1. 程式人生 > >Fragment載入過程分析。

Fragment載入過程分析。

void moveToState(Fragment f, int newState, int transit, int transitionStyle,
            boolean keepActive) {
        // Fragments that are not currently added will sit in the onCreate() state.
        if ((!f.mAdded || f.mDetached) && newState > Fragment.CREATED) {
            newState = Fragment.CREATED;
        }
        if (f.mRemoving && newState > f.mState) {
            // While removing a fragment, we can't change it to a higher state.
            newState = f.mState;
        }
        // Defer start if requested; don't allow it to move to STARTED or higher
        // if it's not already started.
        if (f.mDeferStart && f.mState < Fragment.STARTED && newState > Fragment.STOPPED) {
            newState = Fragment.STOPPED;
        }
        if (f.mState < newState) {
            // For fragments that are created from a layout, when restoring from
            // state we don't want to allow them to be created until they are
            // being reloaded from the layout.
            if (f.mFromLayout && !f.mInLayout) {
                return;
            }
            if (f.mAnimatingAway != null) {
                // The fragment is currently being animated... but! Now we
                // want to move our state back up. Give up on waiting for the
                // animation, move to whatever the final state should be once
                // the animation is done, and then we can proceed from there.
                f.mAnimatingAway = null;
                moveToState(f, f.mStateAfterAnimating, 0, 0, true);
            }
            switch (f.mState) {
                case Fragment.INITIALIZING:
                    if (DEBUG) Log.v(TAG, "moveto CREATED: " + f);
                    if (f.mSavedFragmentState != null) {
                        f.mSavedViewState = f.mSavedFragmentState.getSparseParcelableArray(
                                FragmentManagerImpl.VIEW_STATE_TAG);
                        f.mTarget = getFragment(f.mSavedFragmentState,
                                FragmentManagerImpl.TARGET_STATE_TAG);
                        if (f.mTarget != null) {
                            f.mTargetRequestCode = f.mSavedFragmentState.getInt(
                                    FragmentManagerImpl.TARGET_REQUEST_CODE_STATE_TAG, 0);
                        }
                        f.mUserVisibleHint = f.mSavedFragmentState.getBoolean(
                                FragmentManagerImpl.USER_VISIBLE_HINT_TAG, true);
                        if (!f.mUserVisibleHint) {
                            f.mDeferStart = true;
                            if (newState > Fragment.STOPPED) {
                                newState = Fragment.STOPPED;
                            }
                        }
                    }
                    f.mActivity = mActivity;
                    f.mParentFragment = mParent;
                    f.mFragmentManager = mParent != null
                            ? mParent.mChildFragmentManager : mActivity.mFragments;
                    f.mCalled = false;
                    f.onAttach(mActivity);
                    if (!f.mCalled) {
                        throw new SuperNotCalledException("Fragment " + f
                                + " did not call through to super.onAttach()");
                    }
                    if (f.mParentFragment == null) {
                        mActivity.onAttachFragment(f);
                    }
                    if (!f.mRetaining) {
                        f.performCreate(f.mSavedFragmentState);
                    }
                    f.mRetaining = false;
                    if (f.mFromLayout) {
                        // For fragments that are part of the content view
                        // layout, we need to instantiate the view immediately
                        // and the inflater will take care of adding it.
                        f.mView = f.performCreateView(f.getLayoutInflater(
                                f.mSavedFragmentState), null, f.mSavedFragmentState);
                        if (f.mView != null) {
                            f.mInnerView = f.mView;
                            f.mView = NoSaveStateFrameLayout.wrap(f.mView);
                            if (f.mHidden) f.mView.setVisibility(View.GONE);
                            f.onViewCreated(f.mView, f.mSavedFragmentState);
                        } else {
                            f.mInnerView = null;
                        }
                    }
                case Fragment.CREATED:
                    if (newState > Fragment.CREATED) {
                        if (DEBUG) Log.v(TAG, "moveto ACTIVITY_CREATED: " + f);
                        if (!f.mFromLayout) {
                            ViewGroup container = null;
                            if (f.mContainerId != 0) {
                                container = (ViewGroup)mContainer.findViewById(f.mContainerId);
                                if (container == null && !f.mRestored) {
                                    throwException(new IllegalArgumentException(
                                            "No view found for id 0x"
                                            + Integer.toHexString(f.mContainerId) + " ("
                                            + f.getResources().getResourceName(f.mContainerId)
                                            + ") for fragment " + f));
                                }
                            }
                            f.mContainer = container;
                            f.mView = f.performCreateView(f.getLayoutInflater(
                                    f.mSavedFragmentState), container, f.mSavedFragmentState);
                            if (f.mView != null) {
                                f.mInnerView = f.mView;
                                f.mView = NoSaveStateFrameLayout.wrap(f.mView);
                                if (container != null) {
                                    Animation anim = loadAnimation(f, transit, true,
                                            transitionStyle);
                                    if (anim != null) {
                                        f.mView.startAnimation(anim);
                                    }
                                    container.addView(f.mView);
                                }
                                if (f.mHidden) f.mView.setVisibility(View.GONE);
                                f.onViewCreated(f.mView, f.mSavedFragmentState);
                            } else {
                                f.mInnerView = null;
                            }
                        }
