,
INVALID_WIDTH);
mTabBackgroundResId = a.getResourceId(R.styleable.TabLayout_tabBackground, 0);
mContentInsetStart = a.getDimensionPixelSize(R.styleable.TabLayout_tabContentStart, 0);
mMode = a.getInt(R.styleable.TabLayout_tabMode, MODE_FIXED);
mTabGravity = a.getInt(R.styleable.TabLayout_tabGravity, GRAVITY_FILL);
a.recycle();
// TODO add attr for these
final Resources res = getResources();
mTabTextMultiLineSize = res.getDimensionPixelSize(R.dimen.design_tab_text_size_2line);
mScrollableTabMinWidth = res.getDimensionPixelSize(R.dimen.design_tab_scrollable_min_width);
// Now apply the tab mode and gravity
applyModeAndGravity();
}
/**
* Sets the tab indicator's color for the currently selected tab.
*
* @param color color to use for the indicator
* @attr ref android.support.design.R.styleable#TabLayout_tabIndicatorColor
*/
public void setSelectedTabIndicatorColor(@ColorInt int color) {
mTabStrip.setSelectedIndicatorColor(color);
}
/**
* Sets the tab indicator's height for the currently selected tab.
*
* @param height height to use for the indicator in pixels
* @attr ref android.support.design.R.styleable#TabLayout_tabIndicatorHeight
*/
public void setSelectedTabIndicatorHeight(int height) {
mTabStrip.setSelectedIndicatorHeight(height);
}
/**
* Set the scroll position of the tabs. This is useful for when the tabs are being displayed as
* part of a scrolling container such as {@link ViewPager}.
*
* Calling this method does not update the selected tab, it is only used for drawing purposes.
*
* @param position current scroll position
* @param positionOffset Value from [0, 1) indicating the offset from {@code position}.
* @param updateSelectedText Whether to update the text's selected state.
*/
public void setScrollPosition(int position, float positionOffset, boolean updateSelectedText) {
setScrollPosition(position, positionOffset, updateSelectedText, true);
}
void setScrollPosition(int position, float positionOffset, boolean updateSelectedText,
boolean updateIndicatorPosition) {
final int roundedPosition = Math.round(position + positionOffset);
if (roundedPosition < 0 || roundedPosition >= mTabStrip.getChildCount()) {
return;
}
// Set the indicator position, if enabled
if (updateIndicatorPosition) {
mTabStrip.setIndicatorPositionFromTabPosition(position, positionOffset);
}
// Now update the scroll position, canceling any running animation
if (mScrollAnimator != null && mScrollAnimator.isRunning()) {
mScrollAnimator.cancel();
}
scrollTo(calculateScrollXForTab(position, positionOffset), 0);
// Update the 'selected state' view as we scroll, if enabled
if (updateSelectedText) {
setSelectedTabView(roundedPosition);
}
}
private float getScrollPosition() {
return mTabStrip.getIndicatorPosition();
}
/**
* Add a tab to this layout. The tab will be added at the end of the list.
* If this is the first tab to be added it will become the selected tab.
*
* @param tab Tab to add
*/
public void addTab(@NonNull Tab tab) {
addTab(tab, mTabs.isEmpty());
}
/**
* Add a tab to this layout. The tab will be inserted at position.
* If this is the first tab to be added it will become the selected tab.
*
* @param tab The tab to add
* @param position The new position of the tab
*/
public void addTab(@NonNull Tab tab, int position) {
addTab(tab, position, mTabs.isEmpty());
}
/**
* Add a tab to this layout. The tab will be added at the end of the list.
*
* @param tab Tab to add
* @param setSelected True if the added tab should become the selected tab.
*/
public void addTab(@NonNull Tab tab, boolean setSelected) {
addTab(tab, mTabs.size(), setSelected);
}
/**
* Add a tab to this layout. The tab will be inserted at position.
*
* @param tab The tab to add
* @param position The new position of the tab
* @param setSelected True if the added tab should become the selected tab.
*/
public void addTab(@NonNull Tab tab, int position, boolean setSelected) {
if (tab.mParent != this) {
throw new IllegalArgumentException("Tab belongs to a different TabLayout.");
}
configureTab(tab, position);
addTabView(tab);
if (setSelected) {
tab.select();
}
}
private void addTabFromItemView(@NonNull TabItem item) {
final Tab tab = newTab();
if (item.mText != null) {
tab.setText(item.mText);
}
if (item.mIcon != null) {
tab.setIcon(item.mIcon);
}
if (item.mCustomLayout != 0) {
tab.setCustomView(item.mCustomLayout);
}
if (!TextUtils.isEmpty(item.getContentDescription())) {
tab.setContentDescription(item.getContentDescription());
}
addTab(tab);
}
/**
* @deprecated Use {@link #addOnTabSelectedListener(OnTabSelectedListener)} and
* {@link #removeOnTabSelectedListener(OnTabSelectedListener)}.
*/
@Deprecated
public void setOnTabSelectedListener(@Nullable OnTabSelectedListener listener) {
// The logic in this method emulates what we had before support for multiple
// registered listeners.
if (mSelectedListener != null) {
removeOnTabSelectedListener(mSelectedListener);
}
// Update the deprecated field so that we can remove the passed listener the next
// time we're called
mSelectedListener = listener;
if (listener != null) {
addOnTabSelectedListener(listener);
}
}
/**
* Add a {@link TabLayout.OnTabSelectedListener} that will be invoked when tab selection
* changes.
*
*
Components that add a listener should take care to remove it when finished via
* {@link #removeOnTabSelectedListener(OnTabSelectedListener)}.
*
* @param listener listener to add
*/
public void addOnTabSelectedListener(@NonNull OnTabSelectedListener listener) {
if (!mSelectedListeners.contains(listener)) {
mSelectedListeners.add(listener);
}
}
/**
* Remove the given {@link TabLayout.OnTabSelectedListener} that was previously added via
* {@link #addOnTabSelectedListener(OnTabSelectedListener)}.
*
* @param listener listener to remove
*/
public void removeOnTabSelectedListener(@NonNull OnTabSelectedListener listener) {
mSelectedListeners.remove(listener);
}
/**
* Remove all previously added {@link TabLayout.OnTabSelectedListener}s.
*/
public void clearOnTabSelectedListeners() {
mSelectedListeners.clear();
}
/**
* Create and return a new {@link Tab}. You need to manually add this using
* {@link #addTab(Tab)} or a related method.
*
* @return A new Tab
* @see #addTab(Tab)
*/
@NonNull
public Tab newTab() {
Tab tab = sTabPool.acquire();
if (tab == null) {
tab = new Tab();
}
tab.mParent = this;
tab.mView = createTabView(tab);
return tab;
}
/**
* Returns the number of tabs currently registered with the action bar.
*
* @return Tab count
*/
public int getTabCount() {
return mTabs.size();
}
/**
* Returns the tab at the specified index.
*/
@Nullable
public Tab getTabAt(int index) {
return (index < 0 || index >= getTabCount()) ? null : mTabs.get(index);
}
/**
* Returns the position of the current selected tab.
*
* @return selected tab position, or {@code -1} if there isn't a selected tab.
*/
public int getSelectedTabPosition() {
return mSelectedTab != null ? mSelectedTab.getPosition() : -1;
}
/**
* Remove a tab from the layout. If the removed tab was selected it will be deselected
* and another tab will be selected if present.
