FragmentTabHostpublic class FragmentTabHost extends android.widget.TabHost implements TabHost.OnTabChangeListener| Special TabHost that allows the use of {@link Fragment} objects for
its tab content. When placing this in a view hierarchy, after inflating
the hierarchy you must call {@link #setup(Context, FragmentManager, int)}
to complete the initialization of the tab host.
Here is a simple example of using a FragmentTabHost in an Activity:
{@sample development/samples/Support4Demos/src/com/example/android/supportv4/app/FragmentTabs.java
complete}
This can also be used inside of a fragment through fragment nesting:
{@sample development/samples/Support4Demos/src/com/example/android/supportv4/app/FragmentTabsFragmentSupport.java
complete} |
| Fields Summary |
|---|
| private final ArrayList | mTabs | | private android.widget.FrameLayout | mRealTabContent | | private android.content.Context | mContext | | private FragmentManager | mFragmentManager | | private int | mContainerId | | private TabHost.OnTabChangeListener | mOnTabChangeListener | | private TabInfo | mLastTab | | private boolean | mAttached |
| Constructors Summary |
|---|
public FragmentTabHost(android.content.Context context)
// Note that we call through to the version that takes an AttributeSet,
// because the simple Context construct can result in a broken object!
super(context, null);
initFragmentTabHost(context, null);
| public FragmentTabHost(android.content.Context context, android.util.AttributeSet attrs)
super(context, attrs);
initFragmentTabHost(context, attrs);
|
| Methods Summary |
|---|
| public void | addTab(TabHost.TabSpec tabSpec, java.lang.Class clss, android.os.Bundle args)
tabSpec.setContent(new DummyTabFactory(mContext));
String tag = tabSpec.getTag();
TabInfo info = new TabInfo(tag, clss, args);
if (mAttached) {
// If we are already attached to the window, then check to make
// sure this tab's fragment is inactive if it exists. This shouldn't
// normally happen.
info.fragment = mFragmentManager.findFragmentByTag(tag);
if (info.fragment != null && !info.fragment.isDetached()) {
FragmentTransaction ft = mFragmentManager.beginTransaction();
ft.detach(info.fragment);
ft.commit();
}
}
mTabs.add(info);
addTab(tabSpec);
| | private FragmentTransaction | doTabChanged(java.lang.String tabId, FragmentTransaction ft)
TabInfo newTab = null;
for (int i=0; i<mTabs.size(); i++) {
TabInfo tab = mTabs.get(i);
if (tab.tag.equals(tabId)) {
newTab = tab;
}
}
if (newTab == null) {
throw new IllegalStateException("No tab known for tag " + tabId);
}
if (mLastTab != newTab) {
if (ft == null) {
ft = mFragmentManager.beginTransaction();
}
if (mLastTab != null) {
if (mLastTab.fragment != null) {
ft.detach(mLastTab.fragment);
}
}
if (newTab != null) {
if (newTab.fragment == null) {
newTab.fragment = Fragment.instantiate(mContext,
newTab.clss.getName(), newTab.args);
ft.add(mContainerId, newTab.fragment, newTab.tag);
} else {
ft.attach(newTab.fragment);
}
}
mLastTab = newTab;
}
return ft;
| | private void | ensureContent()
if (mRealTabContent == null) {
mRealTabContent = (FrameLayout)findViewById(mContainerId);
if (mRealTabContent == null) {
throw new IllegalStateException(
"No tab content FrameLayout found for id " + mContainerId);
}
}
| | private void | ensureHierarchy(android.content.Context context)
// If owner hasn't made its own view hierarchy, then as a convenience
// we will construct a standard one here.
if (findViewById(android.R.id.tabs) == null) {
LinearLayout ll = new LinearLayout(context);
ll.setOrientation(LinearLayout.VERTICAL);
addView(ll, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT,
ViewGroup.LayoutParams.FILL_PARENT));
TabWidget tw = new TabWidget(context);
tw.setId(android.R.id.tabs);
tw.setOrientation(TabWidget.HORIZONTAL);
ll.addView(tw, new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT,
ViewGroup.LayoutParams.WRAP_CONTENT, 0));
FrameLayout fl = new FrameLayout(context);
fl.setId(android.R.id.tabcontent);
ll.addView(fl, new LinearLayout.LayoutParams(0, 0, 0));
mRealTabContent = fl = new FrameLayout(context);
mRealTabContent.setId(mContainerId);
ll.addView(fl, new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT, 0, 1));
}
| | private void | initFragmentTabHost(android.content.Context context, android.util.AttributeSet attrs)
TypedArray a = context.obtainStyledAttributes(attrs,
new int[] { android.R.attr.inflatedId }, 0, 0);
mContainerId = a.getResourceId(0, 0);
a.recycle();
super.setOnTabChangedListener(this);
| | protected void | onAttachedToWindow()
super.onAttachedToWindow();
String currentTab = getCurrentTabTag();
// Go through all tabs and make sure their fragments match
// the correct state.
FragmentTransaction ft = null;
for (int i=0; i<mTabs.size(); i++) {
TabInfo tab = mTabs.get(i);
tab.fragment = mFragmentManager.findFragmentByTag(tab.tag);
if (tab.fragment != null && !tab.fragment.isDetached()) {
if (tab.tag.equals(currentTab)) {
// The fragment for this tab is already there and
// active, and it is what we really want to have
// as the current tab. Nothing to do.
mLastTab = tab;
} else {
// This fragment was restored in the active state,
// but is not the current tab. Deactivate it.
if (ft == null) {
ft = mFragmentManager.beginTransaction();
}
ft.detach(tab.fragment);
}
}
}
// We are now ready to go. Make sure we are switched to the
// correct tab.
mAttached = true;
ft = doTabChanged(currentTab, ft);
if (ft != null) {
ft.commit();
mFragmentManager.executePendingTransactions();
}
| | protected void | onDetachedFromWindow()
super.onDetachedFromWindow();
mAttached = false;
| | protected void | onRestoreInstanceState(android.os.Parcelable state)
SavedState ss = (SavedState)state;
super.onRestoreInstanceState(ss.getSuperState());
setCurrentTabByTag(ss.curTab);
| | protected android.os.Parcelable | onSaveInstanceState()
Parcelable superState = super.onSaveInstanceState();
SavedState ss = new SavedState(superState);
ss.curTab = getCurrentTabTag();
return ss;
| | public void | onTabChanged(java.lang.String tabId)
if (mAttached) {
FragmentTransaction ft = doTabChanged(tabId, null);
if (ft != null) {
ft.commit();
}
}
if (mOnTabChangeListener != null) {
mOnTabChangeListener.onTabChanged(tabId);
}
| | public void | setOnTabChangedListener(OnTabChangeListener l)
mOnTabChangeListener = l;
| | public void | setup()
throw new IllegalStateException(
"Must call setup() that takes a Context and FragmentManager");
| | public void | setup(android.content.Context context, FragmentManager manager)
ensureHierarchy(context); // Ensure views required by super.setup()
super.setup();
mContext = context;
mFragmentManager = manager;
ensureContent();
| | public void | setup(android.content.Context context, FragmentManager manager, int containerId)
ensureHierarchy(context); // Ensure views required by super.setup()
super.setup();
mContext = context;
mFragmentManager = manager;
mContainerId = containerId;
ensureContent();
mRealTabContent.setId(containerId);
// We must have an ID to be able to save/restore our state. If
// the owner hasn't set one at this point, we will set it ourself.
if (getId() == View.NO_ID) {
setId(android.R.id.tabhost);
}
|
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