1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.support.v4.app;
18
19import android.support.annotation.AnimRes;
20import android.support.annotation.IdRes;
21import android.support.annotation.IntDef;
22import android.support.annotation.Nullable;
23import android.support.annotation.RestrictTo;
24import android.support.annotation.StringRes;
25import android.support.annotation.StyleRes;
26import android.support.v4.util.Pair;
27import android.view.View;
28
29import java.lang.annotation.Retention;
30import java.lang.annotation.RetentionPolicy;
31
32import static android.support.annotation.RestrictTo.Scope.GROUP_ID;
33
34/**
35 * Static library support version of the framework's {@link android.app.FragmentTransaction}.
36 * Used to write apps that run on platforms prior to Android 3.0.  When running
37 * on Android 3.0 or above, this implementation is still used; it does not try
38 * to switch to the framework's implementation.  See the framework SDK
39 * documentation for a class overview.
40 */
41public abstract class FragmentTransaction {
42    /**
43     * Calls {@link #add(int, Fragment, String)} with a 0 containerViewId.
44     */
45    public abstract FragmentTransaction add(Fragment fragment, String tag);
46
47    /**
48     * Calls {@link #add(int, Fragment, String)} with a null tag.
49     */
50    public abstract FragmentTransaction add(@IdRes int containerViewId, Fragment fragment);
51
52    /**
53     * Add a fragment to the activity state.  This fragment may optionally
54     * also have its view (if {@link Fragment#onCreateView Fragment.onCreateView}
55     * returns non-null) into a container view of the activity.
56     *
57     * @param containerViewId Optional identifier of the container this fragment is
58     * to be placed in.  If 0, it will not be placed in a container.
59     * @param fragment The fragment to be added.  This fragment must not already
60     * be added to the activity.
61     * @param tag Optional tag name for the fragment, to later retrieve the
62     * fragment with {@link FragmentManager#findFragmentByTag(String)
63     * FragmentManager.findFragmentByTag(String)}.
64     *
65     * @return Returns the same FragmentTransaction instance.
66     */
67    public abstract FragmentTransaction add(@IdRes int containerViewId, Fragment fragment,
68            @Nullable String tag);
69
70    /**
71     * Calls {@link #replace(int, Fragment, String)} with a null tag.
72     */
73    public abstract FragmentTransaction replace(@IdRes int containerViewId, Fragment fragment);
74
75    /**
76     * Replace an existing fragment that was added to a container.  This is
77     * essentially the same as calling {@link #remove(Fragment)} for all
78     * currently added fragments that were added with the same containerViewId
79     * and then {@link #add(int, Fragment, String)} with the same arguments
80     * given here.
81     *
82     * @param containerViewId Identifier of the container whose fragment(s) are
83     * to be replaced.
84     * @param fragment The new fragment to place in the container.
85     * @param tag Optional tag name for the fragment, to later retrieve the
86     * fragment with {@link FragmentManager#findFragmentByTag(String)
87     * FragmentManager.findFragmentByTag(String)}.
88     *
89     * @return Returns the same FragmentTransaction instance.
90     */
91    public abstract FragmentTransaction replace(@IdRes int containerViewId, Fragment fragment,
92            @Nullable String tag);
93
94    /**
95     * Remove an existing fragment.  If it was added to a container, its view
96     * is also removed from that container.
97     *
98     * @param fragment The fragment to be removed.
99     *
100     * @return Returns the same FragmentTransaction instance.
101     */
102    public abstract FragmentTransaction remove(Fragment fragment);
103
104    /**
105     * Hides an existing fragment.  This is only relevant for fragments whose
106     * views have been added to a container, as this will cause the view to
107     * be hidden.
108     *
109     * @param fragment The fragment to be hidden.
110     *
111     * @return Returns the same FragmentTransaction instance.
112     */
113    public abstract FragmentTransaction hide(Fragment fragment);
114
115    /**
116     * Shows a previously hidden fragment.  This is only relevant for fragments whose
117     * views have been added to a container, as this will cause the view to
118     * be shown.
119     *
120     * @param fragment The fragment to be shown.
121     *
122     * @return Returns the same FragmentTransaction instance.
123     */
124    public abstract FragmentTransaction show(Fragment fragment);
125
126    /**
127     * Detach the given fragment from the UI.  This is the same state as
128     * when it is put on the back stack: the fragment is removed from
129     * the UI, however its state is still being actively managed by the
130     * fragment manager.  When going into this state its view hierarchy
131     * is destroyed.
132     *
133     * @param fragment The fragment to be detached.
134     *
135     * @return Returns the same FragmentTransaction instance.