*
* @param tab The tab to remove
*/
public void removeTab(Tab tab) {
if (tab.mParent != this) {
throw new IllegalArgumentException("Tab does not belong to this TabLayout.");
}
removeTabAt(tab.getPosition());
}
/**
* Remove a tab from the layout. If the removed tab was selected it will be deselected
* and another tab will be selected if present.
*
* @param position Position of the tab to remove
*/
public void removeTabAt(int position) {
final int selectedTabPosition = mSelectedTab != null ? mSelectedTab.getPosition() : 0;
removeTabViewAt(position);
final Tab removedTab = mTabs.remove(position);
if (removedTab != null) {
removedTab.reset();
sTabPool.release(removedTab);
}
final int newTabCount = mTabs.size();
for (int i = position; i < newTabCount; i++) {
mTabs.get(i).setPosition(i);
}
if (selectedTabPosition == position) {
selectTab(mTabs.isEmpty() ? null : mTabs.get(Math.max(0, position - 1)));
}
}
/**
* Remove all tabs from the action bar and deselect the current tab.
*/
public void removeAllTabs() {
// Remove all the views
for (int i = mTabStrip.getChildCount() - 1; i >= 0; i--) {
removeTabViewAt(i);
}
for (final Iterator i = mTabs.iterator(); i.hasNext(); ) {
final Tab tab = i.next();
i.remove();
tab.reset();
sTabPool.release(tab);
}
mSelectedTab = null;
}
/**
* Set the behavior mode for the Tabs in this layout. The valid input options are:
*
* - {@link #MODE_FIXED}: Fixed tabs display all tabs concurrently and are best used
* with content that benefits from quick pivots between tabs.
* - {@link #MODE_SCROLLABLE}: Scrollable tabs display a subset of tabs at any given moment,
* and can contain longer tab labels and a larger number of tabs. They are best used for
* browsing contexts in touch interfaces when users don’t need to directly compare the tab
* labels. This mode is commonly used with a {@link ViewPager}.
*
*
* @param mode one of {@link #MODE_FIXED} or {@link #MODE_SCROLLABLE}.
* @attr ref android.support.design.R.styleable#TabLayout_tabMode
*/
public void setTabMode(@Mode int mode) {
if (mode != mMode) {
mMode = mode;
applyModeAndGravity();
}
}
/**
* Returns the current mode used by this {@link TabLayout}.
*
* @see #setTabMode(int)
*/
@Mode
public int getTabMode() {
return mMode;
}
/**
* Set the gravity to use when laying out the tabs.
*
* @param gravity one of {@link #GRAVITY_CENTER} or {@link #GRAVITY_FILL}.
* @attr ref android.support.design.R.styleable#TabLayout_tabGravity
*/
public void setTabGravity(@TabGravity int gravity) {
if (mTabGravity != gravity) {
mTabGravity = gravity;
applyModeAndGravity();
}
}
/**
* The current gravity used for laying out tabs.
*
* @return one of {@link #GRAVITY_CENTER} or {@link #GRAVITY_FILL}.
*/
@TabGravity
public int getTabGravity() {
return mTabGravity;
}
/**
* Sets the text colors for the different states (normal, selected) used for the tabs.
*
* @see #getTabTextColors()
*/
public void setTabTextColors(@Nullable ColorStateList textColor) {
if (mTabTextColors != textColor) {
mTabTextColors = textColor;
updateAllTabs();
}
}
/**
* Gets the text colors for the different states (normal, selected) used for the tabs.
*/
@Nullable
public ColorStateList getTabTextColors() {
return mTabTextColors;
}
/**
* Sets the text colors for the different states (normal, selected) used for the tabs.
*
* @attr ref android.support.design.R.styleable#TabLayout_tabTextColor
* @attr ref android.support.design.R.styleable#TabLayout_tabSelectedTextColor
*/
public void setTabTextColors(int normalColor, int selectedColor) {
setTabTextColors(createColorStateList(normalColor, selectedColor));
}
/**
* The one-stop shop for setting up this {@link TabLayout} with a {@link ViewPager}.
*
*
This is the same as calling {@link #setupWithViewPager(ViewPager, boolean)} with
* auto-refresh enabled.
*
* @param viewPager the ViewPager to link to, or {@code null} to clear any previous link
*/
public void setupWithViewPager(@Nullable ViewPager viewPager) {
setupWithViewPager(viewPager, true);
}
/**
* The one-stop shop for setting up this {@link TabLayout} with a {@link ViewPager}.
*
*
This method will link the given ViewPager and this TabLayout together so that
* changes in one are automatically reflected in the other. This includes scroll state changes
* and clicks. The tabs displayed in this layout will be populated
* from the ViewPager adapter's page titles.
*
*
If {@code autoRefresh} is {@code true}, any changes in the {@link PagerAdapter} will
* trigger this layout to re-populate itself from the adapter's titles.
*
*
If the given ViewPager is non-null, it needs to already have a
* {@link PagerAdapter} set.
*
* @param viewPager the ViewPager to link to, or {@code null} to clear any previous link
* @param autoRefresh whether this layout should refresh its contents if the given ViewPager's
* content changes
*/
public void setupWithViewPager(@Nullable final ViewPager viewPager, boolean autoRefresh) {
setupWithViewPager(viewPager, autoRefresh, false);
}
private void setupWithViewPager(@Nullable final ViewPager viewPager, boolean autoRefresh,
boolean implicitSetup) {
if (mViewPager != null) {
// If we've already been setup with a ViewPager, remove us from it
if (mPageChangeListener != null) {
mViewPager.removeOnPageChangeListener(mPageChangeListener);
}
if (mAdapterChangeListener != null) {
mViewPager.removeOnAdapterChangeListener(mAdapterChangeListener);
}
}
if (mCurrentVpSelectedListener != null) {
// If we already have a tab selected listener for the ViewPager, remove it
removeOnTabSelectedListener(mCurrentVpSelectedListener);
mCurrentVpSelectedListener = null;
}
if (viewPager != null) {
mViewPager = viewPager;
// Add our custom OnPageChangeListener to the ViewPager
if (mPageChangeListener == null) {
mPageChangeListener = new TabLayoutOnPageChangeListener(this);
}
mPageChangeListener.reset();
viewPager.addOnPageChangeListener(mPageChangeListener);
// Now we'll add a tab selected listener to set ViewPager's current item
mCurrentVpSelectedListener = new ViewPagerOnTabSelectedListener(viewPager);
addOnTabSelectedListener(mCurrentVpSelectedListener);
final PagerAdapter adapter = viewPager.getAdapter();
if (adapter != null) {
// Now we'll populate ourselves from the pager adapter, adding an observer if
// autoRefresh is enabled
setPagerAdapter(adapter, autoRefresh);
}
// Add a listener so that we're notified of any adapter changes
if (mAdapterChangeListener == null) {
mAdapterChangeListener = new AdapterChangeListener();
}
mAdapterChangeListener.setAutoRefresh(autoRefresh);
viewPager.addOnAdapterChangeListener(mAdapterChangeListener);
// Now update the scroll position to match the ViewPager's current item
setScrollPosition(viewPager.getCurrentItem(), 0f, true);
} else {
// We've been given a null ViewPager so we need to clear out the internal state,
// listeners and observers
mViewPager = null;
setPagerAdapter(null, false);
}
mSetupViewPagerImplicitly = implicitSetup;
}
/**
* @deprecated Use {@link #setupWithViewPager(ViewPager)} to link a TabLayout with a ViewPager
* together. When that method is used, the TabLayout will be automatically updated
* when the {@link PagerAdapter} is changed.
