v13/java/android/support/v13/app/FragmentTabHost.java - platform/frameworks/support - Git at Google

 /*
  * 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.v13.app;

 import android.app.Fragment;
 import android.app.FragmentManager;
 import android.app.FragmentTransaction;
 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;

 import java.util.ArrayList;

 /**
  * Version of {@link android.support.v4.app.FragmentTabHost} that can be
  * used with the platform {@link android.app.Fragment} APIs.  You will not
  * normally use this, instead using action bar tabs.
  */
 public class FragmentTabHost extends TabHost
         implements TabHost.OnTabChangeListener {
     private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
     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 {
         final String tag;
         final Class<?> clss;
         final Bundle args;
         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);
         }

         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<SavedState> CREATOR
                 = new Parcelable.Creator<SavedState>() {
             @Override
             public SavedState createFromParcel(Parcel in) {
                 return new SavedState(in);
             }

             @Override
             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.MATCH_PARENT,
                     ViewGroup.LayoutParams.MATCH_PARENT));

             TabWidget tw = new TabWidget(context);
             tw.setId(android.R.id.tabs);
             tw.setOrientation(TabWidget.HORIZONTAL);
             ll.addView(tw, new LinearLayout.LayoutParams(
                     ViewGroup.LayoutParams.MATCH_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.MATCH_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 ourselves.
         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<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();
         }
     }

     @Override
     protected void onDetachedFromWindow() {
         super.onDetachedFromWindow();
         mAttached = false;
     }

     @Override
     protected Parcelable onSaveInstanceState() {
         Parcelable superState = super.onSaveInstanceState();
         SavedState ss = new SavedState(superState);
         ss.curTab = getCurrentTabTag();
         return ss;
     }

     @Override
     protected void onRestoreInstanceState(Parcelable state) {
         if (!(state instanceof SavedState)) {
             super.onRestoreInstanceState(state);
             return;
         }
         SavedState ss = (SavedState) state;
         super.onRestoreInstanceState(ss.getSuperState());
         setCurrentTabByTag(ss.curTab);
     }

     @Override
     public void onTabChanged(String tabId) {
         if (mAttached) {
             FragmentTransaction ft = doTabChanged(tabId, null);
             if (ft != null) {
                 ft.commit();
             }
         }
         if (mOnTabChangeListener != null) {
             mOnTabChangeListener.onTabChanged(tabId);
         }
     }

     private FragmentTransaction doTabChanged(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;
     }
 }
	/*
	* 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.v13.app;

	import android.app.Fragment;
	import android.app.FragmentManager;
	import android.app.FragmentTransaction;
	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;

	import java.util.ArrayList;

	/**
	* Version of {@link android.support.v4.app.FragmentTabHost} that can be
	* used with the platform {@link android.app.Fragment} APIs. You will not
	* normally use this, instead using action bar tabs.
	*/
	public class FragmentTabHost extends TabHost
	implements TabHost.OnTabChangeListener {
	private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
	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 {
	final String tag;
	final Class<?> clss;
	final Bundle args;
	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);
	}

	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<SavedState> CREATOR
	= new Parcelable.Creator<SavedState>() {
	@Override
	public SavedState createFromParcel(Parcel in) {
	return new SavedState(in);
	}

	@Override
	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.MATCH_PARENT,
	ViewGroup.LayoutParams.MATCH_PARENT));

	TabWidget tw = new TabWidget(context);
	tw.setId(android.R.id.tabs);
	tw.setOrientation(TabWidget.HORIZONTAL);
	ll.addView(tw, new LinearLayout.LayoutParams(
	ViewGroup.LayoutParams.MATCH_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.MATCH_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 ourselves.
	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<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();
	}
	}

	@Override
	protected void onDetachedFromWindow() {
	super.onDetachedFromWindow();
	mAttached = false;
	}

	@Override
	protected Parcelable onSaveInstanceState() {
	Parcelable superState = super.onSaveInstanceState();
	SavedState ss = new SavedState(superState);
	ss.curTab = getCurrentTabTag();
	return ss;
	}

	@Override
	protected void onRestoreInstanceState(Parcelable state) {
	if (!(state instanceof SavedState)) {
	super.onRestoreInstanceState(state);
	return;
	}
	SavedState ss = (SavedState) state;
	super.onRestoreInstanceState(ss.getSuperState());
	setCurrentTabByTag(ss.curTab);
	}

	@Override
	public void onTabChanged(String tabId) {
	if (mAttached) {
	FragmentTransaction ft = doTabChanged(tabId, null);
	if (ft != null) {
	ft.commit();
	}
	}
	if (mOnTabChangeListener != null) {
	mOnTabChangeListener.onTabChanged(tabId);
	}
	}

	private FragmentTransaction doTabChanged(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;
	}
	}