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; import android.os.Parcel; import android.os.Parcelable; import android.text.TextUtils; import android.util.Log; import java.io.FileDescriptor; import java.io.PrintWriter; import java.util.ArrayList; final class BackStackState implements Parcelable { final int[] mOps; final int mTransition; final int mTransitionStyle; final String mName; final int mIndex; final int mBreadCrumbTitleRes; final CharSequence mBreadCrumbTitleText; final int mBreadCrumbShortTitleRes; final CharSequence mBreadCrumbShortTitleText; public BackStackState(FragmentManagerImpl fm, BackStackRecord bse) { int numRemoved = 0; BackStackRecord.Op op = bse.mHead; while (op != null) { if (op.removed != null) numRemoved += op.removed.size(); op = op.next; } mOps = new int[bse.mNumOp * 7 + numRemoved]; if (!bse.mAddToBackStack) { throw new IllegalStateException("Not on back stack"); } op = bse.mHead; int pos = 0; while (op != null) { mOps[pos++] = op.cmd; mOps[pos++] = op.fragment.mIndex; mOps[pos++] = op.enterAnim; mOps[pos++] = op.exitAnim; mOps[pos++] = op.popEnterAnim; mOps[pos++] = op.popExitAnim; if (op.removed != null) { final int N = op.removed.size(); mOps[pos++] = N; for (int i = 0; i < N; i++) { mOps[pos++] = op.removed.get(i).mIndex; } } else { mOps[pos++] = 0; } op = op.next; } mTransition = bse.mTransition; mTransitionStyle = bse.mTransitionStyle; mName = bse.mName; mIndex = bse.mIndex; mBreadCrumbTitleRes = bse.mBreadCrumbTitleRes; mBreadCrumbTitleText = bse.mBreadCrumbTitleText; mBreadCrumbShortTitleRes = bse.mBreadCrumbShortTitleRes; mBreadCrumbShortTitleText = bse.mBreadCrumbShortTitleText; } public BackStackState(Parcel in) { mOps = in.createIntArray(); mTransition = in.readInt(); mTransitionStyle = in.readInt(); mName = in.readString(); mIndex = in.readInt(); mBreadCrumbTitleRes = in.readInt(); mBreadCrumbTitleText = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(in); mBreadCrumbShortTitleRes = in.readInt(); mBreadCrumbShortTitleText = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(in); } public BackStackRecord instantiate(FragmentManagerImpl fm) { BackStackRecord bse = new BackStackRecord(fm); int pos = 0; while (pos < mOps.length) { BackStackRecord.Op op = new BackStackRecord.Op(); op.cmd = mOps[pos++]; if (FragmentManagerImpl.DEBUG) Log.v(FragmentManagerImpl.TAG, "BSE " + bse + " set base fragment #" + mOps[pos]); Fragment f = fm.mActive.get(mOps[pos++]); op.fragment = f; op.enterAnim = mOps[pos++]; op.exitAnim = mOps[pos++]; op.popEnterAnim = mOps[pos++]; op.popExitAnim = mOps[pos++]; final int N = mOps[pos++]; if (N > 0) { op.removed = new ArrayList<Fragment>(N); for (int i = 0; i < N; i++) { if (FragmentManagerImpl.DEBUG) Log.v(FragmentManagerImpl.TAG, "BSE " + bse + " set remove fragment #" + mOps[pos]); Fragment r = fm.mActive.get(mOps[pos++]); op.removed.add(r); } } bse.addOp(op); } bse.mTransition = mTransition; bse.mTransitionStyle = mTransitionStyle; bse.mName = mName; bse.mIndex = mIndex; bse.mAddToBackStack = true; bse.mBreadCrumbTitleRes = mBreadCrumbTitleRes; bse.mBreadCrumbTitleText = mBreadCrumbTitleText; bse.mBreadCrumbShortTitleRes = mBreadCrumbShortTitleRes; bse.mBreadCrumbShortTitleText = mBreadCrumbShortTitleText; bse.bumpBackStackNesting(1); return bse; } public int describeContents() { return 0; } public void writeToParcel(Parcel dest, int flags) { dest.writeIntArray(mOps); dest.writeInt(mTransition); dest.writeInt(mTransitionStyle); dest.writeString(mName); dest.writeInt(mIndex); dest.writeInt(mBreadCrumbTitleRes); TextUtils.writeToParcel(mBreadCrumbTitleText, dest, 