136     */
137    public abstract FragmentTransaction detach(Fragment fragment);
138
139    /**
140     * Re-attach a fragment after it had previously been detached from
141     * the UI with {@link #detach(Fragment)}.  This
142     * causes its view hierarchy to be re-created, attached to the UI,
143     * and displayed.
144     *
145     * @param fragment The fragment to be attached.
146     *
147     * @return Returns the same FragmentTransaction instance.
148     */
149    public abstract FragmentTransaction attach(Fragment fragment);
150
151    /**
152     * @return <code>true</code> if this transaction contains no operations,
153     * <code>false</code> otherwise.
154     */
155    public abstract boolean isEmpty();
156
157    /**
158     * Bit mask that is set for all enter transitions.
159     */
160    public static final int TRANSIT_ENTER_MASK = 0x1000;
161
162    /**
163     * Bit mask that is set for all exit transitions.
164     */
165    public static final int TRANSIT_EXIT_MASK = 0x2000;
166
167    /** @hide */
168    @RestrictTo(GROUP_ID)
169    @IntDef({TRANSIT_NONE, TRANSIT_FRAGMENT_OPEN, TRANSIT_FRAGMENT_CLOSE, TRANSIT_FRAGMENT_FADE})
170    @Retention(RetentionPolicy.SOURCE)
171    private @interface Transit {}
172
173    /** Not set up for a transition. */
174    public static final int TRANSIT_UNSET = -1;
175    /** No animation for transition. */
176    public static final int TRANSIT_NONE = 0;
177    /** Fragment is being added onto the stack */
178    public static final int TRANSIT_FRAGMENT_OPEN = 1 | TRANSIT_ENTER_MASK;
179    /** Fragment is being removed from the stack */
180    public static final int TRANSIT_FRAGMENT_CLOSE = 2 | TRANSIT_EXIT_MASK;
181    /** Fragment should simply fade in or out; that is, no strong navigation associated
182     * with it except that it is appearing or disappearing for some reason. */
183    public static final int TRANSIT_FRAGMENT_FADE = 3 | TRANSIT_ENTER_MASK;
184
185    /**
186     * Set specific animation resources to run for the fragments that are
187     * entering and exiting in this transaction. These animations will not be
188     * played when popping the back stack.
189     */
190    public abstract FragmentTransaction setCustomAnimations(@AnimRes int enter,
191            @AnimRes int exit);
192
193    /**
194     * Set specific animation resources to run for the fragments that are
195     * entering and exiting in this transaction. The <code>popEnter</code>
196     * and <code>popExit</code> animations will be played for enter/exit
197     * operations specifically when popping the back stack.
198     */
199    public abstract FragmentTransaction setCustomAnimations(@AnimRes int enter,
200            @AnimRes int exit, @AnimRes int popEnter, @AnimRes int popExit);
201
202    /**
203     * Used with custom Transitions to map a View from a removed or hidden
204     * Fragment to a View from a shown or added Fragment.
205     * <var>sharedElement</var> must have a unique transitionName in the View hierarchy.
206     *
207     * @param sharedElement A View in a disappearing Fragment to match with a View in an
208     *                      appearing Fragment.
209     * @param name The transitionName for a View in an appearing Fragment to match to the shared
210     *             element.
211     * @see Fragment#setSharedElementReturnTransition(Object)
212     * @see Fragment#setSharedElementEnterTransition(Object)
213     */
214    public abstract FragmentTransaction addSharedElement(View sharedElement, String name);
215
216    /**
217     * Select a standard transition animation for this transaction.  May be
218     * one of {@link #TRANSIT_NONE}, {@link #TRANSIT_FRAGMENT_OPEN},
219     * {@link #TRANSIT_FRAGMENT_CLOSE}, or {@link #TRANSIT_FRAGMENT_FADE}.
220     */
221    public abstract FragmentTransaction setTransition(@Transit int transit);
222
223    /**
224     * Set a custom style resource that will be used for resolving transit
225     * animations.
226     */
227    public abstract FragmentTransaction setTransitionStyle(@StyleRes int styleRes);
228
229    /**
230     * Add this transaction to the back stack.  This means that the transaction
231     * will be remembered after it is committed, and will reverse its operation
232     * when later popped off the stack.
233     *
234     * @param name An optional name for this back stack state, or null.
235     */
236    public abstract FragmentTransaction addToBackStack(@Nullable String name);
237
238    /**
239     * Returns true if this FragmentTransaction is allowed to be added to the back
240     * stack. If this method would return false, {@link #addToBackStack(String)}
241     * will throw {@link IllegalStateException}.
