See the Tab Layout * tutorial.
*/ public class TabHost extends FrameLayout implements ViewTreeObserver.OnTouchModeChangeListener { private TabWidget mTabWidget; private FrameLayout mTabContent; private ListCall setup() before adding tabs if loading TabHost using findViewById(). * However: You do not need to call setup() after getTabHost() * in {@link android.app.TabActivity TabActivity}. * Example:
mTabHost = (TabHost)findViewById(R.id.tabhost);
mTabHost.setup();
mTabHost.addTab(TAB_TAG_1, "Hello, world!", "Tab 1");
*/
public void setup() {
mTabWidget = (TabWidget) findViewById(com.android.internal.R.id.tabs);
if (mTabWidget == null) {
throw new RuntimeException(
"Your TabHost must have a TabWidget whose id attribute is 'android.R.id.tabs'");
}
// KeyListener to attach to all tabs. Detects non-navigation keys
// and relays them to the tab content.
mTabKeyListener = new OnKeyListener() {
public boolean onKey(View v, int keyCode, KeyEvent event) {
switch (keyCode) {
case KeyEvent.KEYCODE_DPAD_CENTER:
case KeyEvent.KEYCODE_DPAD_LEFT:
case KeyEvent.KEYCODE_DPAD_RIGHT:
case KeyEvent.KEYCODE_DPAD_UP:
case KeyEvent.KEYCODE_DPAD_DOWN:
case KeyEvent.KEYCODE_ENTER:
return false;
}
mTabContent.requestFocus(View.FOCUS_FORWARD);
return mTabContent.dispatchKeyEvent(event);
}
};
mTabWidget.setTabSelectionListener(new TabWidget.OnTabSelectionChanged() {
public void onTabSelectionChanged(int tabIndex, boolean clicked) {
setCurrentTab(tabIndex);
if (clicked) {
mTabContent.requestFocus(View.FOCUS_FORWARD);
}
}
});
mTabContent = (FrameLayout) findViewById(com.android.internal.R.id.tabcontent);
if (mTabContent == null) {
throw new RuntimeException(
"Your TabHost must have a FrameLayout whose id attribute is "
+ "'android.R.id.tabcontent'");
}
}
/**
* If you are using {@link TabSpec#setContent(android.content.Intent)}, this
* must be called since the activityGroup is needed to launch the local activity.
*
* This is done for you if you extend {@link android.app.TabActivity}.
* @param activityGroup Used to launch activities for tab content.
*/
public void setup(LocalActivityManager activityGroup) {
setup();
mLocalActivityManager = activityGroup;
}
@Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
final ViewTreeObserver treeObserver = getViewTreeObserver();
if (treeObserver != null) {
treeObserver.addOnTouchModeChangeListener(this);
}
}
@Override
protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
final ViewTreeObserver treeObserver = getViewTreeObserver();
if (treeObserver != null) {
treeObserver.removeOnTouchModeChangeListener(this);
}
}
/**
* {@inheritDoc}
*/
public void onTouchModeChanged(boolean isInTouchMode) {
if (!isInTouchMode) {
// leaving touch mode.. if nothing has focus, let's give it to
// the indicator of the current tab
if (mCurrentView != null && (!mCurrentView.hasFocus() || mCurrentView.isFocused())) {
mTabWidget.getChildTabViewAt(mCurrentTab).requestFocus();
}
}
}
/**
* Add a tab.
* @param tabSpec Specifies how to create the indicator and content.
*/
public void addTab(TabSpec tabSpec) {
if (tabSpec.mIndicatorStrategy == null) {
throw new IllegalArgumentException("you must specify a way to create the tab indicator.");
}
if (tabSpec.mContentStrategy == null) {
throw new IllegalArgumentException("you must specify a way to create the tab content");
}
View tabIndicator = tabSpec.mIndicatorStrategy.createIndicatorView();
tabIndicator.setOnKeyListener(mTabKeyListener);
// If this is a custom view, then do not draw the bottom strips for
// the tab indicators.
if (tabSpec.mIndicatorStrategy instanceof ViewIndicatorStrategy) {
mTabWidget.setStripEnabled(false);
}
mTabWidget.addView(tabIndicator);
mTabSpecs.add(tabSpec);
// The second test is always true except when an application explicitly sets
// mAvoidFirstTabLoad to true.
if (mCurrentTab == -1 && !mAvoidFirstTabLoad) {
setCurrentTab(0);
}
}
/**
* Removes all tabs from the tab widget associated with this tab host.