0); dest.writeInt(mBreadCrumbShortTitleRes); TextUtils.writeToParcel(mBreadCrumbShortTitleText, dest, 0); } public static final Parcelable.Creator<BackStackState> CREATOR = new Parcelable.Creator<BackStackState>() { public BackStackState createFromParcel(Parcel in) { return new BackStackState(in); } public BackStackState[] newArray(int size) { return new BackStackState[size]; } }; } /** * @hide Entry of an operation on the fragment back stack. */ final class BackStackRecord extends FragmentTransaction implements FragmentManager.BackStackEntry, Runnable { static final String TAG = "BackStackEntry"; final FragmentManagerImpl mManager; static final int OP_NULL = 0; static final int OP_ADD = 1; static final int OP_REPLACE = 2; static final int OP_REMOVE = 3; static final int OP_HIDE = 4; static final int OP_SHOW = 5; static final int OP_DETACH = 6; static final int OP_ATTACH = 7; static final class Op { Op next; Op prev; int cmd; Fragment fragment; int enterAnim; int exitAnim; int popEnterAnim; int popExitAnim; ArrayList<Fragment> removed; } Op mHead; Op mTail; int mNumOp; int mEnterAnim; int mExitAnim; int mPopEnterAnim; int mPopExitAnim; int mTransition; int mTransitionStyle; boolean mAddToBackStack; boolean mAllowAddToBackStack = true; String mName; boolean mCommitted; int mIndex; int mBreadCrumbTitleRes; CharSequence mBreadCrumbTitleText; int mBreadCrumbShortTitleRes; CharSequence mBreadCrumbShortTitleText; public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) { writer.print(prefix); writer.print("mName="); writer.print(mName); writer.print(" mIndex="); writer.print(mIndex); writer.print(" mCommitted="); writer.println(mCommitted); if (mTransition != FragmentTransaction.TRANSIT_NONE) { writer.print(prefix); writer.print("mTransition=#"); writer.print(Integer.toHexString(mTransition)); writer.print(" mTransitionStyle=#"); writer.println(Integer.toHexString(mTransitionStyle)); } if (mEnterAnim != 0 || mExitAnim != 0) { writer.print(prefix); writer.print("mEnterAnim=#"); writer.print(Integer.toHexString(mEnterAnim)); writer.print(" mExitAnim=#"); writer.println(Integer.toHexString(mExitAnim)); } if (mPopEnterAnim != 0 || mPopExitAnim != 0) { writer.print(prefix); writer.print("mPopEnterAnim=#"); writer.print(Integer.toHexString(mPopEnterAnim)); writer.print(" mPopExitAnim=#"); writer.println(Integer.toHexString(mPopExitAnim)); } if (mBreadCrumbTitleRes != 0 || mBreadCrumbTitleText != null) { writer.print(prefix); writer.print("mBreadCrumbTitleRes=#"); writer.print(Integer.toHexString(mBreadCrumbTitleRes)); writer.print(" mBreadCrumbTitleText="); writer.println(mBreadCrumbTitleText); } if (mBreadCrumbShortTitleRes != 0 || mBreadCrumbShortTitleText != null) { writer.print(prefix); writer.print("mBreadCrumbShortTitleRes=#"); writer.print(Integer.toHexString(mBreadCrumbShortTitleRes)); writer.print(" mBreadCrumbShortTitleText="); writer.println(mBreadCrumbShortTitleText); } if (mHead != null) { writer.print(prefix); writer.println("Operations:"); String innerPrefix = prefix + " "; Op op = mHead; int num = 0; while (op != null) { writer.print(prefix); writer.print(" Op #"); writer.print(num); writer.println(":"); writer.print(innerPrefix); writer.print("cmd="); writer.print(op.cmd); writer.print(" fragment="); writer.println(op.fragment); if (op.enterAnim != 0 || op.exitAnim != 0) { writer.print(prefix); writer.print("enterAnim=#"); writer.print(Integer.toHexString(op.enterAnim)); writer.print(" exitAnim=#"); writer.println(Integer.toHexString(op.exitAnim)); } if (op.popEnterAnim != 0 || op.popExitAnim != 0) { writer.print(prefix); writer.print("popEnterAnim=#"); writer.print(Integer.toHexString(op.popEnterAnim)); writer.print(" popExitAnim=#"); writer.println(Integer.toHexString(op.popExitAnim)); } if (op.removed != null && op.removed.size() > 0) { for (int i = 0; i < op.removed.size(); i++) { writer.print(innerPrefix); if (op.removed.size() == 1) { writer.print("Removed: "); } else { writer.println("Removed:"); writer.print(innerPrefix); writer.print(" #"); writer.print(num); writer.print(": "); } writer.println(op.removed.get(i)); } } op = op.next; } } } public BackStackRecord(FragmentManagerImpl manager) { mManager = manager; } public int getId() { return mIndex; } public int getBreadCrumbTitleRes() { return mBreadCrumbTitleRes; } public int getBreadCrumbShortTitleRes() { return mBreadCrumbShortTitleRes; } public CharSequence getBreadCrumbTitle() { if (mBreadCrumbTitleRes != 0) { return mManager.mActivity.getText(mBreadCrumbTitleRes); } return mBreadCrumbTitleText; } public CharSequence getBreadCrumbShortTitle() { if (mBreadCrumbShortTitleRes != 0) { return mManager.mActivity.getText(mBreadCrumbShortTitleRes); } return mBreadCrumbShortTitleText; } void addOp(Op op) { if (mHead == null) { mHead = mTail = op; } else { op.prev = mTail; mTail.next = op; mTail = op; } op.enterAnim = mEnterAnim; op.exitAnim = mExitAnim; op.popEnterAnim = mPopEnterAnim; op.popExitAnim = mPopExitAnim; mNumOp++; } public FragmentTransaction add(Fragment fragment, String tag) { doAddOp(0, fragment, tag, OP_ADD); return this; } public FragmentTransaction add(int containerViewId, Fragment fragment) { doAddOp(containerViewId, fragment, null, OP_ADD); return this; } public FragmentTransaction add(int containerViewId, Fragment fragment, String tag) { doAddOp(containerViewId, fragment, tag, OP_ADD); return this; } private void doAddOp(int containerViewId, Fragment fragment, String tag, int opcmd) { fragment.mFragmentManager = mManager; if (tag != null) { if (fragment.mTag != null && !tag.equals(fragment.mTag)) { throw new IllegalStateException( "Can't change tag of fragment " + fragment + ": was " + fragment.mTag + " now " + tag); } fragment.mTag = tag; } if (containerViewId != 0) { if (fragment.mFragmentId != 0 && fragment.mFragmentId != containerViewId) { throw new IllegalStateException("Can't change container ID of fragment " + fragment + ": was " + fragment.mFragmentId + " now " + containerViewId); } fragment.mContainerId = fragment.mFragmentId = containerViewId; } Op op = new Op(); op.cmd = opcmd; op.fragment = fragment; addOp(op); } public FragmentTransaction replace(int containerViewId, Fragment fragment) { return replace(containerViewId, fragment, null); } public FragmentTransaction replace(int containerViewId, Fragment fragment, String tag) { if (containerViewId == 0) { throw new IllegalArgumentException("Must use non-zero containerViewId"); } doAddOp(containerViewId, fragment, tag, OP_REPLACE); return this; } public FragmentTransaction remove(Fragment fragment) { Op op = new Op(); op.cmd = OP_REMOVE; op.fragment = fragment; addOp(op); return this; } public FragmentTransaction hide(Fragment fragment) { Op op = new Op(); op.cmd = OP_HIDE; op.fragment = fragment; addOp(op); return this; } public FragmentTransaction show(Fragment fragment) { Op op = new Op(); op.cmd = OP_SHOW; op.fragment = fragment; addOp(op); return this; } public FragmentTransaction