*/
@Deprecated
public void setTabsFromPagerAdapter(@Nullable final PagerAdapter adapter) {
setPagerAdapter(adapter, false);
}
@Override
public boolean shouldDelayChildPressedState() {
// Only delay the pressed state if the tabs can scroll
return getTabScrollRange() > 0;
}
@Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
if (mViewPager == null) {
// If we don't have a ViewPager already, check if our parent is a ViewPager to
// setup with it automatically
final ViewParent vp = getParent();
if (vp instanceof ViewPager) {
// If we have a ViewPager parent and we've been added as part of its decor, let's
// assume that we should automatically setup to display any titles
setupWithViewPager((ViewPager) vp, true, true);
}
}
}
@Override
protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
if (mSetupViewPagerImplicitly) {
// If we've been setup with a ViewPager implicitly, let's clear out any listeners, etc
setupWithViewPager(null);
mSetupViewPagerImplicitly = false;
}
}
private int getTabScrollRange() {
return Math.max(0, mTabStrip.getWidth() - getWidth() - getPaddingLeft()
- getPaddingRight());
}
void setPagerAdapter(@Nullable final PagerAdapter adapter, final boolean addObserver) {
if (mPagerAdapter != null && mPagerAdapterObserver != null) {
// If we already have a PagerAdapter, unregister our observer
mPagerAdapter.unregisterDataSetObserver(mPagerAdapterObserver);
}
mPagerAdapter = adapter;
if (addObserver && adapter != null) {
// Register our observer on the new adapter
if (mPagerAdapterObserver == null) {
mPagerAdapterObserver = new PagerAdapterObserver();
}
adapter.registerDataSetObserver(mPagerAdapterObserver);
}
// Finally make sure we reflect the new adapter
populateFromPagerAdapter();
}
void populateFromPagerAdapter() {
removeAllTabs();
if (mPagerAdapter != null) {
final int adapterCount = mPagerAdapter.getCount();
for (int i = 0; i < adapterCount; i++) {
addTab(newTab().setText(mPagerAdapter.getPageTitle(i)), false);
}
// Make sure we reflect the currently set ViewPager item
if (mViewPager != null && adapterCount > 0) {
final int curItem = mViewPager.getCurrentItem();
if (curItem != getSelectedTabPosition() && curItem < getTabCount()) {
selectTab(getTabAt(curItem));
}
}
}
}
private void updateAllTabs() {
for (int i = 0, z = mTabs.size(); i < z; i++) {
mTabs.get(i).updateView();
}
}
private TabView createTabView(@NonNull final Tab tab) {
TabView tabView = mTabViewPool != null ? mTabViewPool.acquire() : null;
if (tabView == null) {
tabView = new TabView(getContext());
}
tabView.setTab(tab);
tabView.setFocusable(true);
tabView.setMinimumWidth(getTabMinWidth());
return tabView;
}
private void configureTab(Tab tab, int position) {
tab.setPosition(position);
mTabs.add(position, tab);
final int count = mTabs.size();
for (int i = position + 1; i < count; i++) {
mTabs.get(i).setPosition(i);
}
}
private void addTabView(Tab tab) {
final TabView tabView = tab.mView;
mTabStrip.addView(tabView, tab.getPosition(), createLayoutParamsForTabs());
}
@Override
public void addView(View child) {
addViewInternal(child);
}
@Override
public void addView(View child, int index) {
addViewInternal(child);
}
@Override
public void addView(View child, ViewGroup.LayoutParams params) {
addViewInternal(child);
}
@Override
public void addView(View child, int index, ViewGroup.LayoutParams params) {
addViewInternal(child);
}
private void addViewInternal(final View child) {
if (child instanceof TabItem) {
addTabFromItemView((TabItem) child);
} else {
throw new IllegalArgumentException("Only TabItem instances can be added to TabLayout");
}
}
private LinearLayout.LayoutParams createLayoutParamsForTabs() {
final LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
updateTabViewLayoutParams(lp);
return lp;
}
private void updateTabViewLayoutParams(LinearLayout.LayoutParams lp) {
if (mMode == MODE_FIXED && mTabGravity == GRAVITY_FILL) {
lp.width = 0;
lp.weight = 1;
} else {
lp.width = LinearLayout.LayoutParams.WRAP_CONTENT;
lp.weight = 0;
}
}
int dpToPx(int dps) {
return Math.round(getResources().getDisplayMetrics().density * dps);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// If we have a MeasureSpec which allows us to decide our height, try and use the default
// height
final int idealHeight = dpToPx(getDefaultHeight()) + getPaddingTop() + getPaddingBottom();
switch (MeasureSpec.getMode(heightMeasureSpec)) {
case MeasureSpec.AT_MOST:
heightMeasureSpec = MeasureSpec.makeMeasureSpec(
Math.min(idealHeight, MeasureSpec.getSize(heightMeasureSpec)),
MeasureSpec.EXACTLY);
break;
case MeasureSpec.UNSPECIFIED:
heightMeasureSpec = MeasureSpec.makeMeasureSpec(idealHeight, MeasureSpec.EXACTLY);
break;
}
final int specWidth = MeasureSpec.getSize(widthMeasureSpec);
if (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED) {
// If we don't have an unspecified width spec, use the given size to calculate
// the max tab width
mTabMaxWidth = mRequestedTabMaxWidth > 0
? mRequestedTabMaxWidth
: specWidth - dpToPx(TAB_MIN_WIDTH_MARGIN);
}
// Now super measure itself using the (possibly) modified height spec
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (getChildCount() == 1) {
// If we're in fixed mode then we need to make the tab strip is the same width as us
// so we don't scroll
final View child = getChildAt(0);
boolean remeasure = false;
switch (mMode) {
case MODE_SCROLLABLE:
// We only need to resize the child if it's smaller than us. This is similar
// to fillViewport
remeasure = child.getMeasuredWidth() < getMeasuredWidth();
break;
case MODE_FIXED:
// Resize the child so that it doesn't scroll
remeasure = child.getMeasuredWidth() != getMeasuredWidth();
break;
}
if (remeasure) {
// Re-measure the child with a widthSpec set to be exactly our measure width
int childHeightMeasureSpec = getChildMeasureSpec(heightMeasureSpec, getPaddingTop()
+ getPaddingBottom(), child.getLayoutParams().height);
int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
getMeasuredWidth(), MeasureSpec.EXACTLY);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
}
}
private void removeTabViewAt(int position) {
final TabView view = (TabView) mTabStrip.getChildAt(position);
mTabStrip.removeViewAt(position);
if (view != null) {
view.reset();
mTabViewPool.release(view);
}
requestLayout();
}
private void animateToTab(int newPosition) {
if (newPosition == Tab.INVALID_POSITION) {
return;
}
if (getWindowToken() == null || !ViewCompat.isLaidOut(this)
|| mTabStrip.childrenNeedLayout()) {
// If we don't have a window token, or we haven't been laid out yet just draw the new
// position now
setScrollPosition(newPosition, 0f, true);
return;
}
final int startScrollX = getScrollX();
final int targetScrollX = calculateScrollXForTab(newPosition, 0);
if (startScrollX != targetScrollX) {