*/
public void clearAllTabs() {
mTabWidget.removeAllViews();
initTabHost();
mTabContent.removeAllViews();
mTabSpecs.clear();
requestLayout();
invalidate();
}
public TabWidget getTabWidget() {
return mTabWidget;
}
public int getCurrentTab() {
return mCurrentTab;
}
public String getCurrentTabTag() {
if (mCurrentTab >= 0 && mCurrentTab < mTabSpecs.size()) {
return mTabSpecs.get(mCurrentTab).getTag();
}
return null;
}
public View getCurrentTabView() {
if (mCurrentTab >= 0 && mCurrentTab < mTabSpecs.size()) {
return mTabWidget.getChildTabViewAt(mCurrentTab);
}
return null;
}
public View getCurrentView() {
return mCurrentView;
}
/**
* {@hide}
*/
public void setAvoidFirstTabLoad(boolean flag) {
mAvoidFirstTabLoad = flag;
}
/**
* {@hide}
*/
public void setCurrentTabToZero() {
mCurrentTab = 0;
}
public void setCurrentTabByTag(String tag) {
int i;
for (i = 0; i < mTabSpecs.size(); i++) {
if (mTabSpecs.get(i).getTag().equals(tag)) {
setCurrentTab(i);
break;
}
}
}
/**
* Get the FrameLayout which holds tab content
*/
public FrameLayout getTabContentView() {
return mTabContent;
}
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
final boolean handled = super.dispatchKeyEvent(event);
// unhandled key ups change focus to tab indicator for embedded activities
// when there is nothing that will take focus from default focus searching
if (!handled
&& (event.getAction() == KeyEvent.ACTION_DOWN)
&& (event.getKeyCode() == KeyEvent.KEYCODE_DPAD_UP)
&& (mCurrentView != null)
&& (mCurrentView.isRootNamespace())
&& (mCurrentView.hasFocus())
&& (mCurrentView.findFocus().focusSearch(View.FOCUS_UP) == null)) {
mTabWidget.getChildTabViewAt(mCurrentTab).requestFocus();
playSoundEffect(SoundEffectConstants.NAVIGATION_UP);
return true;
}
return handled;
}
@Override
public void dispatchWindowFocusChanged(boolean hasFocus) {
if (mCurrentView != null){
mCurrentView.dispatchWindowFocusChanged(hasFocus);
}
}
public void setCurrentTab(int index) {
if (index < 0 || index >= mTabSpecs.size()) {
return;
}
if (index == mCurrentTab) {
return;
}
// notify old tab content
if (mCurrentTab != -1) {
mTabSpecs.get(mCurrentTab).mContentStrategy.tabClosed();
}
mCurrentTab = index;
final TabHost.TabSpec spec = mTabSpecs.get(index);
// Call the tab widget's focusCurrentTab(), instead of just
// selecting the tab.
mTabWidget.focusCurrentTab(mCurrentTab);
// tab content
mCurrentView = spec.mContentStrategy.getContentView();
if (mCurrentView.getParent() == null) {
mTabContent
.addView(
mCurrentView,
new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT));
}
if (!mTabWidget.hasFocus()) {
// if the tab widget didn't take focus (likely because we're in touch mode)
// give the current tab content view a shot
mCurrentView.requestFocus();
}
//mTabContent.requestFocus(View.FOCUS_FORWARD);
invokeOnTabChangeListener();
}
/**
* Register a callback to be invoked when the selected state of any of the items
* in this list changes
* @param l
* The callback that will run
*/
public void setOnTabChangedListener(OnTabChangeListener l) {
mOnTabChangeListener = l;
}
private void invokeOnTabChangeListener() {
if (mOnTabChangeListener != null) {
mOnTabChangeListener.onTabChanged(getCurrentTabTag());
}
}
/**
* Interface definition for a callback to be invoked when tab changed
*/
public interface OnTabChangeListener {
void onTabChanged(String tabId);
}
/**
* Makes the content of a tab when it is selected. Use this if your tab
* content needs to be created on demand, i.e. you are not showing an
* existing view or starting an activity.
