Java tutorial
/* * Copyright (C) 2011 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; /** * Static library support version of the framework's {@link android.app.FragmentTransaction}. * Used to write apps that run on platforms prior to Android 3.0. When running * on Android 3.0 or above, this implementation is still used; it does not try * to switch to the framework's implementation. See the framework SDK * documentation for a class overview. */ public abstract class FragmentTransaction { /** * Calls {@link #add(int, Fragment, String)} with a 0 containerViewId. */ public abstract FragmentTransaction add(Fragment fragment, String tag); /** * Calls {@link #add(int, Fragment, String)} with a null tag. */ public abstract FragmentTransaction add(int containerViewId, Fragment fragment); /** * Add a fragment to the activity state. This fragment may optionally * also have its view (if {@link Fragment#onCreateView Fragment.onCreateView} * returns non-null) into a container view of the activity. * * @param containerViewId Optional identifier of the container this fragment is * to be placed in. If 0, it will not be placed in a container. * @param fragment The fragment to be added. This fragment must not already * be added to the activity. * @param tag Optional tag name for the fragment, to later retrieve the * fragment with {@link FragmentManager#findFragmentByTag(String) * FragmentManager.findFragmentByTag(String)}. * * @return Returns the same FragmentTransaction instance. */ public abstract FragmentTransaction add(int containerViewId, Fragment fragment, String tag); /** * Calls {@link #replace(int, Fragment, String)} with a null tag. */ public abstract FragmentTransaction replace(int containerViewId, Fragment fragment); /** * Replace an existing fragment that was added to a container. This is * essentially the same as calling {@link #remove(Fragment)} for all * currently added fragments that were added with the same containerViewId * and then {@link #add(int, Fragment, String)} with the same arguments * given here. * * @param containerViewId Identifier of the container whose fragment(s) are * to be replaced. * @param fragment The new fragment to place in the container. * @param tag Optional tag name for the fragment, to later retrieve the * fragment with {@link FragmentManager#findFragmentByTag(String) * FragmentManager.findFragmentByTag(String)}. * * @return Returns the same FragmentTransaction instance. */ public abstract FragmentTransaction replace(int containerViewId, Fragment fragment, String tag); /** * Remove an existing fragment. If it was added to a container, its view * is also removed from that container. * * @param fragment The fragment to be removed. * * @return Returns the same FragmentTransaction instance. */ public abstract FragmentTransaction remove(Fragment fragment); /** * Hides an existing fragment. This is only relevant for fragments whose * views have been added to a container, as this will cause the view to * be hidden. * * @param fragment The fragment to be hidden. * * @return Returns the same FragmentTransaction instance. */ public abstract FragmentTransaction hide(Fragment fragment); /** * Shows a previously hidden fragment. This is only relevant for fragments whose * views have been added to a container, as this will cause the view to * be shown. * * @param fragment The fragment to be shown. * * @return Returns the same FragmentTransaction instance. */ public abstract FragmentTransaction show(Fragment fragment); /** * Detach the given fragment from the UI. This is the same state as * when it is put on the back stack: the fragment is removed from * the UI, however its state is still being actively managed by the * fragment manager. When going into this state its view hierarchy * is destroyed. * * @param fragment The fragment to be detached. * * @return Returns the same FragmentTransaction instance. */ public abstract FragmentTransaction detach(Fragment fragment); /** * Re-attach a fragment after it had previously been deatched from * the UI with {@link #detach(Fragment)}. This * causes its view hierarchy to be re-created, attached to the UI, * and displayed. * * @param fragment The fragment to be attached. * * @return Returns the same FragmentTransaction instance. */ public abstract FragmentTransaction attach(Fragment fragment); /** * @return <code>true</code> if this transaction contains no operations, * <code>false</code> otherwise. */ public abstract boolean isEmpty(); /** * Bit mask that is set for all enter transitions. */ public static final int TRANSIT_ENTER_MASK = 0x1000; /** * Bit mask that is set for all exit transitions. */ public static final int TRANSIT_EXIT_MASK = 0x2000; /** Not set up for a transition. */ public static final int TRANSIT_UNSET = -1; /** No animation for transition. */ public static final int TRANSIT_NONE = 0; /** Fragment is being added onto the stack */ public static final int TRANSIT_FRAGMENT_OPEN = 1 | TRANSIT_ENTER_MASK; /** Fragment is being removed from the stack */ public static final int TRANSIT_FRAGMENT_CLOSE = 2 | TRANSIT_EXIT_MASK; /** Fragment should simply fade in or out; that is, no strong navigation associated * with it except that it is appearing or disappearing for some reason. */ public static final int TRANSIT_FRAGMENT_FADE = 3 | TRANSIT_ENTER_MASK; /** * Set specific animation resources to run for the fragments that are * entering and exiting in this transaction. These animations will not be * played when popping the back stack. */ public abstract FragmentTransaction setCustomAnimations(int enter, int exit); /** * Set specific animation resources to run for the fragments that are * entering and exiting in this transaction. The <code>popEnter</code> * and <code>popExit</code> animations will be played for enter/exit * operations specifically when popping the back stack. */ public abstract FragmentTransaction setCustomAnimations(int enter, int exit, int popEnter, int popExit); /** * Select a standard transition animation for this transaction. May be * one of {@link #TRANSIT_NONE}, {@link #TRANSIT_FRAGMENT_OPEN}, * or {@link #TRANSIT_FRAGMENT_CLOSE} */ public abstract FragmentTransaction setTransition(int transit); /** * Set a custom style resource that will be used for resolving transit * animations. */ public abstract FragmentTransaction setTransitionStyle(int styleRes); /** * Add this transaction to the back stack. This means that the transaction * will be remembered after it is committed, and will reverse its operation * when later popped off the stack. * * @param name An optional name for this back stack state, or null. */ public abstract FragmentTransaction addToBackStack(String name); /** * Returns true if this FragmentTransaction is allowed to be added to the back * stack. If this method would return false, {@link #addToBackStack(String)} * will throw {@link IllegalStateException}. * * @return True if {@link #addToBackStack(String)} is permitted on this transaction. */ public abstract boolean isAddToBackStackAllowed(); /** * Disallow calls to {@link #addToBackStack(String)}. Any future calls to * addToBackStack will throw {@link IllegalStateException}. If addToBackStack * has already been called, this method will throw IllegalStateException. */ public abstract FragmentTransaction disallowAddToBackStack(); /** * Set the full title to show as a bread crumb when this transaction * is on the back stack. * * @param res A string resource containing the title. */ public abstract FragmentTransaction setBreadCrumbTitle(int res); /** * Like {@link #setBreadCrumbTitle(int)} but taking a raw string; this * method is <em>not</em> recommended, as the string can not be changed * later if the locale changes. */ public abstract FragmentTransaction setBreadCrumbTitle(CharSequence text); /** * Set the short title to show as a bread crumb when this transaction * is on the back stack. * * @param res A string resource containing the title. */ public abstract FragmentTransaction setBreadCrumbShortTitle(int res); /** * Like {@link #setBreadCrumbShortTitle(int)} but taking a raw string; this * method is <em>not</em> recommended, as the string can not be changed * later if the locale changes. */ public abstract FragmentTransaction setBreadCrumbShortTitle(CharSequence text); /** * Schedules a commit of this transaction. The commit does * not happen immediately; it will be scheduled as work on the main thread * to be done the next time that thread is ready. * * <p class="note">A transaction can only be committed with this method * prior to its containing activity saving its state. If the commit is * attempted after that point, an exception will be thrown. This is * because the state after the commit can be lost if the activity needs to * be restored from its state. See {@link #commitAllowingStateLoss()} for * situations where it may be okay to lose the commit.</p> * * @return Returns the identifier of this transaction's back stack entry, * if {@link #addToBackStack(String)} had been called. Otherwise, returns * a negative number. */ public abstract int commit(); /** * Like {@link #commit} but allows the commit to be executed after an * activity's state is saved. This is dangerous because the commit can * be lost if the activity needs to later be restored from its state, so * this should only be used for cases where it is okay for the UI state * to change unexpectedly on the user. */ public abstract int commitAllowingStateLoss(); }