ensureScrollAnimator();
mScrollAnimator.setIntValues(startScrollX, targetScrollX);
mScrollAnimator.start();
}
// Now animate the indicator
mTabStrip.animateIndicatorToPosition(newPosition, ANIMATION_DURATION);
}
private void ensureScrollAnimator() {
if (mScrollAnimator == null) {
mScrollAnimator = new ValueAnimator();
mScrollAnimator.setInterpolator(com.android.support.design.widget.AnimationUtils.FAST_OUT_SLOW_IN_INTERPOLATOR);
mScrollAnimator.setDuration(ANIMATION_DURATION);
mScrollAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animator) {
scrollTo((int) animator.getAnimatedValue(), 0);
}
});
}
}
void setScrollAnimatorListener(Animator.AnimatorListener listener) {
ensureScrollAnimator();
mScrollAnimator.addListener(listener);
}
private void setSelectedTabView(int position) {
final int tabCount = mTabStrip.getChildCount();
if (position < tabCount) {
for (int i = 0; i < tabCount; i++) {
final View child = mTabStrip.getChildAt(i);
child.setSelected(i == position);
}
}
}
void selectTab(Tab tab) {
selectTab(tab, true);
}
void selectTab(final Tab tab, boolean updateIndicator) {
final Tab currentTab = mSelectedTab;
if (currentTab == tab) {
if (currentTab != null) {
dispatchTabReselected(tab);
animateToTab(tab.getPosition());
}
} else {
final int newPosition = tab != null ? tab.getPosition() : Tab.INVALID_POSITION;
if (updateIndicator) {
if ((currentTab == null || currentTab.getPosition() == Tab.INVALID_POSITION)
&& newPosition != Tab.INVALID_POSITION) {
// If we don't currently have a tab, just draw the indicator
setScrollPosition(newPosition, 0f, true);
} else {
animateToTab(newPosition);
}
if (newPosition != Tab.INVALID_POSITION) {
setSelectedTabView(newPosition);
}
}
if (currentTab != null) {
dispatchTabUnselected(currentTab);
}
mSelectedTab = tab;
if (tab != null) {
dispatchTabSelected(tab);
}
}
}
private void dispatchTabSelected(@NonNull final Tab tab) {
for (int i = mSelectedListeners.size() - 1; i >= 0; i--) {
mSelectedListeners.get(i).onTabSelected(tab);
}
}
private void dispatchTabUnselected(@NonNull final Tab tab) {
for (int i = mSelectedListeners.size() - 1; i >= 0; i--) {
mSelectedListeners.get(i).onTabUnselected(tab);
}
}
private void dispatchTabReselected(@NonNull final Tab tab) {
for (int i = mSelectedListeners.size() - 1; i >= 0; i--) {
mSelectedListeners.get(i).onTabReselected(tab);
}
}
private int calculateScrollXForTab(int position, float positionOffset) {
if (mMode == MODE_SCROLLABLE) {
final View selectedChild = mTabStrip.getChildAt(position);
final View nextChild = position + 1 < mTabStrip.getChildCount()
? mTabStrip.getChildAt(position + 1)
: null;
final int selectedWidth = selectedChild != null ? selectedChild.getWidth() : 0;
final int nextWidth = nextChild != null ? nextChild.getWidth() : 0;
// base scroll amount: places center of tab in center of parent
int scrollBase = selectedChild.getLeft() + (selectedWidth / 2) - (getWidth() / 2);
// offset amount: fraction of the distance between centers of tabs
int scrollOffset = (int) ((selectedWidth + nextWidth) * 0.5f * positionOffset);
return (ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_LTR)
? scrollBase + scrollOffset
: scrollBase - scrollOffset;
}
return 0;
}
private void applyModeAndGravity() {
int paddingStart = 0;
if (mMode == MODE_SCROLLABLE) {
// If we're scrollable, or fixed at start, inset using padding
paddingStart = Math.max(0, mContentInsetStart - mTabPaddingStart);
}
ViewCompat.setPaddingRelative(mTabStrip, paddingStart, 0, 0, 0);
switch (mMode) {
case MODE_FIXED:
mTabStrip.setGravity(Gravity.CENTER_HORIZONTAL);
break;
case MODE_SCROLLABLE:
mTabStrip.setGravity(GravityCompat.START);
break;
}
updateTabViews(true);
}
void updateTabViews(final boolean requestLayout) {
for (int i = 0; i < mTabStrip.getChildCount(); i++) {
View child = mTabStrip.getChildAt(i);
child.setMinimumWidth(getTabMinWidth());
updateTabViewLayoutParams((LinearLayout.LayoutParams) child.getLayoutParams());
if (requestLayout) {
child.requestLayout();
}
}
}
/**
* A tab in this layout. Instances can be created via {@link #newTab()}.
*/
public static final class Tab {
/**
* An invalid position for a tab.
*
* @see #getPosition()
*/
public static final int INVALID_POSITION = -1;
private Object mTag;
private Drawable mIcon;
private CharSequence mText;
private CharSequence mContentDesc;
private int mPosition = INVALID_POSITION;
private View mCustomView;
TabLayout mParent;
TabView mView;
Tab() {
// Private constructor
}
/**
* @return This Tab's tag object.
*/
@Nullable
public Object getTag() {
return mTag;
}
/**
* Give this Tab an arbitrary object to hold for later use.
*
* @param tag Object to store
* @return The current instance for call chaining
*/
@NonNull
public Tab setTag(@Nullable Object tag) {
mTag = tag;
return this;
}
/**
* Returns the custom view used for this tab.
*
* @see #setCustomView(View)
* @see #setCustomView(int)
*/
@Nullable
public View getCustomView() {
return mCustomView;
}
/**
* Set a custom view to be used for this tab.
*
* If the provided view contains a {@link TextView} with an ID of
* {@link android.R.id#text1} then that will be updated with the value given
* to {@link #setText(CharSequence)}. Similarly, if this layout contains an
* {@link ImageView} with ID {@link android.R.id#icon} then it will be updated with
* the value given to {@link #setIcon(Drawable)}.
*
*
* @param view Custom view to be used as a tab.
* @return The current instance for call chaining
*/
@NonNull
public Tab setCustomView(@Nullable View view) {
mCustomView = view;
updateView();
return this;
}
/**
* Set a custom view to be used for this tab.
*
* If the inflated layout contains a {@link TextView} with an ID of
* {@link android.R.id#text1} then that will be updated with the value given
* to {@link #setText(CharSequence)}. Similarly, if this layout contains an
* {@link ImageView} with ID {@link android.R.id#icon} then it will be updated with
* the value given to {@link #setIcon(Drawable)}.
*
*
* @param resId A layout resource to inflate and use as a custom tab view
* @return The current instance for call chaining
*/
@NonNull
public Tab setCustomView(@LayoutRes int resId) {
final LayoutInflater inflater = LayoutInflater.from(mView.getContext());
return setCustomView(inflater.inflate(resId, mView, false));
}
/**
* Return the icon associated with this tab.
*
* @return The tab's icon
*/
@Nullable
public Drawable getIcon() {
return mIcon;
}
/**
* Return the current position of this tab in the action bar.
*
* @return Current position, or {@link #INVALID_POSITION} if this tab is not currently in
* the action bar.
*/
public int getPosition() {
return mPosition;
}
void setPosition(int position) {
mPosition = position;
}
/**
* Return the text of this tab.