242     *
243     * @return True if {@link #addToBackStack(String)} is permitted on this transaction.
244     */
245    public abstract boolean isAddToBackStackAllowed();
246
247    /**
248     * Disallow calls to {@link #addToBackStack(String)}. Any future calls to
249     * addToBackStack will throw {@link IllegalStateException}. If addToBackStack
250     * has already been called, this method will throw IllegalStateException.
251     */
252    public abstract FragmentTransaction disallowAddToBackStack();
253
254    /**
255     * Set the full title to show as a bread crumb when this transaction
256     * is on the back stack.
257     *
258     * @param res A string resource containing the title.
259     */
260    public abstract FragmentTransaction setBreadCrumbTitle(@StringRes int res);
261
262    /**
263     * Like {@link #setBreadCrumbTitle(int)} but taking a raw string; this
264     * method is <em>not</em> recommended, as the string can not be changed
265     * later if the locale changes.
266     */
267    public abstract FragmentTransaction setBreadCrumbTitle(CharSequence text);
268
269    /**
270     * Set the short title to show as a bread crumb when this transaction
271     * is on the back stack.
272     *
273     * @param res A string resource containing the title.
274     */
275    public abstract FragmentTransaction setBreadCrumbShortTitle(@StringRes int res);
276
277    /**
278     * Like {@link #setBreadCrumbShortTitle(int)} but taking a raw string; this
279     * method is <em>not</em> recommended, as the string can not be changed
280     * later if the locale changes.
281     */
282    public abstract FragmentTransaction setBreadCrumbShortTitle(CharSequence text);
283
284    /**
285     * Schedules a commit of this transaction.  The commit does
286     * not happen immediately; it will be scheduled as work on the main thread
287     * to be done the next time that thread is ready.
288     *
289     * <p class="note">A transaction can only be committed with this method
290     * prior to its containing activity saving its state.  If the commit is
291     * attempted after that point, an exception will be thrown.  This is
292     * because the state after the commit can be lost if the activity needs to
293     * be restored from its state.  See {@link #commitAllowingStateLoss()} for
294     * situations where it may be okay to lose the commit.</p>
295     *
296     * @return Returns the identifier of this transaction's back stack entry,
297     * if {@link #addToBackStack(String)} had been called.  Otherwise, returns
298     * a negative number.
299     */
300    public abstract int commit();
301
302    /**
303     * Like {@link #commit} but allows the commit to be executed after an
304     * activity's state is saved.  This is dangerous because the commit can
305     * be lost if the activity needs to later be restored from its state, so
306     * this should only be used for cases where it is okay for the UI state
307     * to change unexpectedly on the user.
308     */
309    public abstract int commitAllowingStateLoss();
310
311    /**
312     * Commits this transaction synchronously. Any added fragments will be
313     * initialized and brought completely to the lifecycle state of their host
314     * and any removed fragments will be torn down accordingly before this
315     * call returns. Committing a transaction in this way allows fragments
316     * to be added as dedicated, encapsulated components that monitor the
317     * lifecycle state of their host while providing firmer ordering guarantees
318     * around when those fragments are fully initialized and ready. Fragments
319     * that manage views will have those views created and attached.
320     *
321     * <p>Calling <code>commitNow</code> is preferable to calling
322     * {@link #commit()} followed by {@link FragmentManager#executePendingTransactions()}
323     * as the latter will have the side effect of attempting to commit <em>all</em>
324     * currently pending transactions whether that is the desired behavior
325     * or not.</p>
326     *
327     * <p>Transactions committed in this way may not be added to the
328     * FragmentManager's back stack, as doing so would break other expected
329     * ordering guarantees for other asynchronously committed transactions.
330     * This method will throw {@link IllegalStateException} if the transaction
331     * previously requested to be added to the back stack with
332     * {@link #addToBackStack(String)}.</p>
333     *
334     * <p class="note">A transaction can only be committed with this method
335     * prior to its containing activity saving its state.  If the commit is
336     * attempted after that point, an exception will be thrown.  This is
337     * because the state after the commit can be lost if the activity needs to
338     * be restored from its state.  See {@link #commitAllowingStateLoss()} for
339     * situations where it may be okay to lose the commit.</p>
340     */
341    public abstract void commitNow();
342
343    /**
344     * Like {@link #commitNow} but allows the commit to be executed after an
345     * activity's state is saved.  This is dangerous because the commit can
346     * be lost if the activity needs to later be restored from its state, so
347     * this should only be used for cases where it is okay for the UI state
348     * to change unexpectedly on the user.
349     */
350    public abstract void commitNowAllowingStateLoss();
351}
352