                        f.performActivityCreated(f.mSavedFragmentState);
                        if (f.mView != null) {
                            f.restoreViewState(f.mSavedFragmentState);
                        }
                        f.mSavedFragmentState = null;
                    }
                case Fragment.ACTIVITY_CREATED:
                case Fragment.STOPPED:
                    if (newState > Fragment.STOPPED) {
                        if (DEBUG) Log.v(TAG, "moveto STARTED: " + f);
                        f.performStart();
                    }
                case Fragment.STARTED:
                    if (newState > Fragment.STARTED) {
                        if (DEBUG) Log.v(TAG, "moveto RESUMED: " + f);
                        f.mResumed = true;
                        f.performResume();
                        f.mSavedFragmentState = null;
                        f.mSavedViewState = null;
                    }
            }
        } else if (f.mState > newState) {
            switch (f.mState) {
                case Fragment.RESUMED:
                    if (newState < Fragment.RESUMED) {
                        if (DEBUG) Log.v(TAG, "movefrom RESUMED: " + f);
                        f.performPause();
                        f.mResumed = false;
                    }
                case Fragment.STARTED:
                    if (newState < Fragment.STARTED) {
                        if (DEBUG) Log.v(TAG, "movefrom STARTED: " + f);
                        f.performStop();
                    }
                case Fragment.STOPPED:
                    if (newState < Fragment.STOPPED) {
                        if (DEBUG) Log.v(TAG, "movefrom STOPPED: " + f);
                        f.performReallyStop();
                    }
                case Fragment.ACTIVITY_CREATED:
                    if (newState < Fragment.ACTIVITY_CREATED) {
                        if (DEBUG) Log.v(TAG, "movefrom ACTIVITY_CREATED: " + f);
                        if (f.mView != null) {
                            // Need to save the current view state if not
                            // done already.
                            if (!mActivity.isFinishing() && f.mSavedViewState == null) {
                                saveFragmentViewState(f);
                            }
                        }
                        f.performDestroyView();
                        if (f.mView != null && f.mContainer != null) {
                            Animation anim = null;
                            if (mCurState > Fragment.INITIALIZING && !mDestroyed) {
                                anim = loadAnimation(f, transit, false,
                                        transitionStyle);
                            }
                            if (anim != null) {
                                final Fragment fragment = f;
                                f.mAnimatingAway = f.mView;
                                f.mStateAfterAnimating = newState;
                                anim.setAnimationListener(new AnimationListener() {
                                    @Override
                                    public void onAnimationEnd(Animation animation) {
                                        if (fragment.mAnimatingAway != null) {
                                            fragment.mAnimatingAway = null;
                                            moveToState(fragment, fragment.mStateAfterAnimating,
                                                    0, 0, false);
                                        }
                                    }
                                    @Override
                                    public void onAnimationRepeat(Animation animation) {
                                    }
                                    @Override
                                    public void onAnimationStart(Animation animation) {
                                    }
                                });
                                f.mView.startAnimation(anim);
                            }
                            f.mContainer.removeView(f.mView);
                        }
                        f.mContainer = null;
                        f.mView = null;
                        f.mInnerView = null;
                    }
                case Fragment.CREATED:
                    if (newState < Fragment.CREATED) {
                        if (mDestroyed) {
                            if (f.mAnimatingAway != null) {
                                // The fragment's containing activity is
                                // being destroyed, but this fragment is
                                // currently animating away. Stop the
                                // animation right now -- it is not needed,
                                // and we can't wait any more on destroying
                                // the fragment.
                                View v = f.mAnimatingAway;
                                f.mAnimatingAway = null;
                                v.clearAnimation();
                            }
                        }
                        if (f.mAnimatingAway != null) {
                            // We are waiting for the fragment's view to finish
                            // animating away. Just make a note of the state
                            // the fragment now should move to once the animation
                            // is done.
                            f.mStateAfterAnimating = newState;
                            newState = Fragment.CREATED;
                        } else {
                            if (DEBUG) Log.v(TAG, "movefrom CREATED: " + f);
                            if (!f.mRetaining) {
                                f.performDestroy();
                            }
                            f.mCalled = false;
                            f.onDetach();
                            if (!f.mCalled) {
                                throw new SuperNotCalledException("Fragment " + f
                                        + " did not call through to super.onDetach()");
                            }
                            if (!keepActive) {
                                if (!f.mRetaining) {
                                    makeInactive(f);
                                } else {
                                    f.mActivity = null;
                                    f.mFragmentManager = null;
                                }
                            }
                        }
                    }
            }
        }
       
        f.mState = newState;
    }