*
* @return The tab's text
*/
@Nullable
public CharSequence getText() {
return mText;
}
/**
* Set the icon displayed on this tab.
*
* @param icon The drawable to use as an icon
* @return The current instance for call chaining
*/
@NonNull
public Tab setIcon(@Nullable Drawable icon) {
mIcon = icon;
updateView();
return this;
}
/**
* Set the icon displayed on this tab.
*
* @param resId A resource ID referring to the icon that should be displayed
* @return The current instance for call chaining
*/
@NonNull
public Tab setIcon(@DrawableRes int resId) {
if (mParent == null) {
throw new IllegalArgumentException("Tab not attached to a TabLayout");
}
return setIcon(AppCompatResources.getDrawable(mParent.getContext(), resId));
}
/**
* Set the text displayed on this tab. Text may be truncated if there is not room to display
* the entire string.
*
* @param text The text to display
* @return The current instance for call chaining
*/
@NonNull
public Tab setText(@Nullable CharSequence text) {
mText = text;
updateView();
return this;
}
/**
* Set the text displayed on this tab. Text may be truncated if there is not room to display
* the entire string.
*
* @param resId A resource ID referring to the text that should be displayed
* @return The current instance for call chaining
*/
@NonNull
public Tab setText(@StringRes int resId) {
if (mParent == null) {
throw new IllegalArgumentException("Tab not attached to a TabLayout");
}
return setText(mParent.getResources().getText(resId));
}
/**
* Select this tab. Only valid if the tab has been added to the action bar.
*/
public void select() {
if (mParent == null) {
throw new IllegalArgumentException("Tab not attached to a TabLayout");
}
mParent.selectTab(this);
}
/**
* Returns true if this tab is currently selected.
*/
public boolean isSelected() {
if (mParent == null) {
throw new IllegalArgumentException("Tab not attached to a TabLayout");
}
return mParent.getSelectedTabPosition() == mPosition;
}
/**
* Set a description of this tab's content for use in accessibility support. If no content
* description is provided the title will be used.
*
* @param resId A resource ID referring to the description text
* @return The current instance for call chaining
* @see #setContentDescription(CharSequence)
* @see #getContentDescription()
*/
@NonNull
public Tab setContentDescription(@StringRes int resId) {
if (mParent == null) {
throw new IllegalArgumentException("Tab not attached to a TabLayout");
}
return setContentDescription(mParent.getResources().getText(resId));
}
/**
* Set a description of this tab's content for use in accessibility support. If no content
* description is provided the title will be used.
*
* @param contentDesc Description of this tab's content
* @return The current instance for call chaining
* @see #setContentDescription(int)
* @see #getContentDescription()
*/
@NonNull
public Tab setContentDescription(@Nullable CharSequence contentDesc) {
mContentDesc = contentDesc;
updateView();
return this;
}
/**
* Gets a brief description of this tab's content for use in accessibility support.
*
* @return Description of this tab's content
* @see #setContentDescription(CharSequence)
* @see #setContentDescription(int)
*/
@Nullable
public CharSequence getContentDescription() {
return mContentDesc;
}
void updateView() {
if (mView != null) {
mView.update();
}
}
void reset() {
mParent = null;
mView = null;
mTag = null;
mIcon = null;
mText = null;
mContentDesc = null;
mPosition = INVALID_POSITION;
mCustomView = null;
}
}
class TabView extends LinearLayout {
private Tab mTab;
private TextView mTextView;
private ImageView mIconView;
private View mCustomView;
private TextView mCustomTextView;
private ImageView mCustomIconView;
private int mDefaultMaxLines = 2;
public TabView(Context context) {
super(context);
if (mTabBackgroundResId != 0) {
ViewCompat.setBackground(
this, AppCompatResources.getDrawable(context, mTabBackgroundResId));
}
ViewCompat.setPaddingRelative(this, mTabPaddingStart, mTabPaddingTop,
mTabPaddingEnd, mTabPaddingBottom);
setGravity(Gravity.CENTER);
setOrientation(VERTICAL);
setClickable(true);
ViewCompat.setPointerIcon(this,
PointerIconCompat.getSystemIcon(getContext(), PointerIconCompat.TYPE_HAND));
}
@Override
public boolean performClick() {
final boolean handled = super.performClick();
if (mTab != null) {
if (!handled) {
playSoundEffect(SoundEffectConstants.CLICK);
}
mTab.select();
return true;
} else {
return handled;
}
}
@Override
public void setSelected(final boolean selected) {
final boolean changed = isSelected() != selected;
super.setSelected(selected);
if (changed && selected && Build.VERSION.SDK_INT < 16) {
// Pre-JB we need to manually send the TYPE_VIEW_SELECTED event
sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_SELECTED);
}
// Always dispatch this to the child views, regardless of whether the value has
// changed
if (mTextView != null) {
mTextView.setSelected(selected);
}
if (mIconView != null) {
mIconView.setSelected(selected);
}
if (mCustomView != null) {
mCustomView.setSelected(selected);
}
}
@Override
public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
// This view masquerades as an action bar tab.
event.setClassName(ActionBar.Tab.class.getName());
}
@Override
public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
super.onInitializeAccessibilityNodeInfo(info);
// This view masquerades as an action bar tab.
info.setClassName(ActionBar.Tab.class.getName());
}
@Override
public void onMeasure(final int origWidthMeasureSpec, final int origHeightMeasureSpec) {
final int specWidthSize = MeasureSpec.getSize(origWidthMeasureSpec);
final int specWidthMode = MeasureSpec.getMode(origWidthMeasureSpec);
final int maxWidth = getTabMaxWidth();
final int widthMeasureSpec;
final int heightMeasureSpec = origHeightMeasureSpec;
if (maxWidth > 0 && (specWidthMode == MeasureSpec.UNSPECIFIED
|| specWidthSize > maxWidth)) {
// If we have a max width and a given spec which is either unspecified or
// larger than the max width, update the width spec using the same mode
widthMeasureSpec = MeasureSpec.makeMeasureSpec(mTabMaxWidth, MeasureSpec.AT_MOST);
} else {
// Else, use the original width spec
widthMeasureSpec = origWidthMeasureSpec;
}
// Now lets measure
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
// We need to switch the text size based on whether the text is spanning 2 lines or not
if (mTextView != null) {
final Resources res = getResources();
float textSize = mTabTextSize;
int maxLines = mDefaultMaxLines;
if (mIconView != null && mIconView.getVisibility() == VISIBLE) {
// If the icon view is being displayed, we limit the text to 1 line
maxLines = 1;
} else if (mTextView != null && mTextView.getLineCount() > 1) {
// Otherwise when we have text which wraps we reduce the text size
textSize = mTabTextMultiLineSize;
}
final float curTextSize = mTextView.getTextSize();
final int curLineCount = mTextView.getLineCount();
final int curMaxLines = TextViewCompat.getMaxLines(mTextView);
if (textSize != curTextSize || (curMaxLines >= 0 && maxLines != curMaxLines)) {
// We've got a new text size and/or max lines...
boolean updateTextView = true;
if (mMode == MODE_FIXED && textSize > curTextSize && curLineCount == 1) {
// If we're in fixed mode, going up in text size and currently have 1 line
// then it's very easy to get into an infinite recursion.
