Java tutorial
/* * 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 chao.widget.tablayout; import android.animation.Animator; import android.animation.AnimatorListenerAdapter; import android.animation.ValueAnimator; import android.annotation.SuppressLint; import android.annotation.TargetApi; 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.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.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.ViewCompat; import android.support.v4.view.ViewPager; import android.support.v4.view.animation.FastOutSlowInInterpolator; import android.support.v4.widget.TextViewCompat; import android.support.v7.app.ActionBar; import android.support.v7.widget.AppCompatDrawableManager; import android.text.Layout; import android.text.TextUtils; import android.util.AttributeSet; import android.util.TypedValue; import android.view.Gravity; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.ViewParent; import android.view.accessibility.AccessibilityEvent; import android.view.accessibility.AccessibilityNodeInfo; import android.view.animation.Interpolator; import android.widget.HorizontalScrollView; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.TextView; import android.widget.Toast; 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.design.R.layout.design_layout_tab_icon; import static android.support.design.R.layout.design_layout_tab_text; import static android.support.design.R.style.TextAppearance_Design_Tab; import static android.support.design.R.style.Widget_Design_TabLayout; import static android.support.design.R.styleable.TabLayout_tabBackground; import static android.support.design.R.styleable.TabLayout_tabContentStart; import static android.support.design.R.styleable.TabLayout_tabGravity; import static android.support.design.R.styleable.TabLayout_tabIndicatorColor; import static android.support.design.R.styleable.TabLayout_tabIndicatorHeight; import static android.support.design.R.styleable.TabLayout_tabMaxWidth; import static android.support.design.R.styleable.TabLayout_tabMinWidth; import static android.support.design.R.styleable.TabLayout_tabMode; import static android.support.design.R.styleable.TabLayout_tabPadding; import static android.support.design.R.styleable.TabLayout_tabPaddingBottom; import static android.support.design.R.styleable.TabLayout_tabPaddingEnd; import static android.support.design.R.styleable.TabLayout_tabPaddingStart; import static android.support.design.R.styleable.TabLayout_tabPaddingTop; import static android.support.design.R.styleable.TabLayout_tabSelectedTextColor; import static android.support.design.R.styleable.TabLayout_tabTextAppearance; import static android.support.design.R.styleable.TabLayout_tabTextColor; import static android.support.design.R.styleable.TextAppearance_android_textColor; import static android.support.design.R.styleable.TextAppearance_android_textSize; 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; /** * TabLayout provides a horizontal layout to display tabs. * * <p>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: * <pre> * TabLayout tabLayout = ...; * tabLayout.addTab(tabLayout.newTab().setText("Tab 1")); * tabLayout.addTab(tabLayout.newTab().setText("Tab 2")); * tabLayout.addTab(tabLayout.newTab().setText("Tab 3")); * </pre> * You should set a listener via {@link #setOnTabSelectedListener(OnTabSelectedListener)} to be * notified when any tab's selection state has been changed. * <p> * If you're using a {@link android.support.v4.view.ViewPager} together * with this layout, you can use {@link #setupWithViewPager(ViewPager)} to link the two together. * This layout will be automatically populated from the {@link PagerAdapter}'s page titles.</p> * * <p>You can also add items to TabLayout in your layout through the use of {@link TabItem}. * An example usage is like so:</p> * * <pre> * <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> * </pre> * * * @see <a href="http://www.google.com/design/spec/components/tabs.html">Tabs</a> * * @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 */ /** * * android.support.design.widget.TabLayoutTabView? * * TabLayout??? * * by chao.qin 2017/03/13 * */ public class TabLayout extends HorizontalScrollView { private static final int DEFAULT_HEIGHT_WITH_TEXT_ICON = 72; // dps private static final int DEFAULT_GAP_TEXT_ICON = 6; // dps private static final int INVALID_WIDTH = -1; private static final int DEFAULT_HEIGHT = 48; // dps private static final int TAB_MIN_WIDTH_MARGIN = 0; //dps private static final int FIXED_WRAP_GUTTER_MIN = 16; //dps private static final int MOTION_NON_ADJACENT_OFFSET = 24; private static final int ANIMATION_DURATION = 300; private static final Pools.Pool<Tab> sTabPool = new Pools.SynchronizedPool<>(16); private static final Interpolator FAST_OUT_SLOW_IN_INTERPOLATOR = new FastOutSlowInInterpolator(); /** * 