使用TabLayout实现单行的flowlayout(标签流式布局)
转载请注明出处：http://blog.csdn.net/dreamsever/article/details/75006786
前言
最近项目需求做一个单行的标签选择功能，效果类似下面的，一说到标签选择和流式布局，我想很多同学都会想到鸿洋的FlowLayout，但是很多事情都是不完美的，这个库挺好的，但是不支持单行的标签显示。我想要的是那种单行显示，并且多余的看不到的可以左右滑动。这个时候我想到了今日头条和网易新闻这种头部的选择器，这种效果不是跟我们产品想要的效果差不多吗。然后就开始使用TabLayout实现
开始
关于TabLayout我不想多说，因为网上有太多关于TabLayout的使用的博客，我这里推荐两篇说的比较详细的：
1、Design库-TabLayout属性详解
2、TabLayout子自定义样式
通过上面的两篇博客对TabLayout进行设置我们可以实现大致的效果，先把设置代码贴出来：
<android.support.design.widget.TabLayout
android:id="@+id/tab_tags"
android:layout_width="match_parent"
android:layout_height="38dp"
android:paddingBottom="@dimen/app_marge_5"
style="@style/MyTagTabLayout"
app:tabIndicatorHeight="0dp"
app:tabMode="scrollable">
android.support.design.widget.TabLayout>
<style name="MyTagTabLayout" parent="Widget.Design.TabLayout">
<item name="tabBackground">@drawable/selector_tag_tab_bg
- "tabTextAppearance"
>@style/MyTabTextStyle
- "tabSelectedTextColor"
>@color/white
- "android:clipToPadding">false
- "android:paddingLeft">@dimen/app_marge_14
style>
<style name="MyTabTextStyle" parent="TextAppearance.Design.Tab">
--Tab字体的大小-->
<item name="android:textSize">@dimen/design_tab_text_size
- "android:textColor"
>@color/app_color
- "android:layout_marginRight">@dimen/app_marge_5
- "android:layout_marginLeft">@dimen/app_marge_5
- "textAllCaps">true
style>
//@drawable/selector_tag_tab_bg
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/shape_tag_tab_checked" android:state_selected="true" />
<item android:drawable="@drawable/shape_tag_tab_normal" android:state_selected="false" android:state_focused="false" android:state_pressed="false" />
selector>
//@drawable/shape_tag_tab_normal
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<corners android:radius="4dp" />
<stroke
android:width="@dimen/line_width"
android:color="@color/app_blue" />
shape>到此，其实我们已经实现了单行标签选择器的功能，但是这时候测试同学又给我提出一个问题，那就是产品要求是默认不选择任何一项标签，但是现在默认是选中第一个的。我当时就郁闷（悲剧）了，tablayout是没有默认不选中的功能的，这可怎么办。自定义个单行的flowlayout吗，说实话我相信我可以写，但是时间有限啊，你还不知道写出来会不会有其他问题。改现有的flowlayout的源码，好像难度不亚于自己写个。于是我看了一下Tablayout的源码，顺藤摸瓜找到它为什么非要默认选中一个
好吧细节我就不多说了，最终我还是实现了默认不选中，我把Tablayout的源码改了，感兴趣的可以对比原来Tablayout的源码看一下我做了那些改动，代码如下：
/**
* 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.
*
* An example usage is like so:
*
*
* <android.support.design.widget.TabLayout
* android:layout_height="wrap_content"
* android:layout_width="match_parent">
*
* <android.support.design.widget.TabItem
* android:text="@string/tab_text"/>
*
* <android.support.design.widget.TabItem
* android:icon="@drawable/ic_android"/>
*
* </android.support.design.widget.TabLayout>
*
*
* 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:
*
*
* <android.support.v4.view.ViewPager
* android:layout_width="match_parent"
* android:layout_height="match_parent">
*
* <android.support.design.widget.TabLayout
* android:layout_width="match_parent"
* android:layout_height="wrap_content"
* android:layout_gravity="top" />
*
* </android.support.v4.view.ViewPager>
*
*
* @see Tabs
*
* @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
*/
@ViewPager.DecorView
public class MyTabLayout 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;
/**
* @hide
*/
@RestrictTo(LIBRARY_GROUP)
@IntDef(value = {MODE_SCROLLABLE, MODE_FIXED})
@Retention(RetentionPolicy.SOURCE)
public @interface Mode {}
/**
* Gravity used to fill the {@link MyTabLayout} 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 MyTabLayout}.
*
* @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 ValueAnimatorCompat 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 MyTabLayout(Context context) {
this(context, null);
}
public MyTabLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public MyTabLayout(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);
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 MyTabItem 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 MyTabLayout.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 MyTabLayout.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 MyTabLayout.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() : -2;
}
/**
* 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 MyTabLayout}.