detach(Fragment fragment) { Op op = new Op(); op.cmd = OP_DETACH; op.fragment = fragment; addOp(op); return this; } public FragmentTransaction attach(Fragment fragment) { Op op = new Op(); op.cmd = OP_ATTACH; op.fragment = fragment; addOp(op); return this; } public FragmentTransaction setCustomAnimations(int enter, int exit) { return setCustomAnimations(enter, exit, 0, 0); } public FragmentTransaction setCustomAnimations(int enter, int exit, int popEnter, int popExit) { mEnterAnim = enter; mExitAnim = exit; mPopEnterAnim = popEnter; mPopExitAnim = popExit; return this; } public FragmentTransaction setTransition(int transition) { mTransition = transition; return this; } public FragmentTransaction setTransitionStyle(int styleRes) { mTransitionStyle = styleRes; return this; } public FragmentTransaction addToBackStack(String name) { if (!mAllowAddToBackStack) { throw new IllegalStateException( "This FragmentTransaction is not allowed to be added to the back stack."); } mAddToBackStack = true; mName = name; return this; } public boolean isAddToBackStackAllowed() { return mAllowAddToBackStack; } public FragmentTransaction disallowAddToBackStack() { if (mAddToBackStack) { throw new IllegalStateException("This transaction is already being added to the back stack"); } mAllowAddToBackStack = false; return this; } public FragmentTransaction setBreadCrumbTitle(int res) { mBreadCrumbTitleRes = res; mBreadCrumbTitleText = null; return this; } public FragmentTransaction setBreadCrumbTitle(CharSequence text) { mBreadCrumbTitleRes = 0; mBreadCrumbTitleText = text; return this; } public FragmentTransaction setBreadCrumbShortTitle(int res) { mBreadCrumbShortTitleRes = res; mBreadCrumbShortTitleText = null; return this; } public FragmentTransaction setBreadCrumbShortTitle(CharSequence text) { mBreadCrumbShortTitleRes = 0; mBreadCrumbShortTitleText = text; return this; } void bumpBackStackNesting(int amt) { if (!mAddToBackStack) { return; } if (FragmentManagerImpl.DEBUG) Log.v(TAG, "Bump nesting in " + this + " by " + amt); Op op = mHead; while (op != null) { op.fragment.mBackStackNesting += amt; if (FragmentManagerImpl.DEBUG) Log.v(TAG, "Bump nesting of " + op.fragment + " to " + op.fragment.mBackStackNesting); if (op.removed != null) { for (int i = op.removed.size() - 1; i >= 0; i--) { Fragment r = op.removed.get(i); r.mBackStackNesting += amt; if (FragmentManagerImpl.DEBUG) Log.v(TAG, "Bump nesting of " + r + " to " + r.mBackStackNesting); } } op = op.next; } } public int commit() { return commitInternal(false); } public int commitAllowingStateLoss() { return commitInternal(true); } int commitInternal(boolean allowStateLoss) { if (mCommitted) throw new IllegalStateException("commit already called"); if (FragmentManagerImpl.DEBUG) Log.v(TAG, "Commit: " + this); mCommitted = true; if (mAddToBackStack) { mIndex = mManager.allocBackStackIndex(this); } else { mIndex = -1; } mManager.enqueueAction(this, allowStateLoss); return mIndex; } public void run() { if (FragmentManagerImpl.DEBUG) Log.v(TAG, "Run: " + this); if (mAddToBackStack) { if (mIndex < 0) { throw new IllegalStateException("addToBackStack() called after commit()"); } } bumpBackStackNesting(1); Op op = mHead; while (op != null) { switch (op.cmd) { case OP_ADD: { Fragment f = op.fragment; f.mNextAnim = op.enterAnim; mManager.addFragment(f, false); } break; case OP_REPLACE: { Fragment f = op.fragment; if (mManager.mAdded != null) { for (int i = 0; i < mManager.mAdded.size(); i++) { Fragment old = mManager.mAdded.get(i); if (FragmentManagerImpl.DEBUG) Log.v(TAG, "OP_REPLACE: adding=" + f + " old=" + old); if (old.mContainerId == f.mContainerId) { if (op.removed == null) { op.removed = new ArrayList<Fragment>(); } op.removed.add(old); old.mNextAnim = op.exitAnim; if (mAddToBackStack) { old.mBackStackNesting += 1; if (FragmentManagerImpl.DEBUG) Log.v(TAG, "Bump nesting of " + old + " to " + old.mBackStackNesting); } mManager.removeFragment(old, mTransition, mTransitionStyle); } } } f.mNextAnim = op.enterAnim; mManager.addFragment(f, false); } break; case OP_REMOVE: { Fragment f = op.fragment; f.mNextAnim = op.exitAnim; mManager.removeFragment(f, mTransition, mTransitionStyle); } break; case OP_HIDE: { Fragment f = op.fragment; f.mNextAnim = op.exitAnim; mManager.hideFragment(f, mTransition, mTransitionStyle); } break; case OP_SHOW: { Fragment f = op.fragment; f.mNextAnim = op.enterAnim; mManager.showFragment(f, mTransition, mTransitionStyle); } break; case OP_DETACH: { Fragment f = op.fragment; f.mNextAnim = op.exitAnim; mManager.detachFragment(f, mTransition, mTransitionStyle); } break; case OP_ATTACH: { Fragment f = op.fragment; f.mNextAnim = op.enterAnim; mManager.attachFragment(f, mTransition, mTransitionStyle); } break; default: { throw new IllegalArgumentException("Unknown cmd: " + op.cmd); } } op = op.next; } mManager.moveToState(mManager.mCurState, mTransition, mTransitionStyle, true); if (mAddToBackStack) { mManager.addBackStackState(this); } } public void popFromBackStack(boolean doStateMove) { if (FragmentManagerImpl.DEBUG) Log.v(TAG, "popFromBackStack: " + this); bumpBackStackNesting(-1); Op op = mTail; while (op != null) { switch (op.cmd) { case OP_ADD: { Fragment f = op.fragment; f.mNextAnim = op.popExitAnim; mManager.removeFragment(f, FragmentManagerImpl.reverseTransit(mTransition), mTransitionStyle); } break; case OP_REPLACE: { Fragment f = op.fragment; f.mNextAnim = op.popExitAnim; mManager.removeFragment(f, FragmentManagerImpl.reverseTransit(mTransition), mTransitionStyle); if (op.removed != null) { for (int i = 0; i < op.removed.size(); i++) { Fragment old = op.removed.get(i); old.mNextAnim = op.popEnterAnim; mManager.addFragment(old, false); } } } break; case OP_REMOVE: { Fragment f = op.fragment; f.mNextAnim = op.popEnterAnim; mManager.addFragment(f, false); } break; case OP_HIDE: { Fragment f = op.fragment; f.mNextAnim = op.popEnterAnim; mManager.showFragment(f, FragmentManagerImpl.reverseTransit(mTransition), mTransitionStyle); } break; case OP_SHOW: { Fragment f = op.fragment; f.mNextAnim = op.popExitAnim; mManager.hideFragment(f, FragmentManagerImpl.reverseTransit(mTransition), mTransitionStyle); } break; case OP_DETACH: { Fragment f = op.fragment; f.mNextAnim = op.popEnterAnim; mManager.attachFragment(f, FragmentManagerImpl.reverseTransit(mTransition), mTransitionStyle); } break; case OP_ATTACH: { Fragment f = op.fragment; f.mNextAnim = op.popEnterAnim; mManager.detachFragment(f, FragmentManagerImpl.reverseTransit(mTransition), mTransitionStyle); } break; default: { throw new IllegalArgumentException("Unknown cmd: " + op.cmd); } } op = op.prev; } if (doStateMove) { mManager.moveToState(mManager.mCurState, FragmentManagerImpl.reverseTransit(mTransition), mTransitionStyle, true); } if (mIndex >= 0) { mManager.freeBackStackIndex(mIndex); mIndex = -1; } } public String getName() { return mName; } public int getTransition() { return mTransition; } public int getTransitionStyle() { return mTransitionStyle; } public boolean isEmpty() { return mNumOp == 0; } }