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 dont 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 views width. * Fixed tabs have equal width, based on the widest tab label. * * @see #setTabMode(int) * @see #getTabMode() */ public static final int MODE_FIXED = 1; public static final int MODE_FIXED_COMMON = 2; /** * */ @IntDef(value = { MODE_SCROLLABLE, MODE_FIXED, MODE_FIXED_COMMON }) @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; /** * */ @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<Tab> mTabs = new ArrayList<>(); private Tab mSelectedTab; private final SlidingTabStrip mTabStrip; private int mTabPaddingStart; private int mTabPaddingTop; private int mTabPaddingEnd; private int mTabPaddingBottom; private int mTabTextAppearance; private ColorStateList mTabTextColors; private float mTabTextSize; private float mTabSelectedTextSize; private int mTabTextStyle; private int mTabSelectedTextStyle; private float mTabTextMultiLineSize; private final int mTabBackgroundResId; private int mTabMaxWidth = (1 << 30) - 1; private final int mRequestedTabMinWidth; private final int mRequestedTabMaxWidth; private final int mScrollableTabMinWidth; private int mContentInsetStart; private int mTabGravity; private int mMode; private OnTabSelectedListener mOnTabSelectedListener; private ValueAnimator mScrollAnimator; private ViewPager mViewPager; private PagerAdapter mPagerAdapter; private DataSetObserver mPagerAdapterObserver; private TabLayoutOnPageChangeListener mPageChangeListener; // Pool we use as a simple RecyclerBin private final Pools.Pool<TabView> mTabViewPool = new Pools.SimplePool<>(12); public TabLayout(Context context) { this(context, null); } public TabLayout(Context context, AttributeSet attrs) { this(context, attrs, 0); } @SuppressLint("PrivateResource") public TabLayout(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); 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, Widget_Design_TabLayout); mTabStrip.setSelectedIndicatorHeight(a.getDimensionPixelSize(TabLayout_tabIndicatorHeight, 0)); mTabStrip.setSelectedIndicatorColor(a.getColor(TabLayout_tabIndicatorColor, 0)); mTabPaddingStart = mTabPaddingTop = mTabPaddingEnd = mTabPaddingBottom = a .getDimensionPixelSize(TabLayout_tabPadding, 0); mTabPaddingStart = a.getDimensionPixelSize(TabLayout_tabPaddingStart, mTabPaddingStart); mTabPaddingTop = a.getDimensionPixelSize(TabLayout_tabPaddingTop, mTabPaddingTop); mTabPaddingEnd = a.getDimensionPixelSize(TabLayout_tabPaddingEnd, mTabPaddingEnd); mTabPaddingBottom = a.getDimensionPixelSize(TabLayout_tabPaddingBottom, mTabPaddingBottom); mTabTextAppearance = a.getResourceId(TabLayout_tabTextAppearance, TextAppearance_Design_Tab); // Text colors/sizes come from the text appearance first final TypedArray ta = context.obtainStyledAttributes(mTabTextAppearance, R.styleable.TextAppearance); try { mTabTextSize = ta.getDimensionPixelSize(TextAppearance_android_textSize, 0); mTabTextColors = ta.getColorStateList(TextAppearance_android_textColor); } finally { ta.recycle(); } if (a.hasValue(TabLayout_tabTextColor)) { // If we have an explicit text color set, use it instead mTabTextColors = a.getColorStateList(TabLayout_tabTextColor); } if (a.hasValue(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(TabLayout_tabSelectedTextColor, 0); mTabTextColors = createColorStateList(mTabTextColors.getDefaultColor(), selected); } mRequestedTabMinWidth = a.getDimensionPixelSize(TabLayout_tabMinWidth, INVALID_WIDTH); mRequestedTabMaxWidth = a.getDimensionPixelSize(TabLayout_tabMaxWidth, INVALID_WIDTH); mTabBackgroundResId = a.getResourceId(TabLayout_tabBackground, 0); mContentInsetStart = a.getDimensionPixelSize(TabLayout_tabContentStart, 0); mMode = a.getInt(TabLayout_tabMode, MODE_FIXED_COMMON); mTabGravity = a.getInt(TabLayout_tabGravity, GRAVITY_FILL); a.recycle(); a = context.obtainStyledAttributes(attrs, chao.widget.tablayout.R.styleable.TabLayout); mTabTextSize = a.getDimensionPixelSize(chao.widget.tablayout.R.styleable.TabLayout_tabTextSize, dpToPx(12)); mTabSelectedTextSize = a.getDimensionPixelSize( chao.widget.tablayout.R.styleable.TabLayout_tabSelectedTextSize, (int) mTabTextSize); mTabTextStyle = a.getInt(chao.widget.tablayout.R.styleable.TabLayout_tabTextStyle, 0); mTabSelectedTextStyle = a.getInt(chao.widget.tablayout.R.styleable.TabLayout_tabSelectedTextStyle, 0); 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); mScrollableTabMinWidth = 0; // Now apply the tab mode and gravity applyModeAndGravity(); if (mMode != MODE_SCROLLABLE) { setOverScrollMode(HorizontalScrollView.OVER_SCROLL_NEVER); } } private static final int[] APPCOMPAT_CHECK_ATTRS = { R.attr.colorPrimary }; static void checkAppCompatTheme(Context context) { TypedArray a = context.obtainStyledAttributes(APPCOMPAT_CHECK_ATTRS); final boolean failed = !a.hasValue(0); if (a != null) { a.recycle(); } if (failed) { throw new IllegalArgumentException( "You