Java tutorial
package ru.zabbkit.android.ui.views; /* * 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. */ /* * 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. */ import android.content.Context; import android.content.res.TypedArray; import android.os.Bundle; import android.os.Parcel; import android.os.Parcelable; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentTransaction; import android.util.AttributeSet; import android.view.View; import android.widget.FrameLayout; import android.widget.TabHost; import java.util.ArrayList; /** * * * 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. * * <p> * 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} * * <p> * 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 FixedFragmentTabHost 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; private boolean mIsRetanedFragments = false; static final class TabInfo { private final String tag; private final Class<?> clss; private final Bundle args; private Fragment fragment; TabInfo(final String tag, final Class<?> clss, final Bundle args) { this.tag = tag; this.clss = clss; this.args = args; } } static class DummyTabFactory implements TabHost.TabContentFactory { private final Context mContext; public DummyTabFactory(final Context context) { mContext = context; } @Override public View createTabContent(final String tag) { View v = new View(mContext); v.setMinimumWidth(0); v.setMinimumHeight(0); return v; } } static class SavedState extends BaseSavedState { String curTab; public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() { @Override public SavedState createFromParcel(final Parcel in) { return new SavedState(in); } @Override public SavedState[] newArray(final int size) { return new SavedState[size]; } }; SavedState(final Parcelable superState) { super(superState); } private SavedState(final Parcel in) { super(in); curTab = in.readString(); } @Override public void writeToParcel(final Parcel out, final int flags) { super.writeToParcel(out, flags); out.writeString(curTab); } @Override public String toString() { return "FragmentTabHost.SavedState{" + Integer.toHexString(System.identityHashCode(this)) + " curTab=" + curTab + "}"; } } public FixedFragmentTabHost(final 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 FixedFragmentTabHost(final Context context, final AttributeSet attrs) { super(context, attrs); initFragmentTabHost(context, attrs); } private void initFragmentTabHost(final Context context, final 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); /***** * HERE COMMENT CODE BECAUSE findViewById(android.R.id.tabs) EVERY TIME * IS NULL WE HAVE OWN LAYOUT ******/ } /** * @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 final void setup() { throw new IllegalStateException("Must call setup() that takes a Context and FragmentManager"); } public final void setup(final Context context, final FragmentManager manager) { super.setup(); mContext = context; mFragmentManager = manager; ensureContent(); } public void setup(final Context context, final FragmentManager manager, final int containerId) { 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); } } /** * Added by Dmitry.Kalenchuk for * * @param context * @param manager * @param containerId */ public final void setup(final Context context, final FragmentManager manager, final int containerId, final boolean isREtainedFragments) { setup(context, manager, containerId); mIsRetanedFragments = isREtainedFragments; } 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 final void setOnTabChangedListener(final OnTabChangeListener l) { mOnTabChangeListener = l; } public final void addTab(final TabHost.TabSpec tabSpec, final Class<?> clss, final 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 final void onDetachedFromWindow() { super.onDetachedFromWindow(); mAttached = false; } @Override protected final Parcelable onSaveInstanceState() { Parcelable superState = super.onSaveInstanceState(); SavedState ss = new SavedState(superState); ss.curTab = getCurrentTabTag(); return ss; } @Override protected final void onRestoreInstanceState(final Parcelable state) { SavedState ss = (SavedState) state; super.onRestoreInstanceState(ss.getSuperState()); setCurrentTabByTag(ss.curTab); } @Override public final void onTabChanged(final String tabId) { if (mAttached) { FragmentTransaction ft = doTabChanged(tabId, null); if (ft != null) { ft.commit(); } } if (mOnTabChangeListener != null) { mOnTabChangeListener.onTabChanged(tabId); } } private FragmentTransaction doTabChanged(final 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); } FragmentTransaction fragmentTransaction = ft; if (!newTab.equals(mLastTab)) { if (fragmentTransaction == null) { fragmentTransaction = mFragmentManager.beginTransaction(); } if (mLastTab != null) { if (mLastTab.fragment != null) { fragmentTransaction.detach(mLastTab.fragment); } } if (newTab.fragment == null) { newTab.fragment = Fragment.instantiate(mContext, newTab.clss.getName(), newTab.args); newTab.fragment.setRetainInstance(mIsRetanedFragments); fragmentTransaction.add(mContainerId, newTab.fragment, newTab.tag); } else { fragmentTransaction.attach(newTab.fragment); } mLastTab = newTab; } return fragmentTransaction; } public int getTabsCount() { return mTabs.size(); } }