Fragment載入過程分析。
阿新 • • 發佈:2019-02-08
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; }