need to use a Theme.AppCompat theme " + "(or descendant) with the design library."); } } /** * 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}. * <p> * 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); } private 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 <code>position</code>. * 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) { if (tab.mParent != this) { throw new IllegalArgumentException("Tab belongs to a different TabLayout."); } addTabView(tab, setSelected); configureTab(tab, mTabs.size()); if (setSelected) { tab.select(); } } /** * Add a tab to this layout. The tab will be inserted at <code>position</code>. * * @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."); } addTabView(tab, position, setSelected); configureTab(tab, position); 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); } addTab(tab); } /** * Set the {@link android.support.design.widget.TabLayout.OnTabSelectedListener} that will * handle switching to and from tabs. * * @param onTabSelectedListener Listener to handle tab selection events */ public void setOnTabSelectedListener(OnTabSelectedListener onTabSelectedListener) { mOnTabSelectedListener = onTabSelectedListener; } /** * 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 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<Tab> 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: * <ul> * <li>{@link #MODE_FIXED}: Fixed tabs display all tabs concurrently and are best used * with content that benefits from quick pivots between tabs.</li> * <li>{@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 dont need to directly compare the tab * labels. This mode is commonly used with a {@link ViewPager}.</li> * </ul> * * @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}. * * <p>This method will link the given ViewPager and this TabLayout together so that any * changes in one are automatically reflected in the other. This includes adapter changes, * scroll state changes, and clicks. The tabs displayed in this layout will be populated * from the ViewPager adapter's page titles.</p> * * <p>After this method is called, you will not need this method again unless you want * to change the linked ViewPager.</p> * * <p>If the given ViewPager is non-null, it needs to already have a * {@link PagerAdapter} set.</p> * * @param viewPager The ViewPager to link, or {@code null} to clear any previous link. */ public void setupWithViewPager(@Nullable final ViewPager viewPager) { if (mViewPager != null && mPageChangeListener != null) { // If we've already been setup with a ViewPager, remove us from it mViewPager.removeOnPageChangeListener(mPageChangeListener); } if (viewPager != null) { final PagerAdapter adapter = viewPager.getAdapter(); if (adapter == null) { throw new IllegalArgumentException("ViewPager does not have a PagerAdapter set"); } 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 setOnTabSelectedListener(new ViewPagerOnTabSelectedListener(viewPager)); // Now we'll populate ourselves from the pager adapter setPagerAdapter(adapter, true); } else { // We've been given a null ViewPager so we need to clear out the internal state, // listeners and observers mViewPager = null; setOnTabSelectedListener(null); setPagerAdapter(null, true); } } /** * @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; } private int getTabScrollRange() { return Math.max(0, mTabStrip.getWidth() - getWidth() - getPaddingLeft() - getPaddingRight()); } private 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(); } private 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)); } } } else { removeAllTabs(); } } 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, boolean setSelected) { final TabView tabView = tab.mView; mTabStrip.addView(tabView, createLayoutParamsForTabs()); if (setSelected) { tabView.setSelected(true); } updateTabViews(true); } private void addTabView(Tab tab, int position, boolean setSelected) { final TabView tabView = tab.mView; mTabStrip.addView(tabView, position, createLayoutParamsForTabs()); if (setSelected) { tabView.setSelected(true); } updateTabViews(true); } @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 || mMode == MODE_FIXED_COMMON) && mTabGravity == GRAVITY_FILL) { lp.width = 0; lp.weight = 1; } else { lp.width = LinearLayout.LayoutParams.WRAP_CONTENT; lp.weight = 0; } } private 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: case MODE_FIXED_COMMON: // 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) { if (mScrollAnimator == null) { mScrollAnimator = createAnimator(); mScrollAnimator.setInterpolator(FAST_OUT_SLOW_IN_INTERPOLATOR); mScrollAnimator.setDuration(ANIMATION_DURATION); mScrollAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { scrollTo((Integer) animation.getAnimatedValue(), 0); } }); } mScrollAnimator.setIntValues(startScrollX, targetScrollX); mScrollAnimator.start(); } // Now animate the