*/
public interface TabContentFactory {
/**
* Callback to make the tab contents
*
* @param tag
* Which tab was selected.
* @return The view to display the contents of the selected tab.
*/
View createTabContent(String tag);
}
/**
* A tab has a tab indicator, content, and a tag that is used to keep
* track of it. This builder helps choose among these options.
*
* For the tab indicator, your choices are:
* 1) set a label
* 2) set a label and an icon
*
* For the tab content, your choices are:
* 1) the id of a {@link View}
* 2) a {@link TabContentFactory} that creates the {@link View} content.
* 3) an {@link Intent} that launches an {@link android.app.Activity}.
*/
public class TabSpec {
private String mTag;
private IndicatorStrategy mIndicatorStrategy;
private ContentStrategy mContentStrategy;
private TabSpec(String tag) {
mTag = tag;
}
/**
* Specify a label as the tab indicator.
*/
public TabSpec setIndicator(CharSequence label) {
mIndicatorStrategy = new LabelIndicatorStrategy(label);
return this;
}
/**
* Specify a label and icon as the tab indicator.
*/
public TabSpec setIndicator(CharSequence label, Drawable icon) {
mIndicatorStrategy = new LabelAndIconIndicatorStrategy(label, icon);
return this;
}
/**
* Specify a view as the tab indicator.
*/
public TabSpec setIndicator(View view) {
mIndicatorStrategy = new ViewIndicatorStrategy(view);
return this;
}
/**
* Specify the id of the view that should be used as the content
* of the tab.
*/
public TabSpec setContent(int viewId) {
mContentStrategy = new ViewIdContentStrategy(viewId);
return this;
}
/**
* Specify a {@link android.widget.TabHost.TabContentFactory} to use to
* create the content of the tab.
*/
public TabSpec setContent(TabContentFactory contentFactory) {
mContentStrategy = new FactoryContentStrategy(mTag, contentFactory);
return this;
}
/**
* Specify an intent to use to launch an activity as the tab content.
*/
public TabSpec setContent(Intent intent) {
mContentStrategy = new IntentContentStrategy(mTag, intent);
return this;
}
public String getTag() {
return mTag;
}
}
/**
* Specifies what you do to create a tab indicator.
*/
private static interface IndicatorStrategy {
/**
* Return the view for the indicator.
*/
View createIndicatorView();
}
/**
* Specifies what you do to manage the tab content.
*/
private static interface ContentStrategy {
/**
* Return the content view. The view should may be cached locally.
*/
View getContentView();
/**
* Perhaps do something when the tab associated with this content has
* been closed (i.e make it invisible, or remove it).
*/
void tabClosed();
}
/**
* How to create a tab indicator that just has a label.