// To combat that we check to see if the change in text size
// will cause a line count change. If so, abort the size change and stick
// to the smaller size.
final Layout layout = mTextView.getLayout();
if (layout == null || approximateLineWidth(layout, 0, textSize)
> getMeasuredWidth() - getPaddingLeft() - getPaddingRight()) {
updateTextView = false;
}
}
if (updateTextView) {
mTextView.setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize);
mTextView.setMaxLines(maxLines);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
}
}
void setTab(@Nullable final Tab tab) {
if (tab != mTab) {
mTab = tab;
update();
}
}
void reset() {
setTab(null);
setSelected(false);
}
final void update() {
final Tab tab = mTab;
final View custom = tab != null ? tab.getCustomView() : null;
if (custom != null) {
final ViewParent customParent = custom.getParent();
if (customParent != this) {
if (customParent != null) {
((ViewGroup) customParent).removeView(custom);
}
addView(custom);
}
mCustomView = custom;
if (mTextView != null) {
mTextView.setVisibility(GONE);
}
if (mIconView != null) {
mIconView.setVisibility(GONE);
mIconView.setImageDrawable(null);
}
mCustomTextView = (TextView) custom.findViewById(android.R.id.text1);
if (mCustomTextView != null) {
mDefaultMaxLines = TextViewCompat.getMaxLines(mCustomTextView);
}
mCustomIconView = (ImageView) custom.findViewById(android.R.id.icon);
} else {
// We do not have a custom view. Remove one if it already exists
if (mCustomView != null) {
removeView(mCustomView);
mCustomView = null;
}
mCustomTextView = null;
mCustomIconView = null;
}
if (mCustomView == null) {
// If there isn't a custom view, we'll us our own in-built layouts
if (mIconView == null) {
ImageView iconView = (ImageView) LayoutInflater.from(getContext())
.inflate(R.layout.design_layout_tab_icon, this, false);
addView(iconView, 0);
mIconView = iconView;
}
if (mTextView == null) {
TextView textView = (TextView) LayoutInflater.from(getContext())
.inflate(R.layout.design_layout_tab_text, this, false);
addView(textView);
mTextView = textView;
mDefaultMaxLines = TextViewCompat.getMaxLines(mTextView);
}
TextViewCompat.setTextAppearance(mTextView, mTabTextAppearance);
if (mTabTextColors != null) {
mTextView.setTextColor(mTabTextColors);
}
updateTextAndIcon(mTextView, mIconView);
} else {
// Else, we'll see if there is a TextView or ImageView present and update them
if (mCustomTextView != null || mCustomIconView != null) {
updateTextAndIcon(mCustomTextView, mCustomIconView);
}
}
// Finally update our selected state
setSelected(tab != null && tab.isSelected());
}
private void updateTextAndIcon(@Nullable final TextView textView,
@Nullable final ImageView iconView) {
final Drawable icon = mTab != null ? mTab.getIcon() : null;
final CharSequence text = mTab != null ? mTab.getText() : null;
final CharSequence contentDesc = mTab != null ? mTab.getContentDescription() : null;
if (iconView != null) {
if (icon != null) {
iconView.setImageDrawable(icon);
iconView.setVisibility(VISIBLE);
setVisibility(VISIBLE);
} else {
iconView.setVisibility(GONE);
iconView.setImageDrawable(null);
}
iconView.setContentDescription(contentDesc);
}
final boolean hasText = !TextUtils.isEmpty(text);
if (textView != null) {
if (hasText) {
textView.setText(text);
textView.setVisibility(VISIBLE);
setVisibility(VISIBLE);
} else {
textView.setVisibility(GONE);
textView.setText(null);
}
textView.setContentDescription(contentDesc);
}
if (iconView != null) {
MarginLayoutParams lp = ((MarginLayoutParams) iconView.getLayoutParams());
int bottomMargin = 0;
if (hasText && iconView.getVisibility() == VISIBLE) {
// If we're showing both text and icon, add some margin bottom to the icon
bottomMargin = dpToPx(DEFAULT_GAP_TEXT_ICON);
}
if (bottomMargin != lp.bottomMargin) {
lp.bottomMargin = bottomMargin;
iconView.requestLayout();
}
}
TooltipCompat.setTooltipText(this, hasText ? null : contentDesc);
}
public Tab getTab() {
return mTab;
}
/**
* Approximates a given lines width with the new provided text size.
*/
private float approximateLineWidth(Layout layout, int line, float textSize) {
return layout.getLineWidth(line) * (textSize / layout.getPaint().getTextSize());
}
}
private class SlidingTabStrip extends LinearLayout {
private final Paint mDividerPaint;
private int mSelectedIndicatorHeight;
private final Paint mSelectedIndicatorPaint;
int mSelectedPosition = -1;
float mSelectionOffset;
private int mLayoutDirection = -1;
private int mIndicatorLeft = -1;
private int mIndicatorRight = -1;
private ValueAnimator mIndicatorAnimator;
//*****************************自定义部分 START*****************************
private int mBottomLineHeight;
private int mBottomLineWidth;
private int mBottomLineMode;
private int mSelectedIndicatorWidth;
private int mDividerWidth;
private int mDividerHeight;
private final Paint mBottomLinerPaint;
//*****************************自定义部分 END*****************************
SlidingTabStrip(Context context) {
super(context);
setWillNotDraw(false);
mSelectedIndicatorPaint = new Paint();
//*****************************自定义部分 START*****************************
mBottomLinerPaint = new Paint();
mDividerPaint = new Paint();
//*****************************自定义部分 END*****************************
}
void setSelectedIndicatorColor(int color) {
if (mSelectedIndicatorPaint.getColor() != color) {
mSelectedIndicatorPaint.setColor(color);
ViewCompat.postInvalidateOnAnimation(this);
}
}
void setSelectedIndicatorHeight(int height) {
if (mSelectedIndicatorHeight != height) {
mSelectedIndicatorHeight = height;
ViewCompat.postInvalidateOnAnimation(this);
}
}
void setSelectedIndicatorWidth(int width) {
if (mSelectedIndicatorWidth != width) {
mSelectedIndicatorWidth = width;
ViewCompat.postInvalidateOnAnimation(this);
}
}
//*****************************自定义部分 START*****************************
void setDividerCorlor(int corlor) {
if (mDividerPaint.getColor() != corlor) {
mDividerPaint.setColor(corlor);
ViewCompat.postInvalidateOnAnimation(this);
}
}
void setDividerHeight(int height) {
if (mDividerHeight != height) {
mDividerHeight = height;
ViewCompat.postInvalidateOnAnimation(this);
}
}
void setDividerWidth(int width) {
if (mDividerWidth != width) {
mDividerWidth = width;
ViewCompat.postInvalidateOnAnimation(this);
}
}
void setBottomLineHeight(int height) {
if (mBottomLineHeight != height) {
mBottomLineHeight = height;
ViewCompat.postInvalidateOnAnimation(this);
}
}
void setBottomLineColor(int color) {
if (mBottomLinerPaint.getColor() != color) {
mBottomLinerPaint.setColor(color);
ViewCompat.postInvalidateOnAnimation(this);
}
}
void setBottomLineWidth(int width) {
if (mBottomLineWidth != width) {
mBottomLineWidth = width;
ViewCompat.postInvalidateOnAnimation(this);
}
}
void setBottomLineMode(int mode) {
if (mBottomLineMode != mode) {
mBottomLineMode = mode;
ViewCompat.postInvalidateOnAnimation(this);
}
}
//*****************************自定义部分 END*****************************
boolean childrenNeedLayout() {
for (int i = 0, z = getChildCount(); i < z; i++) {
final View child = getChildAt(i);
if (child.getWidth() <= 0) {
return true;
}
}
return false;
}
void setIndicatorPositionFromTabPosition(int position, float positionOffset) {
if (mIndicatorAnimator != null && mIndicatorAnimator.isRunning()) {
mIndicatorAnimator.cancel();
}
mSelectedPosition = position;
mSelectionOffset = positionOffset;
updateIndicatorPosition();
}
float getIndicatorPosition() {
return mSelectedPosition + mSelectionOffset;
}
@Override
public void onRtlPropertiesChanged(int layoutDirection) {
super.onRtlPropertiesChanged(layoutDirection);
// Workaround for a bug before Android M where LinearLayout did not relayout itself when
// layout direction changed.