indicator mTabStrip.animateIndicatorToPosition(newPosition, ANIMATION_DURATION); } /** * */ private ValueAnimator createAnimator() { return new ValueAnimator(); } private void setSelectedTabView(int position) { final int tabCount = mTabStrip.getChildCount(); if (position < tabCount && !mTabStrip.getChildAt(position).isSelected()) { 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(Tab tab, boolean updateIndicator) { if (mSelectedTab == tab) { if (mSelectedTab != null) { if (mOnTabSelectedListener != null) { mOnTabSelectedListener.onTabReselected(mSelectedTab); } animateToTab(tab.getPosition()); } } else { if (updateIndicator) { final int newPosition = tab != null ? tab.getPosition() : Tab.INVALID_POSITION; if (newPosition != Tab.INVALID_POSITION) { setSelectedTabView(newPosition); } if ((mSelectedTab == null || mSelectedTab.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 (mSelectedTab != null && mOnTabSelectedListener != null) { mOnTabSelectedListener.onTabUnselected(mSelectedTab); } mSelectedTab = tab; if (mSelectedTab != null && mOnTabSelectedListener != null) { mOnTabSelectedListener.onTabSelected(mSelectedTab); } } } 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; return selectedChild.getLeft() + ((int) ((selectedWidth + nextWidth) * positionOffset * 0.5f)) + (selectedChild.getWidth() / 2) - (getWidth() / 2); } 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: case MODE_FIXED_COMMON: mTabStrip.setGravity(Gravity.CENTER_HORIZONTAL); break; case MODE_SCROLLABLE: mTabStrip.setGravity(GravityCompat.START); break; } updateTabViews(true); } private void updateTabViews(final boolean requestLayout) { for (int i = 0; i < mTabStrip.getChildCount(); i++) { TabView child = (TabView) mTabStrip.getChildAt(i); child.setMinimumWidth(getTabMinWidth()); child.setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL); LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) child.getLayoutParams(); updateTabViewLayoutParams(lp); if (mMode == MODE_FIXED_COMMON) { child.setGravity(GravityCompat.START); lp.width = LinearLayout.LayoutParams.WRAP_CONTENT; if (i == mTabStrip.getChildCount() - 1) { lp.weight = 0; } } 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; private TabLayout mParent; private TabView mView; private 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. * <p> * 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)}. * </p> * * @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. * <p> * 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)}. * </p> * * @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(AppCompatDrawableManager.get().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; } private void updateView() { if (mView != null) { mView.update(); } } private 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 = 1; public TabView(Context context) { super(context); if (mTabBackgroundResId != 0) { setBackgroundDrawable(AppCompatDrawableManager.get().getDrawable(context, mTabBackgroundResId)); } ViewCompat.setPaddingRelative(this, mTabPaddingStart, mTabPaddingTop, mTabPaddingEnd, mTabPaddingBottom); setGravity(Gravity.CENTER); setOrientation(VERTICAL); setClickable(true); } @Override public boolean performClick() { final boolean value = super.performClick(); if (mTab != null) { mTab.select(); return true; } else { return value; } } @Override public void setSelected(boolean selected) { final boolean changed = (isSelected() != selected); super.setSelected(selected); if (changed && selected) { sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_SELECTED); if (mTextView != null) { mTextView.setSelected(selected); } if (mIconView != null) { mIconView.setSelected(selected); } } //????textSize chao.qin if (changed) { update(); } } @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; //MODE_FIXED_COMMON ?chao.qin if (mMode != MODE_FIXED_COMMON && 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); /** * ???textSize * * chao.qin */ // 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 || mMode == MODE_FIXED_COMMON) && 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. // final Layout layout = mTextView.getLayout(); // if (layout == null // || approximateLineWidth(layout, 0, textSize) > layout.getWidth()) { // updateTextView = false; // } // } // // if (updateTextView) { // mTextView.setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize); // mTextView.setMaxLines(maxLines); // super.onMeasure(widthMeasureSpec, heightMeasureSpec); // } // } // } } private void setTab(@Nullable final Tab tab) { if (tab != mTab) { mTab = tab; update(); } } private 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(design_layout_tab_icon, this, false); addView(iconView, 0); mIconView = iconView; } if (mTextView == null) { TextView textView = (TextView) LayoutInflater.from(getContext()).inflate(design_layout_tab_text, this, false); addView(textView); mTextView = textView; mDefaultMaxLines = TextViewCompat.getMaxLines(mTextView); } mTextView.setTextAppearance(getContext(), mTabTextAppearance); if (mTabTextColors != null) { mTextView.setTextColor(mTabTextColors); } updateTextAndIcon(mTextView, mIconView); //tabsizestyle mTextView.