android.support.v4.app.FragmentTabHost Maven / Gradle / Ivy
/*
* Copyright (C) 2012 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 android.support.v4.app;
import java.util.ArrayList;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import android.widget.LinearLayout;
import android.widget.TabHost;
import android.widget.TabWidget;
/**
* 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}
*/
public class FragmentTabHost extends TabHost
implements TabHost.OnTabChangeListener {
private final ArrayList mTabs = new ArrayList();
private FrameLayout mRealTabContent;
private Context mContext;
private FragmentManager mFragmentManager;
private int mContainerId;
private TabHost.OnTabChangeListener mOnTabChangeListener;
private TabInfo mLastTab;
private boolean mAttached;
static final class TabInfo {
private final String tag;
private final Class clss;
private final Bundle args;
private Fragment fragment;
TabInfo(String _tag, Class _class, Bundle _args) {
tag = _tag;
clss = _class;
args = _args;
}
}
static class DummyTabFactory implements TabHost.TabContentFactory {
private final Context mContext;
public DummyTabFactory(Context context) {
mContext = context;
}
@Override
public View createTabContent(String tag) {
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
static class SavedState extends BaseSavedState {
String curTab;
SavedState(Parcelable superState) {
super(superState);
}
private SavedState(Parcel in) {
super(in);
curTab = in.readString();
}
@Override
public void writeToParcel(Parcel out, int flags) {
super.writeToParcel(out, flags);
out.writeString(curTab);
}
@Override
public String toString() {
return "FragmentTabHost.SavedState{"
+ Integer.toHexString(System.identityHashCode(this))
+ " curTab=" + curTab + "}";
}
public static final Parcelable.Creator CREATOR
= new Parcelable.Creator() {
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
public FragmentTabHost(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(Context context, AttributeSet attrs) {
super(context, attrs);
initFragmentTabHost(context, attrs);
}
private void initFragmentTabHost(Context context, 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);
}
private void ensureHierarchy(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));
}
}
/**
* @deprecated Don't call the original TabHost setup, you must instead
* call {@link #setup(Context, FragmentManager)} or
* {@link #setup(Context, FragmentManager, int)}.
*/
@Override @Deprecated
public void setup() {
throw new IllegalStateException(
"Must call setup() that takes a Context and FragmentManager");
}
public void setup(Context context, FragmentManager manager) {
ensureHierarchy(context); // Ensure views required by super.setup()
super.setup();
mContext = context;
mFragmentManager = manager;
ensureContent();
}
public void setup(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);
}
}
private void ensureContent() {
if (mRealTabContent == null) {
mRealTabContent = (FrameLayout)findViewById(mContainerId);
if (mRealTabContent == null) {
throw new IllegalStateException(
"No tab content FrameLayout found for id " + mContainerId);
}
}
}
@Override
public void setOnTabChangedListener(OnTabChangeListener l) {
mOnTabChangeListener = l;
}
public void addTab(TabHost.TabSpec tabSpec, Class clss, 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);
}
@Override
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