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
//noinspection WrongConstant
if (mLayoutDirection != layoutDirection) {
requestLayout();
mLayoutDirection = layoutDirection;
}
}
}
@Override
protected void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.EXACTLY) {
// HorizontalScrollView will first measure use with UNSPECIFIED, and then with
// EXACTLY. Ignore the first call since anything we do will be overwritten anyway
return;
}
if (mMode == MODE_FIXED && mTabGravity == GRAVITY_CENTER) {
final int count = getChildCount();
// First we'll find the widest tab
int largestTabWidth = 0;
for (int i = 0, z = count; i < z; i++) {
View child = getChildAt(i);
if (child.getVisibility() == VISIBLE) {
largestTabWidth = Math.max(largestTabWidth, child.getMeasuredWidth());
}
}
if (largestTabWidth <= 0) {
// If we don't have a largest child yet, skip until the next measure pass
return;
}
final int gutter = dpToPx(FIXED_WRAP_GUTTER_MIN);
boolean remeasure = false;
if (largestTabWidth * count <= getMeasuredWidth() - gutter * 2) {
// If the tabs fit within our width minus gutters, we will set all tabs to have
// the same width
for (int i = 0; i < count; i++) {
final LayoutParams lp =
(LayoutParams) getChildAt(i).getLayoutParams();
if (lp.width != largestTabWidth || lp.weight != 0) {
lp.width = largestTabWidth;
lp.weight = 0;
remeasure = true;
}
}
} else {
// If the tabs will wrap to be larger than the width minus gutters, we need
// to switch to GRAVITY_FILL
mTabGravity = GRAVITY_FILL;
updateTabViews(false);
remeasure = true;
}
if (remeasure) {
// Now re-measure after our changes
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
if (mIndicatorAnimator != null && mIndicatorAnimator.isRunning()) {
// If we're currently running an animation, lets cancel it and start a
// new animation with the remaining duration
mIndicatorAnimator.cancel();
final long duration = mIndicatorAnimator.getDuration();
animateIndicatorToPosition(mSelectedPosition,
Math.round((1f - mIndicatorAnimator.getAnimatedFraction()) * duration));
} else {
// If we've been layed out, update the indicator position
updateIndicatorPosition();
}
}
private void updateIndicatorPosition() {
final View selectedTitle = getChildAt(mSelectedPosition);
int left, right;
if (selectedTitle != null && selectedTitle.getWidth() > 0) {
left = selectedTitle.getLeft();
right = selectedTitle.getRight();
if (mSelectionOffset > 0f && mSelectedPosition < getChildCount() - 1) {
// Draw the selection partway between the tabs
View nextTitle = getChildAt(mSelectedPosition + 1);
left = (int) (mSelectionOffset * nextTitle.getLeft() +
(1.0f - mSelectionOffset) * left);
right = (int) (mSelectionOffset * nextTitle.getRight() +
(1.0f - mSelectionOffset) * right);
}
} else {
left = right = -1;
}
setIndicatorPosition(left, right);
}
void setIndicatorPosition(int left, int right) {
if (left != mIndicatorLeft || right != mIndicatorRight) {
// If the indicator's left/right has changed, invalidate
mIndicatorLeft = left;
mIndicatorRight = right;
ViewCompat.postInvalidateOnAnimation(this);
}
}
void animateIndicatorToPosition(final int position, int duration) {
if (mIndicatorAnimator != null && mIndicatorAnimator.isRunning()) {
mIndicatorAnimator.cancel();
}
final boolean isRtl = ViewCompat.getLayoutDirection(this)
== ViewCompat.LAYOUT_DIRECTION_RTL;
final View targetView = getChildAt(position);
if (targetView == null) {
// If we don't have a view, just update the position now and return
updateIndicatorPosition();
return;
}
final int targetLeft = targetView.getLeft();
final int targetRight = targetView.getRight();
final int startLeft;
final int startRight;
if (Math.abs(position - mSelectedPosition) <= 1) {
// If the views are adjacent, we'll animate from edge-to-edge
startLeft = mIndicatorLeft;
startRight = mIndicatorRight;
} else {
// Else, we'll just grow from the nearest edge
final int offset = dpToPx(MOTION_NON_ADJACENT_OFFSET);
if (position < mSelectedPosition) {
// We're going end-to-start
if (isRtl) {
startLeft = startRight = targetLeft - offset;
} else {
startLeft = startRight = targetRight + offset;
}
} else {
// We're going start-to-end
if (isRtl) {
startLeft = startRight = targetRight + offset;
} else {
startLeft = startRight = targetLeft - offset;
}
}
}
if (startLeft != targetLeft || startRight != targetRight) {
ValueAnimator animator = mIndicatorAnimator = new ValueAnimator();
animator.setInterpolator(com.android.support.design.widget.AnimationUtils.FAST_OUT_SLOW_IN_INTERPOLATOR);
animator.setDuration(duration);
animator.setFloatValues(0, 1);
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animator) {
final float fraction = animator.getAnimatedFraction();
setIndicatorPosition(
com.android.support.design.widget.AnimationUtils.lerp(startLeft, targetLeft, fraction),
com.android.support.design.widget.AnimationUtils.lerp(startRight, targetRight, fraction));
}
});
animator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animator) {
mSelectedPosition = position;
mSelectionOffset = 0f;
}
});
animator.start();
}
}
@Override
public void draw(Canvas canvas) {
super.draw(canvas);
// Thick colored underline below the current selection
// if (mIndicatorLeft >= 0 && mIndicatorRight > mIndicatorLeft) {
// canvas.drawRect(mIndicatorLeft, getHeight() - mSelectedIndicatorHeight,
// mIndicatorRight, getHeight(), mSelectedIndicatorPaint);
// }
//*****************************自定义部分 START*****************************
int bottomLineOffset = 0;
int IndicatorOffset = 0;
if (bottomLineMode == 2) {
bottomLineOffset = bottomLineHeight;
IndicatorOffset = mSelectedIndicatorHeight;
}
if (mSelectedIndicatorPaint != null && mIndicatorLeft >= 0 && mSelectedIndicatorHeight > 0 && mSelectedIndicatorWidth != 0
&& mIndicatorRight > mIndicatorLeft) {
int offset = 0;
if (mSelectedIndicatorWidth > 0) {
offset = (mIndicatorRight - mIndicatorLeft - mSelectedIndicatorWidth) / 2;
if (offset < 0) {
offset = 0;
}
}
int a = getHeight() - mSelectedIndicatorHeight - bottomLineHeight + bottomLineOffset;
int b = (getHeight() - bottomLineHeight + bottomLineOffset);
Log.d("", "draw: -----------------IndicatorTop = " + a);
Log.d("", "draw: -----------------Indicatorbottom = " + b);
//底部选中滑动线的绘制(即文字下面表示选中的哪一页)
RectF rectF = new RectF(mIndicatorLeft + offset, getHeight() - mSelectedIndicatorHeight - bottomLineHeight + bottomLineOffset ,