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTabTextSize); mTextView.setTypeface(null, mTabTextStyle); if (mTextView.isSelected()) { mTextView.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTabSelectedTextSize); mTextView.setTypeface(null, mTabSelectedTextStyle); } } else { // Else, we'll see if there is a TextView or ImageView present and update them if (mCustomTextView != null || mCustomIconView != null) { updateTextAndIcon(mCustomTextView, mCustomIconView); } } } 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) { textView.setEllipsize(TextUtils.TruncateAt.END); textView.setMaxLines(1); 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(View v) { final int[] screenPos = new int[2]; getLocationOnScreen(screenPos); final Context context = getContext(); final int width = getWidth(); final int height = getHeight(); final int screenWidth = context.getResources().getDisplayMetrics().widthPixels; Toast cheatSheet = Toast.makeText(context, mTab.getContentDescription(), Toast.LENGTH_SHORT); // Show under the tab cheatSheet.setGravity(Gravity.TOP | Gravity.CENTER_HORIZONTAL, (screenPos[0] + width / 2) - screenWidth / 2, 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; private int mSelectedPosition = -1; private float mSelectionOffset; private int mIndicatorLeft = -1; private int mIndicatorRight = -1; private ValueAnimator 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 || mMode == MODE_FIXED_COMMON) && 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 TabView selectedTabView = (TabView) getChildAt(mSelectedPosition); View selectedTitle = selectedTabView.mTextView; if (selectedTabView.mCustomTextView != null) { selectedTitle = selectedTabView.mCustomTextView; } if (selectedTitle == null) { selectedTitle = selectedTabView; } int left, right; if (selectedTitle != null && selectedTitle.getWidth() > 0) { left = selectedTabView.getLeft() + selectedTitle.getLeft(); right = selectedTabView.getLeft() + selectedTitle.getRight(); if (mSelectionOffset > 0f && mSelectedPosition < getChildCount() - 1) { // Draw the selection partway between the tabs TabView nextTabView = (TabView) getChildAt(mSelectedPosition + 1); TextView nextTitle = nextTabView.mTextView; if (nextTabView.mCustomTextView != null) { nextTitle = nextTabView.mCustomTextView; } left = (int) (mSelectionOffset * (nextTabView.getLeft() + nextTitle.getLeft()) + (1.0f - mSelectionOffset) * left); right = (int) (mSelectionOffset * (nextTabView.getLeft() + nextTitle.getRight()) + (1.0f - mSelectionOffset) * right); } } else { left = right = -1; } setIndicatorPosition(left, right); } private 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 TabView tabView = (TabView) getChildAt(position); View targetView = tabView.mTextView; if (tabView.mCustomTextView != null) { targetView = tabView.mCustomTextView; } if (targetView == null) { // If we don't have a view, just update the position now and return updateIndicatorPosition(); return; } final int targetLeft = tabView.getLeft() + targetView.getLeft(); final int targetRight = tabView.getLeft() + 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 = createAnimator(); animator.setInterpolator(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(lerp(startLeft, targetLeft, fraction), lerp(startRight, targetRight, fraction)); } }); animator.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animator) { mSelectedPosition = position; mSelectionOffset = 0f; } }); animator.start(); } } private int lerp(int startValue, int endValue, float fraction) { return startValue + Math.round(fraction * (endValue - startValue)); } @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(); } private 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. * * <p>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<TabLayout> mTabLayoutRef; private int mPreviousScrollState; private int mScrollState; public TabLayoutOnPageChangeListener(TabLayout tabLayout) { mTabLayoutRef = new WeakReference<>(tabLayout); } @Override public void onPageScrollStateChanged(int state) { mPreviousScrollState = mScrollState; mScrollState = state; } @Override public void onPageScrolled(int position, float positionOffset, 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(int position) { final TabLayout tabLayout = mTabLayoutRef.get(); if (tabLayout != null && tabLayout.getSelectedTabPosition() != position) { // 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); } } private 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 { @Override public void onChanged() { populateFromPagerAdapter(); } @Override public void onInvalidated() { populateFromPagerAdapter(); } } }