*
* @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 MyTabLayout} 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 MyTabLayout} 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 MyTabItem) {
addTabFromItemView((MyTabItem) 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 = ViewUtils.createAnimator();
// mScrollAnimator.setInterpolator(AnimationUtils.FAST_OUT_SLOW_IN_INTERPOLATOR);
// mScrollAnimator.setDuration(ANIMATION_DURATION);
// mScrollAnimator.addUpdateListener(new ValueAnimatorCompat.AnimatorUpdateListener() {
// @Override
// public void onAnimationUpdate(ValueAnimatorCompat animator) {
// scrollTo(animator.getAnimatedIntValue(), 0);
// }
// });
// }
}
// void setScrollAnimatorListener(ValueAnimatorCompat.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;
MyTabLayout 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 implements OnLongClickListener {
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);
}
}
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
@Override
public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
// This view masquerades as an action bar tab.
event.setClassName(ActionBar.Tab.class.getName());
}
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
@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();
}
}
if (!hasText && !TextUtils.isEmpty(contentDesc)) {
setOnLongClickListener(this);
} else {
setOnLongClickListener(null);
setLongClickable(false);
}
}
@Override
public boolean onLongClick(final View v) {
final int[] screenPos = new int[2];
final Rect displayFrame = new Rect();
getLocationOnScreen(screenPos);
getWindowVisibleDisplayFrame(displayFrame);
final Context context = getContext();
final int width = getWidth();
final int height = getHeight();
final int midy = screenPos[1] + height / 2;
int referenceX = screenPos[0] + width / 2;
if (ViewCompat.getLayoutDirection(v) == ViewCompat.LAYOUT_DIRECTION_LTR) {
final int screenWidth = context.getResources().getDisplayMetrics().widthPixels;
referenceX = screenWidth - referenceX; // mirror
}
Toast cheatSheet = Toast.makeText(context, mTab.getContentDescription(),
Toast.LENGTH_SHORT);
if (midy < displayFrame.height()) {
// Show below the tab view
cheatSheet.setGravity(Gravity.TOP | GravityCompat.END, referenceX,
screenPos[1] + height - displayFrame.top);
} else {
// Show along the bottom center
cheatSheet.setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL, 0, height);
}
cheatSheet.show();
return true;
}
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 int mSelectedIndicatorHeight;
private final Paint mSelectedIndicatorPaint;
int mSelectedPosition = -1;
float mSelectionOffset;
private int mIndicatorLeft = -1;
private int mIndicatorRight = -1;
// private ValueAnimatorCompat mIndicatorAnimator;
SlidingTabStrip(Context context) {
super(context);
setWillNotDraw(false);
mSelectedIndicatorPaint = new Paint();
}
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);
}
}
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
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) {
// ValueAnimatorCompat animator = mIndicatorAnimator = ViewUtils.createAnimator();
// animator.setInterpolator(AnimationUtils.FAST_OUT_SLOW_IN_INTERPOLATOR);
// animator.setDuration(duration);
// animator.setFloatValues(0, 1);
// animator.addUpdateListener(new ValueAnimatorCompat.AnimatorUpdateListener() {
// @Override
// public void onAnimationUpdate(ValueAnimatorCompat animator) {
// final float fraction = animator.getAnimatedFraction();
// setIndicatorPosition(
// AnimationUtils.lerp(startLeft, targetLeft, fraction),
// AnimationUtils.lerp(startRight, targetRight, fraction));
// }
// });
// animator.addListener(new ValueAnimatorCompat.AnimatorListenerAdapter() {
// @Override
// public void onAnimationEnd(ValueAnimatorCompat 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);
}
}
}
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 MyTabLayout} 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(MyTabLayout 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 MyTabLayout 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 MyTabLayout 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 MyTabLayout.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 MyTabLayout.OnTabSelectedListener {
private final ViewPager mViewPager;
public ViewPagerOnTabSelectedListener(ViewPager viewPager) {
mViewPager = viewPager;
}
@Override
public void onTabSelected(MyTabLayout.Tab tab) {
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(MyTabLayout.Tab tab) {
// No-op
}
@Override
public void onTabReselected(MyTabLayout.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;
}
}
}
public final class MyTabItem extends View {
final CharSequence mText;
final Drawable mIcon;
final int mCustomLayout;
public MyTabItem(Context context) {
this(context, null);
}
public MyTabItem(Context context, AttributeSet attrs) {
super(context, attrs);
final TintTypedArray a = TintTypedArray.obtainStyledAttributes(context, attrs,
R.styleable.TabItem);
mText = a.getText(R.styleable.TabItem_android_text);
mIcon = a.getDrawable(R.styleable.TabItem_android_icon);
mCustomLayout = a.getResourceId(R.styleable.TabItem_android_layout, 0);
a.recycle();
}
} 最后将原来的布局中的Tablayout换成这个MyTablayout就行了