mIndicatorRight - offset, getHeight() - bottomLineHeight + bottomLineOffset);
//画圆角举行
canvas.drawRoundRect(rectF, 2, 1, mSelectedIndicatorPaint);
}
int h = getHeight();
int c = getHeight() - bottomLineOffset;
int d = (getHeight() - bottomLineHeight - bottomLineOffset);
Log.d("", "draw: -----------------bottomLineTop = " + c);
Log.d("", "draw: -----------------bottomLineBottom = " + d);
//底部分割线的绘制 对应bottomLineMode
if (mBottomLinerPaint != null && bottomLineHeight > 0) {
RectF rectF = new RectF(getPaddingLeft(), getHeight() - IndicatorOffset, getWidth() - getPaddingRight() , getHeight() - bottomLineHeight - IndicatorOffset);
//画圆角举行
canvas.drawRoundRect(rectF, 2, 1, mBottomLinerPaint);
}
//竖直分割线的绘制
if (dividerWidth > 0 && dividerHeight != 0 && getChildCount() > 1) {
int childCount = getChildCount();
for (int i = 0; i < childCount - 1; i++) {
int dividerVOffset = (getHeight() - dividerHeight) / 2;
if (dividerVOffset < 0 || dividerVOffset < 0) {
dividerVOffset = 0;
}
int dividerHOffset = dividerWidth / 2;
RectF rectF = new RectF(getChildAt(i).getRight() - dividerHOffset, dividerVOffset,
getChildAt(i).getRight() + dividerHOffset, getHeight() - dividerVOffset);
canvas.drawRoundRect(rectF, 1, 2, mDividerPaint);
}
}
//*****************************自定义部分 END*****************************
}
}
private static ColorStateList createColorStateList(int defaultColor, int selectedColor) {
final int[][] states = new int[2][];
final int[] colors = new int[2];
int i = 0;
states[i] = SELECTED_STATE_SET;
colors[i] = selectedColor;
i++;
// Default enabled state
states[i] = EMPTY_STATE_SET;
colors[i] = defaultColor;
i++;
return new ColorStateList(states, colors);
}
private int getDefaultHeight() {
boolean hasIconAndText = false;
for (int i = 0, count = mTabs.size(); i < count; i++) {
Tab tab = mTabs.get(i);
if (tab != null && tab.getIcon() != null && !TextUtils.isEmpty(tab.getText())) {
hasIconAndText = true;
break;
}
}
return hasIconAndText ? DEFAULT_HEIGHT_WITH_TEXT_ICON : DEFAULT_HEIGHT;
}
private int getTabMinWidth() {
if (mRequestedTabMinWidth != INVALID_WIDTH) {
// If we have been given a min width, use it
return mRequestedTabMinWidth;
}
// Else, we'll use the default value
return mMode == MODE_SCROLLABLE ? mScrollableTabMinWidth : 0;
}
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
// We don't care about the layout params of any views added to us, since we don't actually
// add them. The only view we add is the SlidingTabStrip, which is done manually.
// We return the default layout params so that we don't blow up if we're given a TabItem
// without android:layout_* values.
return generateDefaultLayoutParams();
}
int getTabMaxWidth() {
return mTabMaxWidth;
}
/**
* A {@link ViewPager.OnPageChangeListener} class which contains the
* necessary calls back to the provided {@link TabLayout} so that the tab position is
* kept in sync.
*
*
This class stores the provided TabLayout weakly, meaning that you can use
* {@link ViewPager#addOnPageChangeListener(ViewPager.OnPageChangeListener)
* addOnPageChangeListener(OnPageChangeListener)} without removing the listener and
* not cause a leak.
*/
public static class TabLayoutOnPageChangeListener implements ViewPager.OnPageChangeListener {
private final WeakReference mTabLayoutRef;
private int mPreviousScrollState;
private int mScrollState;
public TabLayoutOnPageChangeListener(TabLayout tabLayout) {
mTabLayoutRef = new WeakReference<>(tabLayout);
}
@Override
public void onPageScrollStateChanged(final int state) {
mPreviousScrollState = mScrollState;
mScrollState = state;
}
@Override
public void onPageScrolled(final int position, final float positionOffset,
final int positionOffsetPixels) {
final TabLayout tabLayout = mTabLayoutRef.get();
if (tabLayout != null) {
// Only update the text selection if we're not settling, or we are settling after
// being dragged
final boolean updateText = mScrollState != SCROLL_STATE_SETTLING ||
mPreviousScrollState == SCROLL_STATE_DRAGGING;
// Update the indicator if we're not settling after being idle. This is caused
// from a setCurrentItem() call and will be handled by an animation from
// onPageSelected() instead.
final boolean updateIndicator = !(mScrollState == SCROLL_STATE_SETTLING
&& mPreviousScrollState == SCROLL_STATE_IDLE);
tabLayout.setScrollPosition(position, positionOffset, updateText, updateIndicator);
}
}
@Override
public void onPageSelected(final int position) {
final TabLayout tabLayout = mTabLayoutRef.get();
if (tabLayout != null && tabLayout.getSelectedTabPosition() != position
&& position < tabLayout.getTabCount()) {
// Select the tab, only updating the indicator if we're not being dragged/settled
// (since onPageScrolled will handle that).
final boolean updateIndicator = mScrollState == SCROLL_STATE_IDLE
|| (mScrollState == SCROLL_STATE_SETTLING
&& mPreviousScrollState == SCROLL_STATE_IDLE);
tabLayout.selectTab(tabLayout.getTabAt(position), updateIndicator);
}
}
void reset() {
mPreviousScrollState = mScrollState = SCROLL_STATE_IDLE;
}
}
/**
* A {@link TabLayout.OnTabSelectedListener} class which contains the necessary calls back
* to the provided {@link ViewPager} so that the tab position is kept in sync.
*/
public static class ViewPagerOnTabSelectedListener implements TabLayout.OnTabSelectedListener {
private final ViewPager mViewPager;
public ViewPagerOnTabSelectedListener(ViewPager viewPager) {
mViewPager = viewPager;
}
@Override
public void onTabSelected(TabLayout.Tab tab) {
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
// No-op
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
// No-op
}
}
private class PagerAdapterObserver extends DataSetObserver {
PagerAdapterObserver() {
}
@Override
public void onChanged() {
populateFromPagerAdapter();
}
@Override
public void onInvalidated() {
populateFromPagerAdapter();
}
}
private class AdapterChangeListener implements ViewPager.OnAdapterChangeListener {
private boolean mAutoRefresh;
AdapterChangeListener() {
}
@Override
public void onAdapterChanged(@NonNull ViewPager viewPager,
@Nullable PagerAdapter oldAdapter, @Nullable PagerAdapter newAdapter) {
if (mViewPager == viewPager) {
setPagerAdapter(newAdapter, mAutoRefresh);
}
}
void setAutoRefresh(boolean autoRefresh) {
mAutoRefresh = autoRefresh;
}
}
}
Github地址：https://github.com/huangruqi88/TabLayout
参考：https://www.jianshu.com/p/3537979a9f7d