*/
private class LabelIndicatorStrategy implements IndicatorStrategy {
private final CharSequence mLabel;
private LabelIndicatorStrategy(CharSequence label) {
mLabel = label;
}
public View createIndicatorView() {
final Context context = getContext();
LayoutInflater inflater =
(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View tabIndicator = inflater.inflate(R.layout.tab_indicator,
mTabWidget, // tab widget is the parent
false); // no inflate params
final TextView tv = (TextView) tabIndicator.findViewById(R.id.title);
tv.setText(mLabel);
if (context.getApplicationInfo().targetSdkVersion <= Build.VERSION_CODES.DONUT) {
// Donut apps get old color scheme
tabIndicator.setBackgroundResource(R.drawable.tab_indicator_v4);
tv.setTextColor(context.getResources().getColorStateList(R.color.tab_indicator_text_v4));
}
return tabIndicator;
}
}
/**
* How we create a tab indicator that has a label and an icon
*/
private class LabelAndIconIndicatorStrategy implements IndicatorStrategy {
private final CharSequence mLabel;
private final Drawable mIcon;
private LabelAndIconIndicatorStrategy(CharSequence label, Drawable icon) {
mLabel = label;
mIcon = icon;
}
public View createIndicatorView() {
final Context context = getContext();
LayoutInflater inflater =
(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View tabIndicator = inflater.inflate(R.layout.tab_indicator,
mTabWidget, // tab widget is the parent
false); // no inflate params
final TextView tv = (TextView) tabIndicator.findViewById(R.id.title);
tv.setText(mLabel);
final ImageView iconView = (ImageView) tabIndicator.findViewById(R.id.icon);
iconView.setImageDrawable(mIcon);
if (context.getApplicationInfo().targetSdkVersion <= Build.VERSION_CODES.DONUT) {
// Donut apps get old color scheme
tabIndicator.setBackgroundResource(R.drawable.tab_indicator_v4);
tv.setTextColor(context.getResources().getColorStateList(R.color.tab_indicator_text_v4));
}
return tabIndicator;
}
}
/**
* How to create a tab indicator by specifying a view.
*/
private class ViewIndicatorStrategy implements IndicatorStrategy {
private final View mView;
private ViewIndicatorStrategy(View view) {
mView = view;
}
public View createIndicatorView() {
return mView;
}
}
/**
* How to create the tab content via a view id.
*/
private class ViewIdContentStrategy implements ContentStrategy {
private final View mView;
private ViewIdContentStrategy(int viewId) {
mView = mTabContent.findViewById(viewId);
if (mView != null) {
mView.setVisibility(View.GONE);
} else {
throw new RuntimeException("Could not create tab content because " +
"could not find view with id " + viewId);
}
}
public View getContentView() {
mView.setVisibility(View.VISIBLE);
return mView;
}
public void tabClosed() {
mView.setVisibility(View.GONE);
}
}
/**
* How tab content is managed using {@link TabContentFactory}.
*/
private class FactoryContentStrategy implements ContentStrategy {
private View mTabContent;
private final CharSequence mTag;
private TabContentFactory mFactory;
public FactoryContentStrategy(CharSequence tag, TabContentFactory factory) {
mTag = tag;
mFactory = factory;
}
public View getContentView() {
if (mTabContent == null) {
mTabContent = mFactory.createTabContent(mTag.toString());
}
mTabContent.setVisibility(View.VISIBLE);
return mTabContent;
}
public void tabClosed() {
mTabContent.setVisibility(View.GONE);
}
}
/**
* How tab content is managed via an {@link Intent}: the content view is the
* decorview of the launched activity.
*/
private class IntentContentStrategy implements ContentStrategy {
private final String mTag;
private final Intent mIntent;
private View mLaunchedView;
private IntentContentStrategy(String tag, Intent intent) {
mTag = tag;
mIntent = intent;
}
public View getContentView() {
if (mLocalActivityManager == null) {
throw new IllegalStateException("Did you forget to call 'public void setup(LocalActivityManager activityGroup)'?");
}
final Window w = mLocalActivityManager.startActivity(
mTag, mIntent);
final View wd = w != null ? w.getDecorView() : null;
if (mLaunchedView != wd && mLaunchedView != null) {
if (mLaunchedView.getParent() != null) {
mTabContent.removeView(mLaunchedView);
}
}
mLaunchedView = wd;
// XXX Set FOCUS_AFTER_DESCENDANTS on embedded activities for now so they can get
// focus if none of their children have it. They need focus to be able to
// display menu items.
//
// Replace this with something better when Bug 628886 is fixed...
//
if (mLaunchedView != null) {
mLaunchedView.setVisibility(View.VISIBLE);
mLaunchedView.setFocusableInTouchMode(true);
((ViewGroup) mLaunchedView).setDescendantFocusability(
FOCUS_AFTER_DESCENDANTS);
}
return mLaunchedView;
}
public void tabClosed() {
if (mLaunchedView != null) {
mLaunchedView.setVisibility(View.